No abstract

We aimed to discern the seasonal movement patterns, home range sizes, and microhabitat associations of subadult Macrochelys temminckii in a West Tennessee population. Because this population was previously monitored (i.e., telemetry and habitat use) as juveniles after the initial release in 2005, studying the movement ecology and habitat use of the same released cohort 12 years later allows for unique comparisons between hatchling and subadult ecology. We used radio telemetry to collect movement and microhabitat data of 16 subadult M. temminckii during one year. Our results suggest that seasonal and ontogenetic variation in movement patterns and habitat selection occur within a cohort of M. temminckii. Compared to juveniles, subadults used deep slough areas with high overstory tree cover and had larger home ranges (100% minimum convex polygons [MCP]). Additionally, as subadults, the mean distance moved (m) varied among seasons and furthest during summer. Subadults used deeper water, with higher temperatures and significantly more tree canopy cover, than random locations. Overall, the home range estimate for subadults (mean MCP ± SE; 1.64 ± 0.57 ha) was greater than for juveniles (0.044 ± 0.021 ha). These home-range estimates and habitat usage patterns were similar to subadults in other studies. The seasonal and ontogenetic variations suggest that habitat heterogeneity is critical to sustain populations of introduced M. temminckii.

Methods used in wildlife ecology can influence population‐ and community‐level estimates, such as species richness, sex ratio, age and size structure, occupancy and detection probabilities, and community composition. Various trapping and sampling biases exist for freshwater turtles including bait and trap choice and survey technique. To date, no study has investigated the influence of hoop net and mesh size on various population‐ and community‐level estimates. Here, we use detection models to determine if trap and mesh size influence detection probability of nine species of freshwater turtles over 3 consecutive years (2016–2018) in west Tennessee. Additionally, we use multivariate models to determine if freshwater turtle community composition was influenced by hoop trap and mesh sizes. Our results indicated that there was a bias related to mesh size in detection probabilities and community composition. Smaller mesh sized traps were better at detecting smaller‐bodied turtle species, which then changed community species richness but not catch‐per‐unit‐effort estimates (i.e., abundance). Additionally, larger mesh sized traps were better at detecting common snapping turtles (Chelydra serpentina), which supports previous research. Our results suggest that researchers should account for the variation in detection probabilities by mesh size when conducting mark‐recapture and occupancy analyses. Moreover, erroneous inferences about population trends and changes in diversity within turtle communities through time could cause managers to misidentify population declines and conservation value of a site. © 2021 The Wildlife Society.