The boat-billed heron (Cochlearius cochlearius), colloquially known as the boatbill, is an atypical member of the heron family, and was formerly placed in a monotypic family, the Cochleariidae.  It lives in mangrove swamps from Mexico south to Peru and Brazil. It is a nocturnal bird, and breeds semicolonially in mangrove trees, laying two to four bluish-white eggs in a twig nest.


Boat-billed herons feed on shrimp and small fish such as Dormitator latifrons, a species of sleeper goby. They tend to forage in vegetative streams, shallow water, and lagoons. When foraging in streams, they use low-hanging branches and mangrove roots to stand over the water. In ponds they will walk slowly through the water up to 10 cm (4 in) deep or will forage near the water's edge. In order to capture prey they will lunge at fish or scoop the surface of the water with their bills which are uniquely shaped for this method of capture. Additionally, they have been observed using two different feeding techniques; standing and slowly stalking prey, or disturbing the water and chasing prey.
Boat-billed herons will forage nocturnally, and have been seen leaving the roost 30 minutes after sundown to feed. It has been observed that they do not feed when a light source is present such as daylight, moonlight, or artificial light. One study hypothesized that in order to forage for food in the dark and in shallow, muddy water, their bills are sensitive to touch which helps them feel for their prey.


Boat-billed herons range from Mexico to Peru, Brazil, and northeastern Argentina. They are nonmigratory birds that tend to live in seasonal lagoons and estuaries, and nest in mangroves.


The yellow color of the mushrooms is from alkaloids known as birnbaumins. Birnbaumin B is the major compound and has a formula C16H20N6O5 whilst birnbaumin A has one less oxygen molecule. Extraction methods used to isolate these compounds also yield L-tryptophan, a common amino acid which helps build proteins.
A 2015 study succeeded in isolating a number of fatty acids from Leucocoprinus birnbaumii which showed moderate but selective anti-microbial effects. Three fatty acid compounds were isolated and tested against six microorganisms. Of them, linoleic acid displayed some inhibition against Streptococcus pyogenes and less against Staphylococcus aureus, oleic acid had some inhibition of Pseudomonas aeruginosa whilst methyl linoleate had limited inhibition against all three bacteria species. They did not show any results against the other two bacteria they were tested against (E. coli and MRSA) or against the pathogenic yeast strain Candida albicans.


One feature of Leucocoprinus birnbaumii which isn't often described but is frequently visible are the sclerotia amongst the mycelium on the surface of the soil, which is an unusual trait amongst members of the Agaricales. Typically sclerotia are most often discussed in the context of truffles or in the challenges faced by attempts at morel cultivation so are usually associated with large, hardened masses growing under the ground. The sclerotia in L. birnbaumii however are tiny (500-820 μm) hard, elliptical masses on top of the soil amongst the fibrous mycelium which have been described as whitish-beige or pale yellowish white. These have been shown to be genetically identical to the developed mushroom and have previously been cultured to produce mushrooms by introducing them to a substrate of sterilised wheat chaff before introducing the subsequently developed mycelium to a sand, peat, soil and sphagnum moss mix to ultimately fruit. Whilst L. birnbaumii itself is harmless to plants the sclerotia can have economic impacts on the production and sale of Orchids which often have transparent root pots where the sclerotia can collect. Their presence in these containers can reduce the aesthetic value of the plants and have impacts on the water retention of the substrate. Previous studies have noted an apparent propensity for L. birnbaumii to grow amongst Orchids.


Like all Leucocoprinus species, L. birnbaumii is a saprotroph, living on very decayed plant matter (humus or compost). The fungus is common throughout the tropics and subtropics, extending into warmer parts of the temperate zones. Rarely, it appears in cooler areas, fruit bodies having been recorded as far north as England, but these seem to be temporary introductions. In these areas (such as North America, Europe, and Australia) it is more usually found in hothouses and plant pots than in the wild.
iNaturalist suggests that the mushrooms are most commonly observed in the Summer with a peak in July or August, whilst the observations on this site are not always reliable due to misidentification, this seasonality is to be expected from a tropical species that has been introduced into temperate climates. The iNaturalist seasonality chart for L. birnbaumii also closely resembles the monthly pageviews for this species on Wikipedia. The higher number of views this page receives during the summer is suggestive of more people finding these mushrooms in their plant pots and trying to learn what they are whereas for native, wild species the views on their pages tend to peak during the Autumn months when they occur. These sources can only provide an estimation of seasonality in domestic settings and are not an indication of the seasonality in the tropical environments in which it is native.
In a 1907 study the American mycologist Andrew Price Morgan documented Lepiota lutea growing in greenhouses in Columbus, Ohio.
In 2019 a study documented L. birnbaumii growing from the stump of a dead lemon tree in an orchard near Damietta, Egypt during the Autumn.


Leucocoprinus birnbaumii is a small, yellow dapperling mushroom which is frequently found in plant pots and greenhouses. The fruit bodies of Leucocoprinus birnbaumii are agaricoid (mushroom-shaped) and occur singly or in small clumps.
Cap: 2-7.5cm wide in maturity, starting bulbous to cylindrical before expanding to hemispherical or conical and flattening or sometimes appearing umbonate with age. The surface is lemon yellow to sulphur yellow, smooth or slightly powdery and covered in ragged, fibrous scales which are easily removed. The scales are darker yellow or brownish with age and more densely concentrated concentrated towards the centre disc where they often form a patch whilst at the edges they are sparser. The cap edges are striated and grooved (sulcate-striate) with a paler colour present in the grooves whilst the edges curl inwards when young before curving out with age or straightening. The cap flesh is firm when young but becomes softer and more fragile with age, it is a dull whitish colour. Gills: Free and often quite remote from the stem, sulphur yellow, with spacing that can vary from crowded to subdistant at up to 4mm wide. With age the gills may bulge in the middle (ventricose) and the edges can be fringed. Stem: 2.5-9cm long and 2-6mm thick at the top tapering to a bulbous or club shaped base which is 4-15mm thick. The interior is hollow but pithy with a shiny white colour whilst the exterior surface is lemon yellow to sulphur yellow and may discolour brownish with age. It is covered in fine powdery or woolly scales (pruinose to floccose-squamulose) across the full length starting from just above the base. The thin, membranous stem ring is located anywhere between the top and bottom of the stem (superior to inferior) and is movable. The top surface of it is yellow whilst the underside is whitish however the ring is evanescent and may disappear. Spore print: White. Spores: Ellipsoid to amygdaliform with a large germ pore. Dextrinoid. The average size range is 7.7-10.5 x 5.9-7.3 μm. Smell: Indistinct or sometimes mushroomy. Taste: Indistinct. When dry the mushroom may discolour tan or brownish and a similar brown colour is seen in caps of aborted mushroom pins which fail to grow.


The species was first described as Agaricus luteus in 1788 by the English mycologist James Bolton who described an observation from a hothouse near Halifax, three years earlier in 1785. Bolton also provided an illustration of the mushrooms. At the time gilled species were classified as Agaricus and luteus comes from the Latin for yellow or yellow-orange. Bolton suggested the common name of 'Yellow Cottony Agaric' in reference to the soft, scaly texture of the mushroom.
However the name A. luteus had already been used to describe an unrelated Russula species and was published in 1778 by William Hudson so Bolton's A. luteus was illegitimate.
Nonetheless Agaricus luteus continued to be used and in James Sowerby's 1796 book entitled 'Coloured figures of English fungi or mushrooms' his description of Agaricus cepaestipes (now Leucocoprinus cepistipes) also includes A. luteus and A. cretaceus (now Leucocoprinus cretaceus) which he considered to be 'undoubtedly the same species', only differing in colour. So whilst his illustration of L. birnbaumii is intricately drawn, coloured and immediately recognisable today it rather confusingly has the yellow and white species side by side.
Sowerby writes that his observations of this species were made in bark beds around London where he described its presence as 'not uncommon'. He does not explicitly state that the observations were made in greenhouses however he does note that the yellow mushrooms were observed at Sir Abraham Hume's Wormleybury manor. During this period exotic plants from the East Indies and India were being cultivated in greenhouses and stove-heated hothouses at Wormleybury making it likely that this is where the mushrooms were found. This may give an indication as to where the fungi observed originated from.
In 1897 the French mycologist Julien Godfrin described the species as sulphur yellow in colour and classified it as Lepiota lutea. Many popular North American books continued to use this name until the 1980s and it still occasionally arises today.
In 1839 the Czech mycologist August Corda described the same species from Prague where it was found growing in a greenhouse in between pineapple plants by a garden inspector named Birnbaum and so he called it Agaricus Birnbaumii. Corda said the greenhouse was in Count Salm's garden in Prague, likely referring to one of the greenhouses in the gardens of what is today the Prague castle complex which encompasses Salm Palace (Czech: Salmovský palác). Pineapples are still grown in these greenhouses so it is quite possible that descendants of the mushrooms found by Mr. Birnbaum continue to grow amongst them.
The French mycologist Marcel Locquin classified it as Leucocoprinus luteus in 1945 and the German mycologist Rolf Singer reclassified it as Leucocoprinus birnbaumii in 1962.


The long-tailed meadowlark (Leistes loyca) is a passerine bird of southern South America and the Falkland Islands, belonging to the meadowlark genus Leistes in the icterid family that looks very similar to the related endangered species, the Pampas meadowlark.
It is 25 to 28 cm long with a fairly long tail and a long, pointed bill. The male is mostly dark brown with blackish streaking. The breast and throat are bright red and there is a white spot on the face near the base of the bill. The bold supercilium is white behind the eye and red in front of it. Females are paler than the males with the red markings restricted to a wash on the belly and the supercilium and throat are buff.
It breeds in southern Chile and southern and western parts of Argentina. Some birds migrate northwards in winter. An endemic subspecies, L. loyca falklandica, occurs in the Falkland Islands, where it is known as the military starling. Long-tailed meadowlarks are found in open habitats such as grassland where they forage on the ground, feeding mainly on invertebrates.
The nest is made of dry grass and is built by the female. It is placed on or near the ground amongst grass. Whenever the female leaves the nest, she first walks  a few meters from it hiding among the dry grass in order to prevent the nest from being found by predators who see her leave. The same method is used when arriving at the nest, she first lands a few meters from the nest and then walks towards it. Two clutches of two to four eggs are laid during the breeding season. They are bluish-white with dark blotches and streaks.


