Sanderlings eat aquatic and terrestrial invertebrates that are found in their preferred, sandy or tundra open habitats. In the breeding season, along pond or stream edges in tundra, insects are the primary prey, including especially craneflies, midges, and mosquitoes. During winter and migration, when most sanderlings are found along coastlines, they eat mainly small crustaceans, bivalves, polychaete worms, insects, and talitrid amphipods. Examples of important winter and migratory prey are sand crabs, isopods, and horseshoe crab eggs along the Atlantic coast. They will occasionally take plant seeds, buds, roots, and shoots when animal prey is not available. Sanderlings feed by probing with their bills or picking things off the ground. They run just ahead of and behind waves on beaches, probing the soft sand for prey as they go.
Animal Foods: eggs; insects; mollusks; aquatic or marine worms; aquatic crustaceans
Plant Foods: leaves; roots and tubers; seeds, grains, and nuts; bryophytes; algae
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Molluscivore )
When threatened by predators, sanderlings that are on a nest may crouch on the nest, flattened out, or run a short distance and then crouch on the ground, as if protecting a nest. They may also pretend to be injured or mob jaegers in groups. When young are hatched, parents alert young of danger with a sharp call, which causes them to freeze. The cryptic coloration of sanderlings helps to protect them against predation. In their arctic breeding areas, most predation is on eggs and young. Parasitic jaegers (Stercorarius parasiticus) and long-tailed jaegers (Stercorarius longicaudus) have been seen eating eggs and young and glaucous gulls (Larus hyperboreus), snowy owls (Nyctea scandiaca), wolves (Canis lupus), and arctic foxes (Vulpes lagopus) may also take eggs and young. In winter and migration, adults have been preyed on by merlins (Falco columbarius), peregrine falcons (Falco peregrinus), cinereous harriers (Circus cinerea), burowing owls (Athene cunicularia), short-eared owls (Asio flammeus), Sechuran foxes (Lycalopex sechurae), house rats (Rattus rattus), laughing gulls (Larus atricilla), and domestic cats (Felis catus).
Known Predators:
Anti-predator Adaptations: cryptic
Sanderlings are small sandpipers with black legs and feet and a stout, short, black beak. They are from 18 to 20 cm in length and 40 to 100 g. In their non-breeding plumage these sandpipers have a very pale, whitish head, with pale gray upperparts and white underparts. In all plumages they have a dark shoulder patch that extends onto the throat and breast. In flight they have a white wing stripe that is bordered by black. In their breeding plumage the upperparts take on a reddish brown color and the head becomes more deeply colored. Juveniles are similar to adults, but have darker plumage on the upperparts. Females and males are similar, although males tend to be slightly more colorful. They are easily confused with other, similarly-sized sandpipers, but their black bill, pale head, and their sandy, coastal habits help to differentiate them. Birds in breeding plumage may be confused with red-necked stints (Calidris ruficollis), except that these birds lack any dark markings that extend on the neck and chest. Sanderlings also lack a hind toe, helping to distinguish them from other sandpipers, but this is difficult to discern in the field.
Despite their exceptionally large geographic range, there are no described subspecies or regional variants. Some variation in plumage brightness and size has been described.
Range mass: 40 to 100 g.
Range length: 18 to 20 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
The longest recorded lifespan in a sanderling was 13 years. Adult survival is estimated at 83% yearly. Most natural mortality can be attributed to predation and cold stress on young. Sanderling populations are also impacted by human habitat degradation, especially in their beach habitats.
Range lifespan
Status: wild: 13 (high) years.
Sanderlings are found in distinct habitats in the breeding and winter seasons. In winter they are mainly found along sandy beaches, where they probe for food ahead of and behind waves in the active surf zone. They may also forage in mudflats, lagoons, and rocky intertidal areas. They are most common along ocean coasts, but are also found on sandy beaches of inland lakes, prairie potholes, and saline or alkaline flats. In the breeding season, sanderlings are found in the high arctic tundra, where they nest in a variety of habitats, but mainly rocky ridges or slopes near moist tundra or ponds.
