Over a two-year period (2013–2015), we trapped and radio-tracked 20 Tawny Owls at two study sites in northern Spain. We obtained 4257 radio-tracking locations, 328 of which were associated with vocal activity. Home ranges were significantly different between the two study sites (95% minimum convex polygon (MCP) = 125.79 ha vs. 95% MCP = 50.96 ha). Territory size was significantly less than 95% MCP home ranges and not significantly different from 70% MCP home ranges at both study sites, but was significantly larger than 50% MCP home ranges in the second site. Locations with vocal activity tended to be significantly closer to the home range border than random non-vocal locations. However, Tawny Owls focused vocal activity over the 50% MCP and close to the border of 70% MCP at both study sites. Home ranges were not significantly different between sexes for any of the three spatial scales, but male territories were significantly larger than female territories. The vocal behaviours of some owls, mainly females, were negligible or anecdotal (less than five vocalizations detected during the study period), and female territories were significantly smaller than male territories.
Minimum convex polygon, radiotelemetry, spontaneous calls, Strix aluco, territorial behaviour, vocal activity