Animals exhibit a remarkable variety of reproductive strategies, from large mating aggregations to temperature-dependent sex determination.  These strategies have different ecological costs and benefits, and can be adjusted in response to changes in the biotic and abiotic environment, to balance conflicting pressures.  I have been involved in a variety of research projects that examine the nature, costs and benefits of different reproductive tactics of reptiles.

Relevant publications:


Uller, T., While, G. M., Wapstra, E., Warner, D. A., Goodman, B. A., Schwarzkopf, L., Langkilde, T., Doughty, P., Radder, R. S., Rohr, D. H., Bull, C. M., Shine, R., & Olsson, M. 2008. Evaluation of offspring size-number invariants in twelve species of lizard. Journal of Evolutionary Biology 22: 143-151


Allsop D. J., Warner D., Langkilde T., Du W., and Shine R. 2006. Do operational sex ratios influence sex allocation in viviparous lizards with temperature-dependent sex determination?  Journal of Evolutionary Biology 19: 1175-1182


Shine R., Langkilde T., Wall M., and Mason R.T. 2006. Temporal dynamics of emergence and dispersal of garter snakes from a communal den in Manitoba.  Wildlife Research 33: 103-111


The Adaptive Significance of Reproductive Strategies

Langkilde T. and Shine R. 2005. Different optimal offspring sizes for sons and daughters may favor the evolution of temperature-dependent sex determination in viviparous lizards. Evolution 59: 2275-2280


Shine R., Wall M., Langkilde T. and Mason R.T. 2005. Do female garter snakes evade males to avoid harassment or to enhance mate quality? American Naturalist 165: 660-668


Shine R., Wall M., Langkilde T. and Mason R.T. 2005. Battle of the sexes: forcibly-inseminating male garter snakes target courtship to more vulnerable females. Animal Behaviour 70: 1133-1140


Shine R., Langkilde T., Wall M. and Mason R.T. 2005. Alternative male mating tactics in garter snakes, Thamnophis sirtalis parietalisAnimal Behaviour 70: 387-396


Shine R., O’Donnell R., Langkilde T., Wall M.D. and Mason R.T. 2005. Snakes in search of sex: the relationship between mate-locating ability and mating success in male garter snakes. Animal Behaviour 69: 1251-1258


Langkilde T., Alford R.A. and Schwarzkopf L. 2005. No behavioural compensation for fitness costs of autotomy in a lizard. Austral Ecology 30: 713-718


Langkilde T., Schwarzkopf L., and Alford R.A. 2004. The function of tail displays in male rainbow skinks, Carlia jarnoldae. Journal of Herpetology 39: 325-328


Shine R., Lemaster M., Wall M., Langkilde T. and Mason R. 2004. Why did the snake cross the road? Effects of roads on movement and location of mates by garter snakes (Thamnophis sirtalis parietalis). Ecology and Society 9: 9.

[online] URL:


Shine R., Phillips B., Langkilde T., Lutterschmidt D., Waye H. and Mason R.T. 2004. Mechanisms and consequences of sexual conflict in garter snakes (Thamnophis sirtalis, Colubridae). Behavioral Ecology 15: 654-660


Shine R., Langkilde T. and Mason R.T. 2004. Courtship tactics in garter snakes: how does a male’s morphology and behavior influence his mating success? Animal Behaviour 67: 477-483


Shine R., Langkilde T. and Mason R.T. 2003. The opportunistic serpent: male garter snakes adjust courtship tactics to mating opportunities. Behavior 140: 1509-1526


Shine R., Langkilde T. and Mason R.T. 2003. Cryptic forcible insemination: male snakes exploit female physiology, anatomy and behavior to obtain coercive matings. American Naturalist 162: 653-667


Shine R., Langkilde T. and Mason R.T. 2003. Confusion within "mating balls" of garter snakes (Thamnophis sirtalis) - does misdirected courtship to other males impose significant selection on male tactics? Animal Behaviour 66: 1011-1017


Langkilde T., Schwarzkopf L. and Alford R. 2003. An ethogram for adult male rainbow skinks, Carlia jarnoldae. Herpetological Journal 13: 141-148


Langkilde T. and Schwarzkopf L. 2003. Observations of mating behaviour and reproduction in a small tropical scincid lizard Carlia jarnoldae. Herpetological Review 34:325-326









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