nesting. Hayfields and plant communities of buckbrush (Ceonothus cuneatus) and sedges are also important as nest sites. Behavior These birds feed by dabbling in shallow water at the edge of marshes or open water. They mainly eat plants; their diet may include molluscs and aquatic insects. Blue-winged teal are generally the first ducks south in the fall and the last ones north in the spring. Adult drakes depart the breeding grounds well before adult hens and immatures. Most blue-winged teal flocks seen after mid-September are composed largely of adult hens and immatures. The northern regions experience a steady decline in blue-winged teal populations from early September until early November. Blue-winged teal in central migration areas tend to remain through September, then diminish rapidly during October, with small numbers remaining until December. Large numbers of blue-winged teal appear on wintering grounds in Florida, Louisiana, and Texas in September. Reproduction The onset of courtship among immature blue-winged teal often starts in late January or early February. In areas south of the breeding grounds, blue-winged teal are more active in courtship during the spring migration than are most other ducks. Blue-winged teal are among the last dabbling ducks to nest, generally nesting between April 15 and May 15. Few nests are started after mid-July. Chronology of nesting can vary from year to year as a result of weather conditions. At Delta Marshes, Manitoba, blue-winged teal nesting was delayed a week in 1950 due to abnormally cold weather. The nest is a shallow depression on the ground lined with grass and down, usually surrounded by vegetation. Blue-winged teal generally lay 10 to 12 eggs. Delayed nesting and renesting efforts have substantially smaller clutches, averaging five to six eggs. Clutch size can also vary with the age of the hen. Yearlings tend to lay smaller clutches. Incubation takes 21 to 27 days. Blue-winged teal are sexually mature after their first winter. During incubation, the drake leaves its mate and moves to suitable molting cover where it becomes flightless for a period of 3 to 4 weeks. Blue-winged teal ducklings can walk to water within 12 hours after hatching but do not fledge until 6 to 7 weeks. Food habits Blue-winged teal are surface feeders and prefer to feed on mud flats, in fields, or in shallow water where there is floating and shallowly submerged vegetation plus abundant small aquatic animal life. They mostly eat vegetative