Sexual Communication in Cane Toads, Chaunus marinus: What Cues Influence the Duration of Amplexus
When you look for someone to date do you look for someone tall or someone short? Do you notice the one with the dark hair or the light hair? Do you like someone with a sturdy stature, or someone long and lean? If we had stripes or spots, which do you think you would prefer? We are not the only animals who choose our partners. Most species go through a process of sexual selection when choosing a mate because wild animals must have optimal survival and reproduction to continue populations of species. The quality of a mate is represented by the compatibility of genes. To assess the quality of a mate one must interact with other members of the population. Communication through courtship is an important step.
Bowcock, Brown and Shine studied Amplexus or the reproductive position of Cane Toads in 2007. The selection of mates by males was in question because during the mating season, males will mount any female that is the right size. He will do so even if the female is unable to reproduce or if she is unwilling. Unwillingness is not what will deter a male Cane Toad from maintaining amplexus however. This is a problem for the species because it eliminates sexual selection, possibly limiting genetic variation and natural selection. By mating with females who are unable to reproduce the males are wasting energy and sperm by mating with them; it is not conducive for a high reproductive rate.
The calls of Cane Toads where analyzed during breeding season to see if there was a trigger for the calls. The result being that the amplexus position initiates the call in males. It was found that female Cane Toads are mute and therefore have no auditory call. Female Cane Toads use flank vibrations for sexual communication. The stimulus of amplexus dismount was the call of another male but only if its call was longer than the mounted male’s. This suggests that the male with the longer call has outcompeted the male with the shorter call. To dismount because of this seems like a useless response however because the males are already mounted.
To check out this article: http://www.sciencedirect.com.silk.library.umass.edu:2048/science?_ob=ArticleURL&_udi=B6W9W-4RWC89K-4&_user=1516330&_coverDate=04%2F30%2F2008&_alid=1505489860&_rdoc=6&_fmt=high&_orig=search&_origin=search&_zone=rslt_list_item&_cdi=6693&_sort=r&_st=13&_docanchor=&view=c&_ct=4617&_acct=C000053443&_version=1&_urlVersion=0&_userid=1516330&md5=4bc1cef8a54a836159b6a32bac50fa8f&searchtype=a
Bowcock, Brown and Shine studied Amplexus or the reproductive position of Cane Toads in 2007. The selection of mates by males was in question because during the mating season, males will mount any female that is the right size. He will do so even if the female is unable to reproduce or if she is unwilling. Unwillingness is not what will deter a male Cane Toad from maintaining amplexus however. This is a problem for the species because it eliminates sexual selection, possibly limiting genetic variation and natural selection. By mating with females who are unable to reproduce the males are wasting energy and sperm by mating with them; it is not conducive for a high reproductive rate.
The calls of Cane Toads where analyzed during breeding season to see if there was a trigger for the calls. The result being that the amplexus position initiates the call in males. It was found that female Cane Toads are mute and therefore have no auditory call. Female Cane Toads use flank vibrations for sexual communication. The stimulus of amplexus dismount was the call of another male but only if its call was longer than the mounted male’s. This suggests that the male with the longer call has outcompeted the male with the shorter call. To dismount because of this seems like a useless response however because the males are already mounted.
To check out this article: http://www.sciencedirect.com.silk.library.umass.edu:2048/science?_ob=ArticleURL&_udi=B6W9W-4RWC89K-4&_user=1516330&_coverDate=04%2F30%2F2008&_alid=1505489860&_rdoc=6&_fmt=high&_orig=search&_origin=search&_zone=rslt_list_item&_cdi=6693&_sort=r&_st=13&_docanchor=&view=c&_ct=4617&_acct=C000053443&_version=1&_urlVersion=0&_userid=1516330&md5=4bc1cef8a54a836159b6a32bac50fa8f&searchtype=a
Posted by: Amber Kapchinske (1)
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ReplyDeleteDoes this mean that a male toad will copulate with any female unless there is a "better" mate for her in the vicinity? (Better = longer call which leads to dismount.) While that would work for sexual selection, it sounds like a behavior that would be selected against. There just isn't utilitarianism in the animal kingdom. Am I interpreting this wrong?
ReplyDelete- Alice Trei (I deleted my first comment because I forgot to sign my name.)
Thats strange the fact that the females are completely mute while the males in the same species rely heavily on their auditory signaling. Additionally how long does a male need to be mounted before the female will not consider a dismount?
ReplyDeletePatrick Salome