Athene cunicularia hypugaea wintering in a central California urban setting arrive later, leave earlier, prefer sheltered micro-habitat, tolerate rain, and contend with diverse predators

Abstract

The wintering phase of the Western Burrowing Owl (Athene cunicularia hypugaea) life cycle has received little attention in the literature. Small numbers of Burrowing Owls have been observed and recorded since 2008 in the winter season in Cesar Chavez Park, a 90-acre peninsula that forms part of the waterfront of the City of Berkeley. The relative ease of observation in this setting allows study of their arrival and departure dates, selection of micro-habitats, tolerance of human presence, behavior in inclement weather, and response to avian and canine predator threats. Viewed over a decade, fewer owls arrived, arrived later, left earlier, and spent less time in residence. Most owls settled in shoreline rip-rap or in tall vegetation; only one fourth settled in short grass. Owls chose exposure to rain for as long as two days. Owls varied widely in tolerance to human proximity. Owls successfully dealt with avian predators, but displayed stress and in some cases became casualties of loose Canis lupus familiaris. Recommendations for habitat management follow.