Black-Legged Kittiwake (Rissa tridactyla)

             

Class: Aves
Order: Charadriiformes
Family:    Laridae
Size:    Length: 16 to 18 inches  (40 to 46 cm)  Wingspan: 36 to 48 inches (91 to 122 cm)
Weight: 12 to 18 ounces (340 to 510 grams)
Diet: Fish, insects, crustaceans, plankton, molluscs and worms
Distribution: Arctic regions of Europe, Asia and North America
Young:  2 to 3 chicks, once a year
Animal Predators:  Unknown
IUCN Status: No special status
Terms: Young: Chick
Lifespan: Up to 21 years

 

Facts/Trivia:

·     The scientific name, Rissa tridactyla means “kittiwake with three toes.”

·     Kittiwakes have shorter legs than most other gulls and lack a hind claw.

·     The black-legged kittiwake’s plaintive call sounds like its name—kittiwake.

 

Description

Black-legged kittiwakes are members of the gull family. They have short black legs, grey wings with black tips, a white head, white underside and tail, and a yellow bill. 

 

Habitat

These gulls live on Arctic coasts of the North Atlantic and North Pacific oceans, on both coasts of North America as well as the northern coastal waters of Europe and Asia. They nest on offshore islands or narrow coastal cliffs that are inaccessible to humans. During the coldest part of the year, they venture as far south as the Gulf of St. Lawrence, Newfoundland and Maine on the east coast, and California on the west coast.  

 

Feeding Habits

Black-legged kittiwakes feed at the water’s surface, on fish such as sand eels, cod, capelin and pollock. They also eat insects, crustaceans, plankton, molluscs and worms. They dive and even swim underwater to catch food.

 

Reproduction

Black-legged kittiwakes are usually monogamous, with the majority of couples staying together for life. The male and female build a cup-shaped nest of grass, mud and algae on a rocky ledge. Breeding occurs from March to mid-October. They take turns incubating the eggs, which hatch in approximately 25 days. Both parents share the responsibilities of taking care of and feeding the young. When they are about six weeks old, the young kittiwakes take their first flight, but return to the nest to be fed by their parents a few more times before heading out on their own. They acquire full adult plumage by two years of age and begin to breed between three and five. 

 

Behaviour

Unlike most other types of gulls, black-legged kittiwakes spend their winters at sea. They are very sociable birds and during the summer they return to shore to gather in large flocks. 

 

Conservation

The red-legged kittiwake, a close relative of the black-legged kittiwake, is listed as Vulnerable on the IUCN’s red list. The black-legged kittiwake population is not a conservation concern, as records indicate that their numbers have increased in the last 30 years.

 

Sources

http://animaldiversity.ummz.umich.edu/accounts/rissa/r._tridactyla$narrative.html

http://www.aquatic.uoguelph.ca/birds/speciesacc/accounts/gulls/tridacty/account.htm

http://collections.ic.gc.ca/arctic/species/blkittiw.htm

http://museum.gov.ns.ca/mnh/nature/nsbirds/bns0180.htm

Harrison, C. and Greensmith, A. (1993). Birds of the World. London: Dorling Kindersley Limited, p. 151

Saunders, D. (1973). Sea Birds. New York: Grosset and Dunlap, p. 110

National Geographic Field Guide to the Birds of North America, Third Ed. (1999)

Black-Legged Wildlife Fact File, IM Pub, US