A1 Refereed original research article in a scientific journal
Intersexual conflict over precopula duration in mate guarding Crustacea
Authors: JORMALAINEN V, TUOMI J, YAMAMURA N
Publisher: ELSEVIER SCIENCE BV
Publication year: 1994
Journal: Behavioural Processes
Journal name in source: BEHAVIOURAL PROCESSES
Journal acronym: BEHAV PROCESS
Volume: 32
Issue: 3
First page : 265
Last page: 283
Number of pages: 19
ISSN: 0376-6357
DOI: https://doi.org/10.1016/0376-6357(94)90047-7
Abstract
Precopulatory guarding in Crustacea is usually analyzed as a male decision problem. We suggest an alternative possibility that precopula is established as a result of intersexual conflict over precopula duration. Such a conflict can be expected when the male optimum for precopula duration exceeds the female optimum. As a result, males should start precopulatory attempts earlier, while females should resist until close to receptivity. Our analysis reveals two potential sources of conflict: (1) sexual differences in survival probabilities before and during the mate-guarding; and (2) sexual differences in the probability of finding a mate. The latter is perhaps a more probable source of intersexual conflict, since male biased operational sex ratios are common in mate-guarding Crustacea. The former requires that female moulting cycle is synchronous, whereas the latter may operate in populations with asynchronous moulting cycles as well. We further studied the expected intensity of behavioural conflicts in terms of expected present and future fitness gains. In the beginning of the female moulting cycle, there is no conflict. Conflict arises as males start the guarding attempts and females are motivated to resist, and ceases with a decrease in the female's motivation to resist. Several assumptions and predictions of the model are discussed and compared with the behavioural patterns observed in the aquatic isopod Idotea baltica.
Precopulatory guarding in Crustacea is usually analyzed as a male decision problem. We suggest an alternative possibility that precopula is established as a result of intersexual conflict over precopula duration. Such a conflict can be expected when the male optimum for precopula duration exceeds the female optimum. As a result, males should start precopulatory attempts earlier, while females should resist until close to receptivity. Our analysis reveals two potential sources of conflict: (1) sexual differences in survival probabilities before and during the mate-guarding; and (2) sexual differences in the probability of finding a mate. The latter is perhaps a more probable source of intersexual conflict, since male biased operational sex ratios are common in mate-guarding Crustacea. The former requires that female moulting cycle is synchronous, whereas the latter may operate in populations with asynchronous moulting cycles as well. We further studied the expected intensity of behavioural conflicts in terms of expected present and future fitness gains. In the beginning of the female moulting cycle, there is no conflict. Conflict arises as males start the guarding attempts and females are motivated to resist, and ceases with a decrease in the female's motivation to resist. Several assumptions and predictions of the model are discussed and compared with the behavioural patterns observed in the aquatic isopod Idotea baltica.