Both birds are from the same genus order of passerine birds, corvid family —like jays, magpies and nutcrackers, Corvus genus and have a similar colouring. But the American Crow is smaller with a wingspan of about 75 cm and has a fan-shaped tail when in flight with no longer feathers. Their cries are different: the raven produces a low croaking sound, while the crow has a higher pitched cawing cry.
While adult ravens tend to live alone or in pairs, crows are more often observed in larger groups. 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! Individuals living closer to shore tend to be smaller than their offshore relatives, but male and female cod are not different in size, wherever they live.
The Atlantic Cod shares some of its physical features with the two other species of its genus, or group of species, named Gadus. The Pacific Cod and Alaska Pollock also have three rounded dorsal fins and two anal fins. They also have small pelvic fins right under their gills, and barbels or whiskers on their chins. Both Pacific and Atlantic Cod have a white line on each side of their bodies from the gills to their tails, or pectoral fins.
This line is actually a sensory organ that helps fish detect vibrations in the water. The colour of an Atlantic Cod is often darker on its top than on its belly, which is silver, white or cream-coloured. In rocky areas, a cod may be a darker brown colour. Cod are often mottled, or have a lot of darker blotches or spots.
It can weigh up to 63, kilograms and measure up to 16 metres. Females tend to be a bit larger than males — measuring, on average, one metre longer. Its head makes up about a fourth of its body length, and its mouth is characterized by its arched, or highly curved, jaw.
Its skin is otherwise smooth and black, but some individuals have white patches on their bellies and chin. It has large, triangular flippers, or pectoral fins. Its tail, also called flukes or caudal fins, is broad six m wide from tip to tip! Unlike most other large whales, it has no dorsal fin. For a variety of reasons, including its rarity, scientists know very little about this rather large animal. For example, there is little data on the longevity of Right Whales, but photo identification on living whales and the analysis of ear bones and eyes on dead individuals can be used to estimate age.
It is believed that they live at least 70 years, maybe even over years, since closely related species can live as long. Unique characteristics. The Right Whale has a bit of an unusual name. Its name in French is more straightforward; baleine noire, the black whale. The American Eel Anguilla rostrata is a fascinating migratory fish with a very complex life cycle. Like salmon, it lives both in freshwater and saltwater. It is born in saltwater and migrating to freshwater to grow and mature before returning to saltwater to spawn and die.
The American Eel can live as long as 50 years. It is a long, slender fish that can grow longer than one metre in length and 7.
Males tend to be smaller than females, reaching a size of about 0. With its small pectoral fins right behind its gills, absence of pelvic fins, long dorsal and ventral fins and the thin coat of mucus on its tiny scales, the adult eel slightly resembles a slimy snake but are in fact true fish.
Adult eels vary in coloration, from olive green and brown to greenish-yellow, with a light gray or white belly. Females are lighter in colour than males.
Large females turn dark grey or silver when they mature. The American Eel is the only representative of its genus or group of related species in North America, but it does have a close relative which shares the same spawning area: the European Eel. Both have similar lifecycles but different distributions in freshwater systems except in Iceland, where both and hybrids of both species can be found.
The American Lobster Homarus americanus is a marine invertebrate which inhabits our Atlantic coastal waters. As an invertebrate, it lacks bones, but it does have an external shell, or exoskeleton, making it an arthropod like spiders and insects.
Its body is divided in two parts: the cephalothorax its head and body and its abdomen, or tail. On its head, the lobster has eyes that are very sensitive to movement and light, which help it to spot predators and prey, but are unable to see colours and clear images. It also has three pairs of antennae, a large one and two smaller ones, which are its main sensory organs and act a bit like our nose and fingers. Around its mouth are small appendages called maxillipeds and mandibles which help direct food to the mouth and chew.
Lobsters have ten legs, making them decapod ten-legged crustaceans, a group to which shrimp and crabs also belong other arthropods have a different number of legs, like spiders, which have eight, and insects, which have six.
Four pairs of these legs are used mainly to walk and are called pereiopods. The remaining pair, at the front of the cephalothorax, are called chelipeds and each of those limbs ends with a claw.
These claws help the lobster defend itself, but also capture and consume its prey. Each claw serves a different purpose: the bigger, blunter one is used for crushing, and the smaller one with sharper edges, for cutting. The Barn Swallow Hirundo rustica is a medium-sized songbird, about the size of a sparrow. It measures between 15 and 18 centimeters cm in length and 29 to 32 cm in wingspan, and weighs between 15 and 20 grams g. Its back and tail plumage is a distinctive steely, iridescent blue, with light brown or rust belly and a chestnut-coloured throat and forehead.
Their long forked tail and pointed wings also make them easily recognizable. Both sexes may look similar, but females are typically not as brightly coloured and have shorter tails than males. When perched, this swallow looks almost conical because of its flat, short head, very short neck and its long body. Although the average lifespan of a Barn Swallow is about four years, a North American individual older than eight years and a European individual older than 16 years have been observed.
Sights and sounds: Like all swallows, the Barn Swallow is diurnal —it is active during the day, from dusk to dawn. It is an agile flyer that creates very acrobatic patterns in flight. It can fly from very close to the ground or water to more than 30 m heights. When not in flight, the Barn Swallow can be observed perched on fences, wires, TV antennas or dead branches. Both male and female Barn Swallows sing both individually and in groups in a wide variety of twitters, warbles, whirrs and chirps.
They give a loud call when threatened, to which other swallows will react, leaving their nests to defend the area. Freshwater turtles are reptiles, like snakes, crocodilians and lizards. They also have a scaly skin, enabling them, as opposed to most amphibians, to live outside of water. Also like many reptile species, turtles lay eggs they are oviparous.
