Common Raven

Author:  Koa Planedin

Common name: The Common Raven

Scientific Name: Corvus corax

 


Identifying Features
Corvus corax is 22-30 inches in length, has a 40-59 inch wing span, and weighs 1.5-4.4 lbs. C. corax is one of the heaviest passerines. You can tell them apart from crows by their large curved bill and longish graduated wedge shaped tail. They have a deep, distinctive call with a wide complex vocabulary. While in flight, the raven’s feathers make a creaking sound similar to rustled silk.  Due to a rare genetic mutation some crows in the Qualicum area of Vancouver Island appear white with blue eyes.  According to Mike Yip this isn’t albinism since they have pigment.  It is termed leucistic and refers to the reduction in all types of pigment, not just the lack of melanin as in albinism.

Habitat
C. corax thrives in varied, diverse climates all over the world. These range through artic and temperate habitats in North America and Eurasia to the deserts of North Africa, and islands in the Pacific Ocean. This bird is common in Scotland, Wales, northern England, and west Ireland. In Tibet, they have been recorded at altitudes up to 5000m (16,400ft) and 6,350 (20,600ft) on Mount Everest. They are restricted to Sindh district of Pakistan and adjoining regions of north-west India. Most prefer wooded and costal areas.

Food
Ravens are omnivorous. Their diet normally containing insects, berries, seeds, eggs/young of other birds, small mammals, carrion (the flesh of animals killed by other predators),  and they will often eat things not considered “food” (such as human trash, in an urban environment). It’s been said ravens will hunt alongside packs of wolves, sharing their kill. It’s also been said they will go for the eyes first, typically seen in Nordic images. There is evidence supporting these tales, since eye tissue is softer and easier for birds to pick at, and wolves do some of the shredding of the meat, making it a lot easier for ravens to eat. They are often seen as a dark symbol in western culture for their taste for flesh, but are an important part of the ecosystem, as seen in aboriginal tales. They sometimes even eat noxious weeds.

Predators
They are mostly hunted by birds of prey or other scavengers. Hawks, owls, other ravens, and martens are common predators, though most animals don’t seem to go after ravens as a major food source.

Life Cycle
C. corax mate for life. They start showing courtship behavior at 3-4 years of age, around mid-January. Courting rituals include males soaring, swooping, and tumbling in front of females. They will also fly together and preen each other. By mid-March the couple starts roosting and the female typically lays 3-7 green blotched eggs. The female incubates and is fed by her mate during the 3-4 week incubation period. After hatching, both parents feed the young by regurgitating food and water (stored in a throat patch). The young tend to leave the nest after 5 weeks.  In the wild they generally live between 10 to 15 years but have been known to live up to more than 40 years in captivity.

Photos courtesy of Mike Yip

References
Arizona-Sonora Desert Museum (2012), Common Raven, Arizona-Sonora Desert Museum. Retrieved June 11th, 2012.
www.desertmuseum.org/books/nhsd_raven.php

The Alaska Zoo, Common Raven Fast Facts, The Alaska Zoo. Retrieved June 11th, 2012.
www.alaskazoo.org/common-raven

Cornell University (2012), Common Raven, The Cornell Lab or Ornithology. Retrieved June 11th, 2012.
www.birds.cornell.edu/birdsleuth/modules/exploring-bird-behavior/bird-guide/common-raven

Harlequin Duck

Harlequin Duck

Author:  Egor Peshkov and Marlo Osborne-Subasic

Common name: Harlequin Duck

Scientific name: Histrionicus histrionicus

Size: Harlequin Ducks are between 33cm (13 in) and 54cm (21.3 in) long, and weigh 500 grams (1.1lbs) to 726 grams (1.6lbs).


Identifying Features

The Harlequin Duck is an especially handsome creature, due to the males having very similar colouring to a Jester. They have round heads with steep foreheads and stubby bills.  The males have distinctive white patches and stripes on the head and body. They have burgundy wings, with a metallic blue speculum. The females look far less interesting, being mostly dark brown and grey, with just a few white patches on their heads. The young ducks are somewhat like the females. They can often be identified by the spot between their eyes and the bill. They are also darker than the females and they look greyer. The males start to grow the distinct male plumage when they are about 2 to 3 years old.

Habitat

H. histrionicus tends to live on rocky coastlines including bays and in exposed locations such as rivers and fast flowing streams. They can be found flying 3352 metres above sea level during the summer. In the winter they are usually around shallow waters where they spend their time feeding and resting. The birds go to their breeding grounds (streams), sometime in April or early May and don’t return to the sea until June.  They are commonly seen around the shorelines of Victoria and the Gulf Islands.

