Sampling freshwater turtle populations using hoop nets: Testing potential biases

• Published in: Wildlife Society bulletin Vol. 38; no. 3; pp. 580 - 585
• Main Authors: Mali, Ivana, Brown, Donald J., Ferrato, Jacqueline R., Forstner, Michael R. J.
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.09.2014; Wildlife Society
• Subjects: Animal traps; Ecoregions; Fresh water; freshwater turtles; Herpetology; hoop nets; methods; Ponds; sampling; Sampling bias; Texas; Tools and Technology; Turtles; Wildlife conservation; Wildlife management; Wildlife population estimation
• ISSN: 1938-5463; 1938-5463; 2328-5540
• DOI: 10.1002/wsb.427

The baited hoop-net is one of the most heavily used sampling tools for monitoring freshwater turtle populations. In the past several years, we have published a series of studies that tested potential biases associated with this sampling method. For this paper, we used a new experiment to directly test the influence of trap-mouth opening size on both captures and escapes. We also summarized the results from previous studies to direct future research on this topic and provide a useful guide for managers and researchers using this sampling device. In our experiment during May 2013 in Texas, USA, we found that traps with larger mouth-openings were more efficient at capturing turtles, while escapes were minimal for both mouth sizes. Thus, at least within the boundaries we tested here, increasing mouth-opening size is an effective way to increase captures without introducing biases caused by differential escape probabilities.