Welcome to the interactive web schedule for the 2018 Midwest Fish & Wildlife Conference! For tips on how to navigate this site, visit the "Helpful Info" section. To return to the main Conference website, go to: www.midwestfw.org.
Back To Schedule
Tuesday, January 30 • 6:00pm - 9:00pm
Poster Display. Population Demographics of the North American River Otter in Ohio After 12 Years of Harvest

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

AUTHORS: Sara Adamczak, E. Hance Ellington, Stanley Gehrt - School of Environment and Natural Resources, Ohio State University

ABSTRACT: The river otter (Lontra canadensis) was extirpated across large portions of North America by the early 1900’s. They were then reintroduced to Ohio from 1986-1993 and by the early 2000s, the population appeared to be growing rapidly. Subsequently, legal harvest of the reintroduced population began in 2005 and the otter population was monitored from 2005-2007 using harvest data. While the harvesting of river otters has continued, monitoring efforts ceased after the 2007-2008 harvest season, thus the status of the population is unknown. Our goal was to determine the status of river otter population in Ohio using data collected from harvested individuals and by comparing metrics from river otters harvested from 2005-2007 to river otters harvested from 2016-2017. We found that the length and weight of harvested male otters show a slight negative trend (though not significant) over time (2005-2007: 108.2076 cm [n = 207], 2016: 108.5954 cm [n = 35] and 2005-2007:  8.5517 kg [n = 235], 2016: 7.1672 kg [n = 32]). Harvested female otters showed a similar trend (2005-2007: 103.8508 cm [n = 190], 2016: 103.2492 cm [n = 31] and 2005-2007:  7.2802 kg [n = 216], 2016: 6.0681 kg [n = 31]).   The sex ratio of the harvested population has shifted from male biased in 2005-2007 (239 males, 225 females) to nearly equal in 2016 (32 males, 31 females). Using cementum annuli analysis we found that from 2005-2007, 60 % of the harvested individuals were juveniles ( 2 years old). We are currently analyzing the age structure of the 2016 harvested population and will present these results as well. Taken together these results indicate whether or not we have a stable population of river otter in Ohio, as harvest continues.

Tuesday January 30, 2018 6:00pm - 9:00pm CST
Ballroom C & Foyer