The mistle thrush breeds in much of Europe and temperate Asia, although it is absent from the treeless far north, and its range becomes discontinuous in southeast Europe, Turkey and the Middle East. In these warmer southern areas, it tends to be found in the milder uplands and coastal regions. Nominate T. v. viscivorus breeds in Europe and in Asia east to the Ob, beyond which it is replaced by T. v. bonapartei. The southern form T. v. deichleri is resident in North Africa, Corsica and Sardinia.
The mistle thrush is a partial migrant: birds from the north and east of the range wintering in the milder areas of Europe and North Africa. Scandinavian and Russian birds start moving south from mid-September onwards, most birds wintering in Europe, western Turkey and the Middle East. Between mid-October and November, large numbers cross the Strait of Gibraltar and others pass through Cyprus, but there is hardly any migration across the North Sea. Breeding birds in the British Isles and north-west Europe are resident or move only short distances. In the Himalayas, the breeding population moves to nearby lower-altitude sites in winter. Return migration starts mainly from late March, although it can be a month earlier in the Middle East, and northern breeders may not arrive back on their territories until late April or early May. Migration may be by day or night, and typically involves individuals or small groups. Vagrant birds have occurred in the Azores, China, Crete, Faroe Islands, Iceland, Japan, Oman, Saudi Arabia, Sikkim and the United Arab Emirates. In the winter 2017/2018 the first record of a mistle thrush for North America was at Miramichi in New Brunswick.
The mistle thrush is found in a wide range of habitats containing trees, including forests, plantations, hedges and town parks. In the south and east of its range, it inhabits upland coniferous woodland and the range extends above the main tree line where dwarf juniper is present. Breeding occurs at up to 600 m (2,000 ft) in the mountains of North Africa, and occasionally much higher, to 1,700 m (5,600 ft). In the highlands of Europe, its preferred altitude is from 800–1,800 m (2,600–5,900 ft). More open habitats, such as agricultural land, moors and grassy hills, are extensively used in winter or on migration.
There is evidence that this species has changed its natural habitat in at least parts of its range. In Germany and elsewhere in central Europe, it was found only in coniferous forest until the mid-1920s when its range rapidly expanded, first into farmland, and then to suburbs and urban parks. The reasons for this expansion are unclear. In areas of intensive farming, such as eastern England, arable land has in turn largely been abandoned in favour of built-up areas with their greater variety of green habitats.
Perhaps the most notable find of the 118th Christmas Bird Count in Canada was a single vagrant mistle thrush found in Miramichi, New Brunswick. This was the first record for this species in North America. The discovery attracted many birders from Canada and the United States; sightings continued from early December 2017 through late March 2018.


The mistle thrush has an extensive distribution in Europe and western Asia, and its European breeding population is estimated at 9–22.2 million birds. When Asian breeders are added, this gives a global total of 12.2–44.4 million. The species was formerly more restricted in range, and rarely bred even in northern England in the 1700s. It expanded rapidly into lowland and coastal areas of Europe during the 18th century and the first half of the 19th century, colonising areas where it was formerly rare or absent, such as Ireland (where it first bred in 1807), Scotland and the Netherlands. The range also increased in Denmark, Norway, Hungary and Austria.
Although the population now appears to be declining, the decrease is not rapid or large enough to trigger conservation vulnerability criteria. Given its high numbers and very large range, this thrush is therefore classified by the International Union for Conservation of Nature as being of least concern. The perceived decline may be due to the loss of invertebrate-rich pastures and mixed farms through conversion to arable agriculture or more intensively managed grassland. Adult survival, clutch size and fledging success are all lower in arable landscapes than in areas with extensive pasture. In Finland, the loss of ancient forests is thought to have led to a local decline.


Adult birds have pale gray heads and upper parts, light underparts, salmon-pink flanks and undertail coverts, and dark gray wings. Axillars and patch on underwing coverts are red. Their extremely long, forked tails, which are black on top and white on the underside, are characteristic and unmistakable. At maturity, the male may be up to 15 in (38 cm) in length, while the female's tail is up to 30% shorter. The wingspan is 15 cm (5.9 in) and the weight is up to 43 g (1.5 oz). Immature birds are duller in color and have shorter tails. A lot of these birds have been reported to be more than 40 cm (16 in).
They build a cup nest in isolated trees or shrubs, sometimes using artificial sites such as telephone poles near towns. The male performs a spectacular aerial display during courtship with his long tail forks streaming out behind him. Both parents feed the young. Like other kingbirds, they are very aggressive in defending their nest. Clutches contain three to six eggs.
In the summer, scissor-tailed flycatchers feed mainly on insects (grasshoppers, robber-flies, and dragonflies), which they may catch by waiting on a perch and then flying out to catch them in flight (hawking). For additional food in the winter they will also eat some berries.
Their breeding habitat is open shrubby country with scattered trees in the south-central states of Texas, Oklahoma, Kansas; western portions of Louisiana, Arkansas, and Missouri; far eastern New Mexico; and northeastern Mexico. Reported sightings record occasional stray visitors as far north as southern Canada and as far east as Florida and Georgia. They migrate through Texas and eastern Mexico to their winter non-breeding range, from southern Mexico to Panama. Pre-migratory roosts and flocks flying south may contain as many as 1000 birds.
The scissor-tailed flycatcher is the state bird of Oklahoma, and is displayed in flight with tail feathers spread on the reverse of the Oklahoma Commemorative Quarter. Professional soccer team FC Tulsa features a scissor-tailed flycatcher on their crest. The scissor-tailed flycatcher is also displayed in the background of the current license plate.
In eastern Arkansas and western Tennessee, USA, there is a hybrid zone between the scissor-tailed flycatcher and the western kingbird, which are sympatric, ecologically similar sister species. Both these species have simultaneously expanded their breeding ranges eastward over the past 50 years


The Western Kingbird (Tyrannus verticalis) is a large tyrant flycatcher found throughout western environments of North America, as far south as Mexico.

Adults are a combination of both gray and yellow plumage, along with crimson feathers that are hidden until courtship or against intruders. Characteristic of kingbird species, the Western Kingbird is very territorial. Although the Western is often misidentified as Cassin's kingbird, Couch's kingbird, or the Tropical kingbird due to the yellow coloration, it can be distinguished from these other species through its black, squared tail with white edges.


The cinnabar moth (Tyria jacobaeae) is a brightly coloured arctiid moth found as a native species in Europe and western and central Asia then east across the Palearctic to Siberia to China. It has been introduced into New Zealand, Australia and North America to control ragwort, on which its larvae feed. The moth is named after the red mineral cinnabar because of the red patches on its predominantly black wings. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Cinnabar moths are about 20 mm (0.79 in) long and have a wingspan of 32–42 mm (1.3–1.7 in).
Cinnabar moths are day-flying insects with distinctive pinkish-red and black wings. There is little variation in patterning, although on rare occasions the red markings may be replaced with yellow, or the forewing is entirely red with a black border, or the wings are completely black. Like many other brightly coloured moths, it is unpalatable; the larvae use members of the genus Senecio as food plants. Many members of the genus have been recorded as food plants, but of New World Senecio and Packera species, long-term population success has only been confirmed on the North American native plant Senecio triangularis. Other plant species, such as groundsel, are sometimes used, but larval and population survival tends to be reduced. Newly hatched larvae feed from the underneath of ragwort leaves within the area of their old eggs. The larvae absorb toxic and bitter tasting alkaloid substances from the food plants, and assimilate them, becoming unpalatable themselves. The bright colours of both the larvae and the moths act as warning signs, so they are seldom eaten by predators. An exception is among different species of cuckoo which eat hairy and poisonous caterpillars including cinnabar moth larvae.
Females can lay up to 300 eggs, usually in batches of 30 to 60 on the underside of ragwort leaves. When the caterpillars (larvae) hatch they feed on and around the area of the hatched eggs but as they get bigger and moult (instars) they mainly feed on the leaves and flowers of the plant, and can be seen out in the open during the day.
Like several other Arctiinae larvae, cinnabar caterpillars can turn cannibalistic. This is mainly due to lack of food, but they can eat other cinnabar larvae. Initially, the larvae are pale yellow, but later larval stages develop a jet-black and orange/yellow striped colouring. They can grow up to 30 mm (1.2 in), and are voracious eaters; large populations can strip entire patches of ragwort clean, a result of their low predation.
Often, very few survive to the pupal stage, mainly due to them completely consuming the food source before reaching maturity; this could be a possible explanation for their tendency to engage in seemingly random cannibalistic behaviour, as many will die from starvation. Additionally, the larvae are preyed upon by species like the ants Formica polyctena.


The barn owl was one of several species of bird first described in 1769 by the Tyrolean physician and naturalist Giovanni Antonio Scopoli in his  Anni Historico-Naturales. He gave it the scientific name Strix alba. As more species of owl were described, the genus Strix (from the Greek στρίξ, strix, "owl") came to refer solely to the wood owls in the typical-owl family Strigidae; and the barn owl became Tyto alba in the barn-owl family Tytonidae. Tyto alba literally means 'white night owl', from the onomatopoeic Ancient Greek τυτώ (tytō, 'night owl') – compare English "hooter" – and Latin alba, 'white'.
The bird is known by many common names that refer to its appearance, call, habitat, or its eerie, silent flight: white owl, silver owl, demon owl, ghost owl, death owl, night owl, rat owl, church owl, cave owl, stone owl, monkey-faced owl, hissing owl, hobgoblin or hobby owl, dobby owl, white-breasted owl, golden owl, screech owl, straw owl, barnyard owl, and delicate owl. "Golden owl" might also refer to the related golden masked owl (T. aurantia). "Hissing owl" and, particularly in the U.K. and in India, "screech owl" refer to the piercing calls of these birds. The latter name is also applied to a different group of birds, the screech-owls in the genus Megascops.


