Animal Diversity Web

Ge­o­graphic Range

Semi­palmated sand­pipers (Calidris pusilla) are small shore­birds which breed along the coast of the Hud­son Bay and the coast of north­ern Alaska. Dur­ing the non-breed­ing sea­son semi­palmated sand­pipers mi­grate to coastal South Amer­ica, the Caribbean, and Cen­tral Amer­ica. Mi­gra­tion oc­curs in long flights of 3000 to 4000 kilo­me­ters from Canada and the north­ern United States to South Amer­ica. The birds travel in large mi­gra­tory flocks which can vary in size and can be as large as 350,000 in­di­vid­u­als. Some semi­palmated sand­piper pop­u­la­tions fol­low very spe­cific mi­gra­tion paths with reg­u­lar stops at crit­i­cal, re­source-rich lo­ca­tions such as the Bay of Fundy in east­ern Canada, and the Delaware Bay in the United States. Short flight mi­gra­tion is also preva­lent when in­di­vid­u­als or flocks move to closer areas. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Gough, 2012; Lank, et al., 2003; Page and Mid­dle­ton, 1972; Pe­ter­son, et al., 2009; Shep­herd and Boates, 2001; Tsipoura Burger and Burger, 1999; del Hoyo, et al., 1996)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Semi­palmated sand­pipers breed along the shores of north­ern Canada and Alaska on wet sedge or sedge-tun­dra. They se­lect open habi­tats well-suited for breed­ing dis­plays and scrape nests. They gen­er­ally are found run­ning along sandy shore­lines, prob­ing the loose sand for in­ver­te­brates. Ideal for­ag­ing habi­tat in­cludes pools close to lakes and rivers, shrubby river deltas, and sandy areas along the shore. Mi­gra­tion stopover habi­tats may in­clude wet­lands, grassy fields, marshes, or edges of lakes and rivers. Dur­ing non-breed­ing win­ter months, semi­palmated sand­pipers in­habit sandy beaches and in­ter­tidal zones of South Amer­ica, the Caribbean, and Cen­tral Amer­ica. ("The Cor­nell Lab of Or­nithol­ogy", 2009; del Hoyo, et al., 1996)

• Habitat Regions
• temperate
• tropical
• polar
• terrestrial

• Terrestrial Biomes
• tundra
• savanna or grassland

• Aquatic Biomes
• coastal

• Other Habitat Features
• riparian
• estuarine

Phys­i­cal De­scrip­tion

Semi­palmated sand­pipers are small sized shore­bird about 13 to 15 cm long weigh­ing from 21 to 32 g. They have black legs and straight tubu­lar bills which are black or darkly col­ored. Wingspan ranges from 29 to 30 cm. The name 'semi­palmated' refers to the slight web­bing be­tween the 3 front toes. Plumage dif­fers be­tween ju­ve­niles, breed­ing and non­breed­ing adults. Dur­ing the breed­ing sea­son semi­palmated sand­pipers have gray to brown upper body, with a uni­formly scaly pat­tern. The belly is white with darker streaks along the upper breast. Ju­ve­niles vary greatly in plumage, but gen­er­ally have a darker brown cap with a pro­nounced su­per­cil­ium. Non­breed­ing plumage fades to a lighter gray-brown on the upper body with only faint streak­ing on sides of an oth­er­wise white breast. On av­er­age fe­males are slightly larger than males. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Page and Mid­dle­ton, 1972; Pe­ter­son, et al., 2009; del Hoyo, et al., 1996)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike
• female larger

