Movement and habitat ecology of protected species in North Carolina

Abstract

Reptiles and amphibians are declining worldwide, especially from global climate change and habitat loss and fragmentation. Conservation efforts for imperiled species usually involve habitat protection, but are only effective if biologists and land managers have a thorough understanding of a species’ habitat requirements. This prerequisite knowledge is complicated for many herpetofauna because they utilize different habitats throughout their lifetime, such as separate breeding and non breeding habitats. Thus, multiple habitats must be studied and protected for conservation to be successful. This research aimed to better understand the habitat ecology of two protected herpetofaunal species in North Carolina to enhance future conservation. The first species, mountain chorus frogs (Pseudacris brachyphona), are small, terrestrial frogs, and a state species of special concern. Like many amphibians their breeding habitat has been studied, but little is known about their post breeding habitat. Nineteen individuals from two breeding sites were tracked by radio telemetry for approximately 25 days as they left their breeding site to examine their post breeding habitat. Breeding pools were surrounded closely by field and orchard habitats, and more distantly by forest. Frogs traveled 11.4 475.6 m from their breeding site, and no macrohabitat selection was detected among available habitats. However, the majority of individuals from the breeding site nearest the forest entered the forest, and the farthest traveling individuals from the other breeding site did as well. Mountain chorus frogs likely continued moving after 25 days, and were selecting forest habitat. I measured percent cover of vegetation within 1 m2 plots in all habitats, and forest had significantly greater leaf litter and canopy cover than did field and orchard. Likewise, there were significantly more burrows available in the forest than in other habitats. These habitat characteristics would provide greater protection from predators and desiccation in the forest, which could explain preference for forest. The second species studied, the bog turtle (Glyptemys muhlenbergii), is a small freshwater species, that is both federally- and state threatened. The majority of its habitat in the southeastern United States is small wetlands in livestock pastures, dominated by emergent vegetation (rushes and sedges) and with little shrub and canopy cover. I followed the movements of six turtles using radio telemetry from May October 2015 in a unique bog turtle wetland. This site is in Nantahala National Forest, has likely had little human disturbance for 80 years, and approximately half of the wetland is shrub/scrub habitat. Resident turtles significantly preferred shrub/scrub habitat with 68% of locations within this habitat type. I located two nests, both in emergent habitat. Shrub/scrub had significantly greater abundance of deep mud, which could explain turtles’ preference for this habitat. Bog turtles frequently burrow down into mud, and deeper mud might be easier to move through. Females had greater mean daily movement rates and home ranges (8.3 m/day, 0.6064 ha) than males (5.0 m/day, 0.4458 ha), which might be due to nesting migrations to emergent habitat. Thus, bog turtles will utilize shrub/scrub habitat where available, but nest in emergent habitat, likely due to its better thermal environment for offspring development

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