Biological sex identification in the endangered dusky gopher frog (Lithobates sevosa): a comparison of body size measurements, secondary sex characteristics, ultrasound imaging, and urinary hormone analysis methods

Background Accurate sex identification techniques are important for wildlife demographic studies and for genetic management of captive breeding colonies. Various non-invasive methods for identification of biological sex in the weakly dimorphic endangered dusky gopher frog (DGF; Lithobates sevosa) were explored to support planned recovery efforts for this species including breeding and augmentation of wild populations.