The barn owl is the most widespread landbird species in the world, occurring on every continent except Antarctica. Its range includes all of Europe (except Fennoscandia and Malta), most of Africa apart from the Sahara, the Indian subcontinent, Southeast Asia, Australia, many Pacific Islands, and North-, Central-, and South America. In general, it is considered to be sedentary; and, indeed, many individuals, having taken up residence in a particular location, remain there even when better nearby foraging areas are available. In the British Isles, the young seem largely to disperse along river corridors; and the distance travelled from their natal site averages about 9 km (5.6 mi).
In continental Europe the dispersal distance is greater, commonly somewhere between 50 and 100 kilometres (31 and 62 mi) but exceptionally 1,500 km (932 mi), with ringed birds from the Netherlands ending up in Spain and in Ukraine. In the United States, dispersal is typically over distances of 80 and 320 km (50 and 199 mi), with the most travelled individuals ending up some 1,760 km (1,094 mi) from their points of origin. Dispersal movements in the African continent include 1,000 km (621 mi) from Senegambia to Sierra Leone and up to 579 km (360 mi) within South Africa. In Australia there is some migration as the birds move towards the northern coast in the dry season and southward in the wet season, as well as nomadic movements in association with rodent plagues. Occasionally, some of these birds turn up on Norfolk Island, Lord Howe Island, or New Zealand, showing that crossing the ocean is within their capabilities. In 2008, barn owls were recorded for the first time breeding in New Zealand. The barn owl has been successfully introduced into the Hawaiian island of Kauai in an attempt to control rodents; distressingly, it has been found to also feed on native birds.


As its common and scientific names imply, winged elm is most easily recognized by the very broad, thin pair of corky wings that form along the branchlets after a couple of years. The tree generally grows to a maximum height and breadth of about 13 m × 13 m (43 ft × 43 ft), although on fertile alluvial soils such as those of the Mississippi River Delta, some specimens have reached double this height (see 'Notable trees' below). The crown can be either rounded or pyramidal; the branches are pendulous. The leaves are comparatively small for the genus, less than 6.5 cm (2+1⁄2 in) long and less than 2.0 cm (3⁄4 in) broad, oblong-lanceolate to narrowly elliptic, thin in texture, and smooth above with serrate or doubly serrate margins. The leaves turn bright yellow in Autumn. The wind-pollinated perfect apetalous flowers are borne on long pedicels in March and April before the leaves appear. The reddish samaras are also relatively small, less than 8 mm (5⁄16 in) long, narrowly elliptic with two long incurving stigmas at the tip, and usually disperse before the end of April.


Ulmus crassifolia Nutt., the Texas cedar elm or simply cedar elm, is a deciduous tree native to south central North America, mainly in southern and eastern Texas, southern Oklahoma, Arkansas and Louisiana, with small populations in western Mississippi, southwest Tennessee and north central Florida; it also occurs in northeastern Mexico. It is the most common elm tree in Texas. The tree typically grows well in flat valley bottom areas referred to as 'Cedar Elm Flats'. The common name 'cedar elm' is derived from the trees' association with juniper trees, locally known as cedars.


Ungnadia is a genus of flowering plants in the family Sapindaceae containing one species, Ungnadia speciosa, the Mexican buckeye. It is native to northern Mexico, as well as Texas and southern New Mexico in the United States. The name honours Austrian ambassador Baron David von Ungnad, who brought the horse chestnut to Vienna in 1576, introducing the plant into western Europe.
It differs from the buckeyes in the related genus Aesculus  but the seeds and nuts are similar. Another similar related genus is the soapberry (genus Sapindus). Ungnadia seeds are poisonous despite their sweetness, and sometimes used as marbles. The foliage is toxic and rarely browsed by livestock, but bees produce honey from the floral nectar.


Uresiphita reversalis, the genista broom moth or sophora worm, is a moth in the family Crambidae. It was described by Achille Guenée in 1854. U. reversalis was probably native to Mexico before spreading north and becoming established in Los Angeles by 1930 and the San Francisco Bay Area by 1980. It has since been recorded across the United States and in Cuba, Bermuda, Puerto Rico and Jamaica. Both adults and caterpillars are aposematic.


The wingspan is 27–34 mm. The forewings are light to medium brown with dark antemedial and postmedial lines and two dark discal spots. The hindwings are yellow or orange with brownish-gray shading at the apex. Adults are on wing year round in multiple generations per year in the southern part of the range.
The larvae feed on Acacia, Lonicera, Baptisia (including Baptista leucantha), Genista (including  Genista monspessulana) and Lupinus species (including Lupinus arboreus and Lupinus diffusus), Sophora secundiflora, Lagerstroemia indica, Cytius scoparius and Cytius striatus. The larvae have a brownish-green body and a black head with white dots. The species usually overwinters in the pupal stage, but may also overwinter as an adult.


The common murre can venture far from its breeding grounds to forage; distances of 100 km (60 mi) and more are often observed though if sufficient food is available closer by, birds only travel much shorter distances. The common murre mainly eats small schooling forage fish 200 mm (8 in) long or less, such as polar cod, capelin, sand lances, sprats, sandeels, Atlantic cod and Atlantic herring. Capelin and sand lances are favourite food, but what the main prey is at any one time depends much on what is available in quantity. It also eats some molluscs, marine worms, squid, and crustaceans such as amphipods. It consumes 20–32 g (11⁄16–1+1⁄8 oz) of food in a day on average. It is often seen carrying fish in its bill with the tail hanging out.
The snake pipefish is occasionally eaten, but it has poor nutritional value. The amount of these fish is increasing in the common murre's diet. Since 2003, the snake pipefish has increased in numbers in the North-east Atlantic and North Sea and sandeel numbers have declined.


Urnula craterium is a species of cup fungus in the family Sarcosomataceae. It is parasitic on oak and various other hardwood species; it is also saprobic, as the fruit bodies develop on dead wood after it has fallen to the ground. Appearing in early spring, its distinctive goblet-shaped and dark-colored fruit bodies have earned it the common names devil's urn and the gray urn. The distribution of U. craterium includes eastern North America, Europe, and Asia. It produces bioactive compounds that can inhibit the growth of other fungi. The asexual (imperfect), or conidial stage of U. craterium is a plant pathogen known as Conoplea globosa, which causes a canker disease of oak and several other hardwood tree species.


The red-billed blue magpie occurs in a broad swath from the northern parts of the Indian subcontinent, and further eastwards. It ranges from the western Himalayas eastwards into Myanmar, Thailand, Cambodia, Laos, and Vietnam, and through central and eastern China to southwest Manchuria, in evergreen forest and scrub in predominantly hilly or mountainous country. It has adapted to urban habitat, and can be seen in large cities in China such as Beijing and Hong Kong. They nest in trees and large shrubs in a relatively shallow nest. Usually, three to five eggs are laid.
Food is sought both in trees and on the ground. It takes the usual wide range of food, such as invertebrates, other small animals, and fruit and some seeds. It robs nests of eggs and also chicks. Vocal mimicry is very apparent in this species, and its calls are very varied, but the most usual are a grating rattle and a high-pitched whistle somewhat like a flute.


The gray fox (Urocyon cinereoargenteus), or grey fox, is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (Urocyon littoralis) of the California Channel Islands, are the only living members of the genus Urocyon, which is considered to be genetically basal to all other living canids. Its species name cinereoargenteus means "ashen silver".
It was once the most common fox in the eastern United States, and though still found there, human advancement and deforestation allowed the red fox to become the predominant fox-like canid. Despite this post-colonial competition, the gray fox has been able to thrive in urban and suburban environments, one of the best examples being southern Florida. The Pacific States and Great Lakes region still have the gray fox as their prevalent fox.


The island fox is significantly smaller than the related gray fox, and is the smallest fox in North America, averaging slightly smaller than the swift (Vulpes velox) and kit foxes (Vulpes macrotis). Typically, the head-and-body length is 48–50 cm (19–19.5 in), shoulder height 12–15 cm (4.5–6 in), and the tail is 11–29 cm (4.5–11.5 in) long, which is notably shorter than the 27–44 cm (10.5–17.5 in) tail of the gray fox. This is due to the fact that the island fox generally has two fewer tail vertebrae than the gray fox. The island fox weighs between 1 and 2.8 kg (2.2 and 6.2 lb). The male is always larger than the female. The largest of the subspecies occurs on Santa Catalina Island and the smallest on Santa Cruz Island.
The island fox has gray fur on its head, a ruddy red coloring on its sides, white fur on its belly, throat and the lower half of its face, and a black stripe on the dorsal surface of its tail. In general the coat is darker and duller hued than that of the gray fox. The island fox molts once a year between August and November. Before the first molt pups are woolly and have a generally darker coat than adult foxes. A brown phase, with the grey and black fur of the body replaced by a sandy brown and a deeper brown, may occur in the San Clemente Island and San Nicolas Island populations. It is unclear if this is a true color phase, a change that occurs with age, or possibly a change that occurs because of interactions with Opuntia cactus spines that become embedded in the pelt.


Urola nivalis, the snowy urola moth, is a moth of the family Crambidae. It is found from southern Canada and Maine, south to Florida and west to Illinois and Texas.
The wingspan is 15-23 mm. Adults are on wing from May to September in two generations per year.
The larvae feed on various grasses and are considered a pest of Ligustrum species.


Lizards are ectotherms and because of their temperature dependent lifestyle they may not follow predictions of density‐dependent habitat selection models because temperature strongly influences their habitat selection and population structure. Since competition for resources can cause a decrease in fitness, increased population size should cause a decrease in body size and growth rates across the population. In these lizards there is population density-dependent growth for females of this species but not for males. The temperature quality of the environment that these lizards live in also determines body size and composition. Lizards that are raised and produced in crowded spaces and environments with poor resources and lower temperatures grow smaller than lizards in higher quality environments with better suited temperatures and good resources.
It has been suggested that the abundance of rainfall that the ornate tree lizard experiences induce a multitude of changes in this lizard's behaviors. During a four-year study in the grapevine hills of Big Bend National Park in Texas, researchers observed the behavior of this lizard from 1974 to 1978. During 1974 and 1976, precipitation was abundant, however, during 1975 and 1977, there was little precipitation. During the dry years, there is a decrease in available prey and the ornate tree lizard's individual foraging success, growth rates, body masses, and prehibernation lipid levels were significantly lower. Population density was also reduced. These results have led researchers to propose that dry years are stressors which induces changes in diet, behaviors, and health of individuals. Since drought induces food scarcity, there is increased intra-specific competition for resources. Studies have demonstrated that Sceloporus merriami and the U. ornatus lizards also compete interspecifically for resources. Limited resources lowers population density of both lizard species. There is seasonal variation in the intensity of competition between these species which is highly correlated to food availability and the amount of rainfall. Where rainfall varies, the intensity of interspecific competition also varies. Therefore, the state of the environment directly affects competition and food availability for the ornate tree lizard.


