Bovine-avian interactions on dairies: improving cow welfare and farm economic stability by implementing effective and sustainable pest bird deterrence methods

Project Overview

Project Type: Research and Education
Funds awarded in 2016: $238,105.00
Projected End Date: 09/30/2019
Grant Recipient: Washington State University
Region: Western
State: Washington
Principal Investigator:
Dr. Amber Adams-Progar
Washington State University

Annual Reports

Information Products


  • Animal Products: dairy


  • Animal Production: animal protection and health
  • Education and Training: decision support system, demonstration, extension, farmer to farmer, focus group, on-farm/ranch research, workshop
  • Natural Resources/Environment: habitat enhancement, wildlife
  • Pest Management: biological control, disease vectors, prevention, traps
  • Sustainable Communities: sustainability measures

    Proposal abstract:

    The pest bird problem on dairies in the Pacific Northwest (PNW), especially regarding European starlings (Sternus vulgaris), has been compounded with changes in land use and agricultural practices over the past 20-30 years. In other areas of the U.S., the impact of the non-native European starlings on dairies has been linked to significant economic damages (including loss of high-value feed components and subsequent loss of milk production in cows) and disease transmission concerns (including Escherichia coli O157:H7 and Salmonella). In the PNW, dairies have become fewer in number but herd sizes have grown, such that the total number of dairy cows has remained relatively constant. This intensification has led to an increased use of open commodity sheds with high-energy feeds, such as grains and cottonseed, piled high for ease of access by loader tractors. Similarly, tarped, open-face bunker silos for corn silage and haylage have largely displaced enclosed, upright silos. Unfortunately, these newer feed storage practices allow better access for foraging birds. As acreage devoted to blueberry and other fruit crops has dramatically increased in the PNW, dairies are increasingly likely co-located in less than two miles from a fruit crop. This dairy-fruit interface provides an ideal habitat for European starlings to feast on open commodity storage and bunker faces in fall, winter and spring, and then access ripening fruit in summer. Dairy facilities also provide birds with year-round roosting habitats. In a recent survey of approximately 50 dairy producers in Washington, respondents valued their pest bird damage losses between $1,000 and $200,000 per dairy, per year. Furthermore, survey participants described a wide variety of bird deterrent techniques (most commonly shooting, poisoning, and noise harassment) they have implemented on their farms and have observed low levels of both effectiveness and community support. Other bird deterrent options such as professional falconry or native raptor attraction are potentially more cost effective and environmentally sustainable, but most producers do not understand the benefits and costs of these options. By assessing bird populations, feed losses, cow behavior and related health factors, this project will result in a comprehensive identification of economic impacts of pest birds not only to producers but to the entire regional economy. By further conducting pilot efficacy trials of professional falconry and native raptor attraction techniques, the project will provide information on the benefits and costs of sustainable bird deterrence techniques. Recommendation of specific bird deterrent techniques requires an improved understanding of the economic losses dairy producers face due to pest bird damage and the cost effectiveness of various deterrents. Documentation of losses could motivate producers to address this problem. Additional research is needed to quantify the number of pest birds present on dairies and determine the factors affecting the cost effectiveness and sustainability of any specific pest bird control technique on a dairy. Results from a comprehensive survey of dairy producers focusing primarily on producer perceptions of bird damage on their farms, coupled with on-farm bird counts and feed bunk loss experiments, will provide a foundation from which to make pest bird control recommendations in the future. The potential disease vector role of starlings has been documented, although no known studies have evaluated the impact of pest birds on dairy cow behavior and welfare. Video recordings targeting dairy feed bunks will shed light on pest bird-cow interactions that occur when cows are feeding and whether pest bird presence is detrimental to dairy cow welfare. If pest birds are deemed to impose a negative stressor on cows, this factor can be included when determining the need for intervention to control pest bird activity. Documenting feed quality loss (from birds selecting the most nutritious components) and Escherichia coli O157:H7 and Salmonella prevalence (from birds defecating on feed) at the feed bunk, by comparing feed characteristics pre- and post- bird presence, will also lead to a more accurate estimate of bird damage costs. This information will be useful to producers as they consider costs and benefits of implementing pest bird control measures. Throughout this study, dairy producers will be actively engaged with the research team through educational events. Extension outreach seminars and on-farm educational field days will be offered to discuss pest bird issues on dairies, provide demonstrations and study updates, and encourage producer-to-producer conversations on bird deterrent strategies. Extension and popular press publications (including a best management practices checklist on how to make dairies less hospitable to pest birds and more hospitable to beneficial bird species) will also be distributed to share study results with stakeholders, and a cost-benefit analysis tool will be developed for producers. These efforts will help producers: 1) recognize the economic and environmental effect of pest birds on dairies; 2) increase their understanding of alternative bird deterrent techniques; 3) increase their ability to identify and measure bird damage on their dairies; 4) employ the cost-benefit analysis tool to aid in selecting cost-effective bird management methods; 5) implement management practices that will decrease the amount of bird damage on their dairies; and 6) incorporate more economically, socially, and environmentally-sustainable pest bird control practices on their farms.

