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.
Animal Foods: insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans; other marine invertebrates
Primary Diet: carnivore (Molluscivore , Vermivore)
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.
Known Predators:
Anti-predator Adaptations: cryptic
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.
Range mass: 21 to 32 g.
Range length: 13 to 15 cm.
Range wingspan: 29 to 30 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; female larger
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%.
Range lifespan
Status: wild: 16 (high) years.
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.
Habitat Regions: temperate ; tropical ; polar ; terrestrial
Terrestrial Biomes: tundra ; savanna or grassland
Aquatic Biomes: coastal
Other Habitat Features: riparian ; estuarine
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.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
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.
Commensal/Parasitic Species:
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.
Positive Impacts: food
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.
Negative Impacts: crop pest
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.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
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.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
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.
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.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
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.
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)
A small (5 ½ -6 ½ inches) sandpiper, the Semipalmated Sandpiper may be identified by its size), short wings, and dark legs. In summer, this species is mottled brown above with a white belly, streaked breast and throat, and pale white eye-stripes. In winter, this species becomes darker and duller than in summer. Male and female Semipalmated Sandpipers are similar to one another in all seasons. The Semipalmated Sandpiper breeds in high arctic Siberia, Alaska, and Canada south to the Hudson Bay. This species is a long-distance migrant, wintering from Central America and the West Indies south to southern South America. On migration, this species may be seen in the eastern United States and Canada, both in the interior and along the coast. Semipalmated Sandpipers primarily breed on wet tundra. This species may be found in wet grasslands and marshes while on migration, occurring in these habitats (as well as mangroves) during the winter. This species primarily eats insects and larvae, but may also take small snails, crustaceans, and fish. Due to its remote breeding habitat, most birdwatchers never see the Semipalmated Sandpiper during the summer. This species is more likely to be seen in winter and on migration, where it may be observed along the shore probing the mud for food with its bill. Semipalmated Sandpipers are primarily active during the day.
A small (5 ½ -6 ½ inches) sandpiper, the Semipalmated Sandpiper may be identified by its size), short wings, and dark legs. In summer, this species is mottled brown above with a white belly, streaked breast and throat, and pale white eye-stripes. In winter, this species becomes darker and duller than in summer. Male and female Semipalmated Sandpipers are similar to one another in all seasons. The Semipalmated Sandpiper breeds in high arctic Siberia, Alaska, and Canada south to the Hudson Bay. This species is a long-distance migrant, wintering from Central America and the West Indies south to southern South America. On migration, this species may be seen in the eastern United States and Canada, both in the interior and along the coast. Semipalmated Sandpipers primarily breed on wet tundra. This species may be found in wet grasslands and marshes while on migration, occurring in these habitats (as well as mangroves) during the winter. This species primarily eats insects and larvae, but may also take small snails, crustaceans, and fish. Due to its remote breeding habitat, most birdwatchers never see the Semipalmated Sandpiper during the summer. This species is more likely to be seen in winter and on migration, where it may be observed along the shore probing the mud for food with its bill. Semipalmated Sandpipers are primarily active during the day.
The semipalmated sandpiper (Calidris pusilla) is a very small shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific pusilla is Latin for "very small".[2]
It is sometimes separated with other "stints" in Erolia, but, although these apparently form a monophyletic group, the present species' old genus Ereunetes had been proposed before Erolia.
It is a small sandpiper, 13–15 cm (5.1-5.9 in) long and weighing around 20-32 g (0.7-1.1 oz).[3] Wingspan ranges from 13.8-14.6 in (35-37 cm).[4] Adults have black legs and a short, stout, straight dark bill. The body is dark grey-brown on top and white underneath. The head and neck are tinged light grey-brown. This bird can be difficult to distinguish from other similar tiny shorebirds, in particular the western sandpiper; these are known collectively as "peeps" or "stints".
Their breeding habitat is the southern tundra in Canada and Alaska near water. They nest on the ground. The male makes several shallow scrapes; the female chooses one and adds grass and other material to line the nest. The female lays 4 eggs; the male assists in incubation. After a few days, the female leaves the young with the male; the young feed themselves.
These birds forage on mudflats, picking up food by sight and feel (bill). They mainly eat aquatic insects and their larvae, spiders, snails, worms[5] and crustaceans. Semipalmated sandpipers rely heavily on horseshoe crab eggs during spring migration.[5] Females will also eat small mammal bones as an extra source of calcium during egg laying.[5]
They are long distance migrants and winter in coastal South America, with some going to the southern United States and the Caribbean. They migrate in flocks which can number in the hundreds of thousands, particularly in favoured feeding locations such as the Bay of Fundy and Delaware Bay. This species is a rare but regular vagrant to western Europe.
Although very numerous, these birds are highly dependent on a few key stopover habitats during their migration, notably Mary's Point and Johnson's Mills along Shepody Bay, an arm of the Bay of Fundy.[6] During the months of July and August, the Nature Conservancy of Canada runs an information center about these shorebirds in Johnson's Mills, New Brunswick.[7]
The semipalmated sandpiper (Calidris pusilla) is a very small shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific pusilla is Latin for "very small".
It is sometimes separated with other "stints" in Erolia, but, although these apparently form a monophyletic group, the present species' old genus Ereunetes had been proposed before Erolia.
