With a loss of more than 99% of the original native tallgrass prairie landcover today (Powell et al. 2006), decreased sustainable habitat area for the regal fritillary has become a real threat. Drastic declines in regal fritillary populations have led to much concern about the butterfly's future (Kopper et al. 2001). Historically, the regal fritillary's range extended from eastern Colorado to Maine. However, due to habitat loss and large-scale population declines, their range has been far reduced, especially in the east.
From the 1960s through the early 1990s, eastern populations had declined so severely that only a few remain. (Powell et al. 2006) The regal fritillary was once present in 18 states east of Illinois. Today, only three populations remain in the eastern region. These populations have been located east of Indiana: Fort Indiantown Gap Pennsylvania, Radford Army Ammunition Plant in Virginia. Populations in the Midwest and Great Plains are much more widespread; however, they remain extremely vulnerable as their numbers continue to decline. The regal fritillary is not federally listed as an endangered species, but it has been assigned a NatureServe conservation status of G3, which is considered vulnerable (Selby 2007). S. idalia was a Category II species, or a possible candidate for listing under the Endangered Species Act, until 1996 when this category was eliminated by the federal government (Kelly and Debinski 1998).  WildEarth Guardians submitted a new petition to list the species in 2013 (WildEarth Guardians 2013). The findings of formal review have not been published as of 1 May 2014.


The African penguin (Spheniscus demersus), also known as Cape penguin or South African penguin, is a species of penguin confined to southern African waters. Like all extant penguins, it is flightless, with a streamlined body and wings stiffened and flattened into flippers for a marine habitat. Adults weigh an average of 2.2–3.5 kg (4.9–7.7 lb) and are 60–70 cm (24–28 in) tall. The species has distinctive pink patches of skin above the eyes and a black facial mask. The body's upper parts are black and sharply delineated from the white underparts, which are spotted and marked with a black band. The pink glands above their eyes help them with thermoregulation. To cope with changing temperatures, blood is sent to the glands to be cooled by the air.
The African penguin is a pursuit diver and feeds primarily on fish and squid. Once extremely numerous, the African penguin is declining rapidly due to a combination of several threats and is classified as endangered. It is a charismatic species and is popular with tourists. Other vernacular names of the species include black-footed penguin and jackass penguin, due to the species' loud, donkey-like noise, although several related species of South Jackass penguins produce the same sound. They can be found along the coast of South Africa and Namibia.


The Magellanic penguin (Spheniscus magellanicus) is a South American penguin, breeding in coastal Patagonia, including Argentina, Chile, and the Falkland Islands, with some migrating to Brazil and Uruguay, where they are occasionally seen as far north as Espirito Santo. Vagrants have been found in El Salvador, the Avian Island in Antarctica, Australia, and New Zealand. It is the most numerous of the Spheniscus penguins. Its nearest relatives are the African penguin, the Humboldt penguin, and the Galápagos penguins. The Magellanic penguin was named after Portuguese explorer Ferdinand Magellan, who spotted the birds in 1520. The species is listed as being of Least Concern by the IUCN.


Magellanic penguins travel in large groups when hunting for food. In the breeding season, these birds gather in large nesting colonies at the coasts of Argentina, southern Chile, and the Falkland Islands, which have a density of 20 nests per 100 m². The breeding season begins with the arrival of adult Magellanic penguins at the breeding colonies in September and extends into late February and March when the chicks are mature enough to leave the colonies. One of the largest of these colonies is located at Punta Tombo. Nests are built under bushes or in burrows. Two eggs are laid. Incubation lasts 39–42 days, a task which the parents share in 10- to 15-day shifts. The chicks are cared for by both parents for 29 days and are fed every two to three days. Normally, both are raised through adulthood, though occasionally only one chick is raised. A successful Magellanic is considered to be able to raise 0.7 chicks on average per breeding season.
Magellanic penguins lay eggs in warm places where the temperature remains over 20 °C.
The male and female penguins take turns hatching, as they forage far away from their nests. The males return from the sea on the day the second egg is laid to take their turn incubating The second eggs are generally larger and with higher temperature than the first egg. The first one is more likely to survive, but under some conditions both chicks may be raised successfully. Male and female Magellanic penguins overlap in the at-sea areas they use whilst foraging, and show only small difference in foraging behaviours during early chick-rearing.
Magellanic penguins mate with the same partner year after year. The male reclaims his burrow from the previous year and waits to reconnect with his female partner. The females are able to recognize their mates through their call alone.
Once the breeding season is complete, Magellanic penguins migrate north for the winter, where they feed in waters offshore from Peru and Brazil.


The yellow-tail, goldtail moth or swan moth (Sphrageidus similis) is a moth of the family Erebidae. The species was first described by Johann Kaspar Füssli in 1775, and has commonly been placed within the related genus Euproctis. It is distributed throughout Europe to the Urals, then east across the Palearctic to Siberia and south to India and Sri Lanka.
This species has a wingspan of 35–45 mm, the female usually noticeably larger than the male. All parts of the adults are pure white, apart from a bright yellow tip to the abdomen (larger in the female) and a small black or brown tornal mark on the forewing of the male.


Red-breasted sapsuckers breed from southeast Alaska and British Columbia south through the Pacific Coast Ranges of western Washington and Oregon and northern California.
The breeding habitat is usually forest that includes pine, hemlock, Douglas-fir, fir, and spruce, though they are known to use other woodland habitats.


The red-breasted sapsucker begins work on its nest hole in a dead tree, usually a deciduous tree, in April or May, and produces one brood per breeding season. The female lays 4-7 pure white eggs. Both parents feed the young, and the fledglings leave the nest at 23–28 days old. The nest cavity is not reused.


The yellow-bellied sapsucker is found across Canada, eastern Alaska and the northeastern United States. These birds winter in the eastern United States, West Indies and Central America. This species has occurred as a very rare vagrant to Ireland and Great Britain.
When this sapsucker is breeding, it is generally found in deciduous and mixed coniferous forests up to 2,000 metres (6,600 ft) in height. During the non-breeding season, on the other hand, it usually inhabits forests, but the edge of the forest, open woodland, and semi-open habitats are sometimes utilized. It is also seen at larger trees in pastures, clearings, and suburban areas, in addition to the occasional appearance in palm groves. During this time, the yellow-bellied sapsucker ranges from sea level to elevations of 3,200 metres (10,500 ft), and even 3,400 metres (11,200 ft) in some areas, although the bird normally stays between altitudes of 900 and 3,000 metres (3,000 and 9,800 ft).


The yellow-bellied sapsucker usually forages by itself, although it sometimes joins small groups in the winter, and occasionally mixes into flocks of insectivores in the winter.
Arthropods, tree sap, fruits, and nuts compose the majority of the yellow-bellied sapsucker's diet. It also takes bast and cambium from trees. Berries are occasionally eaten, and in the Northern Hemisphere spring, buds are eaten. Arthropod prey is usually in the form of Lepidoptera, Odonata, or both the young and adults of beetles and ants. During the nesting season, insects comprise about half the diet of the adults. During the late Northern Hemisphere summer and throughout the same hemisphere's autumn, sap is the primary food of choice. Cambium is taken throughout the year, although it is primarily eaten during the Northern Hemisphere winter and spring. Fruit is mainly eaten during October to February.
The chicks are fed by both sexes. The primary food is insects which are occasionally coated in tree sap before eaten by the chick. The size of these insects varies by the age of the chicks, with younger chicks being fed smaller insects. The chicks beg for food through vocalizations that can be heard 100 metres (330 ft) away or more, likely stimulating the adults to catch more food. These vocalizations are usually done by the hungriest chick, with the other joining in only when the parent is at the nest. Because of this, the hungriest chick gets fed first. When the chick leaves the nest, it relies on both insects from its parents and sap from the holes they drill.
In the breeding season, this sapsucker prefers to take sap from the trees Betula papyrifera, Acer rubrum, Amelanchier, and Populus grandidentata. Other trees of the genera Populus, Betula, and Acer are also used, in addition to deciduous trees of the genera Salix, Carya, Alnus and coniferous trees of the genera Pinus, Picea, and Abies. In the Northern Hemisphere winter and spring, it usually feeds on conifers, while in its autumn, feeding on rough-barked trees is most common.
Before feeding consistently on a tree, this sapsucker lays down exploratory bands near a live branch. These bands are laid down in horizontal rows. When it finds a tree that is photosynthesizing, then it lays down more holes to feed, about 0.5 centimetres (0.20 in) above the primary bands. These form columns. Each hole is started as an oval elongated horizontally, drilled through the bark and phloem layers to the outside of the xylem. They are then drilled further, with the sapsucker enlarging it vertically, making it yield more sap, but only for a few days. The top holes in each column thus provides phloem sap, and this sapsucker also utilizes the bast from the edges of the holes drilled. In the winter, when the holes are drilled on conifers, bast is likely the most important food.


The crested serpent eagle (Spilornis cheela) is a medium-sized bird of prey that is found in forested habitats across tropical Asia. Within its widespread range across the Indian Subcontinent, Southeast Asia and East Asia, there are considerable variations and some authorities prefer to treat several of its subspecies as completely separate species. In the past, several species including the Philippine serpent eagle (S. holospila), Andaman serpent eagle (S. elgini) and South Nicobar serpent eagle (S. klossi) were treated as subspecies of the Crested serpent eagle. All members within the species complex have a large looking head with long feathers on the back of the head giving them a maned and crested appearance. The face is bare and yellow joining up with the ceres while the powerful feet are unfeathered and heavily scaled. They fly over the forest canopy on broad wings and tail have wide white and black bars. They call often with a loud, piercing and familiar three or two-note call. They often feed on snakes, giving them their name and are placed along with the Circaetus snake-eagles in the subfamily Circaetinae.


The agreeable tiger moth (Spilosoma congrua) is one of three species of white tiger moth which are common in the United States. It has pronounced black eyes, white abdomen, and orange "bib" which set it apart from its cousin the Virginia tiger moth. Like its cousin, it tents its wings when as
at rest.
It was described by Francis Walker in 1855. It is found in the United States, Canada, and possibly India.


