Evidence of Ringtail Expansion Into Idaho, USA

Ringtails (Bassariscus astutus) are widely distributed in the western United States and across much of Mexico, yet due to their relatively low densities and cryptic nature, little is known about their basic ecology even where they are common. Recent public sightings suggest ringtails may have expanded their distribution north into southern Idaho, USA. Currently, ringtails remain unclassified in Idaho thus limiting resources and time available for population monitoring. We attempted to detect these small carnivores in southern Idaho during winter 2023. We deployed 49 camera traps with a combination of lures (i.e., trapping lure, fruit, and orange drink mix) in canyon habitats in southern Idaho near recent ringtail sightings. We detected ringtails nine times on six different camera traps. Although incidental ringtail observations increased in southern Idaho since the early 2000s, our detections were the first to result from a targeted survey effort. Given more than 20 years of incidental sightings and multiple detections during our survey, it appears that ringtails have expanded their range northward into southern Idaho and could be considered a resident species in the state. Further efforts to document reproduction, annual persistence, and an assessment of threats could be next steps if the state wildlife management agency deems it a priority and an appropriate use of resources.