Purple Sandpiper

Calidris maritima

(c) Howard B. Eskin
  • SCOLOPACIDAE
  • Snipe, Sandpipers, Phalaropes, and allies
  • Charadriiformes
  • Correlimos oscuro
  • Bécasseau violet
Introduction
To the Purple Sandpiper, pushing nature's limits is a way of life. Outside the breeding season, this dark, stocky shorebird lives along the north Atlantic coast, scrambling over jagged rocks and jetties to glean food while avoiding the violent surf. Also known as the rock snipe and winter bird, the hardy Purple Sandpiper winters farther north than any other shorebird. The bird is named for the subtle purple sheen on its black feathers, an effect rarely observed by birders.
(c) Howard B. Eskin
Appearance Description
The Purple Sandpiper is 9 inches long with a 17 inch wingspan, and weighs approximately 2.5 ounces. This medium-sized shorebird has a husky build and dark grey plumage. In flight, only the underwing and vent area flash white. The dark bill is moderately long and slightly drooping, with an orangish base. The stout legs are yellow in winter.
Range Map
Courtesy Kenn Kaufman
Range Distribution
The Purple Sandpiper breeds around the Arctic Circle in an uneven distribution. In the Canadian Arctic, it ranges from Banks Island in the west to the eastern end of Baffin Island in the east. In North America, populations winter from Newfoundland to South Carolina.
 
A legend for the range map to the right can be found here.
Habitat
Breeding Purple Sandpipers use a variety of habitats on the arctic tundra: gravel beds, the edges of frozen ground, and heath meadows. During migration and winter, this sandpiper uses rocky shoreline almost exclusively, especially where the tidal action is strong, winds are light, and temperatures are cool to cold.
Feeding
Walking, hopping, and clambering over rocks and tundra, the Purple Sandpiper picks prey items from various surfaces. The breeding diet consists of springtails (flightless insects that live in the soil), flies, aphids, spiders, marine worms, seeds, and berries. The winter diet shifts to include mussels, crustaceans, and beetles.
Reproduction
Purple Sandpipers form long-term monogamous pairs that re-form each breeding season. As snow begins to melt on the tundra, males arrive to establish territories with flight displays, aggressive sparring. chasing, and “fencing,” or running parallel to each other. Courtship includes flight displays, and close chasing. Purple Sandpipers locate nests in tundra with moderate to dense cover. Leaves, sedges, and heather form the base of the nest, which is often lined with down.
 

For about three weeks, Purple Sandpipers share the incubation of four light greenish eggs, variably marked with dark brown and grey. Their eggs are hardy and can survive without incubation for about a day. Upon hatching, chicks are able to walk, feed themselves, and preen; after a few days, they no longer need brooding, and the females usually depart at this time. Males tend to the young for approximately three weeks, until the juvenile Purple Sandpipers can fly well and form flocks for foraging and migration.

Migration

Migration in Purple Sandpipers varies with population. On Greenland, this species appears resident, but other populations migrate between 60 and 2,200 miles. Their large, dense flocks depart the latest among fall shorebirds. Southbound Purple Sandpipers depart after molting and according to age and sex: females leave first, then males, and finally juveniles.  This pattern is reversed in the spring.

CBC Graph
Graph Legend
Annual Population Indices
  • 195,000
  • 15,000
  • Small population size; moderate conservation concern
Population Status Trends
In North America, the Purple Sandpiper has a limited breeding distribution, very small population size, and a narrow wintering habitat. The U. S. Shorebird Conservation Plan designates the Purple Sandpiper as a “species of moderate concern;” its population is listed as “highly imperiled.” Christmas Bird Count data suggest a slight decline in Canada since 1983 and the United States since 1977. Breeding bird surveys are lacking.
 
An explanation of the Annual Indices graph displayed to the right can be found here.
Conservation Issues
Pollutants like PCBs and DDT, oceanfront development, and marine farming threaten Purple Sandpipers during migration and winter. Because the birds require rockweed habitat for winter feeding, the harvesting of rockweed has been banned by the U. S. Fish and Wildlife Service in Maine refuges, and Maine Audubon has sought similar bans for its sanctuaries.
 


The development of seawalls, jetties, and causeways appears to create beneficial wintering habitat for Purple Sandpiper. Such gains may be offset by global warming, which poses a threat to many species of animals and plants living on the immediate coast. For example, the Purple Sandpiper in Great Britain appears to be withdrawing northward and eastward from its traditional winter range in favor of cooler climates. Basic research is needed on the Purple Sandpiper’s remote breeding habitat.

What You Can Do
Participate in a local nature walk to enjoy the beauty of the Purple Sandpiper’s rugged habitat and to appreciate its special adaptions to winter. Audubon sanctuaries and chapters often lead trips to search for winter birds like the Purple Sandpiper. Human-made jetties and seawalls afford the easiest viewing.
 
Pets, children, and walkers can disturb shorebirds by approaching too closely. Keep a respectful distance from Purple Sandpipers along the rocky East Coast shoreline,and give them room to forage and rest.
 
Join efforts to limit development along rocky coasts for shell fisheries, rockweed harvesting, and housing construction.
 
For more actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit our resources page for more information about this species.
Natural History References
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Payne, L. X., and E. P. Pierce. 2002. Purple Sandpiper (Calidris maritima). In The Birds of North America, No. 706 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.

 

 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
Conservation Status References
Donaldson, G. M., et al. Canadian Shorebird Conservation Plan. Canadian Wildlife Service. Minister of Public Works and Government Services, Ottawa, Ontario (2000).
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Payne, L. X., and E. P. Pierce. 2002. Purple Sandpiper (Calidris maritima). In The Birds of North America, No. 706 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Rehfisch, Mark M., et al. “The possible impact of climate change on the future distributions and numbers of waders on Britain's non-estuarine coast.” Ibis 146:1 (September 2004) page 70-81.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
 

U. S. Shorebird Conservation Plan. 2004. High Priority Shorebirds – 2004. Unpublished Report, U.S. Fish and Wildlife Service, 4401 N. Fairfax Drive, MBSP 4107, Arlington, VA 22203 (5 pages).