Long-Distance Migration of Drosophila

A recent paper by Jones et al. (1981) shows that Drosophila pseudoobscura flies released in the open desert can travel long distances. These investigators suggest that such migration can lead to considerable gene flow, and may account for the similarity of allozyme frequencies among populations of this species. It is possible, however, that the vagility of flies released in the desert is not their natural behavior. One would like to know if flies will leave favorable or already-populated areas and traverse those less favorable. The authors report here two release experiments in Death Valley, California, that demonstrate Drosophila will in fact leave oases and venture into the surrounding desert, and also travel from one oasis to another across many kilometers of desert. These results support the hypothesis that Drosophila migration may be more extensive than previously supposed.