Hinterland Who's Who

Bill Abbott Northern Giant Pacific Octopus

Giant Pacific Octopus Underside

The Northern Giant Pacific Octopus (Enteroctopus dofleini) is a large cephalopod mollusk, which means it’s related to gastropods (snails and slugs) and bivalves (clams and oysters). Mollusks are invertebrates, meaning they have no bones. Insects are also invertebrates, but mollusks differ from insects in that they don’t have an exoskeleton. They are cold-blooded, like all invertebrates, and have blue, copper-based blood. The octopus is soft-bodied, but it has a very small shell made of two plates in its head and a powerful, parrot-like beak.

Anatomy of the Giant Pacific Octopus' head

The Giant Pacific Octopus is the largest species of octopus in the world. Specimens have weighed as much as 272 kg and measured 9.6 m in radius (although they can stretch quite a bit), but most reach an average weight of only 60 kg. They’re normally reddish-brown in colour.

Invertebrates

Keith Williams Common Raven Common Raven (15 seconds) Common Raven (Youth) Common Raven Common Raven (30 seconds)

Common Raven showing its hackles and large beak

The Common Raven Corvus corax is one of the heaviest passerine birds and the largest of all the songbirds. It is easily recognizable because of its size (between 54 and 67 centimetres long, with a wingspan of 115 to 150 cm, and weighing between 0.69 and two kilograms) and its black plumage with purple or violet lustre. It has a ruff of feathers on the throat, which are called 'hackles', and a wide, robust bill. When in flight, it has a wedge-shaped tail, with longer feathers in the middle. While females may be a bit smaller, both sexes are very similar. The size of an adult raven may also vary according to its habitat, as subspecies from colder areas are often larger.

A raven may live up to 21 years in the wild, making it one of the species with the longest lifespan in all passerine birds.

American Crow

The Common Raven is often mistaken for an American Crow in southern Canada and the United States. 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). It also has a narrower bill and lacks the raven’s hackles. 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.

Common Raven vs American Crow

Birds

Thinkstock North American Lobster North American Lobster North American Lobster (30-seconds) North American Lobster (youth) North American Lobster (15-seconds)

North American Lobster Head

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. These antennae are able to smell the water to locate prey and touch elements in the lobster’s environment so it can find its way. The lobster’s mouth is located just below its eyes. Around its mouth are small appendages called maxillipeds and mandibles which help direct food to the mouth and chew. Food is then brought to the first of the lobster’s two stomachs, which is just inside its mouth! The lobster’s respiratory system is made of gills, like fish, which are situated on each side of its cephalothorax.

North American Lobster Showing Its Different claws

The lobster’s legs are also found on the cephalothorax. 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 claw used for crushing can be on the lobster’s right or left side, making it “right-handed” or “left-handed”. When a lobster’s limb, claw or antennae becomes damaged or lost, it is regrown when the lobster moults, a process called autotomy or regeneration. Hairs on the lobster’s legs and claws also act as sensory organs and are able to smell.

North American Lobster Missing A Claw

Invertebrates

Susan Enders Chorus Frogs Chorus Frogs Chorus Frogs (Youth) Chorus Frogs (15 seconds) Chorus Frogs (30 seconds) Wetland Wonderland (webisode)

There are two species of chorus frogs here in Canada: the Boreal Chorus Frog (Pseudacris maculata) and the Western Chorus Frog (Pseudacris triseriata). Prior to 1989, all Canadian chorus frogs were considered to be one species, as they are very similar – it’s even hard for scientists to differentiate them! Studies determined, though, that they are indeed different. While the Western Chorus Frog might have slightly shorter legs than the Boreal Chorus Frog, and that their respective calls have different structures, genetics have proven this.

Boreal Chorus Frog (left), Western Chorus Frog (right)

Chorus Frogs are about the size of large grape, about 2.5cm long on average, with a maximum of 4cm. They are pear-shaped, with a large body compared to their pointed snout. Their smooth (although a bit granular) skin varies in colour from green-grey to brownish. They are two of our smallest frogs, but best ways to tell them apart from other frogs is by the three dark stripes down their backs, which can be broken into blotches, by their white upper lip, and by the dark line that runs through each eye. Their belly is generally yellow-white to light green.

Males are slightly smaller than females, but the surest way to tell sexes apart is by the fact that only males call and can inflate their yellow vocal sacs. Adults tend to live only for one year, but some have lived as many as three years.

Their tadpoles (the life stage between the egg and the adult) are grey or brown. Their body is round with a clear tail.

Fish, Amphibians and Reptiles

Dave Gallagher Caribou Caribou (30 seconds) Caribou (60 seconds) Species at Risk in Canada (30 seconds) Species at Risk in Canada (60 seconds) Boreal Forest (30 seconds) Boreal Forest (60 seconds) Tundra (30 seconds) Tundra (60 seconds)

Figure 1: Base of caribou foot

The caribou Rangifer tarandus is a medium-sized member of the deer family, Cervidae, which includes four other species of deer native to Canada: moose, elk, white-tailed deer, and mule deer. All are ungulates, or cloven-hoofed cud-chewing animals. However, only in caribou do both males and females carry antlers. Caribou are similar to and belong to the same species as the wild and domesticated reindeer of Eurasia.

The caribou is well adapted to its environment. Its short, stocky body conserves heat, its long legs help it move through snow, and its long dense winter coat provides effective insulation, even during periods of low temperature and high wind. The muzzle and tail are short and well haired.

Large, concave hooves splay widely to support the animal in snow or muskeg, and function as efficient scoops when the caribou paws through snow to uncover lichens and other food plants. In fact, the name “caribou” may be linked to this ability—it may be a corruption of the Mi’kmaq name for the animal, “xalibu,” which means “the one who paws.” The sharp edges give firm footing on ice or smooth rock. Caribou are excellent swimmers and their hooves function well as paddles. In winter, the hooves grow to a remarkable length, giving the animal firm footing on crusty snow. In summer, the hooves are worn away by travel over hard ground and rocks. The dewclaws, or small toes, are large, widely spaced, and set back on the foot, greatly increasing the weight-bearing area. Scent glands located at the base of the ankles are used when the caribou is in danger: the animal rears up on its hind legs and deposits a scent that alerts other caribou to the menace. (See Figure 1.)

Mammals

Example Species

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HWW releases a new series of videos on the chorus frogs!

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