Abstract

In many species of the sphecid wasp genus Philanthus, males defend their mating territories. Field observations on three species, Philanthus crabroniformis, P. pulcher, and P. psyche, demonstrated that size differences among males influenced the outcome of competition for territories. Body size varies considerably within males of all three species. In P. crabroniformis, 100%, and in P. pulcher, 97% of aggressive interactions on territories were won by the larger of the two contestants. I captured resident males from territories, and then monitored for the arrival of replacement males. These manipulations yielded several interesting results: (1) individuals from large pools of non-territorial males quickly assumed possession of abandoned territories, (2) the original residents removed from territories were significantly larger in mean body size than those that replaced them, and (3) only 8% of the replacing males were larger than the orginal resident of the territory. The results suggest a sizeconditional strategy in which larger males defend or usurp territories and smaller males opportunistically take over territories that have been abandoned (e.g. the resident leaves to feed or is preyed upon).

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.