Social dynamics of group courtship behavior in male red-sided garter snakes (Thamnophis sirtalis parietalis).

Abstract

Mating in red-sided garter snakes is characterized by the formation of mating balls. Up to 100 males simultaneously court single females. The social dynamics of the formation of these mating balls was examined to determine whether the mating balls are formed simply because of a common attraction to the female or whether males are stimulated by the mating balls themselves. A sexually attractive female garter snake appears to be even more attractive to a male when she is being courted by other males than when she is alone. Male garter snakes courted females more actively when other males were also courting the female than when they were alone with her. There is a positive correlation between the number of additional males present and the amount of courtship activity shown by the test male toward the stimulus female. The extent to which the courtship activity of the test males was stimulated by the presence of additional courting males was not influenced by how actively the additional males courted. 145This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.

The Opportunistic Serpent: Male Garter Snakes Adjust Courtship Tactics to Mating Opportunities

“…Similar results have been reported in most previous studies of the same species, with large females attracting more suitors than small females (Aleksiuk & Gregory, 1974;Hawley & Aleksiuk, 1976;Gartska et al, 1982;Shine et al, 2001b). Only one previous study of red-sided garter snakes has reported that female body size did not in uence courtship intensity (Joy & Crews, 1985). Large females stimulate higher tongue-ick rates from mate-searching male snakes (Shine et al, 2003c).…”

“…4c) and heavier-bodied males performed more frequent caudocephalic waves (Table 1). An earlier study of the same population reported a similar result, with more active courtship by large males (Joy & Crews, 1985). Extensive data from eld and arena matings have shown that larger, heavier-bodied males experience higher mating success than do their small, thinner rivals (Shine et al, 2000f).…”

“…Male mate choice is in uenced also by attributes of the female, with large and heavy-bodied females attracting more courtship than small, thin conspeci cs (Aleksiuk & Gregory, 1974;Hawley & Aleksiuk, 1976;Gartska et al, 1982;Shine et al, 2001b). Operational sex ratios within courting groups also may modify the intensity of courtship by each male (Joy & Crews, 1985).…”

How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes

“…Courting wild males (N10) were then placed into each arena, and the proportion of males courting the experimental male was recorded after 10min by an observer who was blind to the experimental treatments. Previous work has shown that male redsided garter snakes exhibit facilitated courtship, where larger groups of competing males induce more vigorous, reliable male courtship behavior in arena trials than assays using single males paired with a female (Joy and Crews, 1985). Courting males were distinguished by conspicuous chin-rubbing behavior where the male tongue-flicks the dorsal surface of the female and aligns his body with hers, a behavior seen only in the reproductive context [see Moore et al (Moore et al, 2000) and for recent ethograms describing male red-sided garter snake reproductive behavior].…”

Endocrine mechanisms mediating temperature-induced reproductive behavior in red-sided garter snakes (Thamnophis sirtalis parietalis)

“…Males were randomly selected from both treatment groups and introduced in groups of eight to simulate natural mating conditions, where the presence of a mating ball facilitates male courtship behavior (Joy and Crews, 1985). Mating balls rarely contain fewer than five males courting a single female because males are attracted to females by both the presence of pheromonal cues expressed on the female's dorsal surface as well as the presence of a mating ball (Joy and Crews, 1985).…”