Meeting Abstract
Identifying reproductively viable partners may be the most important aspect of searching for a mate. When females vary in their reproductive receptivity, it is incumbent upon males to discriminate among females based on the likelihood of successful copulation and fertilization. We have observed that female African giant pouched rats (Cricetomys ansorgei) demonstrate profoundly delayed sexual development, with some adults exhibiting a highly neotenous, fully fused vagina. The lack of vaginal patency presents a tremendous barrier to mating. Based on this unique observation, we tested male preferences towards urine collected from patent and non-patent females. We found that males with longer anogenital distances (AGD; a proximate measure of developmental masculinisation) show differential interest towards patent and non-patent females, preferring patent females. Strikingly, males with short AGDs did not show any differential interest between female odours. Correspondingly, only patent females demonstrated reduced interest in odour from short AGD males; non-patent females did not demonstrate a preference. Our study demonstrates that pouched rats show differential interest in odours closely associated with mate quality, which could help them locate high quality potential mates. We are the first, to our knowledge, to show that the AGD of the evaluator enhances mate preferences and influences their interest evaluation in potential mating partners. We posit that the preference for reproductively available females by masculinised males and the preference for masculinised males by reproductively available females suggests that assortative mating could promote these pairings of proximally-derived traits.