The blue-throated mountaingem is the largest hummingbird found in the USA. It is 11.2 to 12.8 cm (4.4 to 5.0 in) long. Males weigh an average of 8.4 g (0.30 oz) and females 6.8 g (0.24 oz). Both sexes have a medium-length black bill, though there is some variation among the subspecies and females' bills are longer than males'. Both sexes of all subspecies have a conspicuous white stripe behind the eye and a narrower stripe extending backward from the corner of its bill under a blackish cheek patch.
The nominate subspecies is the largest and has the longest bill. Adult males have an iridescent cobalt to cerulean blue gorget with a narrow buffy gray margin. They have mostly bright greenish bronze upperparts that become dark bronzy olive on the rump. They have medium brownish gray underparts with some greenish bronze iridescence on the sides of the breast. The tail is black with some faint indigo iridescence and  white tips on the outer two pairs of feathers. Females have entirely medium gray underparts without the gorget.
Subspecies L. c. phasmorus is the smallest and has the shortest bill. Its upperparts are bright green rather than greenish bronze. Males' underparts are a cold gray rather than brownish gray and females' are dark gray. The iridescence on the sides of the breast is green. The white tips on the tail feathers are wider than those of the nominate.
Subspecies L. c. bessophilus is between the other two subspecies in size. Its upperparts are duller than the nominate's, with less bronze to the green. Males' underparts are brownish gray and females' medium pale gray; like the nominate there is some greenish bronze iridescence on the sides of the breast. The white tips on the tail feathers are the narrowest of all subspecies.


The two northern subspecies of blue-throated mountaingem, and possibly the northernmost of the nominate subspecies, migrate south in winter, but their exact locations are not known. A few individuals remain through winter at feeding stations in southeastern Arizona. The populations in central and southern Mexico are thought to withdraw to lower elevations in winter but this movement has not been fully defined.


The blue-throated mountaingem forages for nectar at a wide variety of flowering plants. The species fed from vary considerably across the bird's wide north–south and elevational ranges. It is common at sugar-water feeders. It hovers to feed on nectar. In some areas it defends patches of large flowers but not those of smaller ones. In the breeding season (especially early when flowers are scarce) and in winter it also feeds on small arthropods. These are taken by hawking, in sustained flight, and by gleaning from bark and foliage. In winter it also feeds on sap from wells created by the Red-naped sapsucker (Syraphicus nuchalis).


The nominate subspecies of blue-throated mountaingem has the largest range. It is found in Mexico's Sierra Madre Oriental and central plateau as far south as Oaxaca. L. c. bessophilus is found in southeastern Arizona, southern New Mexico, and in the northwestern Mexican states of Sonora, Chihuahua, and Durango. L. c. phasmorus is positively known only from the Chisos Mountains of southern Texas, where it breeds, but its non-breeding range is not known. Birds in the northern Mexican state of Nuevo León may also be this subspecies rather than the nominate.
The blue-throated mountaingem is found in a variety of moist forest landscapes. In the US and northern Mexico it occurs in riparian forest (often in canyons), pine-oak forest, and mixed coniferous forest. In central and southern Mexico it tends to favor coniferous forest. In Arizona it is found in the "sky island" mountain ranges, seldom below 1,300 m (4,300 ft) of elevation. Near Mexico City it occurs between 3,600 and 3,900 m (11,800 and 12,800 ft) and in Oaxaca between 2,500 and 3,000 m (8,200 and 9,800 ft).


The blue-throated mountaingem's breeding seasons vary throughout its range. It begins in February in Veracruz, Mexico, and continues to September in some parts of its range. The earliest known egg laying in Arizona was in mid-Apr. In the higher elevations in Mexico laying begins in late May or June. Two clutches per season are common and sometimes three have been documented.
As with all hummingbirds, the female alone constructs the nest and raises the young. The nest is made from soft plant fibers cemented with spider silk. The exterior is camouflaged with green mosses where available; in drier habitats, moss-like dendroid lichens may be used, or the exterior may be left bare. It is typically attached to a tree branch or to roots and stems under natural overhangs. They are also commonly placed on human-made substrates such as a wire or nail under an eave or in a building. The female incubates the two white eggs for 17 to 19 days and fledging occurs 24 to 26 days after hatch.


The fruitbody of Macrolepiota clelandii has a cap that is initially egg-shaped, later becoming convex and then flattened in maturity, reaching diameters of 7.6–12.5 cm (3.0–4.9 in). It has a dark brown umbo and small dark brown scales that show the whitish flesh underneath. These scales are arranged in concentric rings that become increasingly crowded until the umbo, which is completely covered in scales. Small fragments of the partial veil may be left hanging on the cap margin.
The white gills are free from attachment to the stipe and closely spaced. The slender, hollow stipe measures up to 18.7 cm (7.4 in) long, and has a somewhat bulbous base. It has a pale brown colour, and features a ring on its upper half that often detaches to become freely movable up and down the stipe. The mushrooms have no distinctive odour. Its tall stature means the gills are usually clean, having avoided rain splash from the forest floor.
According to Peter Roberts and Shelley Evans, all "parasol" species (i.e., M. procera and its close relatives, including M. clelandii) are edible. Anthony M. Young notes the similarity of M. clelandii to the edible European species M. konradii, but warns "the toxicity of the Australian species is unknown."
Macrolepiota clelandii produces a white spore print. Individual spores are ellipsoid with a small germ pore, smooth, thick-walled, and measure 13.4–24.8 by 9.6–16.0 µm. They have a dextrinoid staining reaction (reddish-brown) with Melzer's reagent. The basidia (spore-bearing cells) are club-shaped, measuring 38.0–50 by 10.2–13.6 µm. They are two-, three-, or four-spored, with sterigmata up to 8.0 µm long. Collections with predominantly four-spored basidia will generally have smaller spores than those with two-spored basidia. Two-spored basidia produce spores with four nuclei. Cheilocystidia are plentiful on the edge of the gill. They have dimensions of 24.8–42.4 by 7.2–10.4 µm, with a cylindrical to club shape. There are no cystidia on the gill face (pleurocystidia). Clamp connections are present in the hyphae.


Macrolepiota clelandii, commonly known as the slender parasol or graceful parasol, is a species of mushroom-forming fungus in the family Agaricaceae. The species is found in Australia and New Zealand, where it fruits singly or in small groups on the ground in eucalypt woodlands, parks, and roadsides. It is a tall mushroom up to roughly 20 cm (8 in), with a broad cap covered with distinctive rings of dark brown scales. The whitish gills on the cap underside are closely spaced and free from attachment to the slender stipe, which has a loose ring on its upper half, and a bulbous base. The edibility of the mushroom is not known with certainty, but closely related parasol mushrooms are edible and some are very sought after.
The fungus, first documented by naturalist John Burton Cleland in the early 20th century, was initially assumed to be the close relative Macrolepiota procera, a European species now known to be absent from Australia. Australian mycologist Cheryl Grgurinovic recognized Cleland's collections as a distinct species, officially describing it in 1997. The fungus has been referred to by several names: M. konradii, M. gracilenta, and M. mastoidea. Else Vellinga showed using molecular phylogenetic analysis that these names refer to European species and were misapplied by Australian authors.


Compared to most Northern American sea ducks, the surf scoter breeds exclusively in North America, mostly in Northern Canada and Alaska. Then, they take different migration routes to spend the winter in more temperate environments.
While small numbers regularly winter in western Europe as far south as the British Isles, the vast majority of surf scoters winter along the Pacific and Atlantic coasts of North America. The Pacific coast host the highest number of individuals and its large wintering range extends over 5000 km, from the Aleutian Islands in Alaska to the Baja Peninsula in Mexico.


The surf scoter mainly feeds on benthic invertebrates. During the breeding period, surf scoters forage in pairs or small groups on a diverse range of freshwater invertebrates. However, the sea ducks feed on marine organisms for the rest of the year, in flocks ranging from a few individuals to several thousands birds. Important foods include crustaceans, herring spawn, gastropods and small bivalves such as mussels.
In late winter and spring, Surf scoters tend to shift their diet according to the relative profitability of the food, showing a level of opportunism. For example, they start feeding in seagrass beds, on epifaunal crustaceans that have increased in size over winter or on Pacific herring eggs (Clupea pallasi), during the fish spawning.
As the prey landscape changes, surf scoters will adjust their foraging effort and habitat selection. Effort is lowest in December, due to high prey abundance, and it increases until mid-February, when prey declines. It increases again in March, probably due to the increasing daylight time for foraging. As the season progresses, surf scoters move to habitats with lower prey declines, instead of staying in habitats poor in prey and increasing their foraging effort.
Surf scoter usually captures its food underwater and consumes it whole. They have been observed to select smaller bivalves than those available, probably because of the energy cost of processing shell matter. They also seem to select slow-swimming epifaunal crustaceans.
Surf scoters consume smaller prey that are located in complex habitat such as mussel beds, which makes them use more visual cues than their congeneric white-winged scoters. They may also visually locate siphons formed by infaunal bivalves to capture them. Gut analysis demonstrated a strong ability to avoid ingesting vegetation while feeding on attached herring eggs.
Flocks of surf scoter appear to dive in a highly synchronous fashion and this synchrony is correlated with the group size.  Dive duration vary with many factors such as prey type, density and profitability, season and water depth.
 Surf scoters increase their dive duration when they are feeding on herring spawning, which are harder to capture than sessile bivalves.
Adult scoters of this species dive for crustaceans and molluscs, while the ducklings live off any variety of freshwater invertebrates.


In a necrotic study on sea ducks, parasitic diseases were an important cause of mortality. The only parasite found in dead surf scoters was the Acanthocephalan Polymorphus spp., which causes peritonitis, an inflammation of the abdomen's lining, and possibly emaciation. Out of 39 studied individuals, seven were fatally affected by this worm. A mortality of about 100 surf scoters was also estimated along the coast of California in the spring of 1995. The other mortality causes included emaciation due to starvation (17 individuals), toxicity from petroleum (3 individuals), and trauma from firearm or collisions in different structures (2 individuals).
Predation of eggs and ducklings have not been studied in detail but bald eagles, golden eagles and mustelids have been identified as the main predators of surf scoters in marine habitats. Marked individuals showed a higher mortality rate in winter than during wing molt.
In November, 2007, an oil spill in San Francisco harbour oiled and killed thousands of birds including many surf scoters. About 40% of the birds affected were from this species. Scientists said that while the species is not endangered it has declined 50 to 70% over the past 40 years and this spill could decrease populations since most of the affected birds are healthy adults.