• Range mass

  21 to 32 g

  0.74 to 1.13 oz

• Range length

  13 to 15 cm

  5.12 to 5.91 in

• Range wingspan

  29 to 30 cm

  11.42 to 11.81 in

Re­pro­duc­tion

Semi­palmated sand­pipers breed from late May to July. Upon ar­riv­ing at the breed­ing grounds, males es­tab­lish ter­ri­to­ries from which to dis­play to fe­males ar­riv­ing about a week later. Males per­form aer­ial dis­plays at 5 to 9 m where they hover and pro­duce "mo­tor­boat" calls. These aer­ial dis­plays are well suited to their rel­a­tively open habi­tat where vis­i­bil­ity is high. The male ex­ca­vates up to 10 to 12 scrapes among sparse veg­e­ta­tion within his ter­ri­tory for fe­males to choose from. The fe­male will then se­lect 2 to 3 of these scrapes (al­though only one is used) to begin lin­ing with veg­e­ta­tion and other or­ganic mat­ter. Semi­palmated sand­pipers form monog­a­mous pairs. (del Hoyo, et al., 1996)

• Mating System
• monogamous

Semi­palmated sand­pipers breed from May through July. After mat­ing, the male de­fends the ter­ri­tory while the fe­male lays eggs in the nest. Fe­males typ­i­cally lay 3 to 4 eggs per brood in 24 to 32 hour in­ter­vals. In­cu­ba­tion of the eggs, which is done by both par­ents, lasts 18 to 22 days. Like all scolopacids, semi­palmated sand­pipers are pre­co­cial at birth and begin ac­tively for­ag­ing within hours of hatch­ing. The young fledge 16 to 19 days after hatch­ing. Semi­palmated sand­pipers reach sex­ual ma­tu­rity at 1 year old. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Hick­lin and Gratto-Trevor, 2010; Pe­ter­son, et al., 2009; del Hoyo, et al., 1996)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

• Breeding interval

  Semipalmated sandpipers produce one brood per year.

• Breeding season

  Semipalmated sandpipers breed from May to July.

• Range eggs per season

  3 to 4

• Average eggs per season

  4

• Range time to hatching

  18 to 22 days

• Range fledging age

  16 to 19 days

• Average fledging age

  19 days

• Average age at sexual or reproductive maturity (female)

  1 years

• Average age at sexual or reproductive maturity (male)

  1 years

Semi­palmated sand­pipers pro­vide parental care for their young start­ing with in­cu­ba­tion by both par­ents. In­cu­ba­tion lasts 20 to 22 days. Both par­ents par­tic­i­pate in feed­ing and pro­tect­ing the young for up to 11 days. Be­tween 6 to 11 days after the chicks hatch the par­ents aban­don the brood at sep­a­rate times with the fe­male being the first to leave nearly 91% of the time. Fe­males stay with their young on av­er­age 6 days after they are hatched then leave their young to be pro­vided for by their mate. The male con­tin­ues to make a night scrape for the young for 6 to 8 days after hatch­ing. The male aban­dons the brood on av­er­age 8 days after fe­male, re­gard­less of whether or not chicks have fledged. (Gratto-Trevor, 1991; del Hoyo, et al., 1996; Gratto-Trevor, 1991; Hick­lin and Gratto-Trevor, 2010; del Hoyo, et al., 1996)

• Parental Investment
• precocial
• male parental care
• female parental care
• pre-fertilization
  • provisioning
  • protecting
    • male
    • female
• pre-hatching/birth
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
  • protecting
    • male
• pre-independence
  • provisioning
    • male
  • protecting
    • male

Lifes­pan/Longevity

An­nu­ally it is es­ti­mated that 50% to 70% of adult semi­palmated sand­pipers sur­vive. Some causes of mor­tal­ity (de­gree of im­pact un­known) in­clude il­le­gal poach­ing on win­ter­ing grounds and bot­u­lism. It has been noted that ju­ve­niles have much lower fat re­serves than adults when they ar­rive at win­ter­ing grounds, but how that af­fects sur­vivor­ship is un­known. Longest known liv­ing in­di­vid­ual was a fe­male at 16 years old. The odds of a sur­vival until age of 16 are 1 in 10000 if sur­vival rate is ~50%. (del Hoyo, et al., 1996; Gratto-Trevor and Vacek, 2001; Hick­lin and Gratto-Trevor, 2010; del Hoyo, et al., 1996)

