Midwest Fish & Wildlife Conference 2018

AUTHORS. Nathan W. Byer, University of Wisconsin-Madison; Brendan N. Reid, American Museum of Natural History; M. Z. Peery, University of Wisconsin - Madison

ABSTRACT. Evolutionary theory predicts that organisms should behave in a manner that maximizes their fitness. However, competing selective pressures may exert opposing influences on fitness components, which may force individuals to make behavioral decisions that balance these tradeoffs. One such tradeoff is that between adult survival and reproductive success, where behaviors associated with reproduction increase the risk of adult mortality. Turtles are expected to prioritize current survival over current reproductive success, as lifetime reproductive success is generally tied to longevity. However, this hypothesized "selfish" behavior has rarely been demonstrated, particular in the context of habitat use. We used information on habitat selection, nesting ecology, and movement ecology to investigate how female Blanding's Turtles in Wisconsin balance factors that affect adult and nest survival. In 2016 and 2017, female Blanding's turtles were tracked from home wetlands to nest locations to determine patterns of movement and nest placement. During these movements, we quantified predation risk to nesting turtles by using baited camera traps, and thermal constraints upon nesting turtles using temperature data loggers placed throughout the landscape and on tracked turtles. Nest survival was approximately 52% in 2016 and 30% in 2017, and varied between nesting areas; furthermore, females differed in distances moved to get to nesting areas. Predation risk and thermal conditions varied spatially, and female turtles appeared to select for warmer temperatures during forays to nesting areas. These results suggest that nesting behavior by turtles may be constrained by spatially-explicit patterns of risk. We plan to investigate these patterns further using long-term mark-recapture and nesting databases collected at our study site.