The Great Knot, Calidris tenuirostris
A long-legged wading bird, The Great Knot, is the largest of the calidrid species. They breed in the tundra of North Siberia, and migrate strongly in the winter to the coasts of Southern Asia through Australia, traveling in very large flocks. They lay about four eggs on the ground in a ground scrape. Great Knots migrate over long distances and use a limited number of staging sites during its annual round trip between the breeding grounds of Russia, and the non breeding grounds of Australia. It is theorized that the birds adopted a “long jump” strategy, flying non-stop from Australia to China’s Yellow Sea region. The Great Knot birds are rarely found in inland wetlands and do not favor sandy beaches.
This bird mainly eats bivalve mollusks, gastropods, invertebrates, polychaete worms, crabs, shrimps, and sea-cucumbers. They have also been known to eat seeds and berries. A man named Tomkovich, observed from the winter breeding grounds in the alpine and the subalpine tundra of Siberia, Russia, that the birds start breeding at 2 years old. A pair takes six to seven days to begin laying, and four to five days to lay four eggs. Incubation period is between 22 to 23 days, and then the fledging occurs between 20 and 25 days.
Distinguishing features of these birds include; the heavily streaked pattern of the head and neck and the grey and white scalloped sides. The head features a white eye brow stripe, and the bill is up to 5 cm, slightly curving downwards. The legs are dark grey or olive green and there is an observable white patch on the rump and upper-tail coverts. Although these birds are usually silent, the calls have been heard and described as a double-noted soft whistle.
Great Knots are related to the more widespread Red Knot. In breeding plumage, the Red Knot can be distinguished by its distinctive red face, throat, and breast. In other plumages, the Great Knot is identified by its larger size, longer bill, deeper chest, and the more streaked upperparts.
Image Caption: Great Knot (Calidris tenuirostris), Laem Phak Bia, Ban Laem, Phetchaburi, Thailand. Credit: JJ Harrison/Wikipedia (CC BY-SA 3.0)