• Range lifespan
  Status: wild

  16 (high) years

Be­hav­ior

Semi­palmated sand­pipers are mi­gra­tory shore­birds with a very large range. Many amass to em­bark on 3000 to 4000 km transat­lantic flights from north­ern Canada to South Amer­ica. Dur­ing the non­breed­ing sea­son, large flocks co­op­er­ate to deter preda­tors such as fal­cons. In con­trast, dur­ing the breed­ing sea­son adults be­have in monog­a­mous pairs which de­fend ter­ri­tory, nest, and young. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Gough, 2012; Gratto-Trevor, 1991; Lank, et al., 2003; Page and Mid­dle­ton, 1972; Pe­ter­son, et al., 2009; Shep­herd and Boates, 2001; Tsipoura Burger and Burger, 1999; del Hoyo, et al., 1996)

• Key Behaviors
• flies
• diurnal
• motile
• migratory
• territorial
• social

Home Range

Ter­ri­tory size varies for semi­palmated sand­pipers. There have been es­ti­mates of 1 ha, how­ever some nest­ing habi­tats have re­ported higher den­si­ties and thus smaller ter­ri­to­ries. (Jehl, 2006)

Com­mu­ni­ca­tion and Per­cep­tion

Semi­palmated sand­pipers use vocal and vi­sual forms of com­mu­ni­ca­tion. Many calls have been linked spe­cific sit­u­a­tions and func­tions. For ex­am­ple, a soft 'cher' is often made from in­di­vid­u­als of a large roost­ing flock to con­vey safety or lack of threat. This 'cher' is quickly re­placed by a loud 'churt' when preda­tors are de­tected. Other calls have been de­scribed for nest de­fense, chick de­fense, in­jury feign­ing, cop­u­la­tion, short-range com­mu­ni­ca­tion be­tween mates, call­ing chicks, and brood­ing.

Males use aer­ial dis­plays to at­tract mates to es­tab­lished ter­ri­to­ries. These dis­plays in­clude a "mo­tor­boat" call given while hov­er­ing in midair.

Semi­palmated sand­pipers per­ceive au­di­tory, tac­tile, vi­sual, and chem­i­cal stim­uli. (Pe­ter­son, et al., 2009)

• Communication Channels
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Semi­palmated sand­pipers uti­lize a prob­ing method to for­age for small in­ver­te­brates on the ground, in mud, or oc­ca­sion­ally under water. Typ­i­cal diet con­sists of chi­rono­mid lar­vae (Diptera), arach­nids, plant seeds, tip­ulid lar­vae (Diptera), dolichopo­did lar­vae (Diptera), snails, Dona­cia adults (Chrysomel­i­dae, Coleoptera), Lispe lar­vae (Mus­ci­dae, Diptera), Agapes lar­vae (Dytis­ci­dae, Coleoptera), Peri­coma lar­vae (Psy­cho­di­dae, Diptera), and Hyr­go­tus adults (Dytis­ci­dae, Coleoptera). Semi­palmated sand­pipers rely heav­ily on horse­shoe crab eggs dur­ing spring mi­gra­tion. Feed­ing be­hav­ior con­sists of run­ning along the water's edge, peck­ing and prob­ing in the ground along damp or flooded mud flats. When in­ver­te­brates are abun­dant, semi­palmated sand­pipers also for­age along marsh edges.

Semi­palmated sand­pipers use both vi­sual and tac­tile for­ag­ing to col­lect food, de­pend­ing on the food source. They ac­tively de­fend feed­ing ter­ri­to­ries year-round, though they are much more vig­i­lant while breed­ing.

