Study of Post–release Data in the North American River Otter (Lutra canadensis)

Abstract

A retrospective study conducted on post–release data of 17 hand–reared North American river otters (Lutra canadensis) over a 14–year period substantiates the effectiveness of the soft release method for this species. Records show that 100 percent of released otters returned to utilize a feeding station at the release site. These return visits ranged from a period of three weeks up to eight months post–release. Twenty–eight percent of these animals returned to the hack station after having sustained injuries. A hack station refers to a site from which an animal is released and is accustomed to receiving food. More than half of the injured animals readmitted required and received medical treatment and were released. The data reveals that river otters respond favorably to this type of release and provides convincing results for long–term success. The results validate this method, as well as demonstrate that slow release played a role in the increased survival rate of the study group. Since the method provides otter pups with backup food and care while they are experiencing life in the wild, it allows them to make and learn from mistakes, which might otherwise prove to be fatal.