But what makes them different to other reptiles is that turtles have a shell. This shell, composed of a carapace in the back and a plastron on the belly, is made of bony plates. These bones are covered by horny scutes made of keratin like human fingernails or leathery skin, depending on the species.
All Canadian freshwater turtles can retreat in their shells and hide their entire body except the Common Snapping Turtle Chelydra serpentina. This shell is considered perhaps the most efficient form of armour in the animal kingdom, as adult turtles are very likely to survive from one year to the next. Indeed, turtles have an impressively long life for such small animals.
Most other species can live for more than 20 years. There are about species of turtles throughout the world, inhabiting a great variety of terrestrial, freshwater and marine ecosystems on every continent except Antarctica and its waters.
In Canada, eight native species of freshwater turtles and four species of marine turtles can be observed. Another species, the Pacific Pond Turtle Clemmys marmorata , is now Extirpated, having disappeared from its Canadian range. Also, the Eastern Box Turtle Terrapene carolina has either such a small population that it is nearly Extirpated, or the few individuals found in Canada are actually pets released in the wild.
More research is needed to know if these turtles are still native individuals. Finally, the Red-eared Slider Trachemys scripta elegans , has been introduced to Canada as released pets and, thus, is not a native species. Females tend to be slightly larger than males but are otherwise identical.
As its name implies, it is pale tan to reddish or dark brown with a slightly paler belly, and ears and wings that are dark brown to black. Contrary to popular belief, Little Brown Bats, like all other bats, are not blind. Still, since they are nocturnal and must navigate in the darkness, they are one of the few terrestrial mammals that use echolocation to gather information on their surroundings and where prey are situated.
The echolocation calls they make, similar to clicking noises, bounce off objects and this echo is processed by the bat to get the information they need. These noises are at a very high frequency, and so cannot be heard by humans. Narwhals Monodon monoceros are considered medium-sized odontocetes, or toothed whales the largest being the sperm whale, and the smallest, the harbour porpoise , being of a similar size to the beluga, its close relative.
Males can grow up to 6. Females tend to be smaller, with an average size of 4 m and a maximum size of 5. A newborn calf is about 1. Like belugas, they have a small head, a stocky body and short, round flippers. 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. The water in their enclosure must be deep enough for them to dive and forage naturally.
Zookeepers feed them a variety of small fish, shrimp, squid, crabs, and shellfish. Most zoos also keep them with other cold-water bird species, like puffins and other species of eiders. Outside of breeding season, these ducks are quite social and live in large groups.
They spend most of their time at sea, and rarely come to land unless they are nesting. Most activity and foraging occur during the day, and they sleep at night, making them diurnal. While they are migrating, flocks of King Eiders sometimes have several thousand birds. Once they reach their breeding ground, pairs form and they do not associate closely with other pairs.
Male courtship includes lots of head bobbing, wing flapping, chasing, calling, and stretching. If he impresses the female, the pair will mate. Males leave shortly after the female lays her eggs, and the females take all responsibility for rearing the ducklings. They lay an average of five eggs, which they incubate for a little over three weeks. The ducklings mature quickly, and begin to fly when they are a little over three weeks old.
Animals Network. Red Angus. Journal of Field Ornithology , 60 4 : Lamothe, P. Biology of the king eider Somateria spectabilis in a freshwater breeding area on Bathurst, Island, N. Edmonton, Alberta, Canada: University of Alberta. Mallory, M. Gilchrist, S. Jamieson, G. Robertson, D. Mauser, D. Jarvis, D. Survival of radio-marked mallard ducklings in northeastern California. The Journal of Wildlife Management , 58 1 : McDougall, P. The anti-predator function of defecation of their own eggs by female Eiders.
Mehl, K. Alisauskas, A. The Auk , 2 : Merkel, F. Mosbech, S. Jamieson, K. The diet of king eiders wintering in Nuuk, Southwest Greenland, with reference to sympatric wintering common eiders. Polar Biology , 30 12 : Miller, E. Williams, S. Jamieson, H. Gilchrist, M. Allometry, bilateral asymmetry and sexual differences in the vocal tract of common eiders Somateria mollissima and king eiders S. Journal of Avian Biology , 38 2 : Mosbech, A. Arctic , 52 2 : Oppel, S.
Powell, M. King Eider foraging effort during the pre-breeding period in Alaska. Powell, L. Ouellet, J. The body size-dependent diet composition of North American sea ducks in winter. PLoS One , 8 6. Palmer, R.
Handbook of North American birds. Phillips, L. The Wilson Journal of Ornithology , 2 : Powell, E. Large-scale movements and habitat characteristics of King Eiders throughout the nonbreeding period. The Condor , 4 : Schiller, E.
Studies on the helminth fauna of Alaska. Some Cestode parasites of eider ducks. The Journal of Parasitology , 41 1 : Sittler, B. Young leave nest shortly after hatching and go to water. Diet Mostly mollusks. Nesting Most pairs are formed in spring, during migration or near breeding grounds. Climate threats facing the King Eider Choose a temperature scenario below to see which threats will affect this species as warming increases.
More News. Explore Similar Birds. The Bird Guide Adopt a Bird. Common Eider Latin: Somateria mollissima. Spectacled Eider Latin: Somateria fischeri. These birds need your help. Get Audubon in Your Inbox Let us send you the latest in bird and conservation news.
Email address. Find Audubon Near You Visit your local Audubon center, join a chapter, or help save birds with your state program. Explore the Network. Become an Audubon Member Membership benefits include one year of Audubon magazine and the latest on birds and their habitats. Join Today.
0コメント