Food of Some Uncommon North American Birds

FOR more than half a century the U.S. Biological Survey has been accumulating information on the food and economic status of birds. During this time considerably more than 200,000 bird stomachs have been assembled, mostly from birds collected primarily for other purposes. Approximately half this number have now been analyzed. Brief to comprehensive reports have been published on some two hundred species. Other species or groups of species have been partially worked, while with still others, relatively little detailed information on food preferences is yet available. Considering the time elapsed and the large number of birds collected, it is perhaps to be expected that the series would include representatives of some forms that are now extinct, rare, or at most only locally abundant. Many have great mobility, which, sometimes augmented by storms, results in their straggling far from their normal range; in this way certain exotic species of birds have come within our borders where a limited number have been collected. In most instances only one or a few stomachs of such wandering, rare, or extinct species have been available for study. The paper gives some information on the food of forty-seven species of birds and is based on the laboratory analysis of the contents of 239 stomachs. The number of stomachs for the various species varied from one to thirty-five. Unfortunately stomachs of all our rare or extinct birds were not available. However, the information presented, though limited and fragmentary, is of interest and value, and unless published in some such form as this, would largely remain buried in the files of the Biological Survey. It is the purpose of this paper to present such data as are available in the Food Habits laboratory of the Biological Survey on the food of nearly fifty uncommon, vanishing or extinct species. Papers from the Section of Food Habits usually treat groups of related species, but in this instance, a heterogeneous lot of species is discussed in systematic order. Among the rarer or extinct species included are the Passenger Pigeon, Carolina Paroquet, Eskimo Curlew, Trumpeter Swan, Ivory-billed Woodpecker, Great White Heron, Roseate Spoonbill, and Everglade Kite. While the larger part of the laboratory examinations were made for this study by the writers, generous and willing assistance was received from several members of our Food Habits Staff--both present members and others who have worked in the laboratory in years gone by. To all of them and to those who have aided in other ways, we extend our sincere thanks.