River Otter Reintroduction in Great Smoky Mountains National Park

Between 26 February and 31 March, 1986, 11 river otter (Lutra canadensis) were obtained from North Carolina, implanted with radio transmitters, and released on Abrams Creek in Great Smoky Mountains National Park. A total of 635 radio locations were obtained on eight otters.

Male home ranges averaged 14.1 km during the study (March - December) while female home ranges averaged 15.9 km. There were no significant differences in home range length (p > 0.05) between sexes.

A total of 75 scats (42 samples) were collected during the study. Food items were calculated on frequency of occurrence. Crayfish occurred in 95% of all samples, followed by fish at 90%. Major fish species eaten were white suckers (57%), stonerollers (50%) and northern hogsuckers (40%). No specific size selection of fish was found. Other food items identified included frogs, turtles, salamanders and insects.

Den sites were identified during the study. Otters used rock crevices/caves 32% of the time, followed by thick vegetation (24%), animal burrows (24%) and vegetative debris (20%).

All but one otter was found to associate with at least one other otter during the study. Ninety-seven percent of the interactions were male/female interactions.

Activity centers (areas where the otter spends 10% or more of its time) were identified for seven of the eight otters. All activity centers were in remote or inaccessible areas. Activity centers were shared by two otters in three instances.

Only one mortality occurred during the study. A male died two weeks after release. Cause of death was not known, but it is likely the animal starved, due to poor condition of his teeth.

No reproduction was recorded during the study. However, males and females interacted throughout the study. Objectives were met for this study and results indicate that the reintroduction was successful. The only remaining question is whether reproduction occurred; further surveys will have to be conducted to verify this important factor.