Via PhysOrg:
Male nursery web spiders (Pisaura mirabilis) prepare silk-wrapped gifts to give to potential mates. Most gifts contain insects, but some gifts are inedible plant seeds or empty exoskeletons left after the prey has already been eaten (presumably by the male himself!).
Males will also ‘play dead’ if a female moves away and then attempt to re-establish mating. New research published in BioMed Central’s open access journal BMC Evolutionary Biology examines the reproductive success of deceitful males and shows that females are not impressed by worthless gifts.
Male spiders were provided with either a potential gift of a fly, or a worthless item, such as a cotton wool ball, a dry flower head, a prey leftover (previously eaten housefly), or no gift at all. All the gifts were approximately the same size, so the females would not be able to tell what the gift was without unwrapping it.
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