Population and behavioural ecology of snakes and lizards

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My research focuses on life-history variation, population ecology, and behavioural ecology of squamate reptiles (lizards and snakes). I propose four projects, each with multiple questions: (1) Individual animals vary in traits (e.g. size) that affect their likelihood of survival and reproduction. Here, I ask which traits most influence an animal's lifetime reproductive success. I also ask which components of a species' life history (e.g. adult survival, birth rate) have the greatest effect on its population growth rate. (2) Laboratory studies suggest that females in better condition when they mate give birth earlier. We will test this effect in free-ranging snakes in the field and determine the mechanisms involved. We also ask whether there are advantages to earlier birth (better survival of offspring, more frequent reproduction of mother). (3) Animals frequently have injuries, suggesting that they have survived an encounter with a predator. However, do predator-induced injuries have delayed negative effects (e.g. reduced growth, reproduction, survival)? Does the incidence of injury vary with anti-predator traits (e.g. camouflage)? Can we detect survival differences between animals with different anti-predator traits? (4) In egg-laying species, the female's pre-laying body temperature presumably is important for development of offspring. If so, do egg-laying females in cool climates retain eggs for longer to gain additional advantages from the female's own body temperature regulation? Alternatively, how selective are females about temperatures of nest sites? Could availability of suitable nest sites limit where egg-laying species can live? Finally, what are the consequences of length of egg retention for growth and future reproduction? I use both field and laboratory methods, including: mark-recapture analysis (1, 2, 3); population matrix analysis (1); radio-tracking (2, 4); temperature-sensitive radio-telemetry (2, 4); experimental manipulation of temperature regimes (2, 4); and spectrophotometric analysis of colour patterns of animals and their backgrounds (3). This work will contribute significantly to our understanding of tradeoffs in life-history traits and behaviour and how they influence population dynamics, which is applicable to conservation.