Sora

Distribution

Soras occur throughout most of North America. Soras breed from Nova Scotia northwest to southern Yukon and Northwest Territories, south to California, Arizona, and New Mexico and northeast to Pennsylvania and New England. Sora wintering grounds include the northern portions of South America, including Ecuador, Columbia, and Venezuela, north through Central America and Mexico to southern California in the West and coastal regions of the Southeast. From southern Kansas south to northern and eastern Texas and east through the inland areas of the southeastern United States, soras are typically only observed during migration in the spring and fall. In a few areas of the western United States, including central California and areas of Arizona and New Mexico, soras may occur year round.

Habitat

Water and emergent vegetation are important sora habitat characteristics.

Food

Soras eat a wide range of foods. Animals that are commonly reported as sora food items include snails , crustaceans , spiders , and insects , mainly beetles , grasshoppers , flies , and dragonflies . Soras often eat the seeds of plants, such as smartweeds, bulrushes, sedges, and barnyard grasses. Seeds of annual wildrice and rice cutgrass are eaten by soras in the eastern United States. A literature review lists crowngrass and rice as relatively important food sources for soras in the Southeast. Plants comprising

Predators

Sora eggs are eaten by several species including American minks , skunks , coyotes , grackles , crows , and herons . Predation of adult soras by American minks, coyotes and peregrine falcons has been reported.

Defense

Although sora nesting activities have been observed from late April through early August, the peak nesting period typically occurs from May to early July. In New York, nesting was initiated in late April. A nest search and literature review study of soras in Colorado reports a clutch initiated in early August. However, mean clutch initiation dates occurred in May and June in regions across the state. Studies from northern Ohio, North Dakota, and Alberta report nesting from May to July. In a review, sora nests with eggs were recorded from early May to early July in Indiana.

Sora females begin construction of saucer-shaped nests on the ground or on a platform over shallow water at the start of egg laying. Clutch sizes typically range from 8 to 13 eggs, although clutch sizes of up to 16 have been reported. Both parents incubate the eggs. Incubation lasts approximately 19 days, although a wide range of incubation periods has been reported in the literature. Eggs hatch over a span of 2 to 13 days. Nestlings are precocial and are capable of walking and swimming short distances ) by the end of their 1st day. Young soras are independent by about 4 weeks of age. Soras brood once per season. Some late broods may be 2nd nesting attempts, but there is only 1 report in the literature of a 2nd brood attempt after a successful nest. For information on breeding behavior of soras, see. For information on conspecific nest parasitism and egg discrimination in soras see.

Sora nest success rates vary across locations and years. In the literature addressing sora apparent nest success, the proportions of successful nests varied from 0.61 in Michigan to 0.833 in Minnesota. In western New York, the nest success rate of 6 sora nests was 0.43, and the daily nest success rate was 0.97. Using data from the Cornell Laboratory of Ornithology's nest record program, nesting success rate of soras in North America was estimated as 0.529 over a 28-day period . On a site in Alberta, 80.6% of eggs successfully hatched, while the following year only 59.6% of eggs hatched. The authors conclude that diminished water level interacting with predators and trampling by cattle resulted in decreased hatching success. During late summer, soras are flightless for a period during their post-nuptial molt.

Migration

Sora's northern migration occurs in spring, primarily in April and May. For instance, in east-central Kansas significantly (p