Thesis Title

Use of Fecal Progestins and Androgen to Determine Gender in the North American River Otter (Lutra Canadensis)

Date of Graduation

Spring 2006


Master of Natural and Applied Science in Agriculture


College of Agriculture

Committee Chair

Dennis Schmitt


Conservation departments in many states have successfully reintroduced river otters over the last twenty years. As a result, the river otter population has become over populated in some areas and is leading to conflicts with humans. Therefore, there is a need for conservation departments to better manage the river otters. Noninvasive methods to monitor fecal steroid metabolites useful in similar carnivore species will provide valuable information to determine gender ratios of wild populations. This study used fecal samples from 4 North American river otters (2 males and 2 females) at Wonders of Wildlife in Springfield, MO to validate testosterone and progesterone radioimmunoassays. Testosterone and progesterone demonstrated parallelism. The mature otters (3 females and 2 males) housed at Wonders of Wildlife and Dickerson Park Zoo in Springfield, MO. These samples were then analyzed to determine progesterone and testosterone levels. Progesterone varied significantly between the male and female at Dickerson Park Zoo from January to March (p≤0.007). Testosterone was significantly higher in the male at Dickerson Park Zoo than the female (p≤0.001). These results indicate that fecal steroid hormones may be beneficial to determine gender and reproductive status in river otters.


river otter, hormones, estrous, gender, reproduction

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© Tracy Northcutt