Ardices curvata, the crimson tiger moth, is a moth of the family Erebidae. It was first described by Edward Donovan in 1805 and it is found in Australia. The species was formerly included in Spilosoma, but later generic status of Ardices was proved by Vladimir Viktorovitch Dubatolov (2005).
The larvae feed on Taraxacum officinale, Phaseolus vulgaris, Pelargonium zonale and Tropaeolum majus.


This species can be found in the Euro-mediterranean-Turaniaan Region, with a more southern distribution than Spilostethus saxatilis.
It is present in Albania, Austria, Bulgaria, Croatia, Cyprus, Czech Republic, France, Germany, Greece, Hungary, Italy, Israel, Malta, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Switzerland, Turkey, Lebanon, in the Afrotropical realm. and in the southern Asia to India and China.


Spinifex sericeus, commonly known as hairy spinifex, rolling spinifex, beach spinifex or coastal spinifex, is a dioecious perennial grass.
It is native to Australia, New Zealand, New Caledonia, and Tonga.
It is an important pioneer species which colonises coastal dunes, binding loose sand with its horizontal runners.
The 1889 book The Useful Native Plants of Australia records that common names included "Spring Rolling Grass" and that it "has no claim whatever as a food plant for stock, and can only be recommended as a sand-binder in fixing drift sands when encroaching on valuable land. For this purpose it deserves more attention than has hitherto been bestowed upon it. It is a plant of comparatively rapid growth, and would give effectual aid in checking the inroads of wind-driven sand, conditionally that the plants be carefully conserved from fire."


Spinulum annotinum, synonym Lycopodium annotinum, known as interrupted club-moss, or stiff clubmoss, is a species of clubmoss native to forests of the colder parts of North America (Greenland, St. Pierre & Miquelon, all 10 provinces and all 3 territories of Canada, Alaska, and mountains of the contiguous United States), as well as Asia (China, Russia, Japan, Korea, Nepal, Assam), and most of Europe. The genus Spinulum is accepted in the Pteridophyte Phylogeny Group classification of 2016 (PPG I), but not in other classifications, which submerge the genus in Lycopodium.
Spinulum annotinum is a common and widespread club-moss spreading by means of horizontal stems running along the surface of the ground. It is usually unbranched or sparingly branched, each branch containing a cone at the top. Leaves have minute teeth on their edges.


The lesser goldfinch (Spinus psaltria) is a very small songbird of the Americas. Together with its relatives the American goldfinch and Lawrence's goldfinch, it forms the American goldfinches clade in the genus Spinus sensu stricto.
The American goldfinches can be distinguished by the males having a black (rarely green) forehead, whereas the latter is (like the rest of the face) red or yellow in the European goldfinch and its relatives. North American males are markedly polymorphic and five subspecies are often named; at least two of them seem to represent a less-progressed stage in evolution, however.


This American goldfinch ranges from the southwestern United States (near the coast, as far north as extreme southwestern Washington) to Venezuela and Peru. It migrates from the colder parts of its U.S. range.
The lesser goldfinch often occurs in flocks or at least loose associations. It utilizes almost any habitat with trees or shrubs except for dense forest, and is common and conspicuous in many areas, often coming near houses. It is common at feeders in the Southwest United States and will come almost anywhere with thistle sock feeders. Flocks of at least six birds will often be seen at feeders. It feeds mostly on tree buds and weed seeds; geophagy has been observed in this species.
The nesting season is in summer in the temperate parts of its range; in the tropics it apparently breeds all-year round, perhaps less often in September and October. It lays three or four bluish white eggs in a cup nest made of fine plant materials such as lichens, rootlets, and strips of bark, placed in a bush or at low or middle levels in a tree.
The moult occurs in two different patterns which coincide with the blackness of the upperparts quite well. Here too is a broad zone of intergradation. Pacific birds moult after breeding, and females shed a few body feathers before breeding too. Juvenile males shed more remiges than females when moulting into adult plumage. East of the 106th meridian west, birds moult strongly before breeding and replace another quantity of feathers afterwards, and post-juvenal moult does not differ significantly between the sexes. However, this seems dependent on the differing rainfall regimes; simply put, birds at least anywhere in the North American range moult most of their plumage at the end of the dry season and may replace more feathers at the end of the wet season.
Considered a Species of Least Concern by the IUCN due to its vast range, it nonetheless seems to be declining locally. For example, it is rare in the Ecuadorean Andes foothills.


This species can be found across the greater part of Eurosiberia and the north of Africa. Its breeding area is separated into two zones, both on each side of the Palearctic realm: the eastern coast of Asia and the central and northern part of Europe.
These birds can be found throughout the year in Central Europe and some mountain ranges in the south of the continent. They are present in the north of Scandinavia and in Russia and they over-winter in the Mediterranean basin and the area around the Black Sea. In China they breed in the Khingan Mountains of Inner Mongolia and in Jiangsu province; they spend winter in Tibet, Taiwan, the valleys of the lower Yangtse River and the south east coast.
The Eurasian siskin is occasionally seen in North America. There is also a similar and closely related North America counterpart, the pine siskin (Spinus pinus).
Their seasonal distribution is also marked by the fact that they follow an anomalous migration pattern. Every few years they migrate southwards in larger numbers and the overwintering populations in the Iberian Peninsula are greatly augmented. This event has been the object of diverse theories, one theory suggests that it occurs in the years when Norway spruce produces abundant seeds in the centre and north of Europe, causing populations to increase. An alternative theory is that greater migration occurs when the preferred food of alder or birch seed fails. This species will form large flocks outside the breeding season, often mixed with redpolls.
It is a bird that does not remain for long in one area but which varies the areas it uses for breeding and feeding, over-wintering from one year to the next.
Its habitat is forested areas at a particular altitude on a mountain side and they have a certain predilection for humid areas. Coniferous woodland, especially spruce, is favoured for breeding. It builds its nest in a tree, laying 2–6 eggs. The British range of this once local breeder has expanded greatly due to an increase in commercial conifer plantations. The siskin also breeds in mixed woodland; while in winter they prefer stubble and crops and areas containing trees with seeds.


The American goldfinch is the state bird of Iowa and New Jersey, where it is called the eastern goldfinch, and Washington, where it is called the willow goldfinch. It was chosen by schoolchildren in Washington in 1951.


The plant is native to western North America from Alaska across southwestern Canada and the Pacific Northwest. It has spread to many other places as an invasive species. It was introduced to Europe as early as 1803, and is considered to be especially invasive in Denmark and Latvia. It is also found in France, Ireland, Slovenia, Sweden, the United Kingdom, Belgium, Germany and Poland.
It occurs most often in riparian habitat types, such as swamps, streambanks, bogs and mudflats. It grows best on moist or semiwet soils with good drainage. It tolerates a variety of soil types as well as gravelly substrates.
Spirea is shade-intolerant, and therefore grows primarily in open marshes among sedges, horsetails, wild blueberries, and other swamp flora, as well as in seral communities.


The dickcissel (Spiza americana) is a small seed-eating migratory bird in the family Cardinalidae. It breeds on the prairie grasslands of the Midwestern United States and winters in Central America, northern Colombia, and northern Venezuela. It is the only member of the genus Spiza, though some sources list another supposedly extinct species (see below).


Their breeding habitat is fields in midwestern North America. Following the breeding season the species migrates in large flocks to southern Mexico, Central America, and northern South America. They may occur as vagrants well outside of their normal range. From 1966 to 2015 the dickcissel experienced a greater than 1.5% population reduction in the northern part of its breeding range and throughout the Midwestern United States.


The black-chinned sparrow breeds in the southwestern United States and throughout much of Mexico north of the Isthmus of Tehuantepec. It is regularly found from northern California east to western Texas, and as far north as southern Nevada and Utah, and has occurred as a vagrant or occasional breeder in Oregon and Colorado. A species of arid and semi-arid places, it lives in chaparral, sagebrush, pine-juniper woodlands, and other brushy shrubland. Much of its habitat is in remote, rugged, and rocky areas. It is significantly less common in edge habitat, and rare near the coast. It is found at elevations ranging from near sea level to 2,400 m (8,000 ft) in the United States, and from 300 to 2,500 m (980 to 8,200 ft) in Mexico. Some birds in Utah may move into desert ecotones as part of a post-breeding dispersal and some northern populations move into Chihuahuan Desert scrub during the winter. Most northern populations move south – primarily into Mexico – during the winter; some move to lower elevations as well. During migration, it is sometimes recorded in montane oak forest, but not in mixed pine-oak forest.


The black-chinned sparrow is one of the species protected by the Migratory Bird Treaty Act. Its overall population has not been quantified, but its numbers are known to be decreasing. Estimates of its global population range from 450,000 to 1,100,000. The North American Breeding Bird Survey shows that the black-chinned sparrow's numbers declined at an average rate of 5.1 percent annually between 1966 and 2003, while Partners in Flight reports that the sparrow's numbers dropped 62 percent between 1970 and 2014. However, it is known to be poorly sampled by breeding bird surveys in several states, including New Mexico and Texas. It is considered to be a "Bird of Conservation Concern" by the US Fish and Wildlife Service. On the other hand, the International Union for Conservation of Nature considers it to be a species of least concern, due to its substantial population and very large range.
The black-chinned sparrow is known to carry several blood parasites, including members of the genera Haemoproteus and Trypanosoma. Specimens carrying West Nile virus have been found dead. Due to its avoidance of edge habitat, the black-chinned sparrow is vulnerable to habitat fragmentation. Because of that vulnerability, it may be a useful species for indicating environmental changes. It may also be adversely affected by climate change; between 2000 and 2020, its breeding range shifted perceptibly northwards. The National Audubon Society predicts that by 2080, none of its current breeding range will still be in use. Its winter range is predicted to be more stable, with some 65 percent of the current area still in use by 2080, and the total area of wintering range in the United States potentially increasing.


