Nest Site Selection and Nest Success of Wood Turtles (Glyptemys insculpta) in Central Maine

Wood turtles (Glyptemys insculpta) have been experiencing widespread declines across their range, but Maine has a reputation of being a stronghold. Based on previous work at our study sites, our population is expected to go extinct within 150 years. To enhance population viability, it is essential to understand nesting requirements and recruitment into sensitive wood turtle populations. This study quantifies nest site selection parameters, such as microhabitat, competition, and estimating nest success and recruitment by providing a better understanding of female nest site selection in a Maine wood turtle population. The main objectives of this study are: (1) to define wood turtle nest site characteristics, (2) determine if these characteristics are influencing nest success and (3) to determine the differences in characteristics between nests and test digs. Over 2 years, we observed and analyzed microhabitat characteristics that females may be selecting for when they test dig or nest. Our results, which are based on multinomial logistic regression models of 15 microhabitat variables, show iButton temperature and humidity, distance to closest overwintering stream and vegetative variables all aided in nest site selection. Out of the 21 of nests, 17 were predated (81%) and 4 were successful (19%) as defined by having at least one successfully hatched egg. Based on an MCestimate, a tool for estimating nest success with competing risks through MATLAB, vegetation above and below the soil, and precipitation showed slight significance in aiding nest success. Our approach for studying nest and test dig microhabitat characteristics has determined which characteristics are important to females when selecting where to nest. This information can be used to aid in increasing nest and hatchling success by emphasizing the need for informed conservation management decisions.