Bracketing the extremes: courtship behaviour of the smallest- and largest-bodied species in the salamander genus Desmognathus (Plethodontidae : Desmognathinae)

With both a 'manageable' number of taxa and moderate levels of behavioural diversity, plethodontid salamanders of the North American subfamily Desmogn athinae offer exciting opportunities for a phyloethological study of courts hip. In moving toward this goal, the present paper reports courtship descri ptions for two taxa with very different biologies: the pygmy salamander Des mognathus wrighti and the blackbelly salamander D. quadramaculatus. Despite similarities in behaviour patterns used to accomplish indirect sperm trans fer by means of the deposition of spermatophores on the substrate (tail-str addle walk), these two taxa greatly differ in the ways by which males stimu late, or 'persuade', females to mate. Male D. wrighti bite and seize their partners in order to provide them with tactile and chemical stimuli. In con trast, male D. quadramaculatus provide these same stimuli, but by head rubb ing and snapping. I end with a comparative survey of courtship in the Desmo gnathinae, and a first attempt to interpret behavioural evolution in the su bfamily using a phyloethological analysis.