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The Food Habits of the Red-winged Blackbird, Agelaius phoeniceus, in Manitoba

1964; Ottawa Field-Naturalists' Club; Volume: 78; Issue: 3 Linguagem: Inglês

10.5962/p.342174

0008-3550

Ralph D. Bird, Lawrie B. Smith,

Lepidoptera: Biology and Taxonomy

Tue Rep-wincep Biacsirp, A gelaius phoeniceus (L.), has been shown to feed on a variety of vegetable and animal material.Beal (1900), examined the stomachs (gizzards) of 1083 Redwings collected throughout the United States at various times of the year and found vegetable matter to be 73.4 per cent of the yearly average with a large proportion being weed seeds.In farmed areas the food of autumn concentrations of Red-wings has been found to be mostly grain; rice in Arkansas (Neff and Meanley, 1957); corn in Ohio (Giltz and Stockdale, 1960) and South Dakota (DeGrazio, 1961); and sunflowers, wheat, oats, and barley in Saskatchewan (Hurd, 1962).Allen (1914) studied the ecology of Red-winged Blackbirds in a cat-tail marsh in New York and examined the stomachs of about 100 birds.He found the food to be nearly 100 per cent vegetable in the spring and autumn, and 100 per cent insects in the mating and nesting periods.This paper reports on food consumed by the Red-winged Blackbird and the habitat occupied by the species during its period of residence in agricultural and marsh areas, in south-central Manitoba, in 1960. MatTERIALS AND METHODSSouthern Manitoba, now intensively cultivated, is situated in the aspen parkland region of Western Canada (Bird, 1961).Red-winged Blackbirds nest in emergent vegetation around bodies of water in the farming area and in large marshes at a distance from cultivated land.'Their use of nesting habitat in two different types of areas gave an opportunity to compare their food habits under disturbed conditions and under relatively natural conditions.Two representative agricultural areas and a marsh were selected for study. Areal. Sunflower and cereal crop area near Altona, ManitobaCereal crops, sunflowers, sugar beets, field peas, corn and alfalfa were grown in this area, which is situated 80 miles southwest of Winnipeg near the North Dakota boundary.A small breeding population of Red-winged Blackbirds occurred along Buffalo Creek.They nested in cattails, Typha latifolia L., and bullrushes, Scirpus spp.In August and September thousands of migrants formed night roosts in the rushes and ranged into the adjacent fields to feed.| Area ll.Cereal crop area northeast of Portage la Prairie, ManitobaIn this district, known locally as Flee Island, barley, wheat, and oats were the main crops.No sunflowers or corn were grown and there was only a small »Contribution No.