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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Aves -> Order Charadriiformes -> Family Scolopacidae -> Species Actitis macularius

Actitis macularius
spotted sandpiper



2008/07/06 01:29:14.922 GMT-4

By Kari Kirschbaum

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Charadriiformes
Family: Scolopacidae
Genus: Actitis
Species: Actitis macularius

Geographic Range

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 .

Habitat

Elevation
4700 m (high)
(15416 ft)


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. ()

These animals are found in the following types of habitat:
temperate ; tropical ; polar ; terrestrial ; saltwater or marine ; freshwater .

Aquatic Biomes:
lakes and ponds; rivers and streams; coastal ; brackish water .

Wetlands: marsh .

Physical Description

Mass
34 to 50 g; avg. 42 g
(1.2 to 1.76 oz; avg. 1.48 oz)


Length
10 to 18 cm
(3.94 to 7.09 in)


Wingspan
37 to 40 cm
(14.57 to 15.75 in)


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. ()

Some key physical features:
endothermic ; bilateral symmetry .

Sexual dimorphism: female larger, sexes colored or patterned differently.

Reproduction

Breeding interval
Female spotted sandpipers can lay up to 5 clutches per breeding season.

Breeding season
Spotted sandpipers breed between May and August.

Eggs per season
20 (high); avg. 20

Time to hatching
19 to 22 days; avg. 21 days

Time to fledging
1 to 24 hours

Time to independence
4 weeks (low)

Age at sexual or reproductive maturity (female)
1 years (average)

Age at sexual or reproductive maturity (male)
1 years (average)

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 systems:
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. ()

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).

Lifespan/Longevity

Extreme lifespan (wild)
12 years (high)

Average lifespan (wild)
109 months
[External Source: Bird Banding Laboratory]


The oldest known spotted sandpiper lived at least 12 years. Most do not live nearly that long. ()

Behavior

Territory Size
28 to 20000 m^2

Spotted sandpipers are diurnal. They can sleep anytime, day or night, but generally sleep whenever it is dark. During the day, spotted sandpipers spend some time on self-maintenance, which involves preening, head scratching, stretching, and bathing.

Spotted sandpipers are fully migratory, with the exception of populations that breed and winter along the west coast of the United States and in some areas in California. Spotted sandpipers migrate during the day and at night. Unlike most shorebirds, they migrate singly or in small groups.

Spotted sandpipers are territorial during the breeding season and in winter. During the breeding season, males and females independently defend territories. For monogamous breeding pairs, the male and female territories are essentially identical. For polyandrous females, the males' territories are subsets within the female's territory. Spotted sandpipers defend their territories aggressively. Territorial disputes typically involve pecking at the head and eyes of the opponent while trying to mount their back, and using the legs, wings and bills to fight.

Spotted sandpipers employ walking, hopping, climbing, and flying as means of locomotion. When walking, the birds exhibit a characteristic up-and-down bobbing motion. They fly with shallow, rapid wingbeats. Spotted sandpipers also occasionally swim and dive for prey. ()

Home Range

The home range of spotted sandpipers is not known. ()

Key behaviors:
terricolous; flies; diurnal ; motile ; migratory ; solitary ; territorial .

Communication and Perception

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. ()

Communicates with:
visual ; acoustic .

Perception channels:
visual ; tactile ; acoustic ; chemical .

Food Habits

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%. ()

Primary Diet:
carnivore (insectivore , eats non-insect arthropods, molluscivore ).

Animal Foods:
amphibians; fish; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms.

Predation

Known predators

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. ()

Ecosystem Roles

Spotted sandpipers affect the populations of the species they eat. They also provide food for their predators.

Economic Importance for Humans: Negative

There are no known adverse effects of spotted sandpipers on humans.

Economic Importance for Humans: Positive

Spotted sandpipers eat a wide variety of insects. It is possible that they help control insects that humans view as pests.

Conservation Status

IUCN Red List: [link]:
Least Concern.

US Migratory Bird Act: [link]:
Protected.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

State of Michigan List: [link]:
No special status.

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. ()

Contributors

Kari Kirschbaum (author, editor), Animal Diversity Web Staff.

Katherine Moore (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.

References

Cialdini, R., G. Orians. 1944. Nesting studies of the Spotted Sandpiper. Passenger Pigeon, 6: 79-81.

Hays, H. 1972. Polyandry in the Spotted Sandpiper. Living Bird, 11: 43-57.

Klekowski, E., L. Klekowski. 1997. "Spotted Sandpiper, *Actitis macularia*" (On-line). Accessed April 7, 2002 at http://www.bio.umass.edu/biology/conn.river/spotted.html.

Maxson, S., L. Oring. 1980. Breeding season time and energy budgets of the polyandrous Spotted Sandpiper. Behaviour, 74: 200-263.

Oring, L., E. Gray, J. Reed. 1997. Spotted Sandpiper (Actitis macularia). Pp. 1-32 in A. Poole, F. Gill, eds. The Birds of North America, Vol. 289. Philadelphia, PA: The Academy of Natural Sciences, and Washington, DC: The American Ornithologists' Union.

2008/07/06 01:29:26.989 GMT-4

To cite this page: Kirschbaum, K. and K. Moore. 2002. "Actitis macularius" (On-line), Animal Diversity Web. Accessed July 09, 2008 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Actitis_macularius.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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