Quantifying the frequency and effects of secondary exposure to rodenticides in barn owls

Project Overview

SW18-063
Project Type: Research and Education
Funds awarded in 2018: $249,546.00
Projected End Date: 03/31/2022
Grant Recipient: California State University
Region: Western
State: California
Principal Investigator:

Commodities

Not commodity specific

Practices

  • Crop Production: application rate management
  • Education and Training: farmer to farmer, on-farm/ranch research
  • Natural Resources/Environment: wildlife
  • Pest Management: biological control, chemical control, integrated pest management
  • Production Systems: agroecosystems

    Proposal abstract:

    Barn owls are a popular component of Integrated Pest Management (IPM) programs for
    the control of rodent pests across the Western United States and contribute to
    sustainable agriculture through integration of natural biological control, enhancing
    the environmental quality of agricultural regions, and sustaining the economic
    viability of farm operations. However, because farmers utilize rodenticides to control
    rodent pests, owls can suffer from both lethal and sub-lethal secondary poisoning.
    Despite the important role that owls can play in providing long-term, sustainable, and
    natural pest control services, we have little understanding of how often owls are exposed
    to rodenticides and what effect this exposure has on their behavior and reproductive
    success.
    To tackle this critical gap in knowledge, our study will address five key objectives:
    1) Determine if rodenticide exposure affects growth rates in owl nestlings;
    2) Understand how land use type, rodenticide applications, and prey choice affect
    the frequency of rodenticide exposure;
    3) Inform predictive models on the efficacy of barn owls for controlling rodent pests
    on farms;
    4) Create stakeholder-verified recommendations for the use of rodenticides in
    combination with barn owls for effective IPM; and,
    5) Disseminate findings to producers through publications, a field-demonstration,
    visits to rural schools, and presentations to pest-control and agricultural groups.
    We will use innovative blood- and fecal- testing methodologies to detect recent
    rodenticide exposure in adult and nestling owls, and will use GPS-tags on adult owls to
    understand where they may be capturing poisoned rodents. Our project team is uniquely
    positioned to execute the research and education proposed in this application. The
    producers on our project team have all utilized barn owls as part of IPM programs for
    rodent control on their land and the academics on our project team have contributed to
    both research and outreach on vertebrate pest control utilizing raptors.

    Project objectives from proposal:

    1) Determine if rodenticide exposure affects growth rates in owl nestlings;
    2) Understand how land use type, rodenticide applications, and prey choice affect
    the frequency of rodenticide exposure;
    3) Inform predictive models on the efficacy of barn owls for controlling rodent pests
    on farms;
    4) Create stakeholder-verified recommendations for the use of rodenticides in
    combination with barn owls for effective IPM; and,
    5) Disseminate findings to producers through publications, a field-demonstration,
    visits to rural schools, and presentations to pest-control and agricultural groups.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.