Narwhals lack a dorsal fin on their backs, but they do have a dorsal ridge about 5 cm high that covers about half their backs. This ridge can be used by researchers to differentiate one narwhal from another.
It is thought that the absence of dorsal fin actually helps the narwhal navigate among sea ice. Unlike other cetaceans —the order which comprises all whales—, narwhals have convex tail flukes, or tail fins. These whales have a mottled black and white, grey or brownish back, but the rest of the body mainly its underside is white.
Newborn narwhal calves are pale grey to light brownish, developing the adult darker colouring at about 4 years old. As they grow older, they will progressively become paler again.
Some may live up to years, but most probably live to be 60 years of age. Although the second, smaller incisor tooth often remains embedded in the skull, it rarely but on occasion develops into a second tusk.
Tusks typically grow only on males, but a few females have also been observed with short tusks. The function of the tusk remains a mystery, but several hypotheses have been proposed.
Many experts believe that it is a secondary sexual character, similar to deer antlers. Thus, the length of the tusk may indicate social rank through dominance hierarchies and assist in competition for access to females. Indeed, there are indications that the tusks are used by male narwhals for fighting each other or perhaps other species, like the beluga or killer whale. A high quantity of tubules and nerve endings in the pulp —the soft tissue inside teeth — of the tusk have at least one scientist thinking that it could be a highly sensitive sensory organ, able to detect subtle changes in temperature, salinity or pressure.
Narwhals have not been observed using their tusk to break sea ice, despite popular belief. Narwhals do occasionally break the tip of their tusk though which can never be repaired. This is more often seen in old animals and gives more evidence that the tusk might be used for sexual competition.
Adult coho salmon have silvery sides and metallic blue backs with irregular black spots. Spawning males have bright red sides, and bright green backs and heads, with darker colouration on their bellies. The fish have hooked jaws and sharp teeth.
Young coho salmon are aggressive, territorial and often vibrantly coloured, with a large orange anal fin edged in black and white. Ptarmigans are hardy members of the grouse family that spend most of their lives on the ground at or above the treeline. Like other grouse, ptarmigans have chunky bodies, short tails and legs, and short, rounded wings. Willow Ptarmigans weigh from to g, White-tailed Ptarmigans weigh about g, and Rock Ptarmigans are intermediate in size. All ptarmigans have feathered feet, unique among chickenlike birds, which improve their ability to walk in snow.
They also have white wings throughout the year. Inflatable red combs above their eyes, which are especially evident in territorial and courting males, are inconspicuous to barely visible in females. Ptarmigans have three seasonal plumages per year, instead of the two that are usual for most birds. These plumages keep the birds, particularly the female, well camouflaged at all times. In winter, all ptarmigans of both sexes are basically white. Whereas White-tailed Ptarmigans have permanently white tail feathers, the tails of Willow and Rock Ptarmigans remain black throughout the year.
In winter, male—and some female—Rock Ptarmigans sport a black stripe that extends through the eye to the bill as if they had put on charcoal goggles to prevent snow blindness , distinguishing them from male Willow Ptarmigans.
In ptarmigans, the moult, or shedding of old feathers, starts with the head and progresses towards the tail. As soon as the spring snowmelt begins, females moult into a barred breeding plumage of brown, gold, and black. Female ptarmigans are difficult to tell apart in spring, but the overall tones of the White-tailed Ptarmigan females are cooler in comparison to those of the other two species. Breeding males delay their moult. The Roseate Tern Sterna dougallii is a seabird that resembles a small gull, but it has the typically slender body, short legs, and long, pointed wings of all terns.
It is closely related to the Common Tern Sterna hirundo and the Arctic Tern Sterna paradisaea and is frequently found in their company. For these reasons, the Roseate Tern is not easy to identify see drawings.
It is a paler grey than Arctic and Common terns, and its tail streamers are considerably longer. The adult Roseate Tern is 33 to 34 cm in length and has a wingspan of 72 to 80 cm. At a weight of approximately to g, an adult is slightly smaller than a Mourning Dove. It has a black forehead and nape, and its upper wing is a pale grey.
Its tail is white with deeply forked outer feathers that give the impression of long streamers when the bird is in flight. The underside of the tern is white, tinged with pink early in the breeding season; however, this pale rosy tint is not a good field mark, or identification characteristic, because it varies from bird to bird, and the colour tends to be bleached out by the sun.
The legs and feet are reddish, and the bill is mostly black, although bills of breeding birds may be red at the base. Male and female birds look alike. The head of the nonbreeding adult is mottled black and white. The juvenile Roseate Tern has a mottled greyish back and rump and dark bill and legs. Chicks are unevenly covered with down, giving them a spiky appearance; their legs are dark purplish to black.
Signs and sounds All terns have a harsh cry, but the Roseate Tern has a distinctive, two-syllable call — kir-rick. This is often the best way of confirming its presence at a colony. Many naturalists and hunters consider the Wood Duck Aix sponsa to be the most beautiful duck in North America, if not the world.
The male in its multi-coloured breeding plumage, worn from October through June, is unexcelled among ducks. The female is less showy, although still beautiful and more colourful than other female ducks.
Wood Ducks are intermediate in size, between the Mallard and Blue-winged Teal; on average, males weigh g and females weigh g. From a distance, the male Wood Duck on the water appears as a dark-bodied, dark-breasted, light-flanked duck with a striped crested head and a light-coloured throat.
