It looks like human males aren’t the only ones giving women cheap gifts to get sex. Male nursery web spiders (Pisaura mirabilis) wrap their gifts in silk to give to females. Most gifts are nice juicy insects, but some are inedible plant seeds or empty exoskeletons that they have already devoured. What cheapskates!
Males will also play dead if a female moves away, then attempt to re-establish sex. Yes, Nursery web spiders are a real class act. New research published in BioMed Central’s open access journal, BMC Evolutionary Biology, examines how successful these males are. It turns out that even cheap gifts are better than no gifts.
Male spiders were given either a potential gift of a fly, or a worthless item, like a cotton wool ball, a dry flower head, or a previously eaten housefly, or no gift at all. All the gifts were about the same size, so the females would not be able to know without unwrapping it. Romeos that offered a gift of any kind were more likely to successfully mate (12 out of 13 times in this study), but the length of time the females allowed males with bad gifts to spend transferring sperm was shorter than those with edible gifts. It was even worse for those bearing no gifts; only 1 out 6 was able to mate when providing no gift. Good gifts insure that your sperm will go places.
Both genders are apparently able to put a value on the gift and modify their behavior accordingly. The males feigned death, triggered by the female attempting to end mating and run away with the gift, in half of the matings with an edible gift, but only once with a worthless gift. Also males and females were sometimes seen fighting over good gifts, but never for a bad gift.
It turns out that spiders, like humans, put a price on mating.