The chipping sparrow (Spizella passerina) is a species of New World sparrow, a passerine bird in the family Passerellidae. It is widespread, fairly tame, and common across most of its North American range.
There are two subspecies, the eastern chipping sparrow and the western chipping sparrow. This bird is a partial migrant with northerly populations flying southwards in the fall to overwinter in Mexico and the southern United States, and flying northward again in spring.
It molts twice a year. In its breeding plumage it has orangish-rust upper parts, gray head and underparts and a distinctive reddish cap. In non-breeding plumage, the cap is brown and the facial markings are less distinct. The song is a trill and the bird has a piercing flight call that can be heard while it is migrating at night.
In the winter, chipping sparrows are gregarious and form flocks, sometimes associating with other bird species. They mostly forage on the ground for seeds and other food items, as well as clambering on plants and trees, feeding on buds and small arthropods. In the west of their range they breed mainly in coniferous forests, but in the east, they choose woodland, farmland, parks and gardens. Breeding starts in late April and May and the nest is often built in a tree.


The field sparrow (Spizella pusilla) is a small New World sparrow in the family Passerellidae. It is about 140 mm (6 in) long and weighs about 12.5 g (0.4 oz). The head is grey with a rust-coloured crown, white eye-ring and pink bill. The upper parts are brown streaked with black and buff, the breast is buff, the belly is white and the tail is forked. There are two different colour morphs, one being greyer and the other more rufous.
The field sparrow is distributed across eastern Canada and the eastern United States, with northern populations migrating southwards to southern United States and Mexico in the fall. The typical habitat of this bird is bushy country with shrubs and grassland. The nest is a cup-shaped construction built on the ground and hidden beneath a bush or clump of grass. The birds forage on the ground or in low vegetation, feeding mainly on seeds and insects. The population is thought to be in slow decline, but it is a common species with a wide range, and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".


The taxonomy is highly confusing. Sporophila corvina was formerly considered a subspecies of Sporophila americana from northeastern South America, in which case the combined species (also incl. S. murallae from western Amazonia) had the common name variable seedeater. They were split based mainly on the work by Stiles (1996), but the taxa east (americana group and murallae) and west (corvina group) of the Andes had actually been considered separate species until they were merged into a single species by Meyer de Schauensee in 1952.
Following the split, additional confusion existed over the correct scientific name for present species. The name Sporophila aurita (Bonaparte, 1850) predates S. corvina by 10 years, and was widely believed to be the correct scientific name. However, the type for S. aurita has since disappeared and the original description was very vague, making it impossible to judge which population the name refers to. The name therefore becomes invalid, instead leading to S. corvina being the correct name.
Even after the split, the males of the remaining taxa have very different plumages, and the common name "variable seedeater" is fully deserved. The mainly black S. c. corvina has been considered a separate species, the black seedeater, from the remaining pied subspecies. As all subspecies hybridize freely wherever they meet, this is generally not recognized anymore. In large parts of Costa Rica and Panama it is impossible to clearly assign individuals to specific subspecies, where most instead show some level of intergradation between S. c. corvina, S. c. hoffmannii and/or S. c. hicksii. Some of these hybrid populations have in the past been recognized as separate subspecies, e.g. semicollaris, fortipes and collaris from Panama alone.


a. The full English name for Steatoda nobilis is "noble false widow". Media coverage usually abbreviates this to "false widow", although Steatoda nobilis is one of several false widows; Steatoda grossa and Steatoda paykulliana are other examples of false widow spiders.


The northern rough-winged swallow is native to Bahamas, Belize, Canada, Cayman Islands, Costa Rica, Cuba, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Puerto Rico, Saint Pierre and Miquelon, Turks and Caicos Islands, and the United States. They are vagrant to Aruba, Barbados, Bonaire, Sint Eustatius and Saba, Curaçao, Dominican Republic, Guadeloupe, and Sint Maarten. The populations in the US and Canada have been found to winter in the southernmost US and further south. While this is true, the populations in Mexico and further south seem to be non-migratory, although local post-breeding movements do occur. This swallow has been found to occur as high as 2,500 m (8,200 ft) in Costa Rica.


Stellaria pubera is widespread and common. Its natural habitat is bottomland forests and mesic forests, where it is often found on rocky slopes. It is found chiefly from Pennsylvania south to Georgia and west to Indiana and Alabama, with scattered populations in New York, New England, Illinois, Nebraska, Mississippi and Louisiana.


The common tern (Sterna hirundo) is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all black. There are several similar species, including the partly sympatric Arctic tern, which can be separated on plumage details, leg and bill colour, or vocalisations.
Breeding in a wider range of habitats than any of its relatives, the common tern nests on any flat, poorly vegetated surface close to water, including beaches and islands, and it readily adapts to artificial substrates such as floating rafts. The nest may be a bare scrape in sand or gravel, but it is often lined or edged with whatever debris is available. Up to three eggs may be laid, their dull colours and blotchy patterns providing camouflage on the open beach. Incubation is by both sexes, and the eggs hatch in around 21–22 days, longer if the colony is disturbed by predators. The downy chicks fledge in 22–28 days. Like most terns, this species feeds by plunge-diving for fish, either in the sea or in freshwater, but molluscs, crustaceans and other invertebrate prey may form a significant part of the diet in some areas.
Eggs and young are vulnerable to predation by mammals such as rats and American mink, and large birds including gulls, owls and herons. Common terns may be infected by lice, parasitic worms, and mites, although blood parasites appear to be rare. Its large population and huge breeding range mean that this species is classed as being of least concern, although numbers in North America have declined sharply in recent decades. Despite international legislation protecting the common tern, in some areas, populations are threatened by habitat loss, pollution, or the disturbance of breeding colonies.


Most populations of the common tern are strongly migratory, wintering south of their temperate and subarctic Northern Hemisphere breeding ranges. First summer birds usually remain in their wintering quarters, although a few return to breeding colonies some time after the arrival of the adults. In North America, the common tern breeds along the Atlantic coast from Labrador to North Carolina, and inland throughout much of Canada east of the Rocky Mountains. In the United States, some breeding populations can also be found in the states bordering the Great Lakes, and locally on the Gulf coast. There are small, only partially migratory, colonies in the Caribbean; these are in The Bahamas and Cuba, and off Venezuela in the Los Roques and Las Aves archipelagos.
New World birds winter along both coasts of Central and South America, to Argentina on the east coast and to northern Chile on the west coast. Records from South America and the Azores show that some birds may cross the Atlantic in both directions on their migration.
The common tern breeds across most of Europe, with the highest numbers in the north and east of the continent. There are small populations on the north African coast, and in the Azores, Canary Islands and Madeira. Most winter off western or southern Africa, birds from the south and west of Europe tending to stay north of the equator and other European birds moving further south. The breeding range continues across the temperate and taiga zones of Asia, with scattered outposts on the Persian Gulf and the coast of Iran. Small populations breed on islands off Sri Lanka, and in the Ladakh region of the Tibetan plateau. Western Asian birds winter in the northern Indian Ocean, and S. h. tibetana appears to be common off East Africa during the Northern Hemisphere winter. Birds from further north and east in Asia, such as S. h. longipennis, move through Japan, Thailand and the western Pacific as far as southern Australia. There are small and erratic colonies in West Africa, in Nigeria and Guinea-Bissau, unusual in that they are within what is mainly a wintering area. Only a few common terns have been recorded in New Zealand, and this species' status in Polynesia is unclear. A bird ringed at the nest in Sweden was found dead on Stewart Island, New Zealand, five months later, having flown an estimated 25,000 km (15,000 mi).
As long-distance migrants, common terns sometimes occur well outside their normal range. Stray birds have been found inland in Africa (Zambia and Malawi), and on the Maldives and Comoros islands; the nominate subspecies has reached Australia, the Andes, and the interior of South America. Asian S. h. longipennis has recent records from western Europe.
The common tern breeds over a wider range of habitats than any of its relatives, nesting from the taiga of Asia to tropical shores, and at altitudes up to 2,000 m (6,600 ft) in Armenia, and 4,800 m (15,700 ft) in Asia. It avoids areas which are frequently exposed to excessive rain or wind, and also icy waters, so it does not breed as far north as the Arctic tern. The common tern breeds close to freshwater or the sea on almost any open flat habitat, including sand or shingle beaches, firm dune areas, salt marsh, or, most commonly, islands. Flat grassland or heath, or even large flat rocks may be suitable in an island environment. In mixed colonies, common terns will tolerate somewhat longer ground vegetation than Arctic terns, but avoid the even taller growth acceptable to roseate terns; the relevant factor here is the different leg lengths of the three species. Common terns adapt readily to artificial floating rafts, and may even nest on flat factory roofs. Unusual nest sites include hay bales, a stump 0.6 m (2 ft) above the water, and floating logs or vegetation. There is a record of a common tern taking over a spotted sandpiper nest and laying its eggs with those of the wader. Outside the breeding season, all that is needed in terms of habitat is access to fishing areas, and somewhere to land. In addition to natural beaches and rocks, boats, buoys and piers are often used both as perches and as night-time roosts.


The common tern breeds in colonies which do not normally exceed two thousand pairs, but may occasionally number more than twenty thousand pairs. Colonies inland tend to be smaller than on the coast. Common terns often nest alongside other coastal species, such as Arctic, roseate and Sandwich terns, black-headed gulls, and black skimmers. Especially in the early part of the breeding season, for no known reason, most or all of the terns will fly in silence low and fast out to sea. This phenomenon is called a "dread".
On their return to the breeding sites, the terns may loiter for a few days before settling into a territory, and the actual start of nesting may be linked to a high availability of fish. Terns defend only a small area, with distances between nests sometimes being as little as 50 cm (20 in), although 150–350 cm (59–138 in) is more typical. As with many birds, the same site is re-used year after year, with a record of one pair returning for 17 successive breeding seasons. Around ninety per cent of experienced birds reuse their former territory, so young birds must nest on the periphery, find a bereaved mate, or move to another colony. A male selects a nesting territory a few days after his arrival in the spring, and is joined by his previous partner unless she is more than five days late, in which case the pair may separate.
The defence of the territory is mainly by the male, who repels intruders of either sex. He gives an alarm call, opens his wings, raises his tail and bows his head to show the black cap. If the intruder persists, the male stops calling and fights by bill grappling until the intruder submits by raising its head to expose the throat. Aerial trespassers are simply attacked, sometimes following a joint upward spiralling flight. Despite the aggression shown to adults, wandering chicks are usually tolerated, whereas in a gull colony they would be attacked and killed. The nest is defended until the chicks have fledged, and all the adults in the colony will collectively repel potential predators.


