Limiting bird damage in fruit crops:
A planning program to identify research directions for the future
Meeting funded by the Specialty Crop Research Initiative of the U.S.D.A.
August 25-27, 2010, Northwest Michigan Horticultural Research Station, Traverse City, MI.
The meeting produced the following outcomes: 1) a network of researchers and stakeholders who have experience with the bird-damage-to-fruit problem and who are now aware of the expertise, activities, and concerns of other members of the network, 2) the research roadmap below that describes the steps necessary to make progress in addressing this issue and 3) a proposal submitted to the Specialty Crop Research Initiative on Jan. 31, 2011, “Limiting bird damage in fruit crops: integrating economic, biological, and consumer information to develop sustainable, long-term solutions”. The proposal summary is at the end of this document.
Please contact Catherine Lindell (firstname.lastname@example.org) for the full citations referred to below.
Background. Fruit production is a critical component of the global economy. Production of blueberries, cherries, and grapes continues to increase (FAO 2010) and ‘Honeycrisp’ apple supply and demand are climbing. The top ten cherry-exporting nations produce a collective annual yield valued at more than one billion dollars (FAO 2007). In addition, increasing human fruit and vegetable consumption is a goal of the Food and Agriculture Organization of the United Nations (2003) and the World Health Organization (2010) because of the strong positive effects of fruits and vegetables on health (e.g. Lock et al. 2005). Thus, addressing threats posed by fruit crop pests and improving productivity and profitability is of great economic and social importance.
Fruit loss to birds is a long-standing and costly problem (Virgo 1971, Dolbeer et al. 1994, Simon 2008) that has received little coordinated attention from researchers, leaving producers with few effective management options. U.S. producers lose tens of millions of dollars each year through direct losses and often ineffective efforts to deter birds (USDA 1998). In addition to outright consumption, birds damage fruit, leading to increased susceptibility to other pests and pathogens (Pritts 2001, Duffy & Schaffner 2002, Holb & Scherm 2008) and reduced product quality; cherry crops, for example, with high proportions of damaged fruit receive low grades from processors and generate less income because they are sold for juice, rather than more profitable end products.
Few techniques consistently deter pest birds from fruit. Scaring birds with acoustics such as cannons and wailers varies in effectiveness (e.g. Summers 1985, Cook et al. 2008). In addition, cannon noise can be a source of friction between producers and their neighbors. Netting can be used to exclude birds from grapes (e.g. Curtis et al. 1994, Somers & Morris 2002) but it is costly and impractical for tree fruits like cherries. Many visual deterrents like Mylar streamers are generally ineffective (Belant & Ickes 1997). Although chemical repellents are in development for some crops (Werner et al. 2007), the standard repellent for fruit (Mesurol®) is no longer labeled for use on food crops. Other repellents are not consistently effective, expensive, and/or affect fruit quality.
Apart from the technical difficulties of bird management, there are the challenges of doing so within an environmentally sustainable framework. Although some pest species like the European Starling are invasive, others are native songbirds that are part of the cultural value of rural, fruit-growing regions and provide recreational activities. In 2006 48 million Americans spent $36 billion on bird watching trips and equipment. This economic activity generated 670,000 jobs (U.S. Fish & Wildlife Service 2006). Birds also play important roles in ecosystems by, for example, eating insects that damage leaves and dispersing seeds of native plants (Sekercioglu 2006). Thus, in a best-case scenario, bird management techniques would be environmentally beneficial and, at a minimum, relatively benign in their environmental impacts.
Priorities for research in order to make progress in addressing this issue.
1. Use of a systems approach. Often producers make decisions about bird management using a trial and error approach in the absence of adequate information about the economics and effectiveness of the techniques under consideration (Tracey et al. 2007). We believe that progress in bird management depends upon using a systems framework to determine the types and intensity of management that should be tested, followed up with robust experimental investigations. A systems approach necessitates considering how system components interact rather than considering them in isolation. For example, crop and pest bird characteristics, levels and spatial patterns of bird damage to crops, economic constraints of producers, and consumer preferences need to be considered together when deciding upon management strategies. These issues are discussed below.
2. Standardized information on the economic impact of bird damage for producers, consumers, and regions. Previous work on the economics of bird damage has focused on damage caused by single bird species or to single crops (e.g. Cummings et al. 2005). Rarely have studies quantified regional variation in damage across a range of crop types. Shwiff et al. (in review) estimated bird and rodent pest damage to California agriculture at $168 million to $504 million. Although only a portion of this damage was caused by birds, the study showed that damage levels are geographically diverse, even within a single state. Similar work has not been conducted in other production regions of the country and the diversity of damage makes it difficult to extrapolate damage levels to other regions. In addition, previous work to estimate economic impacts of alternative management methods is limited (e.g. Avery et al. 1993). Without these types of information, government entities, industry groups, and producers are not able to prioritize resources for the problem or assess the costs and benefits of different management strategies.
3. Region-specific information on the relative importance of different pest bird species and their consumption patterns. Identifying the relative impact of different pest species is a critical step in developing effective management strategies and will be one of our first priorities. Many previous studies have recorded the types and numbers of birds flying into orchards or perched in fruit trees but have not documented whether birds were actually consuming fruit or the damage caused by different species (Guarino et al. 1974, Tobin et al. 1991, Curtis et al. 1994). Inferences based on these types of presence/absence or abundance data could be misleading. For example, American robins, Turdus migratorius, were the most commonly observed bird species in Michigan cherry orchards during traditional surveys in 2010 yet observations of foraging behavior showed that cedar waxwings, Bombycilla cedrorum, actually consumed more fruit than robins (Lindell et al. in prep.). Additionally, the most important bird pests on a particular crop may vary across regions. Cedar waxwings are not as abundant in western North America as eastern North America (Gough et al. 