Friday, 22 February 2013

Necrophilia the way forwards for some frogs

Functional necrophilia: A profitable anuran reproductive strategy
February 2013. Sex is a risky business for many animals. Those who take part in ‘explosive breeding' - where many males gather and compete for a small number of females over a few days - have it particularly tough. Males can become exhausted from the competition and the search for a scarce mate, or from trying to dislodge other males from receptive females. The females themselves can be unintentionally crushed, drowned or simply exhausted under the weight of their many suitors.

Functional necrophilia
But now scientists have discovered that the tiny Central Amazonian frog Rhinella proboscidea has developed an effective, if unsavoury, way of making the most out explosive breeding despite its inherent dangers. Writing in a recent issue of the Journal of Natural History, Brazilian researchers have observed the frog indulging in what they call a ‘functional necrophilia strategy'. In other words, males of the species have been observed extracting oocytes from the abdomens of unfortunate females killed in mating struggles, and then fertilizing them.

Waste not want not
While unpleasant from a human viewpoint, from an evolutionary perspective taking advantage of oocytes from dead females minimises the losses both partners can experience as a result of explosive breeding. The male is able to breed successfully despite not having had access to a live female or expending too much energy in the battle to secure one; the female's eggs are fertilised even though she herself has expired. The existence of this strategy also suggests that there may be possible selection in favour of stronger and more persistent males in explosive breeders; these sorts of males may be not be advantageous to the females themselves - and indeed their determined behaviour can often kill them - but the ‘functional necrophilia' strategy ensures that the species continues despite a lack of live females.

No comments:

Post a comment

You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!

Related Posts with Thumbnails