The Arctic tern (Sterna paradisaea) is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south as Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about 70,900 km (44,100 mi) for birds nesting in Iceland and Greenland and about 48,700 km (30,300 mi) for birds nesting in the Netherlands. These are by far the longest migrations known in the animal kingdom. The Arctic tern  nests once every one to three years (depending on its mating cycle).
Arctic terns are medium-sized birds. They have a length of 28–39 cm (11–15 in) and a wingspan of 65–75 cm (26–30 in). They are mainly grey and white plumaged, with a red/orange beak and feet, white forehead, a black nape and crown (streaked white), and white cheeks. The grey mantle is 305 mm (12.0 in), and the scapulae are fringed brown, some tipped white. The upper wing is grey with a white leading edge, and the collar is completely white, as is the rump. The deeply forked tail is whitish, with grey outer webs.
Arctic terns are long-lived birds, with many reaching fifteen to thirty years of age. They eat mainly fish and small marine invertebrates. The species is abundant, with an estimated two million individuals. While the trend in the number of individuals in the species as a whole is not known, exploitation in the past has reduced this bird's numbers in the southern reaches of its ranges.


The Arctic tern has a continuous worldwide circumpolar breeding distribution; there are no recognized subspecies. It can be found in coastal regions in cooler temperate parts of North America and Eurasia during the northern summer. During the southern summer, it can be found at sea, reaching the northern edge of the Antarctic ice.
The Arctic tern is famous for its migration; it flies from its Arctic breeding grounds to the Antarctic and back again each year. The shortest distance between these areas is 19,000 km (12,000 mi). The long journey ensures that this bird sees two summers per year and more daylight than any other creature on the planet. One example of this bird's remarkable long-distance flying abilities involves an Arctic tern ringed as an unfledged chick on the Farne Islands, Northumberland, UK, in the northern summer of 1982 that reached Melbourne, Australia in October, just three months after fledging – a journey of more than 22,000 km (14,000 mi). Another example is that of a chick ringed in Labrador, Canada, on 23 July 1928. It was found in South Africa four months later.
A 2010 study using tracking devices attached to the birds showed that the above examples are not unusual for the species. In fact, the study showed that previous research had seriously underestimated the annual distances travelled by the Arctic tern. Eleven birds that bred in Greenland or Iceland covered 70,900 km (44,100 mi) on average in a year, with a maximum of 81,600 km (50,700 mi). The difference from previous estimates is due to the birds taking meandering courses rather than following a straight route as was previously assumed. The birds follow a somewhat convoluted course in order to take advantage of prevailing winds. The average Arctic tern lives about 30 years and will, based on the above research, travel some 2.4 million km (1.5 million mi) during its lifetime, the equivalent of a roundtrip from Earth to the Moon more than three times.
A 2013 tracking study of half a dozen Arctic terns breeding in the Netherlands shows average annual migrations of c. 48,700 km (30,300 mi). On their way south, these birds roughly followed the coastlines of Europe and Africa.
Arctic terns usually migrate sufficiently far offshore that they are rarely seen from land outside the breeding season.


The Arctic tern has appeared on the postage stamps of several countries and dependent territories. The territories include Åland, Alderney, and Faroe Islands. Countries include Canada, Finland, Iceland, and Cuba.
Arctic tern migration is a central theme of the 2020 novel Migrations by Charlotte McConaghy.


S. carinatus is found in the states of Alabama, Arkansas, Louisiana, Mississippi, Oklahoma, Florida, and Texas.


At the beginning of the 19th century the little tern was a common bird of European shores, rivers and wetlands, but in the 20th century populations of coastal areas decreased because of habitat loss, pollution and human disturbance.
The loss of inland populations has been even more severe, since due to dams, river regulation and sediment extraction it has lost most of its former habitats. The Little Tern population has declined or become extinct in many European countries, and former breeding places on large rivers like the Danube, Elbe and Rhine ceased. Nowadays, only few river systems in Europe possess suitable habitats; the Loire/Allier in France, the Vistula/Odra in Poland, the Po/Ticino in Italy, the Daugava in Latvia, the Nemunas in Lithuania, the Sava in Croatia and the Drava in Hungary and Croatia. The status of the little tern on the rivers Tagus and lower Danube is uncertain.
The Drava population is one of the most threatened. Old fashioned water management practices, including river regulation and sediment extraction, endanger the remaining pairs. Only 15 pairs still breed on extensive sand or gravel banks along the border between Hungary and Croatia. The WWF and its partners are involved in working for the protection of this bird and this unique European river ecosystem. The little tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.


S. grossum is found throughout Europe, with a few records from western Asia. In the British Isles it is restricted to the New Forest, Dorset, and Somerset Wells and Ireland. It is the largest species of grasshopper to be found in the British Isles.
The habitat is typically wet meadow and marsh throughout its range. In southern England, the species is most often found in "quaking" sphagnum moss bogs.


They are widely distributed across the arid and savanna regions of eastern and southern Africa, extending from South Sudan and Somalia, across East Africa, to South Africa and Namibia. The species is generally absent from the humid forest regions of Central Africa. Over this range, the leopard tortoise occupies the most varied habitats of any African tortoise, including grasslands, thorn-scrub, mesic brushland, and savannas. They can be found at altitudes ranging from sea level to 2,900 m (9,500 ft).


The leopard tortoise is a widespread species and remains common throughout most of its range. Human activities, including agricultural burning, consumption, and especially commercial exploitation in the pet trade, are potential threats, but have not yet caused significant population declines. They are increasingly being bred in captivity for the pet trade. For example, most tortoises exported from Kenya and Tanzania originate in captive-breeding programs, alleviating collection from the wild.
The leopard tortoise has been listed in Appendix II of CITES since 1975, and in 2000, the United States banned their import because of the risk posed by heartwater, an infectious disease carried by tortoise ticks that could seriously impact the US livestock industry.


Stiretrus anchorago, commonly known as the anchor stink bug, is a species of predatory stink bug in the family Pentatomidae. It is found in Central America and North America. It is known to prey upon Epiachnia varivestis and Hypera postica.


The cannonball jellyfish (Stomolophus meleagris), also known as the cabbagehead jellyfish, is a species of jellyfish in the family Stomolophidae. Its common name derives from its similarity to a cannonball in shape and size. Its dome-shaped bell can reach 25 cm (10 in) in diameter and, in the Atlantic and Gulf of Mexico, the rim is sometimes colored with brown pigment. In the Pacific, this jellyfish can also have a blue pigment. Underneath the body is a cluster of oral arms that extend out around the mouth. These arms function in propulsion and as an aid in catching prey. Cannonballs are prominent from North America's eastern seaboard all the way to Brazil, but are also found in parts of the Pacific.


When disrupted, the cannonball secretes a mucus out of its nematocyst that contains a toxin. The toxin harms small fish in the immediate area, and drives away most predators, except for certain types of crabs. Although cannonballs do not commonly sting humans, they do have toxins which can, but not usually, cause cardiac problems in animals and humans. The toxin can cause irregular heart rhythms and problems in the myocardial conduction pathways. Such complications are associated also with toxins of other cnidaria. The toxin is also harmful to the eyes; contact with a nematocyst can be very painful, followed by redness and swelling. However, cannonball jellyfish are mostly harmless to humans. Contact with them may cause the skin to itch slightly, or minor eye irritation. As such they are among the most common causes of minor stings to humans in US and Caribbean waters.


Six subspecies are currently recognised, characterised principally by differences in size and plumage. There is a steady change to the birds' morphology and size the further south they are encountered, with lighter and more greyish plumage, larger body size, and a shorter bill. Southerly populations also show more white plumage in the tail, with less whiteness on the wing.
Strepera graculina graculina is the nominate form, found from the Sydney region north to the Burdekin River in northern Queensland.
Strepera graculina ashbyi, (critically endangered), the western Victorian pied currawong, was described by Australian amateur ornithologist Gregory Mathews in 1913. It is threatened by hybridization with the neighbouring subspecies nebulosa whose range is expanding westwards. A 2000 estimate placed the number of breeding birds at around 250. It resembles subspecies nebulosa, with sooty plumage, a long tail and a short bill. There is some doubt over whether ashbyi, which is little known, is a distinct subspecies or a colour morph of nebulosa. It is thought to have evolved after the two populations became separated by basalt plains in western Victoria, with the return of trees after the abandonment of regular Aboriginal burning in the late 18th century contributing to the remixing of populations. Hybrid forms have been identified in the Grampians and Yarra Valley. Further investigation in 2017 by Peter Menkhorst and Craig Morley established that the type specimen was an immature bird and that its collection point and characteristics placed it within subspecies nebulosa. They also observed there is a population that is abundant (rather than endangered) in the Otway Ranges that has a smaller speculum (wingpatch) than nebulosa and that Mathews had mistaken this for a subspecies of grey currawong, naming it Neostrepera versicolor riordani. They proposed renaming S. g. nebulosa to S. g. ashbyi and the other population as S. g. riordani.
Strepera graculina crissalis, (vulnerable) the Lord Howe currawong was described by English naturalist Richard Bowdler Sharpe in 1877. It appears to have adapted well to human habitation on Lord Howe Island, though the population is small overall, somewhere around 70–80 birds. Although regarded as a subspecies, it has yet to be studied with molecular DNA techniques, which may lead to it being reclassified as a separate species.
Strepera graculina magnirostris is found on the Cape York Peninsula to the Normanby River in northern Queensland. First described by Henry Lake White in 1923, it has a longer and heavier bill and shorter tail than the nominate subspecies. It has been little studied to date.
Strepera graculina robinsoni is found on the Atherton Tableland in northeastern Queensland. First described by Gregory Mathews in 1912, it is combined with magnirostris by some authors. Little researched, it appears to be smaller than other subspecies.
Strepera graculina nebulosa, found in southeastern New South Wales, the Australian Capital Territory and central Victoria, is very similar to the nominate subspecies but has a shorter bill, longer tail and larger wing. Its upperparts are sooty black, a little paler than the nominate subspecies, and underparts sooty black to slate-grey. The white patch on the primary flight feathers is also smaller. It was first defined in 1999 by ornithologists and bird taxonomists Richard Schodde and Ian Mason. There is a hybrid zone with subspecies graculina in southern and central New South Wales, from Eden north to the Illawarra region and stretching northwest to the Blue Mountains.


