COMMON RAVEN RESOURCE USE AND BEHAVIOR AROUND NESTING HABITAT OF THE THREATENED WESTERN SNOWY PLOVER
|Janelle Chojnacki; Cal Poly Humboldt; firstname.lastname@example.org; Dr. Barbara Clucas
Common ravens (Corvus corax) are intelligent, synanthropic predators subsidized by human activity throughout their range. Because of their attraction to human food resources, raven populations are increasing in North America, which has intensified predation risk for many protected species, including the federally threatened Western snowy plover (WSP, Charadrius nivosus nivosus). The breeding population of WSP in northwestern California has continued to fall below recovery goals and ongoing monitoring consistently reveals raven nest predation to be one of the most prominent direct causes of WSP reproductive failure. We are using GPS units to track the movement of ravens captured near WSP nesting beaches in coastal Humboldt County to better understand the factors influencing high raven abundance locally. Preliminary analysis of two years of data have revealed high variation in movement patterns, home range sizes, and apparent anthropogenic food resources based on breeding status and age of the individual, season, as well as surrounding landcover features. These findings, coupled with behavioral observations of ravens at beaches where WSP nest, indicate that raven management strategies such as hazing, egg oiling, or targeting human behavior would best be based on an understanding of raven behavior and surrounding land cover with a targeted site-specific approach.