Pry. Backwell et Ni. Passmore, TIME CONSTRAINTS AND MULTIPLE-CHOICE CRITERIA IN THE SAMPLING BEHAVIOR AND MATE CHOICE OF THE FIDDLER-CRAB, UCA ANNULIPES, Behavioral ecology and sociobiology, 38(6), 1996, pp. 407-416
Active female sampling occurs in the fiddler crab Uca annullipes. Fema
les sample the burrows of several males before remaining to mate in th
e burrow of the chosen partner. Females time larval release to coincid
e with the following nocturnal spring tide and must therefore leave su
fficient time for embryonic development after mating. Here we show how
this temporal constraint on search time affects female choosiness, We
found that, at the start of the sampling period (when time constraint
s are minimal), females selectively sample the larger males in the pop
ulation. Towards the end of the sampling period (when the temporal con
straints increase the costs of sampling), females are less selective.
Furthermore, we suggest that the number of males sampled (and other in
dices of ''sampling effort'') may not be reliable indicators of female
choosiness and may not reflect the strength of female mating preferen
ces under certain conditions. Burrow quality also emerged as an import
ant criterion in final mate choice. Burrow structure potentially influ
ences reproductive success, and mate acceptance based on burrow struct
ure appears to involve a relatively invariant threshold criterion. Sin
ce there is no relationship between male size and burrow quality, fema
les are using at least two independent criteria when choosing potentia
l mates. We envisage mate choice as a two-stage process. First, female
s select which males to sample based on male size. They then decide wh
ether or not to mate with a male based on burrow features. This sampli
ng process explains how two unrelated variables can both predict male
mating success.