Water-Surface Feeding of Blackbirds
Water-surface Feeding of Blackbirds.-Manzanita Lake on the campus of the University of Nevada has extensive growths of the water-weed Anuckaris camzdensis. Each year by the end of May the new growth of this plant forms a. dense mat an inch or less below the water surface. For several years now both Red-winged (Agetius phoeniceus) and Brewer (Euphagus cyanocephalus) blackbirds that nest in the vicinity of the lake have been observed feeding on insects associated with the waterweed. The blackbirds alight on the plants, the water usually coming to the middle or upper part of the birds’ tarsometatarsi. Typically, the wings are then fluttered as the bird hops two or three feet to new vantage points. Less often a bird will walk, even a distance of thirty feet, without moving the wings. The tail, as appeared to be the habit in one individual especially, may be submerged and possibly pressed against the underwater vegetation for support.
The most readily visible food obtained, and certainly the major item for a period of weeks in the early summer, is recently emerged damsel&s. The naiads of this insect crawl to the surface of the waterweed and metamorphose on projections just above the water. The blackbirds have been seen’ repeatedly catching these newly emerged and still pale and flightless adults. On the largest area of waterweed (approximately 30 by 80 feet) as many as five blackbirds at a time have been seen feeding. Most of the birds observed have been female Red-wings, although the males of both species have occasionally been seen similarly surface feeding. This seems largely explained by the constant feeding of the young, apparently chiefly by the females, in nests adjacent to the largest waterweed area.
Brewer Blackbirds of both sexes have been seen several times walking and feeding on pad-lily (Nympltaea) leaves, even one leaf serving to hold up a bird. On two occasions, once on the Truckee River and once on the Carson River, Brewer Blackbirds have been seen hovering over open water and snapping food from the surface. A male of this species was seen similarly to obtain a large piece of bread in Mansanita Lake and carry it to shore to be eaten.-FRANK RICHARDSON, University of Nevada, Reno, Nevada, July 28, 1947.
