Influences of temperature and time on habitat use patterns of a semi-aquatic turtle

Many ectothermic vertebrates have predictable seasonal activity and
habitat use patterns, but variable patterns at fine temporal scales (e.g.,
minutes to days) that are likely influenced by thermoregulatory demands on
behavior. Wood turtles (Glyptemys insculpta) are freshwater turtles known
to use terrestrial environments during their active period. However,
little research has been conducted to quantify the influence of
environmental factors on diel habitat use patterns. We used
fine-resolution global positioning system (GPS) tracking and temperature
data to quantify wood turtle aquatic-terrestrial habitat-use patterns from
May through August 2015 and 2016, focusing on the influence of temporal
variables and environmental temperature. We found that temporal variables
and open canopy air temperature had strong explanatory power for wood
turtle aquatic-terrestrial habitat use patterns, but temperature was a
stronger predictor. Terrestrial activity was positively associated with
air temperature, resulting in a consistent pattern of daytime terrestrial
and nighttime aquatic activity during the pre-nesting period. Male and
female activity patterns diverged during the post-nesting activity period,
with most males returning to the river at night and most females remaining
terrestrial, influenced by females moving farther from the river. The
results of our study provide valuable information to inform population
survey design, habitat management planning, and potential responses to
climate change for this unique species of conservation concern.