Credit: K. JONES

Proc. R. Soc. B doi:10.1098/rspb.2009.1554 (2009)

Male redback spiders can sneak in and quickly copulate with a female after a rival male has already spent hours wooing her, yet avoid the usual penalty of short courtship — being eaten prematurely by his lover.

The female Australian redback spider (Latrodectus hasselti, pictured) eats the male after mating, but sometimes consumes him prematurely — after he's copulated only once. Jeffrey Stoltz and Maydianne Andrade of the University of Toronto in Canada measured the spiders' courtship durations and found that females tend to eat their partners prematurely if courtship is less than 100 minutes long. However, intruder males can mate after a shorter courtship and avoid premature death if an earlier male had already exceeded this 100-minute threshold.

This could lead to lower quality males seeking out, rather than avoiding, competition with rival spider studs, the authors say.