The pied currawong is common in both wet and dry sclerophyll forests, rural and semi-urban environments throughout eastern Australia, from Cape York Peninsula to western Victoria and Lord Howe Island, where it occurs as an endemic subspecies. It has more recently become prevalent in South-East South Australia, in and around Mount Gambier. It has adapted well to European presence, and has become more common in many areas of eastern Australia, with surveys in Nanango, Queensland, Barham, New South Wales, Geelong, Victoria, as well as the Northern Tablelands and South West Slopes regions in New South Wales, all showing an increase in population. This increase has been most marked, however, in Sydney and Canberra since the 1940s and 1960s, respectively. In both cities, the species had previously been a winter resident only, but now remains year-round and breeds there. They are a dominant species and common inhabitant of Sydney gardens.
In general, the pied currawong is sedentary, although some populations from higher altitudes move to areas of lower elevation in winter. However, evidence for the extent of migration is conflicting, and the species' movements have been little studied to date. More recently still, a survey of the population of pied currawongs in southeastern Queensland between 1980 and 2000 had found the species had become more numerous there, including suburban Brisbane. One 1992 survey reported the total number of pied currawongs in Australia had doubled from three million birds in the 1960s to six million in the early 1990s.
The pied currawong is able to cross bodies of water of some size, as it has been recorded from Rodondo Island, which lies 10 km (6.2 mi) off the coast of Wilsons Promontory in Victoria, as well as some offshore islands in Queensland. It has disappeared from Tryon, North West, Masthead and Heron Islands in the
Capricorn Group on the Great Barrier Reef. The presence of the Lord Howe subspecies is possibly the result of a chance landing there.
The pied currawong's impact on smaller birds that are vulnerable to nest predation is controversial: several studies have suggested that the species has become a serious problem, but the truth of this widely held perception was queried in a 2001 review of the published literature on their foraging habits by Bayly and Blumstein of Macquarie University, who observed that common introduced birds were more affected than native birds. However, predation by pied currawongs has been a factor in the decline of Gould's petrel at a colony on Cabbage Tree Island, near Port Stephens in New South Wales; currawongs have been reported preying on adult seabirds. Their removal from the islands halted a decline of the threatened petrels. Furthermore, a University of New England study published in 2006 reported that the breeding success rates for the eastern yellow robin (Eopsaltria australis) and scarlet robin (Petroica boodang) on the New England Tablelands were improved after nests were protected and currawongs culled, and some yellow robins even re-colonised an area where they had become locally extinct. The presence of pied currawongs in Sydney gardens is negatively correlated with the presence of silvereyes (Zosterops lateralis).
The species has been implicated in the spread of weeds by consuming and dispersing fruit and seed. In the first half of the twentieth century, pied currawongs were shot as they were considered pests of corn and strawberry crops, as well as assisting in the spread of the prickly pear. They were also shot on Lord Howe Island for attacking chickens. However, they are seen as beneficial in forestry as they consume phasmids, and also in agriculture for eating cocoons of the codling moth.


The spotted dove (Spilopelia chinensis) is a small and somewhat long-tailed pigeon that is a common resident breeding bird across its native range on the Indian subcontinent and in Southeast Asia. The species has been introduced to many parts of the world and feral populations have become established.
This species was formerly included in the genus Streptopelia with other turtle-doves, but studies suggest that they differ from typical members of that genus. This dove is long tailed buff brown with a white-spotted black collar patch on the back and sides of the neck. The tail tips are white and the wing coverts have light buff spots.
There are considerable plumage variations across populations within its wide range. The species is found in light forests and gardens as well as in urban areas. They fly from the ground with an explosive flutter and will sometimes glide down to a perch. It is also called the mountain dove, pearl-necked dove, lace-necked dove, and spotted turtle-dove.


The laughing dove (Spilopelia senegalensis) is a small pigeon that is a resident breeder in Africa, the Middle East, South Asia, and Western Australia where it has established itself in the wild around Perth and Fremantle. This small long-tailed dove is found in dry scrub and semi-desert habitats where pairs can often be seen feeding on the ground. A rufous and black chequered necklace gives it a distinctive pattern and is also easily distinguished from other doves by its call. Other names include laughing turtle dove, palm dove and Senegal dove while in Asia the name of the little brown dove is often used.


The species is usually seen in pairs or small parties and only rarely in larger groups. Larger groups are formed especially when drinking at waterholes in arid regions. Small numbers assemble on trees near waterholes before flying to the water's edge where they are able to suck up water like other members of the pigeon family. Laughing doves eat the fallen seeds, mainly of grasses, other vegetable matter and small ground insects such as termites and beetles. They are fairly terrestrial, foraging on the ground in grasslands and cultivation. Their flight is quick and direct with the regular beats and an occasional sharp flick of the wings characteristic of pigeons in general.
The male in courtship display follows the female with head bobbing displays while cooing. The male pecks its folded wings in "displacement-preening" to solicit copulation from the female. A female accepts by crouching and begging for food. The male may indulge in courtship feeding before mounting and copulating. Pairs may preen each other. Males may also launch into the air with wing clapping above their backs and then glide down in a gentle arc when displaying. The species has a spread out breeding season in Africa. Almost year-round in Malawi and Turkey; and mainly May to November in Zimbabwe, February to June in Egypt and Tunisia. In Australia the main breeding season is September to November. The nest is a very flimsy platform of twigs built in a low bush and sometimes in crevices or under the eaves of houses. Both parents build the nest with males bringing the twigs which are then placed by the female. Two eggs are laid within an interval of a day between them and both parents take part in building the nest, incubating and feeding the young. Males spend more time incubating the nest during the day. The eggs are incubated after the second egg is laid and the eggs hatch after about 13 to 15 days. Nesting adults may feign injury to distract and draw predators away from the nest. Multiple broods may be raised by the same pair in the same nest. Seven broods by the same pair have been noted in Turkey. Initially the altricial hatchlings are fed with regurgitated crop-milk, a secretion from the lining of the crop of parent birds. The young fledge and leave the nest after about 14 to 16 days. The Jacobin cuckoo sometimes lays its egg in the nests of the laughing dove in Africa.
Feral populations in Australia are sometimes infected by a virus that causes symptoms similar to that produced in parrots by psittacine beak and feather disease. Several ectoparasitic bird lice have been found on the species and include those in the genera Coloceras, Columbicola, Bonomiella and Hohorstiella. A blood parasite Trypanosoma hannae has been recorded in the species. Southern grey shrike have been observed preying on an adult laughing dove in northwestern India while the lizard buzzard is a predator of the species in Africa. South African birds sometimes show a beak deformity in which the upper mandible overgrowth occurs.


The European turtle dove was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae. He placed it with all the other pigeons in the genus Columba and coined the binomial name Columba turtur. The specific epithet turtur is the Latin word for a turtle dove. Linnaeus gave the locality as "India". This was an error and the type locality has been designated as England. The species is now placed in the genus Streptopelia that was introduced in 1855 by the French ornithologist Charles Lucien Bonaparte.
Four subspecies are recognised:
European turtle dove (S. t. turtur) (Linnaeus, 1758) – Europe, Madeira and the Canary Islands to western Siberia
Persian turtle dove (S. t. arenicola) (Hartert, 1894) – Northwest Africa to Iran and western China
Saharan turtle dove (S. t. hoggara) (Geyr von Schweppenburg, 1916) – Air Massif and Hoggar Mountains  (southern Sahara)
Egyptian turtle dove (S. t. rufescens) (Brehm, CL, 1845) – Egypt and northern Sudan
Despite the identical spelling, the "turtle" of the name, derived from Middle English turtle (tortle, turtel, turtul), derived from Old English turtla (male turtle dove), turtle (female turtle dove), ultimately derived from Latin turtur, has no connection with the reptile; "turtle" in this case came originally from Latin turtur, which is onomatopoeic to represent the bird's song. The genus name Streptopelia is from Ancient Greek streptos meaning "collar" and peleia meaning "dove".
A few other doves in the genus Streptopelia are also commonly called "turtle doves":
the Asian Oriental turtle dove S. orientalis and red collared dove S. tranquebarica.
the African dusky turtle dove S. lugens and Adamawa turtle dove S. hypopyrrha.
A few other species from the related Nesoenas and Spilopelia genera, which were both formerly included in the genus, also possess common names containing the term 'turtle dove'.


The tawny owl is non-migratory and has a distribution stretching discontinuously across temperate Europe from Great Britain and the Iberian Peninsula eastwards to western Siberia. It is absent from Ireland (probably because of competition from the long-eared owl), and only a rare vagrant to the Balearic and Canary Islands. In the Himalayas and East Asia it is replaced by the Himalayan owl (Strix nivicolum) and in northwest Africa it is replaced by the closely related Maghreb owl (Strix mauritanica).
This species is found in deciduous and mixed forests, and sometimes mature conifer plantations, preferring locations with access to water. Cemeteries, gardens and parks have allowed it to spread into urban areas, including central London. Although tawny owls occur in urban environments, especially those with natural forests and wooded habitat patches, they are less likely to occur at sites with high noise levels at night. The tawny owl is mainly a lowland bird in the colder parts of its range, but breeds to 550 metres (1,800 ft) in Scotland, 1,600 m (5,200 ft) in the Alps, 2,350 m (7,710 ft) in Turkey, and up to 2,800 m (9,200 ft) in Myanmar.
The tawny owl has a geographical range of at least 10 million km² (3.8 million mi²) and a large population including an estimated 970,000–2,000,000 individuals in Europe alone. Population trends have not been quantified, but there is evidence of an overall increase. This owl is not believed to meet the IUCN Red List criterion of declining more than 30% in ten years or three generations and is therefore evaluated as being of least concern. In the UK it is on the RSPB Amber List of Concern. This species has expanded its range in Belgium, the Netherlands, Norway and Ukraine, and populations are stable or increasing in most European countries. Declines have occurred in Finland, Estonia, Italy and Albania. Tawny owls are listed in Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning international trade (including in parts and derivatives) is regulated.