Habitat Regions: temperate ; tropical ; terrestrial ; saltwater or marine
Terrestrial Biomes: tundra ; desert or dune
Aquatic Biomes: coastal
Sanderlings have one of the widest winter ranges of any shorebird. They are found along the coastlines of all oceans and seas from about 50 degrees north to about 50 degrees south in winter, including both temperate and tropical coastal areas. Their winter range in the Americas includes Pacific coastal areas as far north as British Columbia to northern Chile in the south, and Atlantic coastal areas as far north as southern Maine and southwards to Brazil. They are found throughout the coastlines of the Great Lakes, Gulf of Mexico, and Antillean Islands as well. Winter range outside of the Americas is from the British Isles to the Mediterranean Sea, Caspian Sea and throughout southeast Asia to South Africa, Australia, and many South Pacific islands. In the breeding season they are found in high arctic areas of Greenland, Scandinavia, Russia, Siberia, and Canada.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); ethiopian (Native ); neotropical (Native ); australian (Native ); oceanic islands (Native )
Other Geographic Terms: holarctic
Sanderlings are important predators of marine crustaceans in the intertidal zone. They are found in association with a wide variety of other shorebirds in foraging flocks in winter and migration, including dunlins (Calidris alpina), red knots (Calidris canutus), black-bellied plovers (Pluvialis squatarola), willets (Catoptrophorus semipalmatus), dowitchers (Limnodromus), ruddy turnstones (Arenaria interpres), semipalmated sandpipers (Calidris pusilla), western sandpipers (Calidris mauri), two-banded plovers (Charadrius falklandicus), and white-rumped sandpipers. There is competition among these birds for food items, and larger shorebirds, such as Franklin's gulls (Larus pipixcan) and gray gulls (Larus modestus), will steal prey from sanderlings.
Sanderlings are parasitized by several nematode species that they get by eating aquatic crustaceans.
Commensal/Parasitic Species:
Sanderlings are interesting members of arctic, temperate, and tropical coastal habitats. Historically they were considered a game species and were hunted for market. Arctic natives collected eggs to eat.
Positive Impacts: food
There are no adverse effects of sanderlings on humans.
Sanderlings have a large range and large population sizes, so they are not considered threatened currently. They are protected as a migratory bird by the U.S. Migratory Bird Act. Their breeding habitats in the arctic tundra are threatened by global climate changes, resulting in increased temperatures in the arctic. Their migratory and wintering habitats are threatened by oil spills, beach and wetland development, and other kinds of habitat degradation and contamination. Sanderling populations rely on the timing of seasonally abundant prey at migratory stopovers, such as the breeding of horseshoe crabs on the Atlantic coast of North America. Sanderlings feed on horseshoe crab eggs at a critical point in their migration and the loss of this resource may impact survival during migration and breeding success. Sanderlings will leave areas with heavy human or vehicle use of beaches, further reducing their available habitat.
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
Sanderlings use visual displays and calls during courtship and breeding. Outside of the breeding season they are relatively quiet. It is not thought that they learn calls. Chicks give a chirp when startled that will cause their nestmates to run away, this chirp is similar to the sound used by adults to alert others of a predator ("chidik"). Adults also use a call to tell their hatchlings that the danger has passed. Various other calls are used when departing from the nest, in aggressive interactions, and during displays and copulation.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Mating systems in sanderlings are exceptionally flexible. They vary from monogamy to serial polyandry and polygyny, and can vary regionally and from year to year, depending on conditions. Flexibility in mating systems may be a way of responding to the unpredictability of resources in breeding habitats. However, some studies suggest regional differences in mating strategies may be fixed. Pair bonds are typically formed soon after sanderlings have arrived on the breeding grounds, generally in late May and early June. Males, and sometimes females, perform elaborate displays accompanied by vocalizations. Sometimes multiple birds display together. The display flight is described as a flight at 2 to 10 meters high with the body parallel to the ground and the head held down. Birds move their heads from side to side as they fly and rapidly flutter their wings, followed by a brief glide. The result resembles a fluttering hover and can last up to 2 minutes. This display flight is accompanied by a song. Once a pair bond is formed, the male uses a jerky walk and calls to the female, who calls back. Males and females are inseparable at this time. In some populations one or the other mate will abandon its partner soon after incubation starts.
Mating System: monogamous ; polyandrous ; polygynous ; polygynandrous (promiscuous)
Females choose a nest site in the breeding area and construct a scrape on the ground in an open area and may line it with leaves and lichens. Egg-laying occurs in late June or early July. Females lay 4 greenish, brown spotted eggs, usually at intervals of about 1 per day. They begin to incubate when all eggs are laid. Incubation usually lasts 23 to 27 days but, if incubation is delayed, it may take up to 32 days. Once the eggs hatch, the parents carry the eggshells away from the nest and begin to brood the young. One day after hatching a parent will lead the young away from he nest. Fledging occurs at 12 to 14 days old and the young are independent at 17 to 21 days old. Females lay 1 to 2, rarely 3 clutches, depending on the region and local conditions. If a female lays 2 clutches, her male mate remains with the first brood and the female rears the second brood. Sanderlings breed in the second year after they hatch. Yearlings don't typically arrive on breeding grounds early enough to start breeding.
Breeding interval: Sanderlings lay 1 to 2 clutches each breeding season.
Breeding season: Sanderlings breed from late May through July or early August each year.
Average eggs per season: 4.
