Abstract Full Text Media References(0) Cited By (56)Metrics
The behavior of males near the oviposition site of Scatophaga stercoraria is highly variable, being dependent on male size and on male density conditions. At low density males are often territorial with dominance relationships, the largest male often initiating high intensity attacks. At high densities attacks are much less intense, with more symmetrical interactions among males. Large males are most active under all density conditions. Absence of small males from high density pats, even though there is no apparent attempt to exclude these males, appears to occur for two reasons: Small males may suffer proportionately more harm in interactions than larger males, and success of these males in retaining captured females is extremely low, as shown by extreme differences in takeover rates relative to male size. My finding (BORGIA, 1980a, 1981) that large males are relatively more successful in capturing females under conditions where there are few pats can be explained in terms of these results. However, unlike predictions from avian mating system models, lower variants in male reproductive success occurs not because more powerful males actively exclude others from a more restricted resource base, but as an indirect effect of large males searching for mates. Differences in male behavior under varying density conditions, and by males of different size, show the extreme adaptability of male behavior in Scatophaga. These findings agree with ALCOCx's (1979) suggestion that insect behavior is much less stereotyped than is commonly believed.