 FEATURED BIRDS Semipalmated Sandpiper
Habitat: Semipalmated sandpipers breed on tundra, migrate, then spend winters by sources of water such as mudflats, sandy beaches, lake and pond shores, and wet meadows. Summer Range: The Semipalmated sandpiper breeds in the sub- and mid-arctic regions of Canada and Alaska, specifically along northern and coastal Alaska, across the Canadian Arctic to Labrador, and occasionally eastern Siberia. Canada’s east coast is important for the fall migration, but its lack of food in the spring means that it is not important for the spring migration. Winter Range: Semipalmated sandpipers on the east coast are believed to undertake long transoceanic migrations of 3,000 to 4,000 km as they fly from New England and southern Canada to the coasts of South America and throughout the Caribbean. Those that breed in the western Arctic usually winter on the Pacific Coast of South America. South migration begins in early July. Failed breeders and nonbreeders depart first, followed by adult females, and then males that have left their chicks. The juveniles depart several weeks later, finding their wintering grounds by instinct. Food: Insects and small aquatic invertebrates. Feeding Behaviour: During migration, Semipalmated sandpipers stop at staging areas that provide food and enable fat accumulation required for long flights. The Bay of Fundy is the most important staging site for Semipalmated sandpipers in eastern North America: they can double their weight in less than two weeks eating the small shrimp-like invertebrates in the mudflats there. Breeding Behaviour: This sandpiper breeds near water on open tundra. The rapid migration north for breeding begins in early May. The males arrive a few days before the females and attempt to obtain a territory. The males will often try to retain a territory from previous years. Some mating couples will breed together for three or four years but do not spend winter months together. It is uncommon for both semipalmated sandpipers of a breeding pair to both return to the breeding ground but find different mates. Nest Type and Egg Description: Once the breeding pair is together on their breeding grounds the male makes small scrapes to form depressions in the ground. The female will select one of the scrapes and lays her eggs in it. The nest is usually lined with grasses, moss, and leaves. Egg-laying occurs once the female has found enough food to produce her eggs. Most of these sandpipers lay their eggs in mid- to late June, but a few as late as early July. The clutch size is almost always four eggs, with one egg laid per day. Eggs are quite pointed at the small end. This allows them to fit closer in the nest cup and thus stay warmer in the Arctic environment. The eggs are well camouflaged in light green or brown coloured with dark brown and olive speckles. The parents share incubation duties, generally for about 19 days. Many eggs are lost to predation, and sandpipers are too small to attack predators, relying instead on distraction displays to lure predators away from the nest area. At hatching, the chicks’ eyes are open and their legs are almost adult-sized. Once dry, they stumble about and peck for insects because the parents do not feed their chicks. The chicks are occasionally brooded (kept warm by a parent) during their first week. Females desert their young within 10 days of hatching, but the males stay a little longer, usually until fledging. They begin to fly at about 14 days of age and fly fairly well by 18 days. Juveniles generally do not migrate north in their first year for breeding. Conservation Status: These birds are common and are not under any conservation protection. However, shorebirds are generally vulnerable to human interference because they concentrate in huge numbers in only a few locations on their migratory routes and wintering grounds. Following the Migratory Birds Convention in 1917, numbers of Semipalmated sandpipers increased. A Western Hemisphere Shorebird Reserve Network (WHSRN) has been established to preserve critical areas for shorebirds. The most important sites, called Hemispheric Sites, support over 500,000 shorebirds each year (more than 30 per cent of the flyway population of a species) and have been established throughout North, Central, and South America. Information on this page compiled by Colleen Sutton. Sources BirdLife International. http://www.birdlife.org Committee on the Status of Endangered Wildlife in Canada. http://www.cosewic.gc.ca/eng/sct5/index_e.cfm Cornell Lab of Ornithology. All About Birds. http://www.birds.cornell.edu/AllAboutBirds/. Ehrlich, Paul R. 1988. The Birder’s Handbook. Simon and Schuster, New York. Godfrey, Earl W. 1986. Birds of Canada. National Museums of Canada, Ottawa. Hinterland Who’s Who. http://www.hww.ca Leslie, Scott. 2006. Wetland Birds of North America. Key Porter Books, Toronto. NatureServe. InfoNatura. http://www.natureserve.org/infonatura/
|
