Worthless donations: male deception and female counter play in a nuptial gift-giving spider

BMC Evolutionary Biology

DOI: 10.1186/1471-2148-11-329

Authors:

Albo, MJ; Winther, G; Tuni, C; Toft, S; Bilde, T

Abstract:

Background: In nuptial gift-giving species, benefits of
acquiring a mate may select for male deception by donation of worthless
gifts. We investigated the effect of worthless gifts on mating success in
the spider Pisaura mirabilis. Males usually offer an insect prey wrapped
in silk; however, worthless gifts containing inedible items are reported.
We tested male mating success in the following experimental groups:
protein enriched fly gift (PG), regular fly gift (FG), worthless gift
(WG), or no gift (NG).

Results: Males that offered worthless gifts acquired similar mating
success as males offering nutritional gifts, while males with no gift
experienced reduced mating success. The results suggest that strong
selection on the nuptial gift-giving trait facilitates male deception by
donation of worthless gifts. Females terminated matings faster when males
offered worthless donations; this demonstrate a cost of deception for the
males as shorter matings lead to reduced sperm transfer and thus give the
deceiving males a disadvantage in sperm competition.

Conclusion: We propose that the gift wrapping trait allows males to
exploit female foraging preference by disguising the gift content thus
deceiving females into mating without acquiring direct benefits. Female
preference for a genuine prey gift combined with control over mating
duration, however, counteracts the male deception.

Presented by Liz Harley on 12.01.2012