Discovery of an Alligator Snapping Turtle ( Macrochelys temminckii ) Population in Metropolitan Houston, Harris County, Texas

Habitat loss through urbanization is an important threat to many wildlife species. While some species thrive in suboptimal urbanized conditions, many species appear to be incapable of adapting to urbanization. Despite the adaptability of some reptile species to urban habitats, populations are often small in comparison to those that inhabit areas outside of urban areas where habitat alterations are far less extreme and suitable habitat more expansive. Globally, a disproportionate number of turtle species are facing population declines, local and regional extirpations, and extinction. In the United States, many species are suffering regional population declines. The Alligator Snapping Turtle is the largest species of freshwater turtle in the United States. Despite its large geographic range, distribution data gaps exist for this iconic species. Notably, research on this species in the westernmost portion of its Texas range has been sporadic and not all-encompassing. In surveys beginning in 2016, we documented the presence of a seemingly robust Alligator Snapping Turtle population inhabiting waterways in and around Harris County, Texas, the third most-populous county in the United States. We trapped turtles on a monthly basis from December 2016–October 2018 and captured 23 males, 22 females, and 12 juveniles. Catch-per-unit effort, expressed as captures per net-night, ranged from 0.00–0.83 turtles per net-night, with an overall rate of 0.40 turtles per net-night. Future work with this population should include increasing trapping efforts to calculate population estimates and demographics such as density, biomass, and annual survivability.