Fe­males will also eat small mam­mal bones as an extra source of cal­cium dur­ing egg lay­ing. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Hick­lin and Gratto-Trevor, 2010; Shep­herd and Boates, 2001; del Hoyo, et al., 1996)

• Primary Diet
• carnivore
  • molluscivore
  • vermivore

• Animal Foods
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms
• aquatic or marine worms
• aquatic crustaceans
• other marine invertebrates

Pre­da­tion

The pre­dom­i­nate preda­tors of the semi­palmated sand­piper are mer­lins (Falco colum­bar­ius) and other mem­bers of the fal­con, and ac­cip­i­tor fam­i­lies. Other doc­u­mented preda­tors in­clude snowy owls and some jaegers. (Lank, et al., 2003; Mc­Curdy, et al., 1999; Safriel, 1975)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Merlins (Falco columbarius)
  • Snowy owls (Nyctea scandiaca)
  • Falcons (Falco)
  • Accipitors (Accipitridae)
  • Jaegers (Stercorarius)

Ecosys­tem Roles

Semi­palmated sand­pipers im­pact pop­u­la­tions of their prey. They also are host to par­a­sites such as par­a­sitic ne­ma­todes (Skr­jabin­oclava mor­risoni) which are trans­mit­ted through in­gest­ing am­phipods Corophium vo­lu­ta­tor. Eggs and chicks often are eaten by preda­tors such as gulls, jaegers, and foxes. (Safriel, 1975)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

His­tor­i­cally semi­palmated sand­pipers were hunted as game birds, how­ever this is now il­le­gal in the United States under the Mi­gra­tory Bird Treaty Act of 1918. The mass mi­gra­tion of semi­palmated sand­pipers and other shore­birds is a major at­trac­tion, bring­ing avid bird­ers to coastal stag­ing areas in spring and fall. (Hick­lin and Gratto-Trevor, 2010)

• Positive Impacts
• food

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Spring mi­gra­tion of semi­palmated sand­pipers is crit­i­cally de­pen­dent upon food re­source avail­abil­ity on the stag­ing grounds. Delaware Bay, among other east coast lo­ca­tions, is con­sid­ered an es­sen­tial stopover for the 3000 to 4000 km jour­ney. Spring mi­gra­tion co­in­cides with the spawn­ing of horse­shoe crabs which pro­vides mil­lions of en­ergy-rich eggs to rest­ing semi­palmated sand­pipers. Un­for­tu­nately, the horse­shoe crab in­dus­try ul­ti­mately de­pends on these eggs as well. Semi­palmated sand­pipers then com­pete with the horse­shoe crab in­dus­try and can im­pact the eco­nomic well-be­ing of the in­dus­try. (Berk­son and Shus­ter, Jr., 1999)

• Negative Impacts
• crop pest

Con­ser­va­tion Sta­tus

Semi­palmated Sand­pipers are not threat­ened, how­ever pop­u­la­tion sur­veys start­ing in 1986 have showed a slight de­crease in over­all pop­u­la­tion size. The de­cline is sus­pected to be a re­sult of human ac­tiv­ity. Spe­cific im­pacts by peo­ple in­clude de­struc­tion and ma­nip­u­la­tion of shore­lines and wet­lands which are habi­tats for semi­palmated sand­pipers dur­ing both breed­ing and non­breed­ing sea­sons. Large scale bait­worm har­vest along coastal areas in known stop­ping grounds for semi­palmated sand­pipers has been shown to neg­a­tively af­fect the birds feed­ing habits due to scarcity of food re­sources. Poach­ing of semi­palmated sand­pipers still oc­curs on their win­ter­ing grounds in South Amer­ica and is sus­pected to have a sig­nif­i­cant ef­fect on pop­u­la­tions. Pol­lu­tion is also sus­pected to have a neg­a­tive ef­fect.

Canada and the United States have cre­ated de­tailed con­ser­va­tion plans to pro­tect and en­hance stag­ing grounds for mi­gra­tory shore­birds, in­clud­ing semi­palmated sand­pipers. ("The Cor­nell Lab of Or­nithol­ogy", 2009; Hick­lin and Gratto-Trevor, 2010; Pe­ter­son, et al., 2009; Shep­herd and Boates, 2001; del Hoyo, et al., 1996)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  Protected

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Joseph Landy (au­thor), Florida State Uni­ver­sity, Emily DuVal (ed­i­tor), Florida State Uni­ver­sity, Rachelle Ster­ling (ed­i­tor), Spe­cial Pro­jects.

