The contents of 30 stomachs of 3 swift species, and 96 stomachs of 9 swallow species were analyzed. Most of the birds were shot during the breeding season in the semi-arid grasslands of South Africa. The swifts fed mainly on termite alates and minute nemathoceran Diptera, while the swallows preyed mainly upon minute Coleoptera. Flying ants were an important food constituent in the diets of both swifts and swallows.
ACKNOWLEDGMENTS
I would like to express my gratitude to Mr D. H. De Swardt and Mr R. J. Nuttall (National Museum at Bloemfontein) for providing material for this analysis, and to Dr W R. J. Dean (Tierberg Karoo Research Centre at Prince Albert) for his constructive comments on earlier draft of this paper and for indicating useful references.