Urosaurus ornatus is one of the most widespread and abundant of North American lizards. It inhabits a wide range of states throughout the United States, including California, Nevada, Utah, Colorado, Wyoming, Arizona, New Mexico, and Texas. It is arboreal, semi arboreal, or saxicolous throughout its wide living range and habitats. It can also be found in areas in Mexico including states such as Sonora, Sinaloa, Chihuahua, and Coahuila.
There are large temperature ranges throughout the southwestern United States and these lizards adapt to the different climates that they live in. Their mean body temperatures also change depending on where they are located. If the male lizard was in a montane habitat or a desert habitat their body temperature would be 35 degrees Celsius, but if the male lizard was in a desert riparian habitat its body temperature would be around 38 degrees Celsius. Their changes in body temperatures reflect the climates they live in. These temperature differences also occur between male and female lizards. On average the body temperature of a female is lower than the males body temperature. There is a possibility that this difference in body temperature could be related to the presence or absence of sexual differences between males and females and could also affect the health of the clutch and the size of the clutch.


These lizards tend to be active during every month except December. Both male and female ornate tree lizards emerge only on the warmest days in November and January, however, they engage in extended period of activity in February. When the lizards are active, they tend to occupy open locations in small or large boulders.


There is a direct correlation between the size of the female lizard and the size of the clutch that is produced. As body size increases the clutch size increases as well, making the bigger female lizards have a higher fitness due to size rarity. Body size for the female lizard could be a sought after trait and could be a factor in sexual selection and choosing a mate, a male may go after a larger female knowing that they will produce a larger number of offspring which will help them carry on their genes. There is also a relationship between the environment that the clutch is hatched in and the size of the clutch. Females that lay eggs in wet years tend to have a higher clutch size than females that lay eggs in the dryer years. This is due to temperature dependent reproduction and the effects the environment has on the reproductive process. The optimized temperature for the clutch to reach its maximum size comes with the temperatures associated with the dry season when reproducing.
Reproducing female ornate tree lizards are generally pregnant between late march through august. Additionally, they produce around two to seven eggs in their clutch once a year. The mean clutch size, however, is variable. The size of a female’s clutch varies according to the season, and it will vary according to the geographical location of the female lizard. The latitude the reproducing female inhabits will change in the reproductive outcomes of the females.
All the female's hatchlings will reach sexual maturity within one year of hatching.
The hatchlings produced by the female appear from the middle of June through to November. During the autumn season, however, hatching is highest.
Females will have enlarged ovarian follicles from the beginning of March through August. Additionally, the frequency of pregnant females is the highest during the months of April, July, and August.


During the months of June through to November, male ornate tree lizards have enlarged testes when they reach sexual maturity. When the males emerge in January, they will have small testes, however, their mean testis size becomes progressively larger between the months of February, March, and April. By April, their testis size will level off and by June, the males will generally reach their largest testes size. By July, their testes size will slightly decrease and by August and September, their testes will rapidly decrease.


Historically, American black bears occupied the majority of North America's forested regions. Today, they are primarily limited to sparsely settled, forested areas. American black bears currently inhabit much of their original Canadian range, though they seldom occur in the southern farmlands of Alberta, Saskatchewan and Manitoba; they have been extirpated on Prince Edward Island since 1937. The total Canadian black bear population is between 396,000 and 476,000, based on surveys taken in the mid-1990s in seven Canadian provinces, though this estimate excludes American black bear populations in New Brunswick, the Northwest Territories, Nova Scotia and Saskatchewan. All provinces indicated stable populations of American black bears over the last decade.
The current range of American black bears in the United States is constant throughout most of the Northeast and within the Appalachian Mountains almost continuously from Maine to northern Georgia, the northern Midwest, the Rocky Mountain region, the West Coast and Alaska. However, it becomes increasingly fragmented or absent in other regions. Despite this, American black bears in those areas seem to have expanded their range during the last decade, such as with recent sightings in Ohio, Illinois, and southern Indiana, though these probably do not yet represent stable breeding populations. Sightings of itinerant American black bears in the Driftless Area of southeastern Minnesota, northeastern Iowa, and southwestern Wisconsin are common. In the spring of 2019, biologists with the Iowa Department of Natural Resources confirmed documentation of an American black bear living year-round in woodlands near the town of Decorah in northeastern Iowa, believed to be the first instance of a resident black bear in Iowa since the 1880s.
Surveys taken from 35 states in the early 1990s indicate that American black bears are either stable or increasing, except in Idaho and New Mexico. The overall population of American black bears in the United States has been estimated to range between 339,000 and 465,000, though this excludes populations from Alaska, Idaho, South Dakota, Texas and Wyoming, whose population sizes are unknown. In the state of California, there are an estimated 25,000-35,000 American black bears, making it the largest population of the species in the contiguous United States.
As of 1993, known Mexican black bear populations existed in four areas, though knowledge on the distribution of populations outside those areas has not been updated since 1959. Mexico is the only country where the American black bear is classified as "endangered".
There have been several sightings quite far away from where the American black bear is normally found, such as Union County, North Carolina, and western Nebraska.
There are about 1,500 bears in Great Smoky Mountains National Park. The population density is about two per square mile. They inhabit all elevations in the park.


Throughout their range, habitats preferred by American black bears have a few shared characteristics. They are often found in areas with relatively inaccessible terrain, thick understory vegetation and large quantities of edible material (especially masts). The adaptation to woodlands and thick vegetation in this species may have originally been due to the American black bear having evolved alongside larger, more aggressive bear species, such as the extinct giant short-faced bear and the still-living grizzly bear, that monopolized more open habitats and the historic presence of larger predators, such as Smilodon and the American lion, that could have preyed on American black bears. Although found in the largest numbers in wild, undisturbed areas and rural regions, American black bears can adapt to surviving in some numbers in peri-urban regions, as long as they contain easily accessible foods and some vegetative coverage.
In most of the contiguous United States, American black bears today are usually found in heavily vegetated mountainous areas, from 400 to 3,000 m (1,300 to 9,800 ft) in elevation. For American black bears living in the American Southwest and Mexico, habitat usually consists of stands of chaparral and pinyon juniper woods. In this region, bears occasionally move to more open areas to feed on prickly pear cactus. At least two distinct, prime habitat types are inhabited in the Southeastern United States. American black bears in the southern Appalachian Mountains survive in predominantly oak-hickory and mixed mesophytic forests. In the coastal areas of the Southeast (such as Florida, the Carolinas and Louisiana), bears inhabit a mixture of flatwoods, bays and swampy hardwood sites.
In the northeastern part of the range (the United States and Canada), prime habitat consists of a forest canopy of hardwoods such as beech, maple, birch and coniferous species. Corn crops and oak-hickory mast are also common sources of food in some sections of the Northeast; small, thick swampy areas provide excellent refuge cover largely in stands of white cedar. Along the Pacific coast, redwood, Sitka spruce and hemlocks predominate as overstory cover. Within these northern forest types are early successional areas important for American black bears, such as fields of brush, wet and dry meadows, high tidelands, riparian areas and a variety of mast-producing hardwood species. The spruce-fir forest dominates much of the range of the American black bear in the Rockies. Important non-forested areas here are wet meadows, riparian areas, avalanche chutes, roadsides, burns, sidehill parks and subalpine ridgetops.
In areas where human development is relatively low, such as stretches of Canada and Alaska, American black bears tend to be found more regularly in lowland regions. In parts of northeastern Canada, especially Labrador, American black bears have adapted exclusively to semi-open areas that are more typical habitat in North America for brown bears (likely due to the absence here of brown and polar bears, as well as other large carnivore species).


The fur is soft, with dense underfur and long, coarse, thick guard hairs. The fur is not as shaggy or coarse as that of brown bears. American black bear skins can be distinguished from those of Asian black bears by the lack of a white blaze on the chest and hairier footpads. Despite their name, American black bears show a great deal of color variation. Individual coat colors can range from white, blonde, cinnamon, light brown or dark chocolate brown to jet black, with many intermediate variations existing. Silvery-gray American black bears with a blue luster (this is found mostly on the flanks) occur along a portion of coastal Alaska and British Columbia. White to cream-colored American black bears occur in the coastal islands and the adjacent mainland of southwestern British Columbia. Albino individuals have also been recorded. Black coats tend to predominate in moist areas such as Maine, New York, Tennessee, Michigan and western Washington. Approximately 70% of all American black bears are black, though only 50% of American black bears in the Rocky Mountains are black. Many American black bears in northwestern North America are cinnamon, blonde or light brown in color and thus may sometimes be mistaken for grizzly bears. Grizzly (and other types of brown) bears can be distinguished by their shoulder hump, larger size and broader, more concave skull.
In his book The Great Bear Almanac, Gary Brown summarized the predominance of black or brown/blonde specimens by location:


The brown bear (Ursus arctos) is a large bear species found across Eurasia and North America. In North America, the populations of brown bears are called grizzly bears, while the subspecies that inhabits the Kodiak Islands of Alaska is known as the Kodiak bear. It is one of the largest living terrestrial members of the order Carnivora, rivaled in size only by its closest relative, the polar bear (Ursus maritimus), which is much less variable in size and slightly bigger on average. The brown bear's range includes parts of Russia, Central Asia, the Himalayas, China, Canada, the United States, Hokkaido, Scandinavia, Finland, the Balkans, the Picos de Europa and the Carpathian region (especially Romania), Iran, Anatolia, and the Caucasus. The brown bear is recognized as a national and state animal in several European countries.
While the brown bear's range has shrunk, and it has faced local extinctions across its wide range, it remains listed as a least concern species by the International Union for Conservation of Nature (IUCN) with a total estimated  population in 2017 of 110,000. As of 2012, this and the American black bear are the only bear species not classified as threatened by the IUCN, though the large sizes of both bears may be a disadvantage due to increased competition with humans. Populations that were hunted to extinction in the 19th and 20th centuries are the Atlas bear of North Africa and the Californian, Ungavan and Mexican populations of the grizzly bear of North America. Many of the populations in the southern parts of Eurasia are highly endangered as well. One of the smaller-bodied forms, the Himalayan brown bear, is critically endangered, occupying only 2% of its former range and threatened by uncontrolled poaching for its body parts. The Marsican brown bear of central Italy is one of several currently isolated populations of the Eurasian brown bear and is believed to have a population of just 50 to 60 bears.


