Demography, Morphometrics, and Stomach Contents of Common Ravens Examined as a Result of Controlled Take

Authors

• Corinne M. Gibbe, California Department of Fish and WildlifeFollow
• Kriss K. Neuman, Point Blue Conservation Science
• Jessie Beck, Oikonos Ecosystem Knowledge

Date of this Version

Winter 2021

Document Type

Article

Citation

Human–Wildlife Interactions (Winter 2021) 15(3): article 15 

doi: 10.26077/668c-c06a 

Special topic: Raven management 

Comments

Open access. License: CC BY 4.0

Abstract

Common ravens (Corvus corax; ravens) are known nest predators that have the ability to negatively impact nesting birds, including imperiled species of seabirds and shorebirds. We conducted systematic necropsies of ravens that were lethally controlled in Monterey Bay, California, USA during 2013–2015, in or near western snowy plover (Charadrius nivosus nivosus) nesting areas, in an effort to better understand body condition, overall health, and diet of individual ravens. Raven predation of snowy plover nests has increased over the years in the Monterey Bay study area, and lethal removal of ravens has been employed to reduce predation. Most ravens examined in this study were in moderate to excellent body condition and also exhibited good organ health. There were statistically significant differences between male and female morphometrics (mass, culmen length, and wing length; P < 0.05). Stomach content analysis indicated a varied diet with consumption of animal remains and eggshell fragments, and anthropogenic sources of food (e.g., human food items and human-produced non-food items). Our study provides evidence that lethal control of ravens targeted some individual ravens that were responsible for depredating snowy plover nests.