Pest reduction on agricultural lands due to Hawaiian short-eared owls

Project Overview

Project Type: Professional + Producer
Funds awarded in 2018: $49,755.00
Projected End Date: 03/31/2021
Grant Recipient: University of Hawaii
Region: Western
State: Hawaii
Principal Investigator:
Dr. Melissa Price
University of Hawaii


Not commodity specific


  • Natural Resources/Environment: wildlife
  • Pest Management: biological control
  • Sustainable Communities: public participation, quality of life

    Proposal abstract:

    Hawaii's increased agricultural biodiversity has attracted an influx of non-native and introduced
    avian and rodent pests (1). These pests account for heightened rates of crop perishability, with an
    estimated total of over $100 billion in damage across the United States (2); farms statewide have
    reported up to 80-100% of crop loss due to these pests (1). Diversified crops are more likely to
    sustain damage than the sugarcane and pineapple that previously dominated Hawaii’s
    agricultural industry (1), putting producers and workers seeking to fulfill demand for more
    diversified outputs at economic risk (3). Introduced avian and rodent species also act as vectors
    for disease, dispersal agents for noxious weeds, and competitors with native species (4, 5, 6).
    Pest deterrent techniques are costly, impermanent, and often ineffective (7). Raptors, especially
    owls, have proven an effective form of biocontrol (8, 9, 10, 11, 12, 13, 14). Pueo, or the
    Hawaiian short-eared owl, is the only endemic avian predator on Oahu and Maui (15), with
    pellet content demonstrating a dietary inclination toward non-native avian, rodent, and
    invertebrate species (16). We aim to use a standardized survey protocol to assess the distribution
    and abundance of Pueo on Oahu and Maui agricultural lands; determine Pueo seasonal habitat
    use of agricultural lands, through tagging; examine owl pellets to assess potential reduction in
    crop predation by pest species; and produce a list of possible measures to increase Pueo
    abundance on agricultural lands, to be applied by farmers and landowners. Through farmer-tofarmer
    interactions and a project website, we intend to promote farmer participation in survey
    efforts. Producers have been involved from the inception of this project and will continue to
    advise throughout, in order to achieve a “win-win-win” for the native Pueo, for Hawai‘i
    conservation, and for economic benefits to agriculture.

    Project objectives from proposal:

    1. Assess the distribution and abundance of Pueo on Oahu and Maui agricultural lands.
    We will utilize a standardized survey protocol to assess the distribution and abundance of
    Pueo on agricultural lands. This will subsequently increase potential for the ecological
    stabilization of the species by way of habitat intervention and creation.
    2. Evaluate potential reduction in pest species through diet analysis on owl pellets. Pellet
    content will be examined to assess potential reduction in crop predation by pest species.
    Avian and rodent pest species will be surveyed and compared with pellet results to
    determine which species Pueo prey upon.
    3. Determine seasonal habitat use of agricultural lands by Pueo: Short-eared Owls have
    been documented to forage close to their nesting sites, venturing further only during
    depressed prey availability (28, 43, 44). Pueo will be captured, fitted with auxiliary
    markers, and tracked for approximately one year to identify agricultural habitats used and
    to build home range models for understanding resource use and selection.
    4. Develop Habitat Conservation Recommendations for Producers: We will develop a
    set of Best Management Practices for producers detailing Pueo habitat preferences on
    agricultural lands. These BMPs to increase Pueo abundance on agricultural lands will be
    made available to farmers and landowners through the project website and other venues.
    5. Increase producer and public awareness of the role of Pueo in agriculture: We will
    promote the Pueo as a biological control agent by publishing results online and presenting
    at farm and producer meetings throughout the project and beyond.

    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.