Brown bears are thought to have evolved from Ursus etruscus in Asia. The brown bear, per Kurten (1976), has been stated as "clearly derived from the Asian population of Ursus savini about 800,000 years ago; spread into Europe, to the New World." A genetic analysis indicated that the brown bear lineage diverged from the cave bear species complex approximately 1.2–1.4 million years ago, but did not clarify if U. savini persisted as a paraspecies for the brown bear before perishing. The oldest fossils positively identified as from this species occur in China from about 0.5 million years ago. Brown bears entered Europe about 250,000 years ago and North Africa shortly after. Brown bear remains from the Pleistocene period are common in the British Isles, where it is thought they might have outcompeted cave bears (Ursus spelaeus). The species entered Alaska 100,000 years ago, though they did not move south until 13,000 years ago. It is speculated that brown bears were unable to migrate south until the extinction of the much larger giant short-faced bear (Arctodus simus).
Several paleontologists suggest the possibility of two separate brown bear migrations: inland brown bears, also known as grizzlies, are thought to stem from narrow-skulled bears which migrated from northern Siberia to central Alaska and the rest of the continent, while Kodiak bears descend from broad-skulled bears from Kamchatka, which colonized the Alaskan peninsula. Brown bear fossils discovered in Ontario, Ohio, Kentucky and Labrador show that the species occurred farther east than indicated in historic records. In North America, two types of the subspecies Ursus arctos horribilis are generally recognized—the coastal brown bear and the inland grizzly bear; these two types broadly define the range of sizes of all brown bear subspecies.


Brown bears were once native to Europe, much of Asia, the Atlas Mountains of Africa, and North America, but are now extirpated in some areas, and their populations have greatly decreased in other areas. There are approximately 200,000 brown bears left in the world. The largest populations are in Russia with 120,000, the United States with 32,500, and Canada with around 25,000. Brown bears live in Alaska, east through the Yukon and Northwest Territories, south through British Columbia and through the western half of Alberta. The Alaskan population is estimated at a healthy 32,000 individuals. In the lower 48 states, they are repopulating slowly, but steadily along the Rockies and the western Great Plains.
In Europe, in 2010, there were 14,000 brown bears in ten fragmented populations, from Spain (estimated at only 20–25 animals in the Pyrenees in 2010, in a range shared between Spain, France and Andorra, and some 210 animals in Asturias, Cantabria, Galicia and León, in the Picos de Europa and adjacent areas in 2013) in the west, to Russia in the east, and from Sweden and Finland in the north to Romania (5000–6000), Bulgaria (900–1200), Slovakia (with about 600–800 animals), Slovenia (500–700 animals) and Greece (with about 200 animals) in the south.
In Asia, brown bears are found primarily throughout Russia, thence more spottily southwest to parts of the Middle East, including almost all parts of Kurdistan, to as far south as southwestern Iran, and to the southeast in Northeast China. Brown bears are also found in Western China, Kyrgyzstan, North Korea, Pakistan, Afghanistan and India. They can also be found on the Japanese island of Hokkaidō, which holds the largest number of non-Russian brown bears in eastern Asia with about 2,000–3,000 animals.
This species inhabits the broadest range of habitats of any living bear species.
They seem to have no altitudinal preferences and have been recorded from sea level to an elevation of 5,000 m (16,000 ft) (the latter in the Himalayas). In most of their range, brown bears generally seem to prefer semiopen country, with a scattering of vegetation that can allow them a resting spot during the day. However, they have been recorded as inhabiting every variety of northern temperate forest known to occur.


While the brown bear's range has shrunk and it has faced local extinctions, it remains listed as a Least concern species by the IUCN, with a total population of approximately 200,000. As of 2012, this and the American black bear are the only bear species not classified as threatened by the IUCN. However, the California grizzly bear, Ungava brown bear, Atlas bear and Mexican grizzly bear, as well as brown bear populations in the Pacific Northwest, were hunted to extinction in the 19th and early 20th centuries and many of the southern Asian subspecies are highly endangered. The Syrian brown bear (Ursus arctos syriacus) is very rare and it has been extirpated from more than half of its historic range. One of the smallest-bodied subspecies, the Himalayan brown bear (Ursus arctos isabellinus), is critically endangered, occupying only 2% of its former range and threatened by uncontrolled poaching for its body parts. The Marsican brown bear in central Italy is believed to have a population of just 50–60 bears.


The brown bear has a naturally long life. Wild females have been observed reproducing up to 28 years of age, which is the oldest known age for reproduction of any ursid in the wild. The peak reproductive age for females ranges from four to 20 years old. The lifespan of brown bears of both sexes within minimally hunted populations is estimated at an average of 25 years. The oldest wild brown bear on record was nearly 37 years old. The oldest recorded female in captivity was nearly 40 years old, while males in captivity have been verified to live up to 47 years, with one captive male possibly attaining 50 years of age.
While male bears potentially live longer in captivity, female grizzly bears have a greater annual survival rate than males within wild populations per a study done in the Greater Yellowstone Ecosystem. Annual mortality for bears of any age is estimated at 10% in most protected areas; however, the average annual mortality rate rises to an estimated 38% in hunted populations. Around 13% to 44% of cubs die within their first year even in well-protected areas. Mortality rates of 75–100% among the cubs of any given year are not uncommon. Beyond predation by large predators including wolves, Siberian tigers and other brown bears, starvation and accidents also claim the lives of cubs. Studies have indicated that the most prevalent source of mortality for first-year cubs is malnutrition. By the second and third years of their lives, the annual mortality rate among cubs in the care of their mothers drops to 10-15%.
Even in populations living in protected areas, humans are still the leading cause of mortality for brown bears. The largest amount of legalized brown bear hunting occurs in Canada, Finland, Russia, Slovakia and Alaska. Hunting is unregulated in many areas within the range of the brown bear. Even where hunting is legally permitted, most biologists feel that the numbers hunted are excessive considering the low reproduction rate and sparse distribution of the species. Brown bears are also killed in collisions with automobiles, which is a significant cause of mortality in the United States and Europe.


Brown bears seldom attack humans on sight and usually avoid people. In Russia, it is estimated that 1 in 1,000 on-foot encounters with brown bears results in an attack. They are, however, unpredictable in temperament, and may attack if they are surprised or feel threatened. There are an average of two fatal attacks by bears per year in North America. In Scandinavia, there are only four known cases since 1902 of bear encounters which have resulted in death. The two most common causes for bear attack are surprise and curiosity. Some types of bears, such as polar bears, are more likely to attack humans when searching for food, while American black bears are much less likely to attack. Despite their boldness and potential for predation if the bear is hungry, polar bears rarely attack humans, because they are infrequently encountered in the Arctic sea. Aggressive behavior in brown bears is favored by numerous selection variables. Increased aggressiveness also assists female brown bears in better ensuring the survival of their young to reproductive age. Mothers defending cubs are the most prone to attacking, being responsible for 70% of brown bear-caused human fatalities in North America.
Sows with cubs account for many attacks on humans by brown bears in North America. Habituated or food-conditioned bears can also be dangerous, as their long-term exposure to humans causes them to lose their natural shyness and, in some cases, to associate humans with food. Small parties of one or two people are more often attacked by brown bears than large groups, with only one known case of an attack on a group of six or more. In that instance, it is thought that due to surprise, the grizzly bear may not have recognized the size of the group. In the majority of attacks resulting in injury, brown bears precede the attack with a growl or huffing sound. In contrast to injuries caused by American black bears, which are usually minor, brown bear attacks more often tend to result in serious injury and, in some cases, death. Brown bears seem to confront humans as they would when fighting other bears: they rise up on their hind legs, and attempt to "disarm" their victims by biting and holding on to the lower jaw to avoid being bitten in turn. Due to the bears' enormous physical strength, even a single bite or swipe can be deadly as in tigers, with some human victims having had their heads completely crushed by a bear bite. Most attacks occur in the months of July, August and September, the time when the number of outdoor recreationalists, such as hikers or hunters, is higher. People who assert their presence through noises tend to be less vulnerable, as they alert bears to their presence. In direct confrontations, people who run are statistically more likely to be attacked than those who stand their ground. Violent encounters with brown bears usually last only a few minutes, though they can be prolonged if the victims fight back. In Alberta, two common behaviors by human hunters, imitating the calls of deer to attract them and carrying ungulate carcasses, seem to court aggressive behavior and lead to a higher rate of attack from grizzly bears.
Attacks on humans are considered extremely rare in the former Soviet Union, though exceptions exist in districts where they are not as often pursued by hunters. East Siberian brown bears, for example, tend to be much bolder toward humans than their shyer, more persecuted European counterparts. The delineation in Eurasia between areas where aggressiveness of brown bears tends to increase is the Ural Mountains, although the brown bears of eastern Europe are somewhat more aggressive than those of western Europe. In 2008, a platinum mining compound in the Olyotorsky district of northern Kamchatka was besieged by a group of 30 bears, who killed two guards and prevented workers from leaving their homes. 10 people a year on average are killed by brown bears in Russia, more than all the other parts of the brown bear's international range combined, although Russia also holds more brown bears than all other parts of the world combined. In Scandinavia, only three fatal attacks were recorded in the 20th century.
In Japan, a large brown bear nicknamed "Kesagake" (袈裟懸け, "kesa-style slasher") made history for causing the worst brown bear attack in Japanese history at Tomamae, Hokkaidō during numerous encounters during December 1915. It killed seven people and wounded three others (with possibly another three previous fatalities to its credit) before being gunned down after a large-scale beast-hunt. Today, there is still a shrine at Rokusensawa (六線沢), where the event took place in memory of the victims of the incident.
Within Yellowstone National Park, injuries caused by grizzly attacks in developed areas averaged approximately one per year during the 1930s through to the 1950s, though it increased to four per year during the 1960s. They then decreased to one injury every two years during the 1970s. Between 1980 and 2002, there have been only two human injuries caused by grizzly bears in a developed area. Although grizzly attacks were rare in the backcountry before 1970, the number of attacks increased to an average of approximately one per year during the 1970s, 1980s and 1990s. In Alberta, from 1960 to 1998, the number of attacks by grizzly bears ending in injury were nearly three times more common than attacks ending in injury by American black bears, despite the American black bear being an estimated 38 times more numerous in the province than the grizzly bear.