Life Cycle

What few Histrionicus histrionicus nests have been found, have generally been near streams at the bases of stumps, bushes, and in suitable spots in trees and cliffs. The female lays 5-10 eggs in the months of May and June.  The females stay close to streams to incubate their eggs and then raise the young, which hatch in late June and July. They take the young ducks to the sea in September and October. After being taken to the coast, the drakes moult their baby feathers and get a new plumage resembling that of a female. The mature males are generally found in a flightless condition

Prey

Harlequin Ducks eat mostly marine organisms (mollusks and small fish) and insects (blackfly larvae, stoneflies, caddis flies and midges). They usually dive under the water to capture their prey.  They can also be found walking on the bottom of the river bed looking for larvae under rocks. The Harlequin Ducks must feed continuously due to their high metabolism and small bodies.

Predators

There is very little information available on the predators of the H. histrionicus, but it can be assumed that it has the same predators as most other ducks.   These would include raccoons, hawks, snakes, cats and dogs.  Since the Harlequin Duck is an endangered species, and also does not taste very good, it is not hunted by humans.

Photos by Egor Peshkov and D. Young

References

Guiguet, C.J. (1978) The Birds of British Columbia: 6) Waterfowl. Victoria, B.C.: British Columbia Provincial Museum.

Planet of Birds (November 12, 2011). Harlequin Duck (Histrionicus histrionicus). Retrieved May 10, 2012 from http://www.planetofbirds.com/anseriformes-anatidae-harlequin-duck-histrionicus-histrionicus

Riley, A.; M. Johnson; A. Riley and M. Johnson 2010. “Histrionicus histrionicus” (On-line), Animal Diversity Web. Accessed May 10, 2012 athttp://animaldiversity.ummz.umich.edu/site/accounts/information/Histrionicus_histrionicus.html

Sutton, C.  Nature Canada Preservation Conservation Endangered Species Canada. Retrieved May 9th2012 from http://www.naturecanada.ca/bird_cons_harlequin.asp

Glaucous-winged Gull


Glaucous-winged Gull

By Zach Cameron

Scientific name: Larus glaucescens

Size range:

Length: 19.7-23.2 in (50-59 cm) from head to tail

Wingspan: 47.2-56.3 in (120-143)

Weight: 31.7-42.3 oz (900-1200g)


Identifying Features

The Glaucous-winged Gull is a sizable bird of the Laridae (gull) family, growing to around half a meter in length with a meter and a half wingspan. It can be identified by its web-footed pink legs and a red circle on its large yellow beak as well as its distinctively grey wings and back feathers. The gull has a white tail and chest. The undersides of its wings are also white and it has hints of grey throughout. Males can be distinguished from females by their larger size. Younger gulls are a more grey-brown all over with a black beak and a dark ring around their eyes. With breeding plumage, the feathers around the gull’s head are completely white and a pink circle is directly around both of their eyes. The Glaucous-winged Gull’s non-breeding plumage differs only by the fact that the head feathers are speckled in a grey to brown colouring and lack the ring around the eye. Interbreeding between gull species can make it a challenge to identify them but they can be quickly distinguished by their solely grey and white plumage.

Habitat

Being a coastal sea bird, the Glaucous-winged Gull is usually found close to salt water and a food source. It can be found as far north as the Bering Sea, down to the Pacific coast going through Alaska, British Columbia and into northwestern Washington. During the winter they are commonly found in Asia going down to Japan. They often habitat beaches and rocky shorelines but also go up rivers in search of spawning salmon. These birds have integrated themselves well into man made environments, living around cities, harbours, garbage dumps and following fishing boats out into open waters. They have become especially successful because of garbage dumps; due to the dumps being such a great food source, there has been large increase in the gull population.

Food

Glaucous-winged Gulls are omnivores that will eat just about anything. They are both scavengers and predators that can be found eating garbage and carrion (decaying flesh), stealing from other sea birds such as cormorants and pelicans, and feeding on salmon in the interior and marine animals in the open ocean. These gulls have a very wide diet that includes garbage, fish, seaweeds, mollusks, barnacles, other birds, small mammals, sea urchins and other invertebrates, crustaceans and so on. Being a bird, it uses its flight and speed to capture its prey as well as its large beak as an offensive tool. The birds will also use rocks to break open the harder, protected prey, by dropping the prey from a high height onto the rocks.

