Females Butterflies Can Smell If a Male Butterfly Is Inbred

Mar. 5, 2013 — The mating success of male butterflies is often lower if they are inbred. But how do female butterflies know which males to avoid? New research reveals that inbred male butterflies produce significantly less sex pheromones, making them less attractive to females.

The research was published today in the journal Proceedings of the Royal Society B.

If animals (and humans) breed with a relative their offspring will be inbred and more likely to have genetic disorders. Because of these disorders inbred males are often weaker and, for instance, less able to defend the nest or provide food for their youngsters. To make sure her offspring will have the highest chance of survival and reproduction, females are expected to avoid mating with a weak inbred male. That is, if she is able to recognize who is inbred and who is not.

Erik van Bergen, currently at the University of Cambridge and formerly with Leiden University, where he conducted much of the research, said: "Interestingly, traits used by males to attract the opposite sex are often strongly affected by inbreeding and might be used by females to recognize inbred individuals. For example, inbred male zebra finches produce a lower number of different individual songs and inbred male guppies have less conspicuous colour patterns. Additionally, in one cricket species, the inbred males are known to produce less acoustic signals while trying to attract females."

Continued:  http://www.sciencedaily.com/releases/2013/03/130305200457.htm