Brown bears often figure into the literature of Europe and North America, in particular that which is written for children. "The Brown Bear of Norway" is a Scottish fairy tale telling the adventures of a girl who married a prince magically turned into a bear and who managed to get him back into a human form by the force of her love and after many trials and difficulties. With "Goldilocks and the Three Bears", a story from England, the Three Bears are usually depicted as brown bears. In German-speaking countries, children are often told the fairytale of "Snow White and Rose Red"; the handsome prince in this tale has been transfigured into a brown bear. In the United States, parents often read their preschool age children the book Brown Bear, Brown Bear, What Do You See? to teach them their colors and how they are associated with different animals.
The Russian bear is a common national personification for Russia (as well as the former Soviet Union), despite the country having no appointed national animal. The brown bear is Finland's national animal.
The grizzly bear is the state animal of Montana. The California golden bear is the state animal of California. Both animals are subspecies of the brown bear and the species was extirpated from the latter state.
The coat of arms of Madrid depicts a bear reaching up into a madroño or strawberry tree (Arbutus unedo) to eat some of its fruit, whereas the Swiss city of Bern's coat of arms also depicts a bear and the city's name is popularly thought to derive from the German word for bear. The brown bear is depicted on the reverse of the Croatian 5 kuna coin, minted since 1993.
The Bundesliga club Bayern Munich has a brown bear mascot named Berni. The Chicago National Football League (NFL) franchise is named the Bears. In this context, no differentiation between American black and brown bears is needed. The school mascot for Bob Jones University, Brown University, Cornell University, George Fox University, the University of Alberta, the University of California, Berkeley, the University of California, Los Angeles, the University of California, Riverside, and numerous American high schools is the brown bear.
In the town of Prats de Molló, in Vallespir, French Catalonia, a "bear festival" (festa de l'ós) is celebrated annually at the beginning of spring, in which the locals dress up as bears, cover themselves with soot or coal and oil and "attack" the onlookers, attempting to get everyone dirty. The festival ends with the ball de l'ós (bear dance).


U. ferox is endemic to New Zealand and inhabits coastal and lowland forests and shrublands in the North, South, and Stewart Islands. It is commonly found in clearings or forest margins, often forming large patches, from 0–600 m above sea level. It has also been recorded on the Hen and Chicken Islands along stream-beds.


Usnea longissima is found in boreal forests and coastal woodland in Europe, Asia, and North America. In North America, it is primarily found on the Pacific Coast, and the largest populations are concentrated in the Pacific Northwest. It ranges from Upper Midwest into Canada, the Great Lakes region, and extends to the coast of the Atlantic ocean. It was historically circumboreal, but has been regionally extirpated from areas of Europe and Scandinavia. It has been placed on the Red List of
California Lichens, and is considered Endangered in the Norwegian Red List.
The species grows within the canopies of coniferous trees, primarily those found in old growth Douglas fir forests and near bodies of water. Air pollution heavily affects the metabolic functions of the species, and as a result, populations have declined. Industrial logging has also had detrimental impacts on population numbers.


This species in southern Europe overwinters as a caterpillar. Pupation occurs on the ground near the host plants, usually on fallen leaves and dead vegetation, or pieces of bark and old wood. During mild winters in temperate and typically Mediterranean climates this species hibernates as pupae. Adults of this multivoltine species usually are present from March to early November in three generations a year, but in the tropics, they develop continuously. They fly both day and night and come to light. The polyphagous larvae feed on a range of herbaceous plants, mainly on forget-me-not (Myosotis), Echium, Borago officinalis, Solanum, Plantago lanceolata and Anchusa species. In the Afrotropical realm they mainly feed on Trichodesma zeylanicum, Lithospermum, Heliotropium, Trichodesma and Gossypium species.
Due to their food, the caterpillars accumulate a large amount of alkaloids, consequently also the moths are toxic and unpalatable to birds. The characteristic colouration of its wings serve as a sign of warning to their predators (aposematism).


Utricularia macrorhiza, the common bladderwort, is a perennial suspended aquatic carnivorous plant that belongs to the genus Utricularia. U. macrorhiza is native to North America and eastern temperate Asia.


U. macrorhiza is a floating plant with six to twenty large, bilaterally symmetrical, yellow flowers that appear in June, July, and August, and are held on an erect stem. U. macrorhiza is distinguished from other similar species by its flowers, which are larger than those found on any other bladderwort.
The bladders which give common bladderwort its name are used to trap and consume prey. Small organisms trigger the hairs on the pores of the bladder as they brush against it, causing the pore to open inward, allowing a rush of water into the bladder which pulls the prey in as well. The pore immediately closes behind the prey, which is then digested by enzymes within the bladder. The process of trapping the prey from opening to closing the pore takes place in 0.002 seconds. If large prey becomes stuck in the pore, the prey is digested by the enzymes bit by bit until the pore closes again.


The Florida leaf-footed bug (Acanthocephala femorata) is a species of insect.  The genus name Acanthocephala means "spiny head" and comes from the pointed tylus at the tip of the head. Acanthocephala femorata is found in the continental United States and Mexico.
This insect is considered a pest, eating and causing damage to citrus and roses. The lower rear legs are wider than the upper legs, with serrations. This is especially pronounced in the male. It has long, slim, curving antennae with distinctive orange tips. The body is reddish brown to nearly black.
They have a number of predators and therefore biological control is generally enough to prevent their populations from going out of control. Many do not make it past the larval stage; parasitic flies often lay their eggs within the developing larvae, paralyzing them. They are also eaten by birds and assassin bugs.


The orange-peel doris lives in the intertidal and subtidal zones on rocky shores.


A. australis is one of 20 species in the genus Acanthopagrus, part of the porgy family Sparidae.
The species was first mentioned in scientific literature by Richard Owen in an 1853 work on skeletal material held by the Museum of the Royal College of Surgeons of England. Although he named it Chrysophrys australis, it was insufficiently described and hence designated a nomen nudum. German-British naturalist Albert Günther formally described the surf bream in 1859 using Owen's name. Allan Riverstone McCulloch classified it in the genus Sparus in 1929. Texts up till 1949 used either of these binomial combinations.
Ian Munro used the binomial name Mylio australis in a 1949 review of the Australian "silver breams", preferring Mylio over Acanthopagrus and Roughleya as he found it to be the oldest valid genus name available. However, the validity of Mylio was questioned as its describer—Philibert Commerson—had listed the type as Sparus mylio.
Munro also found that M. australis was in fact two separate species, creating the new species name of Mylio butcheri to accommodate the southern black bream. Munro based this classification on a number of new specimens,
Acanthopagrus australis has a number of common names, many of which are applied to a number of related fish species, both in Australia and worldwide. It was known as the sea bream or surf bream during the spawning season, while black bream was a common name from New South Wales. In Queensland it was known simply as bream. Munro termed it the yellowfin bream. The Department of the Environment, Water, Heritage and the Arts of the Federal Government designated yellowfin bream as preferred name. It has also been designated the standard name by the CSIRO Division of Marine and Atmospheric Research in commercial fishing in Australia. Its name to the local Eora and Darug inhabitants of the Sydney basin has been transcribed as garuma, karngooma, caroom-a and kururma.
The species has also been known to hybridise with the closely related southern black bream forming viable offspring, themselves able to backcross with the parent species. This is only known from one coastal lake where the two species are landlocked together for extended periods, promoting interbreeding and the production of offspring with morphological traits intermediate between the two species. The setting required to cause hybridisation, however is too rare to consider the two species subspecies, or even a single species.


Acanthopleura granulata, common name the West Indian fuzzy chiton (also known as Curbs or Sea Cradles), is a medium-sized tropical species of chiton. This type of chiton's activity does not depend on spring-neap oscillations leading to lower locomotion loss. Its morphology is different from usual chitons as it has a fifth valve, which is split into halves.
This species is common within its range in the tropical Western Atlantic, but it is often not noticed, because its color and texture are similar to the rocks on which it lives. With not many predators the West Indian fuzzy chiton can live up to 40 years.
In countries that used to be part of the British West Indies, these and other common intertidal chitons are known as "curb"; the foot of the animal is eaten by people and is also used as bait for fishing.


The eastern spinebill (Acanthorhynchus tenuirostris) is a species of honeyeater found in south-eastern Australia in forest and woodland areas, as well as gardens in urban areas of Canberra, Sydney, Melbourne and Adelaide. It is around 15 cm long, and has a distinctive black, white and chestnut plumage, a red eye, and a long downcurved bill.


Originally described as Certhia tenuirostris by the English ornithologist John Latham in 1801, it is a member of the small genus Acanthorhynchus with one other, the western spinebill of Western Australia. The generic name is derived from the Greek translation of spinebill, namely acantho-/ακανθο- 'spine' and rhynchos/ρυνχος 'bill'. Its specific epithet is from Latin  tenuis 'narrow' and rostrum 'bill'. Other English names include spine-billed honeyeater and awl-bird or cobbler's awl bird. The eastern spinebill is polytypic, consisting of the subspecies A. t. cairnsensis, A. t. dubius, A. t. halmaturinus, and the nominate subspecies A. t. tenuirostris.
The eastern spinebill forms a superspecies with the closely related western spinebill. Scientists believe the two sister species are descended from a shared ancestor whose once widespread populations were separated by climate change. During a past period of desertification, that ancestor species retreated to refuges in the southwestern and southeastern corners of the continent, and evolved into the two present-day spinebill species. Recent DNA studies have shown that the two spinebills belong to a clade which is a sister taxon to all other honeyeaters.


Eastern spinebills are found in dry sclerophyll forest, scrub and heathland from the Cooktown area in North Queensland south through New South Wales east of the Great Dividing Range, through Victoria and into the Flinders Ranges in eastern South Australia as well as throughout Tasmania. Adaptable, they can be found in urban gardens with sufficient vegetation to act as cover and a food source.