This migratory species breeds in the boreal forests near northern freshwater lakes. Very few nests have been observed but they tend to be near spruce cover, slightly upland to wetland areas.
To complete its molt before migration, the surf scoter travels to a molting site, which differ from the wintering or the nesting site. Because of the vulnerable state of the ducks in those periods, molting sites are assumed to have profitable food and lower predation risks and they are located in bays, inlets or estuaries.
The surf scoter winters in marine habitats near the shore.


Surf scoters form pairs on wintering and staging grounds. Most pairs are formed before the arrival on the breeding grounds. Studies showed a strong fidelity in the nesting areas of surf scoters over the years.
The building of the nest usually starts in mid-May to early June and it occurs on the ground close to the sea, lakes or rivers, in woodland or tundra. Females dig a bowl-shaped nest in the ground and lines it with nearby ground debris and down. About 5 to 9 eggs are laid and each may range from 55 to 79 g (1.9–2.8 oz) and average 43.9 mm (1.73 in) in breadth and 62.4 mm (2.46 in) in length.
The incubation lasts for about 28 to 30 days and is provided by the female only. Occasional (and likely accidental) brood mixing between different females occurs in areas with high densities of nests and hatching is synchronous among the eggs. The female usually chooses a feeding area less than 2 meters deep and protected from strong winds for its offspring. When they reach those food-rich wetland, they begin feeding on their own.  The mother abandons its young before they reach the flight age, at about 55 days.
The fledged offspring congregate in small groups on the breeding area before migrating to the wintering grounds, independently of the adults. Studies in Quebec have demonstrated a duckling mortality of 55-65%, probably influenced by the weather conditions shortly after hatching.


The adult male is on average 1,050 g (2.31 lb) and 48 cm (19 in) in length while the adult female averages about 900 g (2.0 lb) and 44 cm (17 in) in length, making this the smallest species of scoter on average. The surf scoter has a wingspan of 29.9-30.3 in (76-77 cm).
The male is completely velvety black except for white patches on the forehead and the nape. It has a swollen bill, appearing orange at a distance but patterned with white, red and yellow, and a black spot near the base.
The female is browner than the male, with a fairly uniform plumage, slightly darker above than below. Indistinct paler patches are present on the cheeks below the eye and sometimes a whitish patch is on the nape, a unique trait among scoters. The bill is black with green or blue colorations
The juvenile has a plumage similar to the female, but mainly paler and browner, and the breast and belly are whitish
The surf scoter is easily distinguishable from other scoters by the white patch on the head of the adult male and its unique bill pattern. Females and immatures have a bulkier bill with a squarish base and a more flattened head profile than other scoters. The black and the white-winged scoters are physically very similar to the surf scoter but in flight, the surf scoter is the only one with completely dark wings.
Like all sea ducks, the surf scoter becomes flightless during the simultaneous molt of its flight feathers. This vulnerable period happens usually in late July through early August and lasts for about four weeks. Before molting the flight feathers, all waterfowl undergo a complete body molt, replacing the bright colors of the basic plumage of males by the duller alternate or eclipse plumage.
The plumage is a good indicator of the age for male surf scoters, but not for females. Second-year males are similar to adults but may have brownish feathers and/or lack the white forehead patch.


Retiboletus ornatipes, commonly known as the ornate-stalked bolete or goldstalk, is a species of bolete fungus in the family Boletaceae. Originally named Boletus ornatipes by American mycologist Charles Horton Peck in 1878, it was transferred to Retiboletus in 2002.
One guide lists the species as inedible, while another says it is choice.


It breeds in southern Canada, much of the United States, and northern Mexico. It is much less common in the east, where its range is contracting. The populations in Mexico and adjacent states of the United States are resident, but other birds are migratory, wintering in the southern United States, Mexico and south to Guatemala.
It is a very rare vagrant to western Europe, with two accepted records in Great Britain in 1981 and 1991.


They forage on the ground or in low bushes. They mainly eat seeds, but insects, including grasshoppers, are also eaten in the breeding season. They form flocks on migration or in winter.


The breeding habitat is a variety of open habitats including grasslands and cultivation. Lark sparrows nest on the ground, laying three to six eggs in a grass cup nest sheltered by a clump of grass or other vegetation. The eggs are white with black scrawling.


The lark sparrow is distinctive. Adults have a typically sparrow-like dark-streaked brown back, and white underparts except for a dark central spot. The cheeks and crown sides are chestnut, with white eyebrow and crown stripes. The dark tail's corners are also white. Young lark sparrows are duller, and the underparts are streaked.
Measurements:
Length: 5.9-6.7 in (15-17 cm)
Weight: 0.8-1.2 oz (24-33 g)
Wingspan: 11.0 in (28 cm)


The Pacific gull (Larus pacificus) is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a result of competition from the kelp gull, which has "self-introduced" since the 1940s.
Much larger than the ubiquitous silver gull, and nowhere near as common, Pacific gulls are usually seen alone or in pairs, loafing around the shoreline, steadily patrolling high above the edge of the water, or (sometimes) zooming high on the breeze to drop a shellfish or sea urchin onto rocks.


The gulls' diet consists of a number various fish species and invertebrates. They frequently consume crabs, most often the species Ovalipes australiensis and Paragrapsus gaimardii. They also commonly eat Platycephalus bassensis (sand flatheads) and cephalapods, both of which are sourced from their regular consumption of waste from fish which have been cleaned on wharves and beaches. Additionally, they may eat insects, eggs, and other seabirds.
The gulls may be found scavenging abattoirs and in rubbish tips, where they will often steal food from other birds.


Pacific gulls are the only large gulls in their range, besides the occasional kelp gull. This species can range in length from 58 to 66 cm (23 to 26 in) and span 137 to 157 cm (54 to 62 in) across the wings. They typically weigh from 900 to 1,180 g (1.98 to 2.60 lb). This species is mostly white, with dark wings and back, and a very thick (when compared to other gull species), powerful, red-tipped yellow bill. They have salt glands that secrete salty water through the nostrils. Young birds are mottled-brown all over, and attain their adult plumage only gradually; by its fourth year, a young Pacific gull has usually become difficult to tell apart from an adult bird.
Of the two subspecies, the nominate eastern race prefers sheltered beaches, and the western race L. p. georgii is commonly found even on exposed shores. Both subspecies nest in pairs or loose colonies on offshore islands, making a cup of grasses and sticks in an exposed position, and laying two or three mottled brown eggs.


The white-tailed eagle (Haliaeetus albicilla) is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors such as hawks, kites, and harriers. One of up to eleven members in the genus Haliaeetus, which are commonly called sea eagles, it is also referred to as the white-tailed sea-eagle. Sometimes, it is known as the ern or erne (depending on spelling by sources), gray sea eagle and Eurasian sea eagle.
While found across a very wide range, today breeding as far west as Greenland and Iceland across to as far east as Hokkaido, Japan, they are often scarce and very spottily distributed as a nesting species, mainly due to human activities. These have included habitat alterations and destruction of wetlands, about a hundred years of systematic persecution by humans (from the early 1800s to around World War II) followed by inadvertent poisonings and epidemics of nesting failures due to various manmade chemical pesticides and organic compounds, which have threatened eagles since roughly the 1950s and continue to be a potential concern. Due to this, the white-tailed eagle was considered endangered or extinct in several countries. However, some populations have recovered well due to some governmental protections and dedicated conservationists and naturalists protecting habitats and nesting sites and partially regulating poaching and pesticide usage, as well as careful reintroductions into parts of their former range.
White-tailed eagles usually live most of the year near large bodies of open water, including coastal saltwater areas and inland freshwater lakes, wetlands, bogs and rivers. It requires old-growth trees or ample sea cliffs for nesting, and an abundant food supply of fish and birds (largely water birds) amongst nearly any other available prey.  Both a powerful apex predator and an opportunistic scavenger, it is considered a close cousin of the bald eagle (Haliaeetus leucocephalus), which occupies a similar niche in North America.


The white-tailed eagle may be considered a rather inconsistent and partial migrant. The species seldom migrates in the western part of its range, with eagles even breeding as far north as Greenland, Iceland and coastal Norway not moving at all for winter, but for some southward juvenile movements following dispersal. Juveniles overall are more migratory and dispersive and leave natal areas sooner, which is by August–September in northwestern Europe and return later, by March/April, than adults do. Few Norwegian juveniles, per banding studies, were recorded to travel any considerable distance. Extreme cases include one that was found 720 km (450 mi) south of its nest near Karlstad, Sweden, another set of four color-marked first-year juveniles were also recorded to turn up in southern Sweden but one was found down to the Wadden Sea in the Netherlands and it is likely that trickling down numbers of Norwegian post-dispersal juveniles have gone onto form much of the known Dutch white-tailed eagle population. In contrast, young from Finland and Sweden tend to distribute to the southwesterly direction to the shores of the Baltic Sea. One from Finland was recovered 520 km (320 mi) west in northern Norway and another was found as far south as Bulgaria. In more southerly areas, winter movements are drawn-out and irregular, with most mature pairs probably never leaving their nesting haunts year-around. Those that breed on inland waterways may migrate to sea coast. German juveniles usually do not travel far, with most recorded to travel less than 50 km (31 mi) from their nests and a majority staying near the Baltic coast. However, some eagles that hatched from nests in Germany have been found as far south as in Italy, 1,030 km (640 mi) away to the southeast, or to Gironde, France, 1,520 km (940 mi) to the southwest. In several parts of Russia, quite unlike many European populations, the white-tailed eagle seems to be largely migratory. In the far east, the species appear to take different migratory routes in fall and spring, traveling from north-central Kamchatka thru the Kurile islands to Hokkaido in fall, while in spring these eagles travel north through Sakhalin and the Okhotsk Coast. In the White Sea area, southward moments begin in September with most white-tailed eagles being gone by November but in mild winters some adults may remain behind. Some white-tailed eagles from the White Sea were found well over 2,000 km (1,200 mi) away to the west, in countries such as Hungary and Italy. Return spring migration to the White Sea is by February–March. During winter, whether long-distance migrants or short-distance dispersers, white-tailed eagles tend to become gregarious, especially younger juvenile birds. Many such groups can contain up to 10 and, in areas near large breeding populations such as in Norway, at least 30–40 individuals. Wintering congregations at the Baltic coast and on the River Elbe from 37 winters show that arrivals begin in November, with numbers peaking in January and then declining during March and early April. Although juveniles usually return to their natal area some apparently overshoot these areas, such as those returning to Romania or on the Black Sea which have been recorded 330 km (210 mi) north of their natal site and 510 km (320 mi) northeast of their natal site.