Ref­er­ences

2009. "The Cor­nell Lab of Or­nithol­ogy" (On-line).

All About Birds

Berk­son, J., C. Shus­ter, Jr.. 1999. The Horse­shoe Crab: The Bat­tle for a True Mul­ti­ple-use Re­source. Fish­eries Man­age­ment, 24: 6-10. Ac­cessed No­vem­ber 18, 2010 at http://​www.​nmfs.​vt.​edu/​Publications/​The%20Horseshoe%20Crab.​%20The%20Battle%20for%20a%20True.​pdf.

Gough, G. 2012. "United States Ge­o­log­i­cal Sur­vey" (On-line). Patux­ent Bird Iden­ti­fi­ca­tion In­fo­Cen­ter. Ac­cessed Feb­ru­ary 11, 2010 at http://​137.​227.​242.​23/​id/​framlst/​i2460id.​html.

Gratto-Trevor, C., C. Vacek. 2001. Longevity Record and An­nual Adult Sur­vival of Semi­palmated Sand­pipers. THE WIL­SON BUL­LETIN, 113/3: 348-350.

Gratto-Trevor, C. 1991. Parental care in Semi­palmated Sand­pipers Calidris pusilla: brood de­ser­tion by fe­males. Ibis, 133/4: 394-399.

Hick­lin, P., C. Gratto-Trevor. 2010. "The Birds of North Amer­ica" (On-line). Semi­palmated Sand­piper (Calidris pusilla). Ac­cessed No­vem­ber 16, 2010 at http://​bna.​birds.​cornell.​edu/​bna/​species/​006.

Jehl, J. 2006. COLO­NIAL­ITY, MATE RE­TEN­TION, AND NEST-SITE CHAR­AC­TER­IS­TICS IN THE SEMI­PALMATED SAND­PIPER. The Wil­son Jour­nal of Or­nithol­ogy, 18/4: 478–484.

Lank, D., R. But­ler, R. Yden­berg, J. Ire­land. 2003. Ef­fects of pre­da­tion dan­ger on mi­gra­tion strate­gies of sand­pipers. OIKOS, 103: 303-319.

Mc­Curdy, D., M. Forbes, J. Boates. 1999. Ev­i­dence that the par­a­sitic ne­ma­tode Skr­jabin­oclava ma­nip­u­lates host Corophium be­hav­ior to in­crease trans­mis­sion to the sand­piper, Calidris pusilla.. Be­hav­ioral Ecol­ogy, 19: 351-357.

Page, G., L. Mid­dle­ton. 1972. Fat De­pos­tion Dur­ing Au­tumn Mi­gra­tion in the Semi­plated Sand­piper. Bird-Band­ing a Jour­nal of Orn­tho­log­i­cal Ives­ti­ga­tion, 43/2: 85-160.

Pe­ter­son, R., M. Di­Gir­gio, P. Lehmen, M. O'Brien, L. Rosche, B. Thomp­son III. 2009. Field Guide to Birds of North Amer­ica. New York: Houghton Mif­flin Books.

Safriel, U. 1975. On the sig­nif­i­cance of clutch size in ni­d­ifu­gous birds.. Ecol­ogy, 56: 703-708.

Shep­herd, P., J. Boates. 2001. Ef­fects of a Com­mer­cial Bait­worm Har­vest on Semi­palmated Sand­pipers and Their Prey in the Bay of Fundy Hemi­spheric Shore­bird Re­serve. Con­ser­va­tion Bi­ol­ogy, 13/2: 347 - 356.

Tsipoura Burger, N., J. Burger. 1999. Shore­bird diet dur­ing spring mi­gra­tion stopover on Delaware Bay. Con­dor, 101/3: 635-644.

del Hoyo, J., A. El­liott, J. Sar­gatal. 1996. Hand­book of Birds of the World Vol III. Barcelona: Lynx Edi­cions.