The eastern spinebill feeds on nectar from many plants, including the blooms of gum trees, mistletoes Amyema spp., Epacris longiflora, Epacris impressa (common heath), Correa reflexa, and various members of the Proteaceae such as Banksia ericifolia, Banksia integrifolia, Lambertia formosa and Grevillea speciosa, as well as small insects and other invertebrates. A 1982 study in the New England National Park in north-eastern New South Wales found that there was a large influx of birds coinciding with the start of flowering of Banksia spinulosa there. They have been known to feed from exotic plants such as fuchsias.
During periods of abundant flowering there may be periods of low nectar production, and it appears that the eastern spinebill responds to these periodic shortages by storing fat during periods of high nectar production, increasing the amount of time spent feeding, or dropping its day-time metabolic rate to night-time levels.


The hawthorn shield bug (Acanthosoma haemorrhoidale) is a common European shield bug. Its chief food is haws, the fruit of the hawthorn tree, but adults can overwinter on a diet of leaves, and individuals can be found on many potential food plants, including pedunculate oak, sessile oak and whitebeam. They may grow up to 17 mm (0.67 in) long, and are camouflaged in shades of green and brown. Like many so-called "stink bugs", they may release unpleasant odours when disturbed.


Although the body of the reef fish can vary in shade from light to dark blue, the dorsal, anal and caudal fins are golden blue. As juveniles, the edges on their dorsal and anal fins and the rings around their eyes are purple-blue, blue or blue-green. Their colors change during growth from a yellow juvenile, yellow tailed blue subadult and the blue adult phase.
Acanthurus coeruleus exhibits biofluorescence, that is, when illuminated by blue or ultraviolet light, it re-emits it as green, and appears differently than under white light illumination (see image to the right). Biofluorescence may assist in intraspecific communication and camouflage.


Acanthurus triostegus, also known as the convict tang, convict surgeonfish, or manini, is a small surgeonfish in family Acanthuridae of the order Perciformes. It is typically about 17 cm (7 in) long, but some individuals may reach 27 cm. These tangs are widespread. They are found in the Indo-Pacific except for seas around the Arabian Peninsula, in the Pacific at the Hawaiian Islands, and in the Eastern Pacific they are found in the lower Gulf of California and down to Panama, including the Revillagigedo Islands, Clipperton Island, Cocos Island, and Galápagos Islands with some reports throughout the Mediterranean and Adriatic Sea most likely entering through the Suez Canal.


Acanthus mollis, commonly known as bear's breeches, sea dock, bear's foot plant, sea holly, gator plant or oyster plant, is a species of plant in the family Acanthaceae and is native to the Mediterranean region. It is a leafy, clump-forming perennial herb, with a rosette of relatively large, lobed or toothed leaves, and purplish and white flowers on an erect spike.


The shikra (Accipiter badius) is a small bird of prey in the family Accipitridae found widely distributed in Asia and Africa where it is also called the little banded goshawk. The African forms may represent a separate species but have usually been considered as subspecies of the shikra. The shikra is very similar in appearance to other sparrowhawk species including the Chinese goshawk and Eurasian sparrowhawk. They have a sharp two note call and have the typical flap and glide flight. Their calls are imitated by drongos and the common hawk-cuckoo resembles it in plumage.
The shikra is a small raptor (26–30 cm long) and like most other Accipiter hawks, this species has short rounded wings and a narrow and somewhat long tail. Adults are whitish on the underside with fine rufous bars while the upperparts are grey. The lower belly is less barred and the thighs are whitish. Males have a red iris while the females have a less red (yellowish orange) iris and brownish upperparts apart from heavier barring on the underparts. The females are slightly larger. The mesial stripe on the throat is dark but narrow. In flight the male seen from below shows a light wing lining (underwing coverts) and has blackish wing tips. When seen from above the tail bands are faintly marked on the lateral tail feathers and not as strongly marked as in the Eurasian sparrowhawk. The central tail feathers are unbanded and only have a dark terminal band. Juveniles have dark streaks and spots on the upper breast and the wing is narrowly barred while the tail has dark but narrow bands. A post juvenile transitional plumage is found with very strong barring on the contour feathers of the underside. The call is pee-wee, the first note being higher and the second being longer. In flight the calls are shorter and sharper kik-ki ... kik-ki.  The Chinese sparrowhawk is somewhat similar in appearance but has swollen bright orange ceres and yellow legs with the wing tips entirely black.


The shikra is found in a range of habitats including forests, farmland and urban areas. They are usually seen singly or in pairs. The flight is typical with flaps and glides. During the breeding season pairs will soar on thermals and stoop at each other. Their flight usually draws alarms among smaller birds and squirrels. They feed on rodents (including Meriones hurrianae), squirrels, small birds, small reptiles (mainly lizards but sometimes small snakes) and insects. Small birds usually dive through foliage to avoid a shikra and a Small Blue Kingfisher has been observed diving into water to escape. Babblers have been observed to rally together to drive away a shikra. They will descend to the ground to feast on emerging winged termites, hunt at dusk for small bats (such as Cynopterus sphinx) and in rare instances they may even resort to feed on carrion. In one instance a male was found feeding on a dead chick at the nest. Their calls are mimicked by drongos and this behaviour is thought to aid in stealing food by alarming other birds that the drongos associate with.
The breeding season in India is in summer from March to June. The nest is a platform similar to that of crows lined with grass. Both sexes help build the nest, twigs being carried in their feet. Like crows, they may also make use of metal wires. The usual clutch is 3 to 4 eggs (when eggs are removed they lay replacements and one observer noted that they could lay as many as 7 in a season) which are pale bluish grey stippled on the broad end in black. The incubation period is 18 to 21 days.


The shikra was a favourite among falconers in India and Pakistan due to the ease with which it could be trained and was frequently used to procure food for the more prized falcons. They were noted for their pluck and ability to take much larger birds including partridges, crows and even young peafowl. The word shikra or shikara means hunter in the Hindi language (the male was called chipak or chipka based on call) The word Shikra is borrowed from the Urdu word (شِـكْـره) which is derived from the word shikari (شِكارى) meaning hunter.
The word is also used in the French name Le Chicquera which was however given to the red-necked falcon by Levaillant in 1799.
An Indian Navy helicopter base was named INS Shikra in 2009.
The shikra is also the mascot for the 149 Squadron of the Republic of Singapore Air Force, which operates the F5S/T Tiger IIs fighter jets.
Famous Punjabi poet Shiv Kumar Batalvi wrote a poem called "Main Ik Shikra Yaar Banaya" about a lost love wherein he compares her to a shikra.


The northern goshawk has a large circumpolar distribution. In Eurasia, it is found in most areas of Europe excluding Ireland and Iceland. It has a fairly spotty distribution in western Europe (e.g. Great Britain, Spain, France) but is more or less found continuously through the rest of the continent. Their Eurasian distribution sweeps continuously across most of Russia, excluding the fully treeless tundra in the northern stretches, to the western limits of Siberia as far as Anadyr and Kamchatka. In the Eastern Hemisphere, they are found in their southern limits in extreme northwestern Morocco, Corsica and Sardinia, the "toe" of Italy, southern Greece, Turkey, the Caucasus, Sinkiang's Tien Shan, in some parts of Tibet and the Himalayas (India and Nepal), western China and Japan. In winter, northern goshawks may be found rarely as far south as Taif in Saudi Arabia and perhaps Tonkin, Vietnam.
In North America, they are most broadly found in the western United States, including Alaska, and western Canada. Their breeding range in the western contiguous United States largely consists of the wooded foothills of the Rocky Mountains and many other large mountain ranges from Washington to southern California extending east to central Colorado and westernmost Texas. Somewhat discontinuous breeding populations are found in southeastern Arizona and southwestern New Mexico, thence also somewhat spottily into western Mexico down through Sonora and Chihuahua along the Sierra Madre Occidental as far as Jalisco and Guerrero, their worldwide southern limit as a breeding species.
The goshawk continues east through much of Canada as a native species, but is rarer in most of the eastern United States, especially the Midwest where they are not typically found outside the Great Lakes region, where a good-sized breeding population occurs in the northern parts of Minnesota, Illinois, Michigan and somewhat into Ohio; a very small population persists in the extreme northeast corner of North Dakota. They breed also in mountainous areas of New England, New York, central Pennsylvania and northwestern New Jersey, sporadically down to extreme northwestern Maryland and northeastern West Virginia. Vagrants have been reported in Ireland, North Africa (central Morocco, northern Algeria, Tunisia, Libya, Egypt); the Arabian Peninsula (Israel, Jordan, Saudi Arabia), southwest Asia (southern Iran, Pakistan), western India (Gujarat) and on Izu-shoto (south of Japan) and the Commander Islands, and in most of the parts of the United States where they do not breed.