Mammals are usually a quite secondary component of the diet. Although usually better represented than other non-fish and bird prey, their regional importance is variable. In known dietary studies, the mammalian contribution can vary from 0.49% to 41% of prey by number. When mammals are most significant to the diet, it usually due to local white-tailed eagles preying on rabbits and hares with some regularity. In some studies from Scotland, the European rabbit (Oryctolagus cuniculus) and mountain hare (Lepus timidus) were found to contribute as much as nearly 25% of the diet. A similar contribution of European hares (Lepus europaeus) was found in the diet from Austria, where hares were the leading prey species making up 24.35% of 349 prey items (with mammals making up 34.67% of the overall diet). In studies from Germany, European hares were taken fairly often but were numerically secondary prey. Given that these rabbits and hares have average mature weights from 1.8 kg (4.0 lb) in rabbits to 3.8 and 4.2 kg (8.4 and 9.3 lb) in European and Arctic hares (Lepus arcticus), they can make a hearty contribution to the prey biomass when available (although certainly juveniles are attacked as much if not more so than adult rabbits and hares). Other large mammalian prey can include foxes, with 3.2 kg (7.1 lb) Arctic foxes (Vulpes lagopus) being the sixth most regular prey species in Greenland and about a dozen 5.77 kg (12.7 lb) red foxes (Vulpes vulpes) recorded as taken or scavenged in Norway (predaceous attacks on adult red foxes have been reportedly witnessed). In both the offshore islands of Norway, where Arctic hare can be important prey, and Greenland, where the Arctic fox are prey, large numbers of both are taken when their pelage remains white but snow melts prematurely. A white-tailed eagle was once observed to kill and feed on a live adult golden jackal (Canis aureus) that was trapped in a furbearer's trap. White-tailed eagles are known to prey on seal pups but most are likely sickly and perhaps both adult and pup seals are most likely to be eaten as carrion. Four Baikal seal (Pusa sibirica) pups were taken in Lake Baikal. They are considered a predator even for live grey seal (Halichoerus grypus) pups that weigh 11.75 kg (25.9 lb) at birth. In one instance, a white-tailed eagle reportedly tried to attack an adult harbor seal (Phoca vitulina) but was immediately dragged into the water and soon surfaced dying with a broken wing. Similarly, in one anecdote, an eagle drowned while apparently attacking an adult harbor porpoise (Phocoena phocoena). At least seven species of mustelid have been recorded in the white-tailed eagle's diet, from the smallest weasel to, rarely, even adult European otters (Lutra lutra). Another mustelid, the American mink (Neogale vison) was introduced as a furbearer to Finland but then became an invasive pest, as a fast-breeding killer that threatens many native species. In turn, Finnish white-tailed eagles have become the main natural control and may inhibit the mink from breeding via heavy predation. Conversely, the white-tailed eagle have not been known to prey on the critically endangered, native European mink (Mustela lutreola) (perhaps due to its shier habits) which the American mink are known to have been outcompeting in some areas (but the European has mainly declined due to massive overhunting by humans as a furbearer). Kits of larger mammals such as Eurasian (Castor fiber) and North American beavers (Castor canadensis) (introduced) and of European badger (Meles meles) have been found as prey.
The most widely reported mammalian prey known (albeit usually as a supplemental prey species) in the non-native muskrat (Ondatra zibethicus), which averages about 1.1 kg (2.4 lb), and may be taken from "muskrat farms" or feral wetland populations. While largely a supplemental prey item, a respectable number of 137 were recorded in the diet from Finland. Also, a study on the Ili delta in Kazakhstan has shown up to 30–43% of prey remains at eyries to consist of muskrat in spring and fall but only 14% in summer (for unknown reasons). In total, about 20 rodent species are known in the white-tailed eagle's prey spectrum. In some of the coldest climes of Russia, such as in the Ural mountains or the Kola peninsula, white-tailed eagles have been recorded to live on surprisingly high numbers of small rodents, comprising 13.8% and more than 21% of all prey remains, respectively. Even agile red squirrels (Sciurus vulgaris) may be caught from trees in some cases. The smallest rodents known in the prey spectrum are the 27.4 g (0.97 oz) common vole (Microtus arvalis) and the 23.4 g (0.83 oz) wood mouse (Apodemus sylvaticus) but mammalian prey down to the size of 8.1 g (0.29 oz) common shrews (Sorex araneus), indeed the smallest vertebrate known to have been preyed upon, has been recorded. On the other end of the size scale from rodents, more than a dozen ungulate species have been found in the foods of white-tailed eagles, but a very large proportion of this is likely from carrion found already dead. Very large food sources such as horses (Equus ferus caballus), moose (Alces alces), cattle (Bos taurus) and European bison (Bison bosanus) are certainly visited as carrion always. Wild ungulate species known to have their young attacked by white-tailed eagles in variable numbers may include deer such as reindeer (Rangifer tarandus), red deer (Cervus elaphus) and European roe deer (Capreolus capreolus) and wild boar (Sus scrofa). Boar made up 7.1% of the prey remains at Polesski Reserve, Belarus. At least two successful attacks on adult roe deer have been reported, which could potentially weigh around 25.4 kg (56 lb) (their average mature weight), in addition to several cases of predation on young roe deer. A yearling juvenile male eagle scaling 5 kg (11 lb), newly reintroduced into the wild on the isle of Rùm killed a healthy, 7 kg (15 lb) red deer calf within a couple of days. One of the primary causes of the white-tailed eagles persecution by humans is that white-tailed eagles often feed on domestic sheep (Ovis aries) and goats (Capra aegagrus hircus), especially lambs and kids. However, they do not necessarily take healthy specimens and often feed on them after death, instead. Of 36 cases of feeding on lambs and kids by white-tailed eagles in Norway, only 12 could be proven to have been taken alive by the eagles.
Prey of other animal classes is rarely taken by white-tailed eagles. Particularly, the diversity of reptiles known in the prey spectrum, at only six species, is quite paltry when compared to the many species known to be hunted by the bald eagle. Further among amphibians only two species of toad are known to be taken. The Ural mountains is the only region where some diversity of reptile and amphibian species have been reported in their diet. In only the white-tailed eagles nesting in Hokkaido, they've been known to hunt large cephalopods such as robust clubhook squid (Onykia robusta) and giant Pacific octopus (Enteroctopus dofleini), though likely mainly younger specimens and those collected and perhaps injured by large-scale fishing operations. White-tailed eagle juveniles have been seen rarely foraging for unidentified clams and mussels on the Rhine. However, the miscellaneous shells of marine mussels and snails found in Norway are probably usually consumed secondarily from the stomachs of eiders. An exceptional number of insects, amounting to 24% of food items by number, were found in the foods of white-tailed eagles in Augustów Primeval Forest, almost entirely Odonata. The source of this food is not clear as the white-tailed eagle is far too large and bulky a raptor to invest much time in pursuit of insects.


White-tailed eagles may be found in varied habitat but usually are closely associated with water and generally occurs in lowland areas. Although mainly a lowland species, the species is known to live at elevations of 1,500 to 2,300 m (4,900 to 7,500 ft) so long as there is water access in some parts of Central Asia and Siberia. In coastal areas, the species may range from high sea cliffs down to low-lying islands and archipelagos. Especially in winter, many white-tailed eagles often frequent low coastal spots, estuaries and coastal marshes. Several studies have supported that coastal areas are preferred when available during winter. In many areas, white-tailed eagles can seem to switch freely between usually cliff habitat and wooded spots for nesting sites and the center of their home range habitat. In some areas, such as Japan, this species may occur in regions with intensive human fishing activity and they may become unusually partially habituated to this human presence. Inland, white-tailed eagles usually require secluded woods, forested areas or groups of trees with tall mature trees and access to freshwater wetlands such as lakes, river systems, marshes or extensive, low-disturbance farmland. In the alluvial wetlands of Croatia, 95% of nests were found within 4 km (2.5 mi) of deep freshwater. In some areas, white-tailed eagles readily visit commercial fish farms, carp ponds and similar areas with easily accessible food but they will usually avoid areas where human disturbances (especially noisy varieties such as construction, water sporting and heavy boating activities and hunting) commonly occur. However, forestry activity and resulting lessened numbers of tall mature trees and large tree stands in Estonia was found to affect breeding white-tailed eagles less so than it seemed to affect breeding black storks (Ciconia nigra). On the other hand, from studying wintering white-tailed eagles in partially or heavily disturbed wetlands in parts of the Netherlands shows that such areas cannot support the eagles for any long-term period and may only be visited for a day or two by individual eagles. Conversely, reviews of the rapidly increasing Danish population have found that when well-protected, they may regularly forage in habitats near significant humans populations, even in the outskirts of cities, and they can also successfully breed in such locations.