    Project objectives from proposal:

    List of Objectives

    1. Survey producers. Distribute a survey to all Washington dairy producers to determine perceived rates of feed consumption and destruction and scope of the pest bird issue. Utilize the survey process to identify cooperators for field research (Year 1). Estimate the economic impact of dairy losses to the regional economy (Year 2).

    2. Outreach. Conduct Extension outreach including educational workshops, field days, producer-to-producer discussions, professional presentations and publications on pest bird issues and control measures (see also outreach methodologies and scholarly publications sections, below). a) Provide information on bird identification, detrimental versus beneficial bird species, techniques for the encouragement of beneficial bird species, and professional falconry demonstrations (Years 1-3). b) Develop peer-reviewed articles, popular press publications, factsheets, videos, and website links, including best bird management practices, to further share project results and recommendations (Year 3).

    3. Field data collection. Record pest bird counts, bird-induced feed quality changes and pathogen prevalence at the feed bunk, and bird-cow interactions throughout fall-winter seasons at select dairies. This will document: a) The prevalence of specific pest and beneficial bird species through weekly sunrise and sunset bird counts at 10 dairies, repeated over six months (Year 1). b) Occurrences of established night roosts at dairies (Year 1). c) Feed quality losses and pathogen prevalence due to bird presence and feeding habits at the bunk. Perform sampling and lab analysis at 1-2 select dairies during fall-winter to compare bird-accessible and bird-excluded feed samples (Years 1-2). d) Effects of bird numbers on cow behavior and welfare. Place video cameras at feed bunks on two select dairies fall-winter, and analyze footage to quantify prevalence of aversion or other behaviors by cows. Data will provide an understanding of pest bird impacts on cow welfare, including impacts on milk production, due to stress and interference with feed access (Years 1-2).

    4. Perform pilot efficacy trials of professional falconry, native raptor attraction, and bird exclusion netting on select dairies. a) Native raptor attraction techniques, including kestrel falcon and barn owl nest box and perch installations, will be encouraged through outreach (objective 2 above). At least five producers adopting these techniques will be followed for pilot efficacy data. Numbers of pest birds pre- and post-installation will be noted (Years 2-3). b) At least two producers with established starling night roost populations in their barns will be selected for a pilot analysis of professional falconry, in conjunction with large-scale exclusion netting, to deter roost habituation of starlings. Numbers of birds continuing to roost will be noted (Years 2-3).

    5. Create a web-based tool for producers to help them choose an economically-efficient bird deterrent method, given their site-specific bird damage issues. Data from Years 1 and 2 will provide the foundation for the tool to estimate the benefits and costs associated with different bird deterrent methods.

    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.