A Recipe for Success:
Reintroduction of River Otter in Indiana
By Shawn Rossler
The sight of a wild river otter swimming, sliding, or vocalizing is an experience everyone should have the opportunity to enjoy at least once in their lifetime. Thanks in part to the Indiana DNR Division of Fish & Wildlife (DFW), this opportunity is now a reality for Hoosiers willing to visit or navigate one of the state’s waterways. However, this wasn’t always the case.
River otters were extirpated from many Midwestern states due to habitat degradation and unregulated harvest. In Indiana, river otters received protection in 1921, but the efforts were too little, too late. Except for a few sparse reports, otters were essentially unheard of and remained a missing piece of aquatic systems throughout much of the 1900s. Talks of reintroducing otters to Indiana started in the late 1970s, but concerns over habitat quality stalled efforts. The pros and cons of reintroductions were discussed on and off over the course of two decades.
During the late 1980s and early ’90s, other Midwestern states were having the same conversation and began experimenting with river otter reintroductions. One of the most involved otter reintroductions was completed by the Missouri Department of Conservation. The Missouri framework was extremely successful and eventually served as a template for many states, including Ohio, Kentucky, and Illinois.
The proven track record of successful reintroductions in other states reignited the otter conversations in Indiana. At the request of the public, the DNR Fish & Wildlife nongame program conducted a feasibility study to determine if river otter reintroductions were viable in Indiana. Staff from the DNR Fish & Wildlife and U.S. Fish & Wildlife Service completed an extensive review of Indiana’s river basins. Biologists reviewed all watersheds with consideration to habitat quality, socio-economic concerns, reintroduction logistics, regulatory provisions, and funding for such a large project. All Indiana watersheds were ranked as to which was most likely to give otters the best opportunity to survive. The areas showing the most promise were the Muscatatuck River, Tippecanoe River, and Patoka River basins.
In early 1995, 25 otter were released at Muscatatuck National Wildlife Refuge. They were fitted with internal radio transmitters that allowed biologists to track their movement and determine their survival and dispersal. The results of the preliminary release were promising, and the decision was made to move forward with additional releases. Over a five-year period, 303 otters were transported from Louisiana and released at 12 sites in northern and southern Indiana.
Partnerships were a critical part of the reintroduction. After being transported from Louisiana, otters were housed temporarily at Purdue University, where they went through a complete physical and received veterinary care to ensure they were in the best health prior to release.
The Indiana State Trappers Association provided fish needed to feed the otters prior to their release, and many Hoosiers made financial contributions to the nongame fund that directly supported the reintroductions.
After the otters were released, DNR Fish & Wildlife staff continued to monitor trend information gathered from annual bridge and stream surveys, citizen reports, and incidental mortality reporting. The five-year reintroduction program was completed in 1999, and it didn’t take long to see that the released otters took an immediate liking to Indiana.
The reintroduction recipe was so successful that by 2005 otters were removed from the state’s endangered species list. It has been 20 years since the first release and almost 10 years since delisting. River otters have now been documented in 80 percent of Indiana counties, and all information indicates the otter population continues to expand.
Although original release sites were in northern and southern Indiana, otters are now moving into central Indiana. Data from the feasibility study indicated the habitat in central Indiana wasn’t considered ideal for river otters, but some otters have found suitable habitat to survive. Work to improve water quality in the state has likely benefited river otter expansion.
Thanks to the hard work and dedication of DNR Fish & Wildlife and partners, river otters are expanding in Indiana and now occupy much of their historic range, representing a success story for wildlife conservation. As with similar wildlife success stories in Indiana (white-tailed deer, wild turkey, and beaver) there is usually a next chapter. DNR Fish & Wildlife is currently preparing to ensure the next chapter is also a success. The goal is to use modern wildlife management techniques to guarantee river otters continue to do well and remain part of the Hoosier landscape for the benefit, enjoyment, and memories of future generations.
Shawn Rossler is the Furbearer Biologist with the Indiana Department of Natural Resources, Division of Fish & Wildlife.