The Ural owl was named by Peter Simon Pallas in 1771 as Strix uralensis, due to the type specimen having been collected in the Ural mountains range. While the Urals fall around the middle of the species’ distribution, some authors such as Karel Voous lamented that a more broadly appropriate than Ural owl wasn’t derived for the English common name. In other languages, the species is referred to as Slaguggla, or “attacking owl”, in Swedish, Habichtskauz, or “goshawk-owl”, in German or as the “long-tailed owl” in Russian. The Ural owl is a member of the Strix genus, which are quite often referred to as wood owls. Conservatively, about 18 species are currently represented in this genus, typically being medium to large sized owls, characteristically round-headed and lacking ear tufts, which acclimate to living in forested parts of various climatic zones. Four owls native to the neotropics are sometimes additionally included with the Strix genus but some authorities have also included these in a separate but related genus, Ciccaba. Strix owls have an extensive fossil record and have long been widely distributed. The genetic relationship of true owls is somewhat muddled and different genetic testings has variously indicated that Strix owls are related to disparate appearing genera like Pulsatrix, Bubo and Asio.
The tawny owl is thought to be a close relative of the Ural owl. Authors have hypothesized that the origin of the species divide followed Pleistocene continental glaciations segregated a southwest or southern group in temperate forest (i.e. the tawny) from an eastern one inhabiting cold, boreal ranges (i.e. the Ural). The species pattern is mirrored in other bird species, i.e. the European green woodpecker (Picus viridus) from the more northern transcontinental grey-headed woodpecker (Picus canus). After retreat of the continental ice masses, the ranges more recently penetrated each other. While the life history details of the tawny and Ural owls are largely corresponding, nonetheless the species have a number of morphological differences and are largely adapted to different climates, times of activity and habitats. Based on Strix fossil species from Middle Pleistocene (given the name Strix intermedia) in variously the Czech Republic, Austria and Hungary show from leg and wing bones indicate an animal of intermediate form and size between Ural and tawny owls. However, fossils of a larger and differently proportioned Strix owl than a tawny owl, identified as Strix brevis, from Germany and Hungary from before the Pleistocene (i.e. Piacenzian) and as well as diagnosed Ural owl fossils from disparate southerly deposits in Sardinia from the Early Pleistocene and in Middle Pleistocene deposits in the Pannonian Basin as well as much later during the early Holocene from far to the west in Belgium, France and Switzerland suggest a more complicated evolutionary and distributional history. A hybrid was recorded in captivity between a male Ural and a female tawny owl, which managed to produce two offspring that were intermediate in size and had a more complex song that was also shared some characteristics with both species’ vocalizations.
Some species in America, such as namely the barred owl, are at times thought to be so closely related as well to the extreme that the Ural and barred and spotted owls (Strix occidentalis), have been considered to potentially be part of a species complex or even within the same species. However, there is no evidence nor likelihood that the Strix owls between America and Eurasia ever formed a continuous population given their adaptation to well-forested areas as well as the fact that the barred owl is more ecologically similar to the more generalized tawny owl, despite being of intermediate size between tawny and Ural owls (closer in size to the latter), and that the tawny does not range anywhere close to the boundary between North America and Russia as does the Ural. Certainly the most ambiguous aspect of the relations of Ural owl is the Père David's owl which has both historically and currently been considered either an isolated subspecies of the Ural owl or a distinct species. It is thought that the Père David's is likely a glacial relict of the mountainous forest of western China where plant and animal life often remain reminiscent of pre-glacial life. Recent study has indicated that the Père David's owl is valid species based on appearance, voice, and life history differences, though genetic studies have shown a somewhat muddled diversity between races of the Ural owls species complex. It has been recognized by The Clements Checklist of Birds of the World but BirdLife International and IUCN still classify it as a subspecies of the Ural owl.


The Ural owl has a large distribution. In mainland Europe, its modern distribution is quite spotty, with the species being found in central Europe in southeastern Germany, central and eastern areas of the Czech Republic, southern Austria, all but western Slovenia, and spottily but broadly in several areas of western, southern and northeastern Poland. The distribution in Germany is particularly nebulous (and perhaps aided by reintroductions branching from the well-known Bavarian population), with evidence of Ural owls apparently residing (and possibly nesting) considerably away from currently known haunts in Egge far to the west and mysteriously turning up rather to the north in Harz and Lüneburg Heath. In eastern Europe, the species is found in eastern Croatia, Bosnia and Herzegovina, western Serbia, montane west-central Bulgaria, montane central Romania, much of Slovakia, southwestern Ukraine, southern and eastern Lithuania, northern Belarus, eastern Latvia and much of Estonia. In Scandinavia, its distribution is quite broad, though it is only found in southeastern part of Norway, as Ural owls may be found ranging across most of Sweden and Finland but is absent from the northern stretches as well as southern Sweden (largely the peninsular area). Its range in Russia is extensive but it is absent from areas where habitat is not favorable. In western and European Russia, it is found as far south roughly as the Bryansk, Moscow and northern Samara north continuously to Kaliningrad, the southern part of the Kola Peninsula and Arkhangelsk. In the eponymous Ural region, it is found from roughly Komi south to Kamensk-Uralsky. In the general area of Siberia, the Ural owl is found widely discontinuing its typical range in the foothills of the Altai Mountains to the west and being found north roughly as far as Batagay in the east. The species’ distribution is continuous to the Russian Far East to as far as Okhotsk Coast and Magadan, Khabarovsk Krai and Sakhalin. Out of Russia, the range of the Ural owl continues into northeastern Mongolia, Northeastern China inland nearly as far as Beijing and down to Shandong and throughout the Korean Peninsula. The Ural owl is also distributed through all five of the main islands of Japan (i.e. only absent from Okinawa/Ryukyu Islands to the south). Vagrancy has been reported in Europe and Russia, which may account for sightings of the species almost throughout Germany. Furthermore, as many 16 records exist of the species turning until in northern Italy.


Ural owls tend to occur in mature but not too dense primary forest, which can variously be in coniferous, mixed or deciduous areas. Normally, they prefer to be close to an opening. These are often compromised by forest bogs with wet ground underfoot is overgrown by a mixture of spruce, alder and/or birch or by damp heathland with scattered trees. Predominant trees in much of the range are often spruce, fir and pine forests in north and alder, beech and birch with mixtures of the above conifers in the south. Quite often they are adapted to high elevation forest in mountains, but in remote wildlands they can adapt equally well to areas down to sea level.
In the Carpathian mountains, they tend to favor almost exclusively beech-dominated forests, normally at elevations of 250 to 450 m (820 to 1,480 ft) above sea level. Forest characteristics of these beech-dominated woods showed that during forest management showed they need at least 100 ha (250 acres) of woods to persist, with parts of the forests needing to be at least 45–60 years old. Carpathian Ural owls typically occur far from human habitations and woodland edge not surrounded by forest and typically avoid parts of the forest with steep slopes or with dense undergrowth. Carpathian birds often preferred areas with glades that bear gaps between the trees often around 25 m (82 ft) or so and usually with plentiful broken trees. Young, post-dispersal owls in the Carpathians birds show less strong habitat preferences and may utilized wooded corridors that often are connected to remaining ideal habitat areas. Reportedly the countries of Slovakia, Slovenia then Romania have the most extensive ideal habitat in the Carpathians and resultingly have the highest local densities of Ural owls, perhaps in all of Europe. Forest predominant in beech were also seemingly preferred by the reintroduced Ural owls in Bavarian Forest, again with old growth preferred with plentiful sun exposure. Bavarian owls occurred in areas that were also often rich in large mammals since their preference for access to parts of the forest with broken trees and openings often coincided. Further north in Latvia, forests inhabited were usually far older than was prevalent in the regional environment, usually with a preference for forest areas with trees at least 80 years old. Finnish populations apparently most often occur in spruce dominated forest, usually having discreetly segregated forest preferences apart from sympatric species of owls except for the boreal owl, which also preferred spruce areas but occurred more regularly when the dominant Ural owls are scarce. In the taiga of western Finland, it was found that biodiversity was consistently higher in the vicinity of Ural owl nests than outside these vicinities, rendering the Ural owl as perhaps a “keystone species” for the local ecosystem. Riverine forests with birch and poplar are often utilized in the taiga as well as spruce or fir forests (montane taiga) in the Ussuri river area. Generally in northern climes such as Finland and western Russia, wherein the Lapland area the Ural owl is likely to reach the northernmost part of its range, it is adaptive to Subarctic areas possibly up to the tree line but does not adapt as well as the great grey owl to areas of dwarf forest just south of the tundra, generally needing taller, more mature forests to the south of this.
Historically, they normally occur in remote, little disturbed areas far from human habitations. The Ural owl is largely restricted from areas where forest fragmentation has occurred or park-like settings are predominant, as opposed to the smaller, more adaptive tawny owl which acclimates favorably to such areas. On the contrary, in some peri-urbanized areas of Russia, such as the metropolitan parks and gardens so long as habitat is favorable and encouraging of prey populations, the Ural owl has been known to successfully occur. Some towns and cities whose region hold some populations of Ural owls are Chkalov, Kirov, Barnaul, Krasnoyarsk and Irkutsk, and even sometimes Leningrad and Moscow. Changes in nesting habits due to the erection of nest boxes has almost allowed Ural owls to nest unusually close to human habitations in the western part of the range, especially in Finland. An exceptional record of synanthropization in this species for Europe was recorded in Košice, Slovakia where a 10-15 year apparent increase of an unknown number of owls have been observed between the months of November and June. At least one Ural owl was recorded to habituate the city of Ljubljana in Slovenia but there was no evidence it was able to breed or establish a territory given the limited nature of woodlands in the vicinity.


