Graduation Date

Fall 2016

Document Type

Dissertation/Thesis

Program

Master of Science degree with a major in Natural Resources, option Wildlife

Committee Chair Name

Dr. Mark Colwell

Committee Chair Email

mark.colwell@humboldt.edu

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Daniel Barton

Second Committee Member Email

daniel.barton@humboldt.edu

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Barbara Clucas

Third Committee Member Email

barbara.clucas@humboldt.edu

Third Committee Member Affiliation

HSU Faculty or Staff

Fourth Committee Member Name

Dr. Micaela Szykman Gunther

Fourth Committee Member Email

micaela.szykman.gunther@humboldt.edu

Abstract

Common ravens (Corvus corax) are intelligent generalists and a principal predator affecting population recovery of several threatened and endangered species, including the threatened western snowy plover (Charadrius nivosus nivosus). In Humboldt County, raven predation is a primary cause of low nest survival. Nest exclosures, cages around eggs that preclude entry by predators but allow plovers access to incubate, are known to increase nest success. However, speculation exists that exclosures may attract predators. The aims of this study were to summarize corvid distribution on Clam Beach County Park and Little River State Beach, evaluate habitat features associated with corvid activity on the ground, assess how ravens respond to exclosures around artificial plover nests, and to determine if this response changed over time. I used raven tracks as an index to quantify raven activity. Using Generalized Linear Mixed Models (GLMMs), I evaluated overall raven response and response within each of five 28-day trials. There was no evidence that ravens were attracted to exclosures, nor that their responses changed over time. These results suggest that the use of exclosures may be a viable option for managing raven nest predation in Humboldt County in the future.

Citation Style

Journal of Wildlife Management

Included in

Ornithology Commons

Share

 
COinS