Testing automated howling devices in a wintertime wolf survey

Abstract

Previous tests of the automated acoustic device, referred to as a howlbox, effectively identified the presence of wolves (Canis lupus) during the summer, near rendezvous sites. Howlboxes are self-contained devices that broadcast simulated wolf howls and record howls made in response, and are of interest in remote locations to document the presence of dispersing wolves and new wolf packs. It is unclear whether the howlbox can also detect wolves during the winter when wolves are more mobile. We tested the howlbox's ability to detect wolves in an area with approximately 3 wolves/100 km2 and overlapping pack territories in western Wyoming, USA, during January–May 2011. Howlboxes detected wolves in only 1.1% (n = 185, 95% CI = 0.1–3.8%) of the surveys, but we recorded wolf tracks within 50 m of howlboxes 14.8% (n = 54, 95% CI = 6.6–27.1%) of the time. Though howlboxes seldom recorded wolf howls, our findings suggest the possibility that howlboxes may attract wolves in areas with overlapping pack territories during the winter. © 2013 The Wildlife Society.