Ural owls regularly live concurrently in different parts of their range with other owl species. Most sympatric species also share a preference for small mammals, largely voles, especially when they occur in relatively northerly temperate places such as the haunts of the Ural owls. Thus, the Ural owl is frequently considered to be a competitor with sympatric owl species. Most especially, the Ural owl has often being compared and studied in areas of sympatry with its close cousin, the tawny owl. The tawny owl may co-exist with Ural owls today in many parts of the latter’s European distribution, including southern Fennoscandia, eastern and central Europe and European Russia. The dietary habits of the two species are largely concurrent, as in Uppland, Sweden, where prey species and groups were almost identical in rank of importance to their diets (i.e. field vole, water vole, Apodemus species, birds and frogs). On Mount Krim in Slovenia, both tawny and Ural owls took the same primary prey species but the tawny owl was shown to be adaptable to alternate prey during the low part of the vole population cycle while the Ural was less adaptive to alternate prey. The diets were largely similar between tawny and Ural owls as well in the Bavarian Forest of Germany but the tawny species took proportionately fewer field voles and more insects, and was estimated to take prey weighing on average 43% less than that taken by Ural owls. In Finland, food niche breadth for Ural owls overlapped about 73% with the tawny owl but the mean prey size was more than twice as much for the Ural owl, 38.4 g (1.35 oz) for tawny vs 78.1 g (2.75 oz) for Ural, and the tawny owl was recorded to take non-mammalian prey significantly more so than Ural owls. In Belarus, tawny owl prey sizes were between 31 and 49% smaller on average (utilizing two different calculation methods) than those of Ural owl but the smaller species had a considerably greater food niche breadth, which averaged 12.96 for tawnys and 5.48 for Urals. Compared to the tawny owl, the Ural owl is considerably larger in size and talon size (which is about 30% greater in the Ural), with the talon shape further indicating their different ecological roles, being proportionately shorter and more curved in tawny owls in accordance with its more varied diet and heavier and straighter in the Ural owl for dispatching relatively larger mammals. It is known that when ranges overlap between tawny and Ural owls, the Ural owl tends to dominate and sometimes kill the tawny owl. In Slovenia, Ural owls actually responded more consistently to recorded calls of tawny owls (40% of call exposures causing a vocal or physical response) than to recordings of calls of their own species (34% of call exposures eliciting a response). However, cases of interspecific killing between the species are fairly infrequent, and recent study indicates that the tawny owl’s relatively checkered distribution in northerly areas such as Fennoscandia is not likely due to this competition but rather due to the regional habitat type favoring the Ural owl. The tawny owl is not as well suited to taiga habitats as is the Ural species and locally are less suited to alternate nest sites (i.e. nesting in areas lacking tree cavities or nest boxes, whereas the Ural can locally also use old bird nests and tree stumps). Warming average temperatures in Fennoscandia have appeared to effect many owl species negatively due to the limiting nature on vole cycles, but the tawny owl, being confined to the south, has had the most decreased effect locally due to the lowering vole numbers (and despite their general ability to adapt to different prey) while the Ural owl, in central Finland at least, is not yet showing as drastic a negative effect due to this. Similarly, the tawny owl and Ural owl are largely segregated by altitudinal range and habitat in eastern Europe (i.e. the Carpathian mountains) and Poland, with little evidence that this is due to interspecific competition or predation but rather the suitably of the montane habitats. Here the tawny owl tends to occur at lower elevations while the Ural owl occupies the foothill forests at higher elevations. Generally, despite higher densities of the Ural in some mountainous parts of central and eastern Europe, the tawny owl is far more numerous in all countries of that region than the Ural owl. In Slovakia, 13.3% of Ural owl territories overlapped with those of tawny owls, a relatively low overlap given the overall environment. Despite the Ural owl’s presumed dominance, in Slovenia, a tawny owl was observed to fiercely attack a Ural owl until it left the vicinity, though it is not clear whether this was a territorial encounter or antipredator mobbing. In Poland, during post-dispersal in winter tawny owls were able to temporarily utilize parts of Ural owl territories, taking advantage of the Ural owls less aggressive behaviour outside of the breeding season.
Ural owls do not generally occur with other Strix owls excepting the tawny owl but overlap in much of their range also with the great grey owl, which furthermore ranges farther north and into the Americas as well. Despite its large size, the great grey owl is a dietary specialist on voles, relying almost exclusively on them. Its dietary restrictions are indicated by its foot morphology, with the great grey owl possessing talons that are conspicuously finer, smaller and less powerful looking than those of the Ural owl despite the slightly larger overall foot size (in correspondence with its body mass) of the great grey. Within the taiga that both the great grey and Ural owls prefer, great grey owls have been shown to nest in a wide diversity of locations, with more nest types overall than the Ural, but it does not normally use tree cavities as do the other two European Strix owls and seldom occurs in areas where conifers are not dominant anywhere in its range, such as riparian zones where forest can diversify to become mixed with deciduous trees. The difference in nest site usage and narrower dietary habits of the great grey are thought to mitigate most serious competition between the great grey and Ural owls. A larger owl than either species, however, is the Eurasian eagle-owl. The Ural owl is considerably smaller-bodied (around three times lighter), with a wingspan around 35% smaller and smaller talons and feet, so a competitive advantage is apparent even between the species’ morphology. The eagle-owl also takes a large number of small prey such as voles but is conspicuously more variable in alternate foods. Across a similar but generally much broader distribution (both in latitude and longitude), eagle-owls take about three times as many prey species as do Ural owls, including much more species from all prey taxon, and also occur in a broader range of habitat types. Being much larger and (based on morphology) presumably much more powerful, the eagle-owl is able to take much larger prey than the Ural owl. More locally, in Finland, the Ural owl took proportionately more European water voles, overall birds and amphibians than did the eagle-owls but took far fewer gamebirds. The eagle-owls are likely avoided when possible by the Ural. Upon evidence, Ural owls are fairly regular in occurrence in North Ostrobothnia, where eagle-owls are rare to absent, but in South Ostrobothnia the Urals are scarce, possibly because the eagle-owls are relatively common. However, habitat differences may segregate the two species as well. In Finland, the eagle-owl appears to prefer pine-dominated forest while the Ural prefers spruce-dominated forests. Elsewhere, eagle-owls may frequent rocky areas where available (for nesting) and often hunt in more diverse and often more open areas, and in such areas Ural owls are rare to absent. Being smaller than the great grey owl and Eurasian eagle-owl, it is projected that the Ural owl can live off of less food overall than them. It is estimated that over a 6 month period, an Ural owl needs about 22.8 kg (50 lb) of food while a great grey owl needs about 27.4 kg (60 lb) and an eagle-owl needs about 54.8 kg (121 lb). The Ural owl has the potential to encounter other larger owls such as the snowy owl (Bubo scandiacus) in winter and the Blakiston's fish owl (Bubo blakistoni) in the far east of the range, but are unlikely to interact extensively given the differences in habitat usage.
Apart from the aforementioned species, most other owl species that the Ural owl encounters in its range are significantly smaller. Furthermore, the Ural owl tends to dominate these species when encounters occur and so may be avoided. One species that often shares similar habitat and prey preferences with the Ural owl is the boreal owl. However, based on territory spacing, the boreal owls can appear to more strictly avoid the tawny owl, which is known to be highly aggressive in its territorial behaviour year-around while studies have indicated territorial exclusion by Ural owls is largely confined to the breeding season. It was hypothesized, however, in forested southern Poland that boreal owls selected nest sites not out of avoidance of tawny owls but based on the availability of suitable nesting sites. In the south Poland study, tawny owls usually occurred more so in fir-spruce woodland. In Slovenia, it was theorized that boreal owls incidentally benefited from the exclusion of tawny owls by dominant Ural owls when the three species occurred in adjacent habitats. However, evidence indicates that the boreal owls faces higher mortality when they nest too close to Ural owls, i.e. within about 2 km (1.2 mi). A similar relationship has been detected between the Ural owl and the Eurasian pygmy owl (Glaucidium passerinum), a species less than half the size of a boreal owl. However, the pygmy owl usually selected different forest types than Ural owls in areas of sympatry, in particular fir woodland, wherein the Ural tends to be rare or absent. However, ecological interactions were detected in Slovenia, as the pygmy owl was observed to display antipredator behaviour against Ural owls. Despite the different preferred forest habitat, 46.3% of ranges of Ural and Eurasian pygmy owls overlapped in Slovakia. Quite little is known about the ecological interactions between the Ural owl and the northern hawk owl (Surnia ulula), another boreal owl, despite a shared propensity for utilizing snags as nest sites. Hawk owls are also routine vole predators but share more ecological characteristics with the great grey owl than the Ural owls, in particular their nomadic behaviours and irruptive movements. Furthermore, hawk-owl’s stronger tendency for diurnality may further provide a degree of partitioning.
The best known aspect of interspecific interactions with other owls and assorted other predators is interspecific predations. The Ural owl is at times vulnerable to predation by larger predators when encounters occur. Undoubtedly, the most dangerous predator is likely the Eurasian eagle-owl. Other predators known to prey upon Ural owls have included golden eagles (Aquila chrysaetos), eastern imperial eagle (Aquila heliaca), mountain hawk-eagle (Nisaetus nipalensis) and Eurasian lynx (Lynx lynx) as well as diurnal raptors that are only slightly larger, including the northern goshawk and lesser spotted eagle (Clanga pomarina). In most cases mentioned above, the age of the Ural owl taken by the predators are not usually specified (although any of the first three large eagles are certainly capable of striking down Ural owls potentially of any age). In some cases, goshawks have been known to kill parent Ural owls apparently entirely out of competition (despite different main food sources) and lay their eggs on a nest still containing the owls’ eggs. Predators specifically noted to have taken young Ural owls, usually of around fledgling age or shortly post-dispersal (especially those used in reintroductions) have additionally included red foxes (Vulpes vulpes), European pine martens (Martes martes) and great grey owls. In Primorsky Krai, Asian badgers (Meles leucurus) and raccoon dogs (Nyctereutes procyonoides) are mentioned as potential or likely predators of Ural owls nests as well. In one recorded instance, a Ural owl that was observed seemingly trying to prey upon a non-native American mink (Neogale vison) was seen to lose the confrontation when the mink turned the tables, having apparently overpowered, killed and ate the owl. Although predation events upon Ural owls are widely reported, the relative number of incidents of such are very low and singular. South of the Arctic, it can be considered to rival the great grey owl as the owl species that is second least vulnerable to predation, behind the apex predator eagle-owls. The Ural owl is itself a fairly formidable predator of smaller owl species, although not as prolific a killer as are eagle-owls and northern goshawks. Among the owls Ural owls have been known to have preyed upon are Indian scops owl (Otus lettia), collared scops owl (Otus bakkamoena), northern hawk-owls, tawny owls, Eurasian pygmy owls, boreal owls and long-eared owls. Diurnal raptors are also sometimes vulnerable to predation by Ural owls, including grey-faced buzzards (Butastur indicus), Eurasian sparrowhawk (Accipiter nisus), common kestrel (Falco tinniculus) and even apparent adult northern goshawks. Thus the Ural owl, coupled with a very low known rate of natural predations, appears to occupy a similar position in the intraguild predatory hierarchy as the goshawk. In Finland, both smaller owls and diurnal raptors such as sparrowhawks and even buzzards appear to avoid nesting near Ural owls. In addition, Ural owls are known to have successfully have chased off actively nesting goshawks as well as European honey buzzards (Pernis apivorus), common buzzards (Buteo buteo) and black kites (Milvus migrans) in order to claim the nests for themselves. Despite their potential predation on smaller mesopredators, when nest boxes for European pied flycatchers (Ficedula hypoleuca) were experimentally placed in the area of Ural owl nests, productivity lowered, and it is possibly because mesopredators were often attracted to the corresponding food base of the owls. On the contrary, experimental ground nests put out by researchers with random poultry eggs in central Finland were shown to be incidentally protected by the fierce presence of Ural Owls. In the Finnish ground placed almost directly under the Ural nest none at all were preyed upon, while in those placed 100 m (330 ft) away, 8.3% were predated, and those within 200–400 m (660–1,310 ft) experienced an average predation rate of 58.3%. At a great distance, at 500–900 m (1,600–3,000 ft) all ground nests were predated.


