During one winter I was hiking in the rocky mountains with several friends. We came across a field and there were what seemed to be hundreds of caribou. I would compare that experience to seeing the northern lights because it made me feel so in touch with the beauty of nature. They can also be found in northern europe and asia; however, they are usually referred to as reindeer and more commonly found domestically. Caribou are found in tundra and taiga regions depending on the season.
They move around during the year in order to find the best shelter and nutrients. Appearance: Caribou have dense, chocolate-brown coats of hair with a white neck and flank backside. They have two layers of fur to keep them extra warm a tougher outer coat of hair as well as a soft and wooly undercoat.
Their hair contains air pockets that helps to keep the animal warm and also makes them more buoyant while swimming. Caribou have wide, fur covered feet that help them stay warm and move through diverse terrain. The hooves have a hollow like shape right at the bottom with sharp edges. These characteristic allow their hooves to act as snowshoes during the winter. Interestingly, the shape of the hooves are also great for travelling through water like paddles.
Large regional herds of between 50, and , animals travel seasonally, taking advantage of food resources while avoiding predators and coastal insects. The ancient caribou once shared grazing grounds with prehistoric mammals such as mastodons and woolly mammoths.
The extensive annual migrations are one of the main reasons caribou continue to exist while many other species have gone extinct. In North America, caribou herds still use the same migration routes and river crossing points their ancestors used as much as 27, years ago. While there are still large wild herds of caribou, some have been tended by humans going back 3, years. Caribou are the only deer to have been domesticated on such a widespread basis.
The spring melt of arctic snow triggers pregnant females to begin the annual caribou migration to calving grounds, where the herd will pause briefly while calves are born.
Although parts of the migration routes are used almost every year, there are variations in the specific routes that are taken, depending on weather, snow conditions, and where caribou spent the winter. As a result, caribou migrate different distances each year. Migration probably helps caribou access the best type of food available during each season, and also helps the herd avoid predation because predators are generally less mobile, and thus only have access to the caribou for part of each year.
Some weather conditions, such as the first severe storm in the fall, seem to stimulate caribou to begin migrating toward their winter ranges and spring migration is probably stimulated by the pregnant cows feeling the instinct to go to their preferred calving grounds. For large herds such as the Porcupine Caribou herd in the Arctic National Wildlife Refuge, the caribou must keep moving so they don't eat all the available food.
We can't tell you how many die while crossing rivers, although this undoubtedly does happen. We do know, however, that caribou have been encountering rivers for many thousands of years, and yet the herds survive. Caribou have many strategies that help them cross rivers. They including the calves are excellent swimmers, and their hollow winter hair helps them float high in the water.
Caribou do not always plunge blindly into rivers: sometimes they scout out safer crossing areas or wait for better crossing conditions. We've observed migrating pregnant females decide not to cross a raging river, but instead, give birth before crossing. To biologists, a population is a group of animals that commonly interbreed among themselves, but do not interbreed with animals from neighboring populations. In the case of caribou, breeding between neighboring herds does occur, but is usually much less common than breeding between caribou within a herd.
Each herd maintains a unique calving range, separated from those of other herds. Most caribou herds are named after the area where they are found, or a prominent geographic feature of their range. Do caribou stand around and let wolves eat them? It sometimes may look like caribou are ignoring predators such as wolves or bears. Unless they are incapacitated, however, caribou will run from a predator who gets too close to them.
There are three characteristics of caribou that may make them appear to show less than the expected amount of fear toward a predator:. They know what's a safe distance from a predator, and they can tell by watching how a wolf or bear is behaving whether the predator is a threat. So it is very possible to see a bear or wolf pass through a herd of caribou.
While the predator ambles along, the caribou do not run away, but continue to feed or walk. When the predator begins running toward a group or an individual animal, then those caribou run away. When caribou are not alarmed, they walk slowly, extending the head forward and downward. When alarmed, caribou perform a special behavior to warn other caribou of danger. They'll do this if a predator gets too close, but isn't about to catch them or after they figure out that you're a person sitting on a rock.
An alarmed caribou will trot with the head held high and parallel to the ground, and the short, normally floppy tail held up in the air. They gallop very quickly when being chased closely by a predator. Caribou and reindeer are the same species Rangifer tarandus. Caribou are native to North America, while reindeer are found in Scandinavia and northern Asia, where some have been domesticated.
Domestic reindeer are herded by humans and used for food and for pulling sleds. They generally are smaller and have shorter legs than caribou. Caribou are found throughout Alaska and northern Canada, and along the west coast of Greenland.
Caribou used to live in Maine and the northern Great Lakes states, but they are no longer found in those areas. A small, endangered woodland caribou herd exists along the Canadian border with northern Idaho and northwest Montana. An unusual situation exists at South Georgia, an island near Antarctica, where reindeer from Norway were introduced in the early 's.
Because of the opposite seasons in the southern hemisphere, these animals had to change the timing of breeding and calving by a half year. The woodland caribou in that region live in old growth forests. They do not migrate very far between their summer and winter ranges less than 40 miles, in some cases , but they are very sensitive to human disturbance and to forest loss. Woodland caribou do poorly when forests are fragmented into small areas by roads or by logging operations. As human activities increase, woodland caribou, and other animals sensitive to disturbance, have disappeared.
Only a few areas in the United States still support woodland caribou, and the animals are endangered in these areas. There are currently four very large herds of caribou and wild reindeer: the Porcupine Herd, the Western Arctic herd in northwest Alaska, the Qamanirjuag Herd in Nunavut, Canada, and the Taimyr Peninsula herd in northern Siberia. Each herd is currently estimated at over , individuals.
Due to different census techniques and schedules, as well as annual fluctuations in populations, it is not possible to say for certain which of these three herds is currently the largest. Several caribou herds in northern and northeastern Canada that used to be quite large have recently declined to very low numbers, causing concern about the future of these herds. Adult caribou range in size from 3 to 4 feet tall. Their size and weight varies by sex and region. For example, caribou are fairly small in northern Alaska.
Males average about to pounds, females about pounds. In southern Alaska, caribou are considerably larger -- males average to pounds and females average to pounds. Caribou are the only deer in which both sexes have antlers. Males shed their antlers in late fall, just after the breeding season young males retain their antlers longer that mature males. Pregnant females keep their antlers all winter and shed them soon after the calves are born in the spring.
Non-pregnant females shed their antlers during the winter. Caribou do not store much of their fat in muscle tissue, so their meat is leaner than beef which often is "marbled" with fat. Caribou meat is considered more healthy than beef, and is quite tasty. 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. 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.
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