In mating game, animals make the best of bad situation
Animals faced with a less-than-ideal selection of potential matescan compensate to increase the chances their offspring will survive, scientists said Tuesday.
In a study thatlooked acrossseveral species, scientists writing in the Proceedings of the National Academy of Sciences said males and females will try to increase the number of offspring they produce if they are forced into a mating pair not to their liking.
"When female 'choosers' were in enforced pairs with males they did not prefer, they laid more eggs," said University of Georgia ecology and genetics professor Patricia Adair Gowaty in a statement.
"Similarly, when males are paired with females they do not prefer, they ejaculate more sperm. This compensation seems to be a way of making the best of a bad job."
The experiments used Tanzanian cockroaches, fruit flies, pipefish, wild mallard ducksand feral house mice, and put constraints — through increased competition — on their ability to choose their mate.
"Just how an individual finds its best mate isn't really known," said Gowaty, "though there's some evidence that he or she may be somehow sensing the advantage of the potential mate's immune system in relation to the chooser's own."
The authors speculate the increased egg count for females may increase the chances of producingoffspring more capable of standing up to disease.
They note that while several species have adopted the compensation strategy, they found it doesn't quite beat getting first choice of a mate. Placing experimental constraints on mating preferences lowered the viability of offspring in each of the studies, the authors found.