Effects of hoop-net mouth opening on capture success of Rio Grande Cooters (Pseudemys gorzugi)

Therefore, identifying and minimizing these biases, especially when studying elusive and conservation-sensitive species, is important.The Rio Grande Cooter (Pseudemys gorzugi) is a medium to large riverine turtle whose range is limited to the lower Rio Grande watershed in New Mexico and Texas in the USA and Tamaulipas, Nuevo León, and Coahuila in Mexico (Degenhardt et al. 1996;Ernst and Lovich 2009).This species can be locally abundant in the USA, but the overall densities across its range are low (Bailey et al. 2014).The Black River, a tributary of the Pecos River in Eddy County, New Mexico, is the only system where juvenile P. gorzugi are readily observed and captured via hoop-nets (Mali et al. 2018).Systematic annual surveys using traditional hoop nets to capture P. gorzugi in the Black River began in 2016 (Mali et al. 2018).During the first six years, we caught turtles of various sizes (straight-line carapace length = 33-300 mm).