Individual white-tailed eagles tend to be remarkably consistent on egg-laying times from year to year, seemingly regardless of surrounding weather conditions. Egg laying does vary of course by latitude. Historic breeders from Israel and Iran (where they still usually breed) were reported to lay eggs in January, while in Greece and the lower Volga river it is during February, in Germany mostly during March and in the subarctic of Lapland, Finland and northern Russia, to as late as late April to early May. White-tailed eagles in Scotland seem to have average egg laying about three weeks later, late March to early April, than those in coastal Norway. Even near Arctic in Finland, eggs were found as early as 5 March despite ranging often to as late as May. Younger pairs may nest later on average than older ones. In white-tailed eagles, many (perhaps a majority) of clutches consist of two eggs, especially in Irish and Scottish nests, with three egg clutches being considered uncommon to rare there. Four egg clutches have been recorded on the Isle of Skye, as well as in at least Poland, Romania and Norway. Clutch size in Scotland averages 1.56, while in Norway it is 2.16. The eggs are a broad oval shape and dull white in colour, sometimes with a glossy sheen and are usually unmarked but for occasional yellowish stain. Fresh egg weigh from 120 to 148 g (4.2 to 5.2 oz), with an average of approximately 135 g (4.8 oz) for the first egg and 124 g (4.4 oz) for the second. If replacement clutch is laid, usually a single egg is laid which may weigh as little as 112 g (4.0 oz). Average egg dimension seem to keep in accordance with the female body size, smallest mean size known were from Turkey where the average dimensions were 71.8 mm × 56.2 mm (2.83 in × 2.21 in) to the largest in three surveys from Greenland, where they were 78 mm × 59.3 mm (3.07 in × 2.33 in). In 54 eggs from Scotland they ranged from 67.5 to 84.2 mm (2.66 to 3.31 in), averaging 75.8 mm (2.98 in), in height by 53.4 to 64 mm (2.10 to 2.52 in), averaging 58.7 mm (2.31 in), in width. In comparison, 90 eggs from mainland Europe ranged from 66 to 88.2 mm (2.60 to 3.47 in), averaging 73.4 mm (2.89 in), by 54 to 63.5 mm (2.13 to 2.50 in), averaging 57.6 mm (2.27 in). Eggs may be compromised quickly by frost and snow in relatively early clutches. Incubation starts as soon as the first egg is laid. In the species, a 2–3 day interval between the first and second egg being laid (as well as hatching) is recorded. The female does up to 80–90% of incubation and all known nighttime incubating. However, in Norway, the male of a pair could contribute up to about 27% of incubation to daylight hours. There may be as many as 11 changes of the incubating individual within a day. The longest period recorded the clutch was unguarded was 20 minutes, although one pair perched nearby the nest without incubating for 48 minutes. The clutches in Norway left alone only 2–4% of the time. In some cases female may do all the incubation alone, however. When the female is off the nest, she sometimes kills prey and returns with a full crop, but prey capture during incubation is often up to the male. Late into incubation, shift changes decreases and the female will sit tight and will crouch down at the approach of a human rather than leave the nest. Calling and displaying are reduced during incubation, but occasionally both may leave the clutch and display still. The time range for incubation can vary from 34 to 46 days, but usually are between 38 and 42 days. A calculated mean time range for incubation of 38.3 days.


The white-tailed eagle's diet is varied, opportunistic and seasonal. Prey specimens can often include fish, birds and, mostly in a secondary capacity, mammals. White-tailed eagles are powerful predators and capable of attacking large prey of considerable sizes but, like most predators, prefer prey that is vulnerable and easy for them to capture. Especially during the winter (and opportunistically in all seasons), many birds of the species live largely as scavengers, usually by coming across available carrion or watching for the activity of corvids, vultures or other raptors. White-tailed eagles in northeastern Germany were shown to hunt mostly from perches, in a "sit-and-wait" style, usually from a prominent tree perch. Like other sea eagles, they can only capture fish normally in the littoral zone, seldom hunting fish when they exceed a water depth of 1.5 to 2 m (4.9 to 6.6 ft). In addition to trees, they may also use crags, hillocks or high grassy tussocks as hunting perches so long as the perch provides a good overall view of the environment. Fish tend to be grabbed in a shallow dive after a short distance flight from a perch, usually with the eagles only getting their feet wet. Occasionally, though, white-tailed eagles have been recorded plunging right into water, usually while hunting on the wing at a height of at least 200 m (660 ft). In Norway, plunge-diving is considered rare. At times they will also fish by wading into shallows, often from shores or gravel islands. The species will at times variously follow fishing boats, readily exploits commercial fisheries, stocked lakes, carp ponds and the like, and scavenges dead fish or fish-offal in a wide range of situations. When it comes to non-fish prey, it has been said that white-tailed eagles often hunt by flying low over sea coast or lakeshore and attempt to surprise victims. However, the hunting success rates on healthy birds can be low as revealed in studying wintering eagles in Sweden attempting to hunt mallards (Anas platyrhynchos). White-tailed eagles also regularly pirate food from otters and other birds including cormorants, gulls, ospreys, corvids and various other raptors. Carrion is often the primary food source during lean winter months, with fish and ungulates preferred but everything from cetaceans to livestock to even humans being eaten after death. From studies of captive white-tailed eagles, daily food requirements were estimated at 500 to 600 g (1.1 to 1.3 lb), which is equivalent to about 10% of the birds' body weight, with crop contents commonly of 190–560 g (0.42–1.23 lb). Some semi-captive juveniles on the isle of Rùm, Scotland could eat up to 1.4 kg (3.1 lb) in one sitting. However, in Norway, it was estimated that a family of wild white-tailed eagles including each adult and three fledglings were consuming on average up to 625 g (1.378 lb) per bird each day. Furthermore, one male consumed an estimated 2 kg (4.4 lb) in a single meal upon capturing a large fish. The crop can bulge to the size of a small grapefruit after they've consumed a large meal.
Many studies have reflected that the primary foods of white-tailed eagles are fish and water birds. These are the primary food as well for other sea eagle species. However, unlike most Haliaeetus, including the bald eagle and Steller's sea eagle, the water birds tend to take the primary position in the diet. From 26 accumulated food studies for this species, prey remains and pellets show that about 48.5% of the diet is made up of birds, 39.95% by fish, 9.95% by mammals and 1.6% by other foods. In total, more than 300 prey species are known throughout the bird's range. However, based on studies of prey remains and pellets in laboratories from Greenland white-tailed eagles, birds were shown to be biased in both kinds of remains (pellets and prey remains) whereas in situ study and direct nest observation favor fish. Going on pellet/remains alone here in Greenland from 557 items in the 1979 study, 68% of the diet would’ve been represented by birds and only 20% by fish but comprehensive observation shifted it to show fish were the primary food at 58% and birds were secondary at 30%. This study claimed this is often because the bones of fish are dissolved by the large digestive tract of the eagles upon consumption and may thus leave almost nothing in remains and to some extent in pellets. Subsequent studies here showed a much stronger preference for fish in Greenland by 1983, as fish comprised an extreme 91.8% of 660 items. However, this kind of direct continuous observation of food deliveries to nests is not always possible. Furthermore, despite similar bias for prey that is large and leaves conspicuous remains (including any larger fish, bird or mammal), in the bald eagle it was found that fish were usually detectable and dominant in remains and pellets. Most modern biologists may need to leave some fish unidentified but will account for different methodologies of prey study to get the most complete picture attainable. During winter, mammal prey can become more important in foods locally, as indicated in Scotland and shown in Norway and eastern Germany. As much as 41% of the diet can be made up of mammals, as was the case on the Kola Peninsula. There is evidence of strong seasonal shifts in food habits in several parts of the range, usually the largest portions of fish are caught during warmer months while birds and mammals are more important in the colder months, especially in coastal areas such as Norway when preferred fish prey often move to deeper water during winter. Among both fish and bird prey, it is thought that a majority that are caught weigh between 0.5 and 3 kg (1.1 and 6.6 lb). At times it has been said that "most" prey of white-tailed eagles will weigh only 0.5 to 1 kg (1.1 to 2.2 lb). However, the mean prey sizes caught can show greater variability. Three studies showed that mean prey size varied from 578 g (1.274 lb) in the Wigry National Park, Poland,1,062.1 g (2.342 lb) in the Rybinsk Reservoir, Russia and 1.72 kg (3.8 lb) in the Volga-Kama Nature Reserve, Russia. Thus, the mean prey size falls just slightly short of the mean prey mass of the golden eagle, which globally averages about 1.35 to 1.63 kg (3.0 to 3.6 lb).


The white-tailed eagle is one of the largest living birds of prey. It is the largest of the dozen species of eagle found in Europe and the largest eagle across its distribution, excluding the Russian Far East and (during the winter) Hokkaido, Japan, where it co-exists with its larger cousin, Steller's sea eagle. The white-tailed eagle is sometimes considered the fourth largest eagle in the world and is, on average, the fourth heaviest eagle in the world. The only extant eagle species known to be more massive in mean bulk are the Steller's sea eagle (Haliaeetus pelagicus), the harpy eagle (Harpia harpyja) and the Philippine eagle (Pithecophaga jefferyi). The white-tailed eagle measures anywhere from 66 to 94 cm (26 to 37 in) in total length with a typical wingspan of 1.78 to 2.45 m (5 ft 10 in to 8 ft 0 in). This species may have the largest wingspan of any living eagle. The Steller's sea eagle, which is larger in weight, total length and non-wing standard measurements, may be the closest rival for median wingspan amongst living eagles. Average wingspans are not known for the Steller's species, however white-tailed eagles do appear to outsize the average wingspan of the wedge-tailed eagle (Aquila audax), which is sometimes also titled the largest winged extant eagle (however one wedge-tail did possess the largest wingspan ever verified for an extant eagle). In one sample from Norway, five male white-tailed eagles were found to average 2.26 m (7 ft 5 in) and eight females were found to average 2.37 m (7 ft 9 in). In another sample of wild birds of unspecified origin, five males were found to average 2.1 m (6 ft 11 in) and seven females averaged 2.3 m (7 ft 7 in). Record wingspans have included a specimen from Greenland which measured 2.53 m (8 ft 4 in) while another specimen apparently spanned 2.6 m (8 ft 6 in). The bald eagle broadly overlaps in size with the white-tailed eagle. In direct comparison, the white-tailed eagle averages somewhat larger in body mass than the bald eagle and may be marginally larger in bill and talon size, although these linear aspects can be quite similar between the two species. The white-tailed eagle does have a significantly larger wing chord and average wingspan than the bald eagle, but the latter usually possesses a longer tail, resulting in a larger total length than the white-tailed eagle and a larger mean tarsal length.
Size variation is generally a clinal trend and is normally quantified using standard measurements such as wing, tail and tarsal length, or body mass, rather than wingspan or total length. As expected for many widely distributed animals of varied lineages, the white-tailed eagle conforms to Bergmann's rule in that more northerly birds tend to outsize those found relatively closer to the Equator. Average size also decreases from west to east across its distribution. The largest white-tailed eagles appear to be found in Greenland, these being slightly larger than those from Scotland and Scandinavia and notably larger than eagles from central Europe, especially in proportions of the wing area. Those from the southerly portions of the breeding range, such as Asia Minor (principally Turkey), southern Kazakhstan, and Korea Bay, appear to be the smallest-bodied population but there have been limited measurements and published weights known for these extremely sporadic and rare Asian populations of eagle. Furthermore, weights of fully grown eagles from Greenland are not known. Unlike many accipitrids, juvenile white-tailed eagles (and seemingly other sea eagles as well) are often of similar weight to the adults, although the juveniles typically have a somewhat larger average wing and tail length than the adults. In the white-tailed eagle, body mass can typically range from 4 to 6.9 kg (8.8 to 15.2 lb) in females. The slightly smaller male may typically weigh from 3.1 to 5.4 kg (6.8 to 11.9 lb). Average weights in European white-tailed eagles can range from 4.02 kg (8.9 lb) in five males and 5.11 kg (11.3 lb) in nine females to (from the reintroduced birds of Scotland of Norwegian stock) 4.98 kg (11.0 lb) in 39 males and 6.06 kg (13.4 lb) in 43 females. In comparison, the weight ranges for white-tailed eagles from Northeast China were claimed to be only 2.8 to 3.78 kg (6.2 to 8.3 lb) in males and 3.75 to 4.6 kg (8.3 to 10.1 lb) in females. The heaviest female white-tailed eagles can apparently weigh as much as 7.5 to 8 kg (17 to 18 lb) and even males can sometimes weigh up to 6.5 kg (14 lb), which would make the largest males perhaps the heaviest recorded modern male eagle, as male harpy and Philippine eagles (being more sexually dimorphic in favor of the female) are not known to exceed 5 kg (11 lb) (the highest weights for male Steller's sea eagle are not known). The global mean body mass of white-tailed eagles is estimated at approximately 5 kg (11 lb). The average female Steller's sea eagle may weigh just under 25% more than the average female white-tailed eagle (the average weight of male Steller's is not known) while the average European golden eagle may weigh about 11–12% less than the average European white-tailed eagle and the bald eagle species as a whole about 10% less than the white-tailed eagle species.