The Ural owl is not a densely populated bird but can be locally not uncommon. The IUCN estimates that there are between 350,000 and 1,200,000 individuals living in the wild globally. Most decreases in recent history have been reported from areas where hollow and broken trees were removed from forests. In Estonia, managed forest almost invariably have fewer Ural owls than undisturbed forest has because of reduction of snags and other natural cavities to use. However, the general trends are positive for most European Ural owl populations. The erection of nest boxes has caused population increases in several parts of the range, especially Finland. In eastern Europe, it is one of the more stable owl species, though it is far less numerous overall than some (i.e. tawny, long-eared, and little owls (Athene noctua)). Several population increase and expansions have been detected in central and eastern Europe for Ural owls in recent history, in sync with other owls considered boreal species (i.e. great grey, boreal, Eurasian pygmy). Previous records indicated staple populations in the 1980s for Ural owls in the western Carpathian mountains (estimated at about 1000 pairs) and northern Belarus (at 50-100 pairs). By the 1990s, the number had grown to 1000-1500 pairs in the western Carpathians and to 220-1350 pairs in northern Belarus. By 2005, the numbers were up to 3500 pairs in Carpathians and a drastic increase to 2700-4300 pairs in Belarus. In the Czech Republic, partially due to deliberate reintroductions, the numbers went from 1-5 pairs in 1985-89 to 25-40 pairs by 2001-2003. In selected plots of southeastern Poland, Belarus and Latvia, densities went from 1-2 pairs per 100 km² (39 sq mi) to 10 pairs per 100 km² (39 sq mi). In these three countries, northern population now much higher density than southern ones, i.e. 5-8.1 pairs per 100 km² (39 sq mi) in north to 3.1-3.6 pairs per 100 km² (39 sq mi) in the south. A range expansion of Ural owls was detected in western Ukraine (in the general region of Roztochya Biosphere Reserve and Yavorivskyi National Park). in 2005-07 up to 1.7-2 pair per 10 km² (3.9 sq mi) whereas in the past (i.e. to the 1990s) the species was a rare vagrant to this area. This density of this Ukrainian population is higher than seemingly most in Scandinavia and Belarus but lower than in southwestern Poland and Slovenia; while whether this represents a population increase or merely a population shift is unknown nor its relation to forestry. In some parts of Slovakia, such as Slanské vrchy, Vihorlat and the Ondavská Highlands the density of pairs may be up to a pair per square kilometer, perhaps the highest known specieswide. 400-500 Slovenian pairs from 1973-1994 is as of 2006 is estimated at 1400-2500 pairs. In the Orava region of Slovakia, the population may have increased fivefold during the above stated years. While many owl species (eagle-owl, long-eared, boreal) have appeared to have generally declined in period of 1982-2007 in Finland, to the contrary Ural owls increased by about 1% (excluded from these estimates were too difficult to analyze northerly nomadic owl species). In every regard but number of nestlings that were ringed (in which it also trails the Eurasian pygmy), it has been observed the Ural is the 2nd commonest detected breeding owl after the boreal owl in Finland with  2545 territories found, 1786 nests observed and 4722 nestlings ringed. An increase of the population was found in the Moscow region where tall stands remained despite the rather developed environment nearby.
Occasionally, Ural owls are vulnerable to flying into manmade objects. In most parts of the range, they are less vulnerable than many other large birds of prey (in part because of their preference for remote forests) but certainly a few are likely to be claimed as such. Many such mortalities are due to wire collisions and electrocutions, which are likely increase especially as populations expand and move into areas closer to human habitations. Other collision kills, such as with glass buildings and, widely, with various automobiles, may too potentially be on the increase. Though historically subject to some degree of persecution, Ural owls were spared from the worst of it perhaps by nesting in remote forests and possibly by being generally less predatory to small domestic fowl, game animals and the like than large raptorial birds like Eurasian eagle-owls, golden eagles and northern goshawks, all of which were badly persecuted and thusly reduced. Like other wild birds, Ural owls may be vulnerable to some degree of mortality due to diseases and infections but these are unlikely to compromise overall populations. A case of the bacterial infectious disease Tularemia was observed in an ural owl as was Usutu virus in a single bird. 71.4% of 14 wild Ural owls in Japan had blood parasites while a smaller but still present number of Acanthocephala and roundworms were detected in known European data. Many Japanese Ural owls were also found to be vulnerable to biting lice.


The barred owl was first described by Philadelphia naturalist Benjamin Smith Barton in 1799. The species was named due to the varied directions the dusky markings take on their underside.
The barred owl is roughly intermediate in size between the larger Ural and the smaller tawny owl, but the structural features of its relatively short and decurved claws more so resemble the tawny species as does their dietary and habitat ecology. The spotted owl has been hypothesized to be within a superspecies with the barred owl. However, genetic testing reveals very early divergence (likely at or near their ancestor's entry to North America) between spotted and barred owls. A fossil species once called Strix brea from the early Pleistocene in California does little to resolve the ancestry of modern species, given its ambiguous relation to any living Strix. The fossil species was larger (more similar in size and slenderness to the spotted owl, albeit with a slightly smaller skull and geographically isolated from that species) and longer-legged than either the spotted and barred owls, and is now considered to be in a separate genus, Oraristrix. Pleistocene era fossils of probable barred owls are known from Florida, Tennessee and Ontario.


The subspecies of the barred owl vary mostly by region, with slight to moderate variation by coloring, size and extent of feathering on the toes. Although several have been described in the past, the barred owl may include only three subspecies, subsequent to the separation of the fulvous and cinereous forms.
S. v. varia (Barton, 1799): The northern barred owl. This race lives throughout the Northeastern United States and the Upper Midwest, ranging as far south as Oklahoma, the Carolinas and northern Georgia. It is also considered to comprise all western "invader" birds found as far west as California and British Columbia. However, genetic study of westerly birds show a substantial isolation, possibly up to the subspecific level, of the western and eastern populations of the northern owls, with an estimated divergence of around 7,000 years, perhaps indicating an unknown history of the species in remote forests of northern and central Canada (far west of what was considered their original distribution) that radiated more recently to comprise the western populations. This race is generally the typical mid gray-brown variety of barred owl. However, a paler variation with very washed out markings and a more pure whitish base color is known (in eastern Canada such as Quebec), formerly considered a race S. v. albescens, as well as darker and browner variation in northern Minnesota (formerly S. v. brunnescens). This race is fairly large (described as the largest race on average with the probable separation of the cinereous owl).  The wing chord and tail length may measure from 312 to 340 mm (12.3 to 13.4 in) and 215 to 230 mm (8.5 to 9.1 in) in males and 320 to 352 mm (12.6 to 13.9 in) and 224 to 257 mm (8.8 to 10.1 in) in females. One nominate bird had a tarsus length of 63.5 mm (2.50 in) and the culmen from the cere may measure 23.5 to 30 mm (0.93 to 1.18 in).
S. v. georgica (Latham, 1801): The southern barred owl or, alternately, the Florida barred owl. This subspecies is found in southern North Carolina closer to the coast along to broadly through Georgia and all of Florida. This is the smallest of the three subspecies on average. Known wing chord lengths can vary from 315 to 357 mm (12.4 to 14.1 in). Tail length is 205 to 231 mm (8.1 to 9.1 in) and the bill from the cere is 23 to 28 mm (0.91 to 1.10 in). Males in Florida were found to weigh from 681 to 800 g (1.501 to 1.764 lb), with averages in two samples of 718 and 744 g (1.583 and 1.640 lb), while two females weighed 850 and 875 g (1.874 and 1.929 lb), respectively. It therefore appears to show less pronounced sexual dimorphism than the northern barred owl race.
S. v. helveola (Bangs, 1899): The Texas barred owl. Comprises most barred owls found in Texas. The distributional range is considered to range as far north as Lee County, east to Chambers County, west to Kerr County and south to Nueces County. In this race, the ground coloration tends to pale gingery-cream and the back and head tend to be a pale brown ranging into an almost cinnamon color. The toes can vary from rather bare to slightly bristled. This race is similar to other barred owls in size, perhaps averaging marginally smaller than those in the nominate race, but its bill and feet are larger on average than the preceding two races.