image: Spadefoot toad males of the species S. bombifrons generally call from the side of their breeding ponds in locations where they occur with the closely related spadefoot, S. multiplicata. By contrast, S. multiplicata males call from floating positions toward the middle of the ponds. S. bombifrons females that mate with S. multiplicata males therefore bypass males of their own species at the sides of the ponds and venture to the middle of the ponds where S. multiplicata are calling. This image relates to an article that appeared in the Nov. 9, 2007 issue of the journal Science, published by AAAS. The study, by Dr. Karen Pfennig at University of North Carolina, Chapel Hill in Chapel Hill, NC, was titled "Facultative Mate Choice Drives Adaptive Hybridization." view more
Credit: Image © Science