Saturday, 22 October 2011

Chestnut-collared longspur

Calcarius ornatus

Photo by Robert Royse (Robert Royse's Bird Photography)

Common name:
chestnut-collared longspur (en); escrevedeira-de-peito-preto (pt); pectrophane à ventre noir (fr); arnoldo ventinegro (es); rothalsammer (de)

Order Passeriformes
Family Emberizidae

This species breeds in the prairies of the northern Great Plains in Canada and the United States. They migrate south to winter in the southern United States, from western Oklahoma to south-eastern Arizona and into northern Mexico.

The chestnut-collared longspur is 13-17 cm long and weighs 18-23 g.

Historically, this species was associated with prairies grazed by the great bison herds of North America. Nowadays they are mostly found in short and mixed-grass prairies, preferring pastures and mowed areas such as airstrips, as well as grazed native prairie habitats. During winter they are mostly found in open cultivated fields.

They mostly feed on grains such as wheat and seeds of native plants, but also eat insects and other invertebrates.

Chestnut-collared longspurs are monogamous and breed in May-June. The female excavates and build the nest on the ground, where she lays 3-5 eggs. The female incubates the eggs alone for 10-13 days, while the male guards the nest against predators. The chicks are fed by both parents and fledge 10 days after hatching, but continue to receive food from the male for another 2 weeks.

IUCN status - NT (Near-Threatened)
This species has a large breeding range and a global population estimated at 5,6 million individuals. The population has undergone a large decline over the last 4 decades, declining at a rate of 25,2% per decade. The main threat to this species is the conversion of native prairies to cropland and urban developments on their breeding grounds. Other threats include brood-parasitism by brown-headed cowbirds Molothrus ater, high levels of nest predation and human disturbance near the nesting sites.

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