Predators

Adult Glaucous-winged Gulls do not have much in terms of predators. Bald eagles are known to eat the gulls throughout their lifetime as well as skuas, crows, and ravens who will steal gull eggs. The Glaucous-winged gull itself is a large predator of the species which often resorts to cannibalism of the younger and smaller chicks and eggs.

Life Cycle

Glaucous-winged Gulls usually live to around 10 years old but have been known to live almost three times as long. They reach breeding age and adult plumage at 4 years old and will go to the same place and keep the same mate for most or all of their lives. They usually nest between April and August and lay 1 to 5 eggs. Their nests are made up of whatever they can gather in the area, using anything from seaweeds, plants, driftwood and even garbage. They nest on top of buildings, on beaches, in trees, islands, and cliff faces. Chicks will hatch around 27 days after the eggs are first laid and can usually fly at 44 days old. Glaucous-winged Gulls regularly breed with other species of gull (such as the Herring and California Gulls) when their territories cross.

Illustration by Zach Cameron, Photograph by Lydia Young

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Black Oystercatcher

The Black Oystercatcher

By Leah Brett

Common name: Black Oystercatcher

Scientific name: Haematopus bachmani

Size range: 35cm to 43 cm


Identifying features

The Black Oystercatcher is an all black shorebird. What stands out in this bird is the bright red long bill and the yellow ring around the eye. The size of these birds resembles a common crow except for the bare short pinkish yellow legs.

Habitat

Black Oystercatchers can be found along the rocky shoreline of the Pacific coast as far south as California and north to Alaska. Though they can be seen as individuals, they are often found in small groups poking their beaks among the rocks and seaweed looking for small prey with other shorebirds such as Gulls and Sandpipers.

Food

The main diet of Oystercatchers includes mussels and limpets. These shellfish seem to be in abundance on the West Coast though other kinds of easy prey such as small crabs, barnacles or sea worms in tidal pools or among seaweed is common as well. They use their beak for stabbing the abductor muscle that holds the shell open and pull out the soft tissue with the tip of its sharp bill.

Predators

Because of their small size Black Oystercatchers are easy prey to Eagles, Gulls, Minks, Otters, Ravens, Weasels, Wolverines and Bears. The only defence they have is when they are alarmed, they take flight with a loud piercing whistle.

Life Cycle

Black Oystercatchers live approximately 15 years. They nest on non-forested islands with shelled or gravel beaches usually the same place every year. The nest is made out of a few shells or rock fragments in a small depression just above the high tide line. The female lays 2 to 3 eggs at a time once a year in spring. Incubation is 24 to 29 days. The chicks are downy with “salt and pepper” specks for the first 4 weeks until the adult feathers grow in.

Photos by D. Young

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Canada Goose

Identifying Features The Canada Goose is a large waterfowl most recognizable for its long, black neck and white cheeks and chinstrap. Due to its dependence on water, it has webbed feet to aid its swimming. It’s head and neck are primarily black, they have a tan breast and a brown back. They also have wide […]

Black Oystercatcher

The Black Oystercatcher

By Leah Brett

Common name: Black Oystercatcher

Scientific name: Haematopus bachmani

Size range: 35cm to 43 cm


Identifying features

The Black Oystercatcher is an all black shorebird. What stands out in this bird is the bright red long bill and the yellow ring around the eye. The size of these birds resembles a common crow except for the bare short pinkish yellow legs.

Habitat

Black Oystercatchers can be found along the rocky shoreline of the Pacific coast as far south as California and north to Alaska. Though they can be seen as individuals, they are often found in small groups poking their beaks among the rocks and seaweed looking for small prey with other shorebirds such as Gulls and Sandpipers.

Food

The main diet of Oystercatchers includes mussels and limpets. These shellfish seem to be in abundance on the West Coast though other kinds of easy prey such as small crabs, barnacles or sea worms in tidal pools or among seaweed is common as well. They use their beak for stabbing the abductor muscle that holds the shell open and pull out the soft tissue with the tip of its sharp bill.

Predators

Because of their small size Black Oystercatchers are easy prey to Eagles, Gulls, Minks, Otters, Ravens, Weasels, Wolverines and Bears. The only defence they have is when they are alarmed, they take flight with a loud piercing whistle.

Life Cycle

Black Oystercatchers live approximately 15 years. They nest on non-forested islands with shelled or gravel beaches usually the same place every year. The nest is made out of a few shells or rock fragments in a small depression just above the high tide line. The female lays 2 to 3 eggs at a time once a year in spring. Incubation is 24 to 29 days. The chicks are downy with “salt and pepper” specks for the first 4 weeks until the adult feathers grow in.

Photos by D. Young

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