September diet and reproductive state ofUta stansburiana(Phrynosomatidae) at Isla San Roque, Baja California Sur, México

In September 1994 we studied the only reptile species,Uta stansburiana elegans, at Isla San Roque off the Pacific coast of Baja California Sur. Three censuses of lizards were made over all the island. Outside the census transect, 10 adult lizards of each sex were collected. Analysis of data obtained from the reproductive tracts and stomach contents are shown. A seaweed fly of the family Coelopidae (Diptera) was the principal prey. Behavioural data suggested the existence of reproductive activity in the lizard individuals seen, which was confirmed by analysis of the reproductive tract.