Spotted sandpipers use vocalizations and physical displays to communicate. The calls of spotted sandpipers are largely variations on a weet note, that is repeated at different pitches, intensities and rates to communicate different messages. Vocalizations can be used to communicate alarm, to maintain contact with chicks, in courtship, and to distract predators from one's nest. Physical displays are used to threaten others, to solicit a mate and to show submission, among other purposes.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Spotted sandpipers are common and widespread. Global population estimates appear to be stable at about 250,000 individuals. Threats to spotted sandpipers include pesticide poisoning, hunting and injury and foot loss due to leg-banding.
Spotted sandpipers are not threatened or endangered. They are listed as a species of "least concern" by the IUCN, and are not listed under any of the CITES appendices. They are, however, protected under the U.S. Migratory Bird Act.
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: no special status
The eggs of this species weigh about 9.6 g and take about 21 days for incubation, with the time decreasing as the season progresses. When they hatch, A. macularius are covered with down and weigh about 6.0 g. Within the first day, they are walking, eating and stretching their wings. Hunting for immobile food starts at 1-2 days, and stalking moving prey begins at 3-5 days. Actitis macularius chicks are brought up mostly by the male, and feed themselves. At about 11 days, chicks start to lift off the ground. At about 15 days, chicks show weak flight, and at about 18 days, chicks can completely lift themselves off the ground and fly a significant distance. Actitis macularius begin breeding at 1 year. (Maxson and Oring, 1980; Oring, et al., 1997)
There are no known adverse effects of spotted sandpipers on humans.
Spotted sandpipers eat a wide variety of insects. It is possible that they help control insects that humans view as pests.
Spotted sandpipers affect the populations of the species they eat. They also provide food for their predators.
Spotted sandpipers are opportunistic carnivores. They eat nearly all animals that are small enough for them to eat, with the exception of toad tadpoles. Examples of commonly eaten foods include midges, fish, mayflies, flies, grasshoppers, crickets, beetles, worms, caterpillars, mollusks, crustaceans, spiders, and carrion.
Spotted sandpipers forage on the ground. They capture most prey by thrusting their head forward and catching the prey in their bill. They also catch prey by pecking the ground, hopping to catch flying insects, and picking insects off of vegetation. Often, spotted sandpipers will dip insects in water before eating them, although the reason for this is unclear. Spotted sandpipers are visual hunters, mainly using sight to catch prey. When breeding, females increase their food intake to offset the energy spent producing eggs. While incubating, males increase their time dedicated to finding and catching prey by 44.9%.
Animal Foods: amphibians; fish; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Molluscivore )
Spotted sandpipers (Actitis macularius) are found throughout North and Central America, including the western Caribbean islands. Their breeding range extends from the northern Arctic to the southern United States. Their wintering grounds range from the extreme southern United States to southern South America, along with all the Caribbean islands. Spotted sandpipers live year-round along the western coast of the United States and in parts of California. They are found in very small numbers across parts of Europe, Russia, Siberia and on Canton and Marshall Islands in the Pacific Ocean.
Biogeographic Regions: nearctic (Native ); palearctic ; neotropical (Native ); oceanic islands
Spotted sandpipers breed in a variety of habitats ranging in elevation from sea level to 4,700 m. Females typically defend a breeding territory that includes a shoreline (of a stream or lake, for example), a semi-open area for nesting and patches of dense vegetation. These territories may be found in sage-brush, grasslands, forests, fields, lawns and parks among other habitats.
During spring and fall migrations, spotted sandpipers prefer freshwater habitats, such as lakes, rivers and marshes, though they can also be found along the coasts and in estuaries. In winter, spotted sandpipers can be found in coastal and interior areas, nearly anywhere where water is present.
Range elevation: 0 to 4,700 m.
Habitat Regions: temperate ; tropical ; polar ; terrestrial ; saltwater or marine ; freshwater
Terrestrial Biomes: savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest
Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water
Wetlands: marsh
Other Habitat Features: suburban ; riparian ; estuarine
The oldest known spotted sandpiper lived at least 12 years. Most do not live nearly that long.
Range lifespan
Status: wild: 12 (high) years.
Average lifespan
Status: wild: 109 months.
Spotted sandpipers are medium-sized sandpipers, 10 to 18 cm long with wingspans of 37 to 40 cm. Females are 20 to 25% larger than males, weighing 43 to 50 g compared to 34 to 41 g for males. Spotted sandpipers are brown to olive gray on their crown, nape, back and wings, and bright white on their face, throat, chest and belly. Their common name derives from the bold black spots on their white undersides. Females tend to have larger spots that extend lower on the belly compared to males. While in flight, spotted sandpipers display a white wing-stripe and a plain rump and tail.
Range mass: 34 to 50 g.
Range length: 10 to 18 cm.
Range wingspan: 37 to 40 cm.
Sexual Dimorphism: female larger; sexes colored or patterned differently
Other Physical Features: endothermic ; bilateral symmetry
Spotted sandpiper eggs are vulnerable to predation by predators such as deer mice, mink, weasels, river otters, yellow-headed blackbirds, red-winged blackbirds, song sparrows and ruddy turnstones. Chicks are predated by common grackles, American crows, gulls and mink. Adult spotted sandpipers are taken by least weasels, short-tailed weasels and a variety of raptors.
When threatened, spotted sandpipers perform a display by positioning their body upright and their bill forward. They extend their wings outward and upward, raise their breast feathers, open their bill and fan their tail. Nesting spotted sandpipers may also fake an injury, known as the Broken Wing Display in order to draw predators away from their nest. The Broken Wing Display is performed by crawling low to the ground with the wings flapping on the ground and the tail spread and lowered while squealing.
Known Predators:
Spotted sandpipers are polyandrous. Females of this species may mate with upwards of 4 mates each year. Females may begin with one mate with whom they share parental responsibilities. As additional males arrive, females compete for additional mates, leaving the males to perform the majority of parental care.
Mating System: polyandrous
Spotted sandpipers breed between May and August. Females establish a breeding territory about 4 days before males begin arriving. They then court a mate, and the pair builds a nest together. The nests are built in the ground and consist of weeds or stems padding a shallow depression in the dirt. They are typically located in marshes, on coastlines, and near other water sources. The female then lays a clutch of 4 eggs (occasionally 3). Each female may lay up to 5 clutches per year. The eggs are incubated for 19 to 22 days (average 21 days) by the male and by the female to a lesser extent. The chicks are precocial; they are able to walk within four hours of hatching and are able to feed themselves soon thereafter. They are brooded primarily by the male for the first several days after hatching. The young sandpipers remain with their parent(s) for at least 4 weeks after hatching. After becoming independent, the young sandpipers join post-breeding flocks. These sandpipers will be able to breed the next summer when they are about 1 year old.
Breeding interval: Female spotted sandpipers can lay up to 5 clutches per breeding season.
Breeding season: Spotted sandpipers breed between May and August.
Range eggs per season: 20 (high) .
Average eggs per season: 20.
Range time to hatching: 19 to 22 days.
Average time to hatching: 21 days.
Range fledging age: 1 to 24 hours.
Range time to independence: 4 (low) weeks.
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 ; sperm-storing
Male spotted sandpipers provide the majority of parental care. Females contribute in varying amounts to nest building, incubation and raising the chicks during the fledgling stage.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female); pre-independence (Protecting: Male, Female)