The western banded gecko is secretive and nocturnal, with individuals remaining hidden during the day and emerging after sunset to forage for food. C. variegatus preys on small insects and spiders, and is one of the few reptiles that control scorpion populations by eating baby scorpions. Individuals prefer warm nights around 80°F, and they can often be seen near human habitations looking to make an easy meal of the insects attracted to landscape or porch lighting.
C. variegatus is preyed upon by many species including coyotes, foxes, snakes, larger lizards, and even large invertebrates such as tarantulas and solpugids. If captured, C. variegatus may squeak and may discard its tail in an attempt to distract the predator and escape. To deter predation, it can also curl its tails over its body to mimic a scorpion.
Breeding occurs during April and May. Females lay up to three clutches of one to two soft-shelled eggs in the spring and summer. Eggs hatch after six weeks.


The western banded gecko (Coleonyx variegatus) is a species of lizard in the family Eublepharidae. The species is native to the southwestern United States and adjacent northwestern Mexico. Five subspecies are recognized.


The western banded gecko is a terrestrial lizard, ranging in total length (including tail) from 4–6 inches (10–15 cm). Hatchlings measure 1 inch (2.5 cm). The body is sandy-colored with dark crossbands broken into patches. The tiny scales give its skin a silky texture. Unlike typical geckos, it has prominent eyes with movable lids.


The western banded gecko is found in a wide range of habitats, including creosote bush and sagebrush desert, pinyon-juniper woodland, and catclaw-cedar-grama grass associations in the eastern part of its range and chaparral areas in the west. Its elevational range extends from below sea level to about 1,520 m (4,990 ft) asl.


Xylaria polymorpha, commonly known as dead man's fingers, is a saprobic fungus. It is a common inhabitant of forest and woodland areas, usually growing from the bases of rotting or injured tree stumps and decaying wood. It has also been known to colonize substrates like woody legume pods, petioles, and herbaceous stems. It is characterized by its elongated upright, clavate, or strap-like stromata poking up through the ground, much like fingers. The genus Xylaria contains about 100 species of cosmopolitan fungi. Polymorpha means "many forms". As its name suggests, it has a very variable but often club-shaped fruiting body (stroma) resembling burned wood.
Often this fungus is found with a multitude of separate "digits" but at times the individual parts will be fused together.
Belonging to the phylum of fungus known as Ascomycetes (division Mycota) known as the sac fungi, they are characterized by a saclike structure, the ascus, which contains anything from four to eight ascospores in the sexual stage. The sac fungi are separated into subgroups based on whether asci arise singly or are borne in one of several types of fruiting structures, or ascocarps, and on the method of discharge of the ascospores. Many ascomycetes are plant pathogens, some are animal pathogens, a few are edible mushrooms, and many live on dead organic matter (as saprobes). The largest and most commonly known ascomycetes include the morel and the truffle, however, X. polymorpha is an inedible variety.
The dark fruiting body (often black or brown, but sometimes shades of blue/green) is white on the inside, with a blackened dotted area all around. This blackened surrounding area is made up of tiny structures called perithecia. The perithecia hold a layer of asci which contain the ascospores. The asci elongate into the ostiole, and discharge the ascospores outward. The spore distribution is a lengthy process, sometimes taking several months to complete this part of the life cycle, this is not a common trait amongst fungi, as is normally a much swifter process.
In springtime this fungus often produces a layer of white or bluish asexual spores called conidia, which grow on its surface and surrounding area.


As remarked above, the great grey shrike has apparently become extinct as a breeding bird in Switzerland and the Netherlands. Overall, its stocks seem to be declining in the European part of its range since the 1970s. In North America, the populations seem to have been stable by contrast, except in the east. The increase and decline seem to be reactions to changing land use, with an increase as the number of agricultural workers declined after World War II and land fell fallow, declining again when land consolidation (see e.g. Flurbereinigung) had seriously depleted the number of hedgerows and similar elevated growth formerly common amidst the agricultural landscape. For such a predatory bird, the indiscriminate use of pesticides (which will accumulate in adult carnivores and inhibit breeding success) around the 1960s probably had a detrimental influence on stocks too.
Altogether, the great grey shrike is common and widespread and not considered a threatened species by the IUCN (though they still include L. meridionalis in L. excubitor). Wherever it occurs, its numbers are usually many hundreds or even thousands per country. Its stronghold is the region around Sweden, where at least almost 20,000, perhaps as many as 50,000 were believed to live in the late 20th century. However, in some countries it is not robustly established; in Estonia only a few hundred are found, with less than 200 in Belgium and some more or less than 100 in Latvia and Lithuania, respectively. The 10 birds or so in Denmark might disappear because of a few years of adverse circumstances. By contrast, in Luxembourg plentiful high-quality habitat is found; though the number of great grey shrikes in this tiny country is necessarily limited, the average population density there is 25 times as high as in Lithuania.


The great grey shrike (Lanius excubitor) is a large songbird species in the shrike family (Laniidae). It forms a superspecies with its parapatric southern relatives, the Iberian grey shrike (L. meridionalis), the Chinese grey shrike (L. sphenocerus) and the American loggerhead shrike (L. ludovicianus). Males and females are similar in plumage, pearly grey above with a black eye-mask and white underparts.
Breeding takes place generally north of 50° northern latitude in northern Europe and Asia. Most populations migrate south in winter to temperate regions. The great grey shrike is carnivorous, with rodents making up over half its diet.


The great grey shrike eats small vertebrates and large invertebrates. To hunt, this bird perches on the topmost branch of a tree, utility pole or similar elevated spot in a characteristic upright stance some metres/yards (at least one and up to 18 m/20 yd) above ground. Alternatively, it may scan the grassland below from flight, essentially staying in one place during prolonged bouts of mainly hovering flight that may last up to 20 minutes. It will drop down in a light glide for terrestrial prey or swoop hawk-like on a flying insect. Small birds are sometimes caught in flight too, usually by approaching them from below and behind and seizing their feet with the beak. If no prey ventures out in the open, great grey shrikes will rummage through the undergrowth or sit near hiding places and flash their white wing and tail markings to scare small animals into coming out. As noted above, it will sometimes mimic songbirds to entice them to come within striking distance.
Typically, at least half the prey biomass is made up from small rodents from the Cricetidae (voles, lemmings) and Murinae (Eurasian mice and sometimes young Eurasian rats). Shrews, songbirds, lizards, and frogs and toads (typically as tadpoles) make up most of the remaining vertebrate prey. Birds are generally of little importance however, except in spring when male songbirds are engaged in courtship display and often rather oblivious of their surroundings, in late summer when inexperienced fledglings abound, and in winter when most small mammals hibernate. Occasionally bats, newts and salamanders, and even fish are eaten. Prey animals may exceptionally be almost as large as the birds themselves, for example chicks of the willow ptarmigan (Lagopus lagopus) or a young stoat. Large arthropods are the second-most important prey by quantity, though not by biomass; in the latter respect they are only a bit more important than birds, except as food for nestlings where they usually form a substantial part of the diet. Most important among invertebrate prey are insects, especially beetles, crickets and grasshoppers, and bumblebees and wasps. Invertebrate prey of minor importance are spiders and scorpions, crayfish and isopods, snails, and oligochaete worms. Carrion and berries are rarely if ever eaten; though it might occasionally plunder songbird nests this is not well documented and it is not known to eat eggs.
Prey is killed by hitting it with the hooked beak, aiming for the skull in vertebrates. If too large to swallow in one or a few chunks, it is transported to a feeding site by carrying it in the beak or (if too large) in the feet. The feet are not suited for tearing up prey, however. It is rather impaled upon a sharp point – thorns or the barbs of barbed wire – or wedged firmly between forking branches. Thus secured, the food can be ripped into bite-sized pieces with the beak. Orthoptera that the birds have recognized as containing noxious chemicals are left impaled in the larder for several days, until the chemicals that usually deter predators have been degraded. Great grey shrikes have also been observed to impale common toads (Bufo bufo) and skin them – by ripping open the back skin and pulling it over the head – to avoid contamination of the meat by the toxic skin secretions. Large bones and similar inedible parts of prey animals are usually not ingested, but smaller ones such as tiny bones or the elytra of beetles are eaten and later regurgitated as pellets.
The basic metabolic rate of the great grey shrike is around 800 milliwatts, or somewhat more than 11 milliwatts per gram of body mass. An adult of this species needs about 50 g (1.8 oz) of prey a day, probably somewhat more in winter. Under most circumstances, this would thus translate to one or two rodents, one or two additional vertebrate prey animals (including rodents), and up to a single vertebrate prey item's worth of invertebrates. Surplus food may be impaled for storage. These "larders" are typically around 1 m (3.3 ft) above ground and can be found anywhere within the birds' territory, but tend to be rather in the general vicinity of nest sites than far away from them.