Range time to hatching: 23 to 32 days.
Range fledging age: 12 to 14 days.
Range time to independence: 17 to 21 days.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Both parents incubate, brood, and protect the young. In areas or years when females can lay a second, or even third, clutch, they will abandon their male mate with the first clutches and then care for the final clutch on their own. Young are precocial at hatching and can walk and feed themselves. They are brooded and protected by the parents until a few days after they fledge, usually from 17 to 21 days after hatching.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female); pre-independence (Protecting: Male, Female)
Regular passage visitor and winter visitor.
While many North Americans know this small (7-8 inches) sandpiper as a plain, gray bird of the winter shoreline, the Sanderling has a summer plumage that is much more striking. During the breeding season, the Sanderling is rusty-red speckled with brown above with a bold white eye-stripe, black bill, black legs, and black wing edges. In winter, this species sheds its summer colors and becomes gray above with a white breast and throat. Male and female Sanderlings are similar in summer and winter plumages. The Sanderling breeds across the high arctic and winters on every continent except Antarctica. In North America, this species breeds primarily on islands in far northern Canada. Sanderlings that breed in Canada migrate south in winter, when they may be found along the coasts of the Americas from central Canada to southern South America. In the Old World, this species breeds in northern Siberia, wintering as far south as the Mediterranean Sea, West Africa, South Asia, Australasia, and Oceania. In summer, Sanderlings breed on relatively dry, open tundra. During the winter, this species primarily inhabits shorelines of sandy beaches. The diet of the Sanderling is comprised mostly of small aquatic invertebrates such as crustaceans and mollusks, although insects may also be eaten when available. Due to its remote breeding habitat, most birdwatchers never see Sanderlings during the summer. In winter, this species may be observed in groups probing the sand for food with their bills and running to avoid incoming waves. This species is primarily active during the day.
While many North Americans know this small (7-8 inches) sandpiper as a plain, gray bird of the winter shoreline, the Sanderling has a summer plumage that is much more striking. During the breeding season, the Sanderling is rusty-red speckled with brown above with a bold white eye-stripe, black bill, black legs, and black wing edges. In winter, this species sheds its summer colors and becomes gray above with a white breast and throat. Male and female Sanderlings are similar in summer and winter plumages. The Sanderling breeds across the high arctic and winters on every continent except Antarctica. In North America, this species breeds primarily on islands in far northern Canada. Sanderlings that breed in Canada migrate south in winter, when they may be found along the coasts of the Americas from central Canada to southern South America. In the Old World, this species breeds in northern Siberia, wintering as far south as the Mediterranean Sea, West Africa, South Asia, Australasia, and Oceania. In summer, Sanderlings breed on relatively dry, open tundra. During the winter, this species primarily inhabits shorelines of sandy beaches. The diet of the Sanderling is comprised mostly of small aquatic invertebrates such as crustaceans and mollusks, although insects may also be eaten when available. Due to its remote breeding habitat, most birdwatchers never see Sanderlings during the summer. In winter, this species may be observed in groups probing the sand for food with their bills and running to avoid incoming waves. This species is primarily active during the day.
The sanderling (Calidris alba) is a small wading bird. The name derives from Old English sand-yrðling, "sand-ploughman".[2] The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific, alba, is Latin for "white".[3]
It is a circumpolar Arctic breeder, and is a long-distance migrant, wintering south to South America, South Europe, Africa, and Australia. It is highly gregarious in winter, sometimes forming large flocks on coastal mudflats or sandy beaches.
It is somewhat unlike other sandpipers in appearance, which has led to the suggestion that it should be placed into a monotypic genus Crocethia. A more recent review (Thomas et al., 2004) indicates, however, that the sanderling is a fairly typical "stint" or small sandpiper and should be separated from the large knots with its closest relatives in a distinct genus.
This bird is similar in size to a dunlin, but stouter, with a thick bill. It shows a strong white wingbar in flight, and runs along the sandy beaches it prefers with a characteristic "bicycling" action of its legs, stopping frequently to pick small food items. It eats small crabs and other small invertebrates. In spring, birds migrating north from South America consume large numbers of horseshoe crab eggs in the Delaware Bay area.
In spring, the birds arrive on the High Arctic breeding grounds (see map), where they lay 3–4 eggs in a ground scrape. On the nesting grounds, these birds mainly eat insects and some plant material.
The sanderling was described by the German naturalist Peter Simon Pallas in 1764 and given the binomial name Trynga alba.[4][5][6]
The sanderling is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
The sanderling is a small plump sandpiper, 18–20 cm (7.1–7.9 in) in length. Its weight ranges from 40–100 g (1.4–3.5 oz). The winter bird is very pale, almost white apart from a dark shoulder patch. This is the source of the specific name, alba, which is the Latin for "white". Later in the summer, the face and throat become brick-red. The juvenile bird is spangled black and white, and shows much more contrast than the adult.
