Evaluation of a Simulated Howling Survey for Wolves

Wolf (Canis lupus) packs were surveyed using simulated howling survey (Harrington and Mech 1982) in a $1,400-\text{km}^{2}$ area of northcentral Minnesota with a known density of radio-marked packs. Mean distance that wolf howls could be heard was 2 km (n = 74 trials). Howling at 55 sites indicated the presence of 5 packs and resulted in a density estimate (7.5 packs/1,000 km2) that was imprecise (95% CI = 2.5-16.4/1,000 km2) and 1.7 × greater than the actual density (4.3/1,000 km2). Because of logistical and statistical constraints, the technique is not practical for surveying large (e.g., state- or province-wide) areas, but simulated howling is useful for locating packs in smaller areas.