TY - JOUR
T1 - Genetic evidence for sexual selection in black ratsnakes, Elaphe obsoleta
AU - Blouin-Demers, Gabriel
AU - Gibbs, H. Lisle
AU - Weatherhead, Patrick J.
N1 - Funding Information:
We are grateful to G. Carfagno, H. McCracken, A. Moenting, E. O'Grady, J. Row, J. Svec, C. Verreault and T. Volk for their help with fieldwork, to L. Blanchard, L. DeSousa, J. Díaz and L. Tabak for their help with the laboratory work, and to two anonymous referees for comments on the manuscript. We thank Queen's University and staff at the Queen's University Biological Station for logistical support and the Canadian Wildlife Foundation, Carleton University, the Endangered Species Recovery Fund, the Natural Sciences and Engineering Research Council of Canada, Ohio State University, the Ontario Ministry of Natural Resources, Parks Canada, the University of Illinois and the University of Ottawa for financial support. All of our work was conducted with the approval of the animal care committees at Carleton University and at the University of Illinois.
PY - 2005/1
Y1 - 2005/1
N2 - We investigated benefits of polyandry and phenotypic correlates of male mating success in black ratsnakes. We used 10 microsatellite loci to identify the sires of 375 hatchlings from 34 clutches with known mothers. Multiple paternity occurred in 88% of clutches, despite the fact that ratsnakes mate when dispersed. The incidence of multiple paternity did not vary with female size or with clutch size. Hatching success tended to be higher in multiply sired clutches, but offspring from these clutches were not longer or heavier. We identified 34 males as the sires of 144 hatchlings. Most instances where sires could not be identified resulted from exclusion of all 426 potential sires that we screened. Unidentified sires were probably males that hibernated outside our study area and thus were not included in the intensive sampling at hibernacula in the study area. Among males that sired offspring, body size but not tail length contributed to success, consistent with male-biased sexual size dimorphism and male-male combat shown by this species. Large males were more successful primarily by siring more offspring per clutch rather than by siring offspring in more clutches. This may be a result of greater success in sperm competition. Neither body condition nor genetic similarity to the female was related to male mating success. Our results, in conjunction with published data on movement patterns, suggest that snakes of both genders can benefit from actively seeking multiple matings.
AB - We investigated benefits of polyandry and phenotypic correlates of male mating success in black ratsnakes. We used 10 microsatellite loci to identify the sires of 375 hatchlings from 34 clutches with known mothers. Multiple paternity occurred in 88% of clutches, despite the fact that ratsnakes mate when dispersed. The incidence of multiple paternity did not vary with female size or with clutch size. Hatching success tended to be higher in multiply sired clutches, but offspring from these clutches were not longer or heavier. We identified 34 males as the sires of 144 hatchlings. Most instances where sires could not be identified resulted from exclusion of all 426 potential sires that we screened. Unidentified sires were probably males that hibernated outside our study area and thus were not included in the intensive sampling at hibernacula in the study area. Among males that sired offspring, body size but not tail length contributed to success, consistent with male-biased sexual size dimorphism and male-male combat shown by this species. Large males were more successful primarily by siring more offspring per clutch rather than by siring offspring in more clutches. This may be a result of greater success in sperm competition. Neither body condition nor genetic similarity to the female was related to male mating success. Our results, in conjunction with published data on movement patterns, suggest that snakes of both genders can benefit from actively seeking multiple matings.
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U2 - 10.1016/j.anbehav.2004.03.012
DO - 10.1016/j.anbehav.2004.03.012
M3 - Article
AN - SCOPUS:11144332586
SN - 0003-3472
VL - 69
SP - 225
EP - 234
JO - Animal Behaviour
JF - Animal Behaviour
IS - 1
ER -