Infanticide by male house sparrows: gaining time or manipulating females?
The killing of genetically unrelated young by males has been viewed as a strategy that forces victimized females to advance the onset of their next fertile period, thus infanticidal males gain a time advantage that may be crucial to maximize reproductive success. Among females that may raise several broods in a year, a failure occurring relatively earlier in the time-course of the previous breeding attempt may result in an increased investment in the next breeding attempt. This female strategy may be exploited by males in their own interest, and may strongly select for male infanticidal behaviour. I demonstrate that, in the house sparrow, females mated with infanticidal males re-laid earlier, initiated more breeding attempts and fledged more offspring than females mated with non-infanticidal males. These results suggest that both the time saving and the manipulation of female investment are independent mechanisms conferring advantages that may have selected for male infanticide in the studied population.
Veiga
José P
JP
Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, 28006 Madrid, Spain. jpveiga@mncn.csic.es
D000374:Aggression; D000818:Animals; D005260:Female; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D012727:Sex Characteristics; D012919:Social Behavior; D020308:Songbirds / Q000502:physiology*; D013997:Time Factors