The northern goshawk has relatively short, broad wings and a long tail, typical for Accipiter species and common to raptors that require maneuverability within forest habitats. For an Accipiter, it has a relatively sizeable bill, relatively long wings, a relatively short tail, robust and fairly short legs and particularly thick toes. Across most of the species' range, it is blue-grey above or brownish-grey with dark barring or streaking over a grey or white base color below, but Asian subspecies in particular range from nearly white overall to nearly black above. Goshawks tend to show clinal variation in color, with most goshawks further north being paler and those in warmer areas being darker but individuals can be either dark in the north or pale in the south. Individuals that live a long life may gradually become paler as they age, manifesting in mottling and a lightening of the back from a darker shade to a bluer pale color. Its plumage is more variable than that of the Eurasian sparrowhawk (Accipiter nisus), which is probably due to higher genetic variability in the larger goshawk. The juvenile northern goshawk is usually a solid to mildly streaky brown above, with many variations in underside color from nearly pure white to almost entirely overlaid with broad dark cinnamon-brown striping. Both juveniles and adults have a barred tail, with 3 to 5 dark brown or black bars. Adults always have a white eye stripe or supercilia, which tends to be broader in northern Eurasian and North American birds. In North America, juveniles have pale-yellow eyes, and adults develop dark red eyes usually after their second year, although nutrition and genetics may affect eye color as well. In Europe and Asia, juveniles also have pale-yellow eyes while adults typically develop orange-colored eyes, though some may have only brighter yellow or occasionally ochre or brownish eye color. Moulting starts between late March and late May, the male tends to moult later and faster than the female. Moulting results in the female being especially likely to have a gap in its wing feathers while incubating and this may cause some risk, especially if the male is lost, as it inhibits her hunting abilities and may hamper her defensive capabilities, putting both herself and the nestlings in potential danger of predation. The moult takes a total of 4–6 months, with tail feathers following the wings then lastly the contour and body feathers, which may not be completely moulted even as late as October.
Although existing wing size and body mass measurements indicate that the Henst's goshawk (Accipiter henstii) and Meyer's goshawk (Accipiter meyerianus) broadly overlap in size with this species, the northern goshawk is on average the largest member of the genus Accipiter, especially outsizing its tropic cousins in the larger Eurasian races. The northern goshawk, like all Accipiters, exhibits sexual dimorphism, where females are significantly larger than males, with the dimorphism notably greater in most parts of Eurasia. Linearly, males average about 8% smaller in North America and 13% smaller than females in Eurasia, but in the latter landmass can range up to a very noticeable 28% difference in extreme cases. Male northern goshawks are 46 to 61 cm (18 to 24 in) long and have a 89 to 105 cm (35 to 41 in) wingspan. The female is much larger, 58 to 69 cm (23 to 27 in) long with a 108 to 127 cm (43 to 50 in) wingspan. In a study of North American goshawks (A. g. atricapillus), males were found to average 56 cm (22 in) in total length, against females which averaged 61 cm (24 in). Males from six subspecies average around 762 g (1.680 lb) in body mass, with a range from all races of 357 to 1,200 g (0.787 to 2.646 lb). The female can be up to more than twice as heavy, averaging from the same races 1,150 g (2.54 lb) with an overall range of 758 to 2,200 g (1.671 to 4.850 lb). Among standard measurements, the most oft-measured is wing chord which can range from 286 to 354 mm (11.3 to 13.9 in) in males and from 324 to 390 mm (12.8 to 15.4 in) in females. Additional, the tail is 200–295 mm (7.9–11.6 in), the culmen is 20–26.3 mm (0.79–1.04 in) and the tarsus is 68–90 mm (2.7–3.5 in).


Northern goshawks normally only vocalize during courtship or the nesting season. Adult goshawks may chatter a repeated note, varying in speed and volume based on the context. When calling from a perch, birds often turn their heads slowly from side to side, producing a ventriloquial effect. The male calls a fast, high-pitched kew-kew-kew when delivering food or else a very different croaking guck or chup. The latter sound has been considered by some authors similar to that of a person snapping the tongue away from the roof the mouth; the males produce it by holding the beak wide open, thrusting the head up and forward, than bringing it down as the sound is emitted, repeated at intervals of five seconds. This call is uttered when the male encounters a female. Two calls have been recorded mainly from brooding females in the race A. g. atricapillus: a recognition scream of short, intense notes (whee-o or hee-ya) which ends in harsh, falsetto tone; then a dismissal call given when the male lingers after delivering food, consisting of a choked, cut-off scream. Meanwhile, the adult female's rapid strident kek-kek-kek expresses alarm or intent to mob towards threatening intruders. This is often done when mobbing a predator such as a great horned owl (Bubo virginianus) and as it progresses the female's voice may lower slightly in pitch and becomes harsh and rasping. As the intensity of her attacks increases, her kakking becomes more rapid and can attain a constant screaming quality. Females often withdraw into the treetops when fatigued, and their calls are then spaced at longer intervals. Males respond to interlopers or predators with a quieter, slower gek gek gek or ep ep ep. A call consisting of kek…kek.kekk kek kek-kek-kek is used mainly by females in advertisement and during pre-laying mutual calling. Both sexes also may engage in kakking during copulation. Vocalizations mainly peak in late courtship/early nesting around late March to April, can begin up to 45 minutes before sunrise, and are more than twice in as frequent in the first three hours of daylight as in the rest of the day. Occasionally hunting northern goshawks may make shrill screams when pursuing prey, especially if a lengthy chase is undertaken and the prey is already aware of its intended predator.


The northern goshawk appears to have diversified in northern, central Eurasia and spread both westwards to occupy Europe and, later on, eastwards to spread into North America across the Bering Land Bridge. Fossil remains show that goshawks were present in California by the Pleistocene era. Two non-exclusive processes could have occurred to cause the notably color and size variation of northern goshawks throughout its range: isolation in the past enabled gene combinations to assort as distinct morphs that suited conditions in different geographical areas, followed by a remixing of these genotypes to result in clines, or subtle variation in modern selection pressures led to a diversity of hues and patterns. As a result of the high variation of individual goshawks in plumage characteristics and typical trends in clinal variation and size variations that largely follow Bergmann's rule and Gloger's rule, an excessive number of subspecies have been described for the northern goshawk in the past. In Europe (including European Russia) alone, 12 subspecies were described between 1758 and 1990. Most modern authorities agree on listing nine to ten subspecies of northern goshawks from throughout its range.
 A. g. gentilis (Linnaeus, 1758) – The nominate race is distributed through most of the species current European range, excluding northern Fennoscandia, northwestern Russia and possibly some of the Mediterranean islands they inhabit. Outside of Europe, this subspecies' range extends south to northwestern Africa (almost entirely Morocco) and east in Eurasia to Urals, the Caucasus and Asia Minor. It is a typically large subspecies, with high levels of sexual dimorphism. The wing chord of males ranges from 300 to 342 mm (11.8 to 13.5 in) and of females from 336 to 385 mm (13.2 to 15.2 in). Body mass is variable, range from 517 to 1,110 g (1.140 to 2.447 lb) in males and from 820 to 2,200 g (1.81 to 4.85 lb) in females. In some cases, the largest adult females (including some exceptionally big females which are the heaviest goshawks known from anywhere) from within a population are up to four times heavier than the smallest adult males, although this is exceptional. The highest average weights come from central Fennoscandia, where the sexes weigh on average 865 g (1.907 lb) and 1,414 g (3.117 lb), respectively. The lowest come from Spain, where goshawks of this race weigh a median of 690 g (1.52 lb) in males and 1,050 g (2.31 lb) in females. The nominate race is generally a dark slaty-brown color on its back and wing coverts with a blackish-brown head. The supercilium is thin and the underside is generally creamy with heavy dark barring. On average, in addition to their smaller size, nominate goshawks to the south of the race's distribution have thinner supericilia and broader and denser barring on the underside. An aberrant “isabelline” morph is known mainly from central and eastern Europe, where the goshawk may be a general beige color (somewhat similar to the pale birds from the races albidus and buteoides), but such birds appear to be very rare.
A. g. arrigonii (Kleinschmidt, 1903) – This is an island race found on the Mediterranean isles of Sardinia and Corsica. It averages smaller and weaker-footed than goshawks from the nominate race. The wing chord measures 293 to 308 mm (11.5 to 12.1 in) in males and 335 to 347 mm (13.2 to 13.7 in) in females. This race is typically a more blackish brown above with almost fully black head, while the underside is almost pure white and more heavily overlaid with black barring and conspicuous black shaft-streaks. This subspecies is not listed by all authorities but is often considered valid.
A. g. buteoides (Menzbier, 1882) – This race is characteristic of the northern stretches of the western Eurasian range of goshawks, being found as a breeding species from northern Fennoscandia to western Siberia, ranging as far as the Lena River. In the eastern portion of its distribution, many birds may travel south to central Asia to winter. This is a large race, averaging larger than most populations of the nominate race but being about the same size as the big nominate goshawks with which they may overlap and interbreed with in Fennoscandia. The wing chord in males ranges from 308 to 345 mm (12.1 to 13.6 in) while that of females ranges from 340 to 388 mm (13.4 to 15.3 in). The body mass of males has been reported from 870 to 1,170 g (1.92 to 2.58 lb), with an average of 1,016 g (2.240 lb), while that of females is reportedly 1,190 to 1,850 g (2.62 to 4.08 lb), with an average of 1,355 g (2.987 lb). Usually, this race is an altogether paler colour than the nominate, being blue-grey above with a dusky-grey crown and a broad supercilium. The underside is white with rather fine blackish-brown barring. Pale flecking on the feather shafts sometimes result in barred appearance on the contour feathers of the nape, back and upper wing. Many birds from this subspecies also have a tan to pale brown eye color. These two characteristics are sometimes considered typical of this race, but individuals are rather variable. In western Siberia, about 10% of birds of this race are nearly pure white (similar to albidus) with varied indications of darker streaking.
A. g. albidus (Menzbier, 1882) – This race of goshawk is found in northeastern Siberia and Kamchatka. Many birds of this race travel south for the winter to Transbaikalia, northern Mongolia and Ussuriland. This race continues the trend for goshawks to grow mildly larger eastbound in Eurasia and may be the largest known race based on the midpoint of known measurements of this race, although limited sample sizes of measured goshawks shows they broadly overlap in size with A. g. buteoides and large-bodied populations of A. g. gentilis. The wing chord can range from 316 to 346 mm (12.4 to 13.6 in) in males and from 370 to 388 mm (14.6 to 15.3 in) in females. Known males have scaled from 894 to 1,200 g (1.971 to 2.646 lb) while a small sample of females weighed have had a body mass between 1,300 and 1,750 g (2.87 and 3.86 lb). This is easily the palest race of northern goshawk. Many birds are pale grey above with much white about the head and very sparse barring below. However, about half of the goshawks of this race are more or less pure white, with at most only a few remnants of pale caramel flecking about the back or faint brownish markings elsewhere.
A. g. schvedowi (Menzbier, 1882) – This race ranges from the Urals east to the Amurland, Ussuriland, Manchuria, west-central China and sporadically as a breeder into Sakhalin and the Kuril islands. A. g. schvedowi averages smaller than the other races on the mainland of Eurasia, with seemingly the highest sexual dimorphism of any goshawk race, possibly as an adaptation to prey partitioning in the exceptionally sparse wooded fringes of the desert-like steppe habitat that characterizes this race's range. The wing chord has been found to measure 298 to 323 mm (11.7 to 12.7 in) in males and 330 to 362 mm (13.0 to 14.3 in) in females. Body mass of 15 males was found to be merely 357 to 600 g (0.787 to 1.323 lb) with a mean of 501 g (1.105 lb), the lowest adult weights known for this species, while two adult females scaled 1,000 and 1,170 g (2.20 and 2.58 lb), respectively, or more than twice as much on average. Beyond its smaller size, its wings are reportedly relatively shorter and feet relatively smaller and weaker than other Eurasian races. In color, this race is typically a slate-grey above with a blackish head and is densely marked below with thin brown barring.
A. g. fujiyamae (Swann & Hartert, 1923) – Found through the species' range in Japan, from the islands of Hokkaido south to the large island of Honshu, in the latter down to as far south as forests a bit north of Hiroshima. A fairly small subspecies, it may average slightly smaller than A. g. schvedowi linearly, but it is less sexually dimorphic in size and weighs slightly more on average. The wing chord is the smallest known from any race, 286 to 300 mm (11.3 to 11.8 in) in males and 302 to 350 mm (11.9 to 13.8 in) in females. However, the weights of 22 males ranged from 602 to 848 g (1.327 to 1.870 lb), averaging 715 g (1.576 lb) while 22 females ranged from 929 to 1,265 g (2.048 to 2.789 lb), averaging 1,098 g (2.421 lb). The coloration of this race is not dissimilar from A. g. schvedowi, but is still darker slate above and they tend to have heavier barring below, probably being the darkest race on average, rivaled only by the similar insular race from the opposite side of the Pacific, A. g. laingi.
A. g. atricapillus (Wilson, 1812) – Sometimes simply referred to as the American goshawk. This subspecies occupies a majority of the species' range in North America, excluding some islands of the Pacific Northwest and the southern part of the American Southwest. American goshawks are generally slightly smaller on average than most Eurasian ones, although there are regional differences in size that confirm mildly to Bergmann's rule within this race. Furthermore, sexual dimorphism in size is notably less pronounced in American goshawks than in most Eurasian races. Overall, the wing chord is 308 to 337 mm (12.1 to 13.3 in) in males and 324 to 359 mm (12.8 to 14.1 in) in females. Size within atricapillus based on body mass seems to be highest in interior Alaska, followed by the Great Lakes, is intermediate in the northwest United States from eastern Washington to the Dakotas as well as in southeast Alaska thence decreasing mildly along the Pacific in Oregon and California and smallest of all within the race in the Great Basin and Colorado Plateau states (i.e. Nevada, Utah and northern and central Arizona). Conspicuously, wing size did not correspond to variations in body mass and more southerly goshawks were frequently longer winged than the more massive northerly ones. Male atricapillus goshawk have been found to weigh from 655 to 1,200 g (1.444 to 2.646 lb) and females from 758 to 1,562 g (1.671 to 3.444 lb). The lightest reported mean weights were from goshawks in northern and central Arizona, weighing a mean of 680 g (1.50 lb) in males and 935 g (2.061 lb) while the highest were from a small sample of Alaskan goshawks which weighed some 905 g (1.995 lb) in males and 1,190 g (2.62 lb) in females. Almost identical mean weights for goshawks as in Alaska were recorded for goshawks from Alberta as well. This race is typically a blue-gray color above with a boldly contrasting black head and broad white supercilia. American goshawks are often grayish below with fine gray waving barring and, compared to most Eurasian goshawks, rather apparent black shaft streaks which in combination create a vermiculated effect that is all-together messier looking than in most Eurasian birds. From a distance, atricapillus can easily appear solidly all-gray from the front. Due to this, the adult goshawk in America is sometimes called the “gray ghost”, a name also somewhat more commonly used for adult male hen harriers.  Birds from mainland Alaska tend to be paler overall with more pale flecking than other American goshawks.
A. g. laingi (Tavernier, 1940) – This insular race is found on the Queen Charlotte Islands and Vancouver Island. This subspecies is slightly smaller than the goshawks found on the mainland and is linearly the smallest race on average in North America. The wing chord of males can range from 312 to 325 mm (12.3 to 12.8 in) and that of females is 332 to 360 mm (13.1 to 14.2 in) and is on average nearly 5% smaller than those sampled goshawks from the nearby mainland. These goshawks are characteristically darker than mainland goshawks with the black of the crown extending to the interscapulars. The underside is a sootier gray overall.
A. g. apache (van Rossem, 1938) – The range of this subspecies extends from southern Arizona and New Mexico down throughout the species' range in Mexico. This subspecies has the longest median wing size of any race, running contrary to Bergmann's rule that northern birds should outsize southern ones in widely distributed temperate species. In males the wing chord ranges from 344 to 354 mm (13.5 to 13.9 in) while in females it ranges from 365 to 390 mm (14.4 to 15.4 in). However, in terms of body mass, it is only slightly heavier than the goshawks found discontinuously somewhat to the north in the Great Basin and the Colorado Plateau and lighter than the heaviest known American goshawks from Alaska, Alberta and Wisconsin despite exceeding the goshawks from these areas in wing size. The weight of 49 males ranged from 631 to 744 g (1.391 to 1.640 lb), averaging 704 g (1.552 lb), while that of 88 females from two studies ranged from 845 to 1,265 g (1.863 to 2.789 lb), averaging 1,006 g (2.218 lb). Aside from its overall larger size, apache reportedly averages larger in foot size than most other American goshawks. Birds of this race tend to be darker than other American goshawks aside from the laingi type birds. Due to its shortage of distinct features beyond proportions, this is considered one of the more weakly separated among current separate subspecies, with some authors considering it merely a clinal variation of atricapillus. Even the greater wing size in southern birds follows a trend for the wing chord to increase in size in the south on the contrary to body mass.