Generally, its breeding range is found in Eurasia and northern Africa. In the high mountains of the Altai-Tian Shan region, it ranges south perhaps as far as 42° northern latitude. Its northern limit is generally 70° northern latitude. It is only found as a vagrant in Iceland, the British Isles, the Mediterranean region (excluding the Iberian Peninsula and perhaps Romania but including Cyprus), and Korea. There do not appear to be breeding records from the entire Kamchatka Peninsula; in Switzerland, the present day Netherlands and southern Germany small populations were found in the mid-20th century but have declined or even disappeared since then.
Except for the subspecies bianchii which is largely all-year resident, and subspecies excubitor in the temperate European parts of its range with their mild maritime climate, the species is a short-distance migrant. The migrations are triggered by scarcity of food and therefore, according to prey population levels, the winter range might little extend south beyond the breeding range, or be entirely parapatric to it. The populations of the Central Asian mountains mostly migrate downslope rather than southwards. Females are more prone to migration than males; they do not appear to migrate, on average, longer or shorter distances than males, and consequently are the dominant sex in many parts of the winter range. Birds leave for winter quarters a more or less short time after breeding – July to October, with most birds staying to September – and return to nest mainly in March/April, but some only arrive in May. In recent decades, the number of birds remaining on the breeding grounds all year has been noted to increase e.g. in Fennoscandia, whereas for example borealis seems to be as rare a winter visitor in northern Ohio as it was a century ago.
The preferred habitat is generally open grassland, perhaps with shrubs interspersed, and adjacent lookout points. These are normally trees – at forest edges in much of the habitat, but single trees or small stands at the taiga-tundra border. In steppe, it will utilize any isolated perch, be it fence posts, power lines or rocks. In general, some 5–15 perching sites per hectare habitat seem to be required. It avoids low grassland with no lookouts and nesting opportunities (trees or large shrubs), as well as dense forest with no hunting ground. Apart from grassland, the birds will utilize a variety of hunting habitats, including bogs, clearings or non-industrially farmed fields. Breeding birds appear to have different microhabitat desires, but little detail is known yet.


Great grey shrikes breed during the summer, typically once per year. In exceptionally good conditions, they raise two broods a year, and if the first clutch is destroyed before hatching they are usually able to produce a second one. Their monogamous pair bond is strong during the breeding season and loosens over winter; birds often choose a different mate than the year before. To seek out potential mates, males will venture outside their breeding territories. If a female thus encountered finds a male to her liking, she will visit to see whether they get along well and inspect the nesting sites he can offer. The courtship period is generally longer than in the Iberian grey shrike (L. meridionalis), usually starting about March and lasting to April/May. At first, the female rebuffs the male, only allowing him to feed her. Males give increasingly vocal displays and show off the white markings of the wings in flight and of the tail by fanning it and turning away from the female. He also occasionally turns to sit at a right angle to her. Eventually, the female will join in the male's displays, and the songs will become duets. To feed females and to show off their hunting prowess, males will make their food caches in conspicuous places during this time. When presenting nesting sites, males give the variety of calls described above and jerk their head and fanned tail.
Copulation is typically initiated by the male bringing an attractive prey item to the female. With both giving begging calls, they approach until they are side by side. The male then raises and swings his body left and right a few times, and passes the prey to the female, followed by the actual copulation. The gatherings of neighbour groups (see above) cease when nesting is underway, and when the eggs are nearly ready to lay, the male guards his partner closely, perching higher than her to watch for threats and frequently feeding her. This apparently ensures her physical well-being rather than preventing extra-pair copulations, as neighbouring males will stray through each other's territory to snatch a quick fling with the resident females. In this, they have almost a one-in-three chance of success, and consequently the average grey shrike nest is very likely to contain offspring of more than one male. Females may deposit their eggs in neighbours' nests, but this seems to occur more rarely; in general, mated females are fairly reclusive after their eggs have started developing. A full clutch of eggs can be produced by a female in about 10–15 days.
Nests are built in April or May more than 1 m (3.3 ft) above ground in trees. This height varies according to habitat, but while nests have been found almost 40 m (44 yd) up, most are 2–16 m above ground. Presence of mistletoes or vines like common ivy (Hedera helix) on side branches near the trunk (where nests are preferentially built) will make a tree markedly more attractive. Fieldfares (Turdus pilaris) nesting in the vicinity will also increase the desirability of nest sites to great grey shrikes, which moreover often refuse to prey upon these thrushes' nestlings though the opportunity is there. Apparently, the two species are more efficient in spotting potential nest predators – in particular corvids – early on and mobbing them off cooperatively than either is on its own. Otherwise, there is no clear preference for particular taxa of nesting trees, provided they are sufficiently dense. Conifers seem to have become more popular with European L. excubitor in recent decades, but a diversity of deciduous trees is used just as well. Far more rarely, large and especially thorny shrubs are used for nesting. The actual nesting site is chosen by the male; the courtship visits of the female are mainly to form and strengthen the pair bond. Also, though the partners build the nest together, the male collects most of the nesting material. The cup nest is quite sizable, measuring 20–28 cm (7.9–11.0 in) in outer diameter. Its body is constructed of coarse vegetable material – mainly large twigs and chunks of moss, though bits of fabric and rubbish may be added. The interior cup is 8–12 cm (3.1–4.7 in) in diameter and 10–15 cm (3.9–5.9 in) deep; it is lined with fine twigs and roots, lichen, hair and feathers. Building a nest from scratch takes a pair one to two weeks, but if nests of the previous year in good locations remain usable, they are repaired rather than discarded.
Laying usually takes place in May. The clutch numbers three to nine eggs, typically around seven, with North American clutches tending to be larger on average than European ones. If a second clutch is produced in one breeding season, it is smaller than the first one. The eggs have a white background colour, usually with a grey hue and sometimes with a blue one; they are patterned with blotches of yellowish- to reddish-brown and purplish-grey, often denser around the blunt end. They measure around 26 mm (1.0 in) in length and 19.5 mm (0.77 in) in width. Incubation takes around 16 days but may be closer to three weeks for large clutches; it is generally done only by the female. While the male may briefly take over incubating, his task during this time is to provide food. The altricial nestlings hatch naked, blind and pink-skinned, weighing c. 4 g (0.14 oz); their skin turns darker after a few days. The inside of their beak is pink and they probably lack spots or other prominent marks; the wattles at the corners of the mouth are yellow as in many passerines. As the nestlings grow, the female broods them, and later on assists in providing food. The young fledge after 2–3 weeks, typically in late June or early July; they become independent of their parents about 3–6 weeks later. Sometimes, a parent will single out particular fledglings (possibly the weakest ones) and focus their care and feeding on these during this time. Other adults have occasionally been recorded assisting in feeding a pair's offspring; it is not clear whether these helpers at the nest are offspring of previous years, or unrelated non-breeding "floaters" or breeding neighbours.
Common cuckoos (Cuculus canorus) have been noted as regular brood parasites of L. e. excubitor in the past; for reasons unknown this has ceased since the late 1970s or so. It may well be that the cuckoo's gens laying eggs similar to those of the great grey shrike has become extinct. Among predators of eggs and nestlings, corvids (Corvidae) – extremely close relatives of the shrikes (Laniidae) as it happens – are most significant.
Usually more than half of all nests manage to hatch at least one young, and around three-quarters of all eggs laid hatch, suggesting that if eggs are lost before hatching, it usually is the entire clutch. Half to three-quarters of the hatched young successfully fledge under most circumstances. They will become sexually mature in their first spring and often attempt to breed right away. On average, great grey shrikes get a chance at four breeding attempts during their life, with most birds in the wild getting eaten by a bird of prey or carnivorous mammal or dying of other causes before the end of their fifth winter. Raptorial birds are the main threat to shrikes after fledging, with regular predators including species as small as little owls (which are close to the same size as the shrike). The maximum documented lifespan, however, is 12 years.


An adult great grey shrike is a medium-sized passerine about as large as a big thrush, measuring from 22 to 26 cm (8.7 to 10.2 in) long. It typically weighs around 60 to 70 g (2.1 to 2.5 oz), although some subspecies are noticeably smaller or larger, and even in the nominate subspecies adult weights between 48 and 81 g (1.7 and 2.9 oz) are recorded. The wings are around 11.4 cm (4.5 in) and the tail around 10.9 cm (4.3 in) long in the nominate subspecies, its bill measures about 23 mm (0.91 in) from tip to skull, and the tarsometatarsus part of its "legs" (actually feet) is around 27.4 mm (1.08 in) long. Wingspan can range from 30 to 36 cm (12 to 14 in).
The general colour of the upperparts is pearl grey, tinged brownish towards the east of its Eurasian range. The cheeks and chin as well as a thin and often hard-to-see stripe above the eye are white, and a deep black mask extends from the beak through the eye to the ear coverts; the area immediately above the beak is grey. The scapulars (shoulder feathers) are white, and the wings are black with a white bar made up by the bases of the primary remiges, continuing slightly offset onto the bases of the secondary remiges in some regions. The tail is black, long, and pointed at the tip; the outer rectrices have white outer vanes. The underparts are white, slightly tinged with grey in most subspecies. In particular the breast is usually darker and sometimes browner than the rest of the light underside, and may appear as an indistinct band between the lighter belly and white throat. In the subspecies around the North Pacific in particular and in females elsewhere too, there may be faint brownish bars on the breast. The bill is large and hooked at the tip and coloured nearly black, but pale at the base of the under mandible (though the extent varies seasonally). The legs and feet are blackish.
Males and females are about the same size, and do not differ conspicuously in appearance except by direct comparison. In the female the underparts are greyer and are usually visibly barred greyish-brown, and the white wing and tail markings are characteristically less in extent (though this is rarely clearly visible except in flight). Fledged young birds are heavily tinged greyish-brown all over, with barring on the upperside and indistinct buffy-white markings. The tips of the tertiary remiges and the wing coverts are also buffy, with a black band in the latter. In the North American subspecies borealis, the fledglings are tinged quite brown indeed on upperside and wings, and have sharp and dark underside bars. In Eurasia, fledglings moult into a female-like plumage with the tertiary bars usually remaining in autumn. Across its range, the young acquire the adult plumage in their first spring.