At close range, its iridescent plumage, red eyes, and black, red, and white bill are conspicuous. A white eye-ring, light-coloured throat, and fine crest distinguish the female from both the male Wood Duck and females of other species. Both sexes usually show a downward pointing crest at the back of the head, and their long broad square tails are distinctive features in flight.
The wings of Wood Ducks are highly characteristic. The primary wing feathers, which are the 10 outermost flight feathers attached to the wing beyond the wrist, are dark in colour.
The outer vanes of these feathers look as if they have been sprayed with aluminum paint. The Wood Duck is the only North American duck so marked. Shorebirds form one of the most interesting, important, and spectacular groups of birds in Canada. They comprise a diverse group of species, including the plovers, oystercatchers, avocets, stilts, turnstones, sandpipers, yellowlegs, snipes, godwits, curlews, and phalaropes.
To the uninitiated, many species of shorebirds, especially the smaller sandpipers, appear confusingly similar, representing variations on a design involving long legs, a long bill, sharp, dynamic wings, and a streamlined body.
These design features all reflect the lifestyle for which the birds are adapted—long legs for wading in water or on mudflats or marshes, the long bill for searching for tiny animal and insect prey by probing into Arctic tundra or a variety of substrates, and long wings and a streamlined body for swift flight over long distances.
The Redhead Aythya americana is a well-known and widely distributed North American diving duck. The adult male is a large, grey-backed, white-breasted duck with a reddish-chestnut head and black neck and chest.
It resembles the larger male Canvasback. The adult female is a large, brown-backed, white-breasted duck with a brown head, whitish chin, abrupt forehead, short, broad bill, and pearl-grey wing patches.
Female Redheads, although larger, may be confused with female Ring-necked Ducks and scaups. In autumn young Redheads resemble adult females, although their breast plumage is dull grey-brown, rather than white. During November and December, the young begin to develop the adult plumage, which has almost completely grown in by February.
The genus Aythya, to which the Redhead belongs, includes 12 species, all of which are well adapted to diving. The body is rounded and thick with large feet, legs set back on the body, and a broad bill. Body shapes vary from the big, long-necked, long-billed Canvasback to the short-billed scaup. Skip to main content. Photo: Susan Enders. At a Glance This animal: -is two species of small frogs, about the size of a grape -is an amphibian; it needs both aquatic and terrestrial habitats to survive -is most easily noticed in the spring because of its loud call -is at risk in Canada Tweet.
Common Raven vs American Crow Birds Atlantic Cod Atlantic Cod Youth Atlantic Cod 15 seconds Atlantic Cod 30 seconds Atlantic Cod The Atlantic Cod Gadus morhua is a medium to large saltwater fish: generally averaging two to three kilograms in weight and about 65 to centimetres in length, the largest cod on record weighed about kg and was more than cm long!
The Atlantic Cod may live as long as 25 years. Unique characteristics The Right Whale has a bit of an unusual name. Barn Swallow photo by J. Little Brown Bat. Youth Wolf youth. Classic Wolf 30 seconds. Classic Wolf 15 seconds. Classic Wolf long version. Classic Sugar Maple long version. Youth Sugar Maple Youth. Classic Sugar Maple 30 seconds. Youth Sugar Maple 15 seconds. Vintage The Bison.
Vintage Whooping Crane. Vintage Snowy Owl Original. Vintage Loon Original. Classic Sea Otter. Youth Sea Otter Youth. Western chorus frogs usually range from between 1 and 1.
In most cases, the females are a little bigger than the males. Western chorus frogs' skin has an uneven and damp texture. Their toes are web-free. These nocturnal frogs can thrive in many types of environments, as long as they're sufficiently moist. Some examples of suitable and common western chorus frog habitats are meadows, wetlands, marshes, ponds, surroundings of forests and agricultural sites.
They occasionally reside in urban locales, but are particularly fond of airy environments. Western chorus frogs generally are drawn to transient bodies of water -- a means of staying away from fish.
Fish frequently feed on tadpoles and juveniles of the species, after all. Scientific Name. Common Name Synonyms. Statewide, except in southeastern Missouri, where it hybridizes with and also is replaced by the upland chorus frog. Habitat and Conservation This frog is most abundant in prairies but also occurs on agricultural lands, in large river floodplains, and on the grassy edges of marshes.
After breeding season, they take shelter in animals burrows; under boards, logs, or rocks; in clumps of grass; or in loose soil. Breeding sites are usually in flooded fields, ditches, woodland ponds, marshes, and river sloughs as well as farm ponds.
This is often the first frog to become active in the spring. Food Boreal chorus frogs eat a variety of small insects and spiders. Status Common. Also, western chorus frogs still exist as a species — but not in Missouri. As ornithologists do with bird names, herpetologists assign official common names to reptile and amphibian species to correspond exactly with the scientific names.
Life Cycle Life Cycle. Breeding begins in late February or early March and peaks in April. Males chorus in temporary bodies of water and in fishless farm ponds. The male fertilizes the eggs as the female lays and attaches them to submerged grasses just below the surface, in clusters of 5— These hatch within a week, depending on water temperature.
Metamorphosis occurs in 6—8 weeks. This species overwinters in the ground and does not burrow very deep.
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