As typical of the genus Accipiter (as well as unrelated forest-dwelling raptors of various lineages), the northern goshawk has relatively short wings and a long tail which make it ideally adapted to engaging in brief but agile and twisting hunting flights through dense vegetation of wooded environments. This species is a powerful hunter, taking birds and mammals in a variety of woodland habitats, often utilizing a combination of speed and obstructing cover to ambush their victims. Goshawks often forage in adjoining habitat types, such as the edge of a forest and meadow. Hunting habitat can be variable, as in a comparison of habitats used in England found that only 8% of landscapes used were woodlands whereas in Sweden 73-76% of the habitat used was woodland, albeit normally within 200 m (660 ft) of an opening. In North America, goshawks are generally rather more likely than those from Eurasia to hunt within the confines of mature forest, excluding areas where prey numbers are larger outside of the forest, such as where scrub-dwelling cottontails are profuse. One study from central Sweden found that locally goshawks typically hunt within the largest patches of mature forests, selecting second growth forest less than half as often as its prevalence in the local environment. The northern goshawk is typically considered a perch-hunter. Hunting efforts are punctuated by a series of quick flights low to the ground, interspersed with brief periods of scanning for unsuspecting prey from elevated perches (short duration sit-and-wait predatory movements). These flights are meant to be inconspicuous, averaging about 83 seconds in males and 94 seconds in females, and prey pursuits may be abandoned if the victims become aware of the goshawk too quickly. More sporadically, northern goshawks may watch from prey from a high soar or gliding flight above the canopy. One study in Germany found an exceptional 80% of hunting efforts to be done from a high soar but the author admitted that he was probably biased by the conspicuousness of this method. In comparison, a study from Great Britain found that 95% of hunting efforts were from perches. A strong bias for pigeons as prey and a largely urbanized environment in Germany explains the local prevalence of hunting from a soaring flight, as the urban environment provides ample thermals and obstructing tall buildings which are ideal for hunting pigeons on the wing.
Northern goshawks rarely vary from their perch-hunting style that typifies the initial part of their hunt but seems to be able to show nearly endless variation to the concluding pursuit. Hunting goshawks seem to not only utilize thick vegetation to block them from view for their prey (as typical of Accipiters) but, while hunting flying birds, they seem to be able to adjust their flight level so the prey is unable to see its hunter past their own tails. Once a prey item is selected, a short tail-chase may occur. The northern goshawk is capable of considerable, sustained, horizontal speed in pursuit of prey with speeds of 38 mph (61 km/h) reported. While pursuing prey, northern goshawks has been described both “reckless” and “fearless", able to pursue their prey through nearly any conditions. There are various times goshawks have been observed going on foot to pursue prey, at times running without hesitation (in a crow-like, but more hurried gait) into dense thickets and brambles (especially in pursuit of galliforms trying to escape), as well as into water (i.e. usually waterfowl). Anecdotal cases have been reported when goshawks have pursue domestic prey into barns and even houses. Prey pursuits may become rather prolonged depending upon the goshawk's determination and hunger, ranging up to 15 minutes while harrying a terrified, agile squirrel or hare, and occasional pair hunting may benefit goshawks going after agile prey. As is recorded in many accipitrids, hunting in pairs (or “tandem hunting”) normally consist of a breeding pair, with one bird flying conspicuously to distract the prey, while the other swoops in from behind to ambush the victim. When gliding down from a perch to capture prey, a goshawk may not even beat its wings, rendering its flight nearly silent. Prey is killed by driving the talons into the quarry and squeezing while the head is held back to avoid flailing limbs, frequently followed by a kneading action until the prey stops struggling. Kills are normally consumed on the ground by juvenile or non-breeding goshawks (more rarely an elevated perch or old nest) or taken to a low perch by breeding goshawks. Habitual perches are used for dismantling prey especially in the breeding season, often called “plucking perches", which may be fallen logs, bent-over trees, stumps or rocks and can see years of usage. Northern goshawks often leave larger portions of their prey uneaten than other raptors, with limbs, many feathers and fur and other body parts strewn near kill sites and plucking perches, and are helpful to distinguish their kills from other raptors such as large owls, who usually eat everything. The daily food requirements of a single goshawks are around 120 to 150 g (4.2 to 5.3 oz) and most kills can feed a goshawk for 1 to 3 days. Northern goshawks sometimes cache prey on tree branches or wedged in a crotch between branches for up to 32 hours. This is done primarily during the nestling stage. Hunting success rates have been very roughly estimated at 15–30%, within average range for a bird of prey, but may be reported as higher elsewhere. One study claimed hunting success rates for pursuing rabbits was 60% and corvids was 63.8%.