Black-headed grosbeaks range from the Pacific Coast to the middle of the US Great Plains and from southwestern Canada to the mountains of Mexico.
US and Canadian birds are highly migratory, wintering in Mexico. In the Great Plains, the range of the black-headed grosbeak and the rose-breasted grosbeak overlap and they have interbred somewhat. After the breeding season, they tend to seek out berry-rich areas. They migrate south early in the fall and return to the north late in the spring and have been known to do so in flocks.


The black-headed grosbeak eats pine and other seeds, berries, insects and spiders, and fruit. During the summer, it mostly eats spiders, snails, and insects. It is one of the few birds, along with the black-backed oriole, that can safely eat the poisonous monarch butterfly. In their wintering grounds, this grosbeak consumes many monarch butterflies, perhaps over one million per year in the overwintering colonies in Mexico. However, only the black-headed grosbeak is physiologically insensitive to the cardiac glycoside heart poisons in the monarchs, which monarch caterpillars sequester from their milkweed host plants and are retained by adults even after metamorphosis, which protects them from most predaceous birds. The same genetic changes that confer resistance to the poisons in the monarch and its relatives were found to have evolved in the black-headed grosbeak in a case of convergent evolution. The cellular target of the heart poisons is the first extracellular loop of the sodium pump, a critical ion pump needed for nerve cells to fire and heart cells to contract. Two of the grosbeak's four copies of the gene encoding this protein have changes that are also found in insects adapted to feeding on plants producing the cardiac glycosides. In one of the copies, it has the same genetic changes at position 111 and 119 as in the common grow and other Euploea butterflies closely related to the monarch, and in another copy, position 111 has the same change as Largus bugs, which feed on dogbane plants that produce cardiac glycosides The mutations at positions 111 and 119 have been shown together, but not alone, to confer resistance to the heart poisons in insects through positive, intramolecualr epistasis. In the breeding season, the black-headed grosbeak comes to bird feeders for sunflower and other types of seed, and fruit, and also joins northern orioles at feeders with grape jelly.


The black-headed grosbeak prefers to live in deciduous and mixed wooded areas. It likes to be in areas with large trees and thick bushes, such as patches of broadleaved trees and shrubs within conifer forests, including streamside corridors, river bottoms, lakeshores, wetlands, and suburban areas.


Females build nests among the dense foliage on an outer branch of tall broadleaved trees or shrubs, 3–35 ft (0.91–10.67 m) above ground. They occasionally build in dense shrubs such as blackberry. The nest is in the shape of an open saucer, made of fine grass, rootlets, twigs, bark, and conifer needles. It is often lined with rootlets, hair, and fine plant material. The female lays two to five pale green, blue, or gray eggs that are spotted with reddish and dark brown. The eggs are incubated by the male and female for 12–14 days. After the eggs have hatched, the fledglings leave the nest in about 11 or 12 days, but they are unable to fly for another two weeks. The young are fed by both adults. The black-headed grosbeak's monogamy is under study, but pair bonds generally last for only one breeding season. They typically have one brood per season, though two broods have been documented in foothills of the Sacramento Valley in California.


Measurements:
Length: 7.1–7.5 in (18–19 cm)
Weight: 1.2–1.7 oz (34–48 g)
Wingspan: 12.6 inches (32 cm)
The black-headed grosbeak is similar in size to a common starling. As per its name, the male has a black head, and black wings and tail with prominent white patches. Its breast is dark to tawny orange in color, and its belly is yellow. The female has a brown head, neck, and back with sparrow-like black streaks. She also has white streaks down the middle of her head, over her eyes, and on her cheeks. Her breast is white, and wings and tail are grayish-brown with two white wing bars and yellowish wing edges.


American crocodiles are apex predators, and any aquatic or terrestrial animal they encounter in freshwater, riparian and coastal saltwater habitats is potential prey.
The snout of the American crocodile is broader than some specialized fish-eating crocodilians (e.g., gharials and freshwater crocodiles), allowing it to supplement its diet with a wider variety of prey. In addition the snout gets even broader and bulkier as the animal matures, a sign for a shift in prey items. Prey species have ranged in size from the insects taken by young American crocodiles to full-grown cattle taken by large adults, and can include various birds, mammals, turtles, crabs, snails, frogs, fish, and occasionally carrion. In Haiti, hatchling and juvenile American crocodiles lived primarily off of fiddler crabs (Uca ssp.), making up 33.8% and 62.3% of the diet by weight, respectively. Elsewhere, aquatic insects and their larvae and snails are near the top of the food list for American crocodiles at this very early age. Immature and subadult American crocodiles, per a study in Mexico, have a more diverse diet that can include insects, fish, frogs, small turtles, birds and small mammals. One specimen of 1.2 m (3 ft 11 in) had a catfish, a mourning dove and a bare-tailed woolly opossum in its stomach.
In Florida, bass, tarpon and especially mullet, large crabs, snakes, mammals that habit the riparian and coastal regions of the Everglades, such as opossums and raccoons appeared to be the primary prey of American crocodiles. In Haiti, adults appeared to live largely off of various birds, including herons, storks, flamingos, pelicans, grebes, coots and moorhens, followed by concentrations of marine fish including Tilapia and Cichlasoma, at times being seen to capture turtles, dogs and goats. One 3 m (9 ft 10 in) adult from Honduras had stomach contents consisting of a 1.5 m (4 ft 11 in) crocodile of its own species, a turtle shell and peccary hooves. It was noted that historically in Mexico that, among several local farmers, the capturing of livestock by American crocodiles has been a source of some conflict between humans and American crocodiles and large adults occasionally can become habitual predators of goats, dogs, pigs and cattle. In Quintana Roo, Mexico, most prey that could be determined was fish for sub-adults and adults with sub-adults having a broader prey base than either younger or adult American crocodiles. In Costa Rica, American crocodiles have been recorded hunting and killing adult female olive ridley sea turtles (Lepidochelys olivacea) when they come to nest around beaches. Reportedly, these American crocodiles hunt primarily in the first few hours after nightfall, especially on moonless nights, although they will feed at any time. It hunts in the typical way for most crocodilian, ambushing terrestrial prey when it comes to edge of the water or is sitting in shallows and dragging it down to be drowned or attempting to ambush aquatic prey from near the surface of the water.


The American crocodile (Crocodylus acutus) is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida and the coasts of Mexico to as far south as Peru and Venezuela.
The habitat of the American crocodile consists largely of coastal areas. It is also found in river systems, but tends to prefer salinity, resulting in the species congregating in brackish lakes, mangrove swamps, lagoons, cays, and small islands. Other crocodiles also have tolerance to saltwater due to salt glands underneath the tongue, but the American crocodile is the only species other than the saltwater crocodile to commonly live and thrive in saltwater. They can be found on beaches and small island formations without any freshwater source, such as many cays and islets across the Caribbean. They are also found in hypersaline lakes; one of the largest known populations inhabits Lago Enriquillo in the Dominican Republic.
The American crocodile is one of the largest crocodile species. Males can reach lengths of 6.1 m (20 ft 0 in), weighing up to 907 kg (2,000 lb). On average, mature males are more in the range of 2.9 to 4.1 m (9 ft 6 in to 13 ft 5 in) in length weighing up to about 400 kg (880 lb). As with other crocodile species, females are smaller, rarely exceeding 3.8 m (12 ft 6 in) in length even in the largest-bodied population.
Like any other large crocodilian, the American crocodile is potentially dangerous to humans, but it tends not to be as aggressive as some other species. American crocodiles coexist with the American alligator in Florida, and with the smaller spectacled caiman within Central America and Florida.


New hatchlings are about 27 cm (10+1⁄2 in) in length and about 60 g (2 oz) in mass. The average adult in the continental rivers can range from 2.9 to 4 m (9 ft 6 in to 13 ft 1 in) long and weigh up to 382 kg (842 lb) in males, while females can range from 2.5 to 3 m (8 ft 2 in to 9 ft 10 in) and weigh up to 173 kg (381 lb), the lower total length representing their average size at sexual maturity, the upper representing the expected upper size limit for the respective sex in most known populations. Common weights of adult American crocodiles in Florida may range from 57.2 to 238 kg (126 to 525 lb) with corresponding lengths of 2.5 to 3.85 m (8 ft 2 in to 12 ft 8 in). With extensive conservation efforts underway, there appears to be an increase in the number of large American crocodiles in Florida, some of the largest reportedly exceeding 4 m (13 ft 1 in) in length. Eight adult American crocodiles from Costa Rica ranged in total length from 2.82 to 4.83 m (9 ft 3 in to 15 ft 10 in). Exceptionally large specimens may arguably exceed 5 m (16 ft 5 in), possibly reaching or exceeding 6.1 m (20 ft 0 in), but such specimens are unverified and possibly dubious although some are arguably supported by size projections from skull lengths.


The American crocodile is the most widespread of the four extant species of crocodiles from the Americas. They are saltwater-tolerant, and have thus been capable of colonizing a multitude of islands within the Caribbean, and on some coastal Pacific islands as well. They inhabit waters such as mangrove swamps, river mouths, fresh waters, and salt lakes, and can even be found at sea, hence their wide distribution throughout southern Florida, the Greater Antilles (excluding Puerto Rico and Isla de la Juventud, where they are replaced by the introduced spectacled caiman), Martinique, southern Mexico (including the Yucatán Peninsula), Central America, and the South American countries of Colombia, Peru, Venezuela (including on Margarita Island), and Ecuador. The American crocodile is especially plentiful in Costa Rica.
American crocodiles coexist with the smaller spectacled caiman within Central America. The only other crocodiles present within the American crocodile's range are the Morelet's crocodile, and the critically endangered Cuban and Orinoco crocodiles. In addition, an American/Cuban crocodile hybrid was recently discovered in the Cancún area of Mexico. The crocodile likely originated in the Zapata Swamp of Cuba (the only place where these wild hybrids exist, and where the two species are sympatric), and swam to the Yucatán Peninsula.