Proceedings of the Vertebrate Pest Conference

Nutria are large semi-aquatic, herbivorous rodents native to South America, but were brought to the United States in the early 1900s for the fur farming industry. At high densities, nutria damage marsh vegetation. To more effectively manage nutria, we identified effective attractants and designed a multiple capture trap (MCT). Four lures (nutria urine, nutria fur extract, synthetic anal gland secretion, and a commercially available apple-based lure) were examined under field conditions, using leg-hold traps. A total of 285 nutria were captured during a 10-day trial with 1,000 trap-nights. All lures tested increased trapping success from 42% to 120% over untreated traps, with nutria fur extract being the most effective. Additionally, the lures did not attract nontarget animals. Next, we tested the MCT: 6 were baited with foods (carrots, corn, and sweet potatoes), and another 6 used trays of fertilized marsh plants as the lure. During the 10-day trial, with 122 trap-nights, 10 nutria were caught in the food-baited traps and 12 in the marsh plant-baited traps. As many as 3 nutria were captured overnight in one trap. On two occasions, individual nutria escaped the traps when approached by a person. No non-target animals were captured, however, it was suspected that swamp rabbits were entering the MCTs to feed and then were able to go back out the “one-way door”.