If its size is misjudged, a sanderling in breeding plumage can be mistaken for some varieties of stint, or a sanderling in winter plumage can be mistaken for a dunlin or red knot. It can be told from other small wading birds, given good views, by its lack of a hind toe. Its behavior is also distinctive.
The sanderling breeds in the High Arctic areas of North America, Europe and Asia. In North America, it breeds in the Canadian Arctic Archipelago, Nunavut, Greenland (and to a lesser extent Alaska). In Eurasia, it breeds in Spitsbergen and areas of northern Russia from the Taymyr Peninsula to the New Siberian Islands. In the northern winter, it has a nearly cosmopolitan distribution across the world's marine coasts. It is a complete migrant, travelling between 3,000 to 10,000 km (1,900 to 6,200 mi) from its breeding grounds to its wintering sites. Birds that travel further also arrive later and leave sooner. Most adults leave the breeding grounds in July and early August, whereas juvenile birds leave in late August and early September. The northward migration begins in March at the southern end of their winter distribution.[9]
The breeding habitat of the sanderling is coastal tundra north of 5 °C (41 °F) July isotherm. The species typically chooses nesting sites on dry stony areas near wet areas, from 60 m (200 ft) above sea level to 800 m (2,600 ft). During the winter and its migration, it is most commonly found on coastal sandy beaches, but also occurs on tidal sand flats, mud flats and the shores of lakes and rivers. More infrequently, it may occur on rocky shores.[9]
The sanderling consists of two subspecies:
Sanderlings feed on invertebrate prey buried in the sand in the upper intertidal zone. In North America, this diet largely consists of the isopods Excirolana linguifrons, Excirolana kincaidii, and the mole crab, Emerita analoga. When the tide is out, these crustaceans live in burrows some way beneath the surface. When the tide comes in, they move into the upper layers of sand and feed on the plankton and detritus that washes over them with each wave. They then burrow rapidly down again as the water retreats. They leave no marks on the surface, so the sanderlings hunt for them by plunging their beaks into the sand at random, consuming whatever they find. Their bills can penetrate only 2 or 3 cm (0.79 or 1.18 in) and as the water swirls around and retreats, the sand is softer; this makes it easier for the birds' beaks to penetrate further. In the spring, when much breeding activity is taking place in the benthic community, there may be as many as 4000 invertebrates per square metre, but their average size is smaller than later in the year. The birds appear to rush madly around at the edge of the surf, but in reality they are maximising their chances of catching as many prey animals as possible when they are at their most vulnerable near the surface.[10]
At breeding time sanderlings are territorial, with the male aggressively defending its territory. They may either form monogamous pairs or polyandrous (one female and two male) pairings.[9]
Sanderling at High Island, Texas
A Sanderling in Cagayan de Oro, Philippines
A flock displaying their distinctive behavior of running with the ebb and flow of waves (while feeding). Willapa Bay, near Tokeland, Washington.
Resting at the Monterey Bay Aquarium aviary.
Floreana Island, Galapagos Islands
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A banded bird
Running
ID composite
Sanderling in Monterey, California
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Sanderling on the island of Amrum, Schleswig-Holstein
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Sanderlings feeding in Quogue, New York
The sanderling (Calidris alba) is a small wading bird. The name derives from Old English sand-yrðling, "sand-ploughman". The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific, alba, is Latin for "white".
It is a circumpolar Arctic breeder, and is a long-distance migrant, wintering south to South America, South Europe, Africa, and Australia. It is highly gregarious in winter, sometimes forming large flocks on coastal mudflats or sandy beaches.
It is somewhat unlike other sandpipers in appearance, which has led to the suggestion that it should be placed into a monotypic genus Crocethia. A more recent review (Thomas et al., 2004) indicates, however, that the sanderling is a fairly typical "stint" or small sandpiper and should be separated from the large knots with its closest relatives in a distinct genus.
This bird is similar in size to a dunlin, but stouter, with a thick bill. It shows a strong white wingbar in flight, and runs along the sandy beaches it prefers with a characteristic "bicycling" action of its legs, stopping frequently to pick small food items. It eats small crabs and other small invertebrates. In spring, birds migrating north from South America consume large numbers of horseshoe crab eggs in the Delaware Bay area.
In spring, the birds arrive on the High Arctic breeding grounds (see map), where they lay 3–4 eggs in a ground scrape. On the nesting grounds, these birds mainly eat insects and some plant material.
The sanderling was described by the German naturalist Peter Simon Pallas in 1764 and given the binomial name Trynga alba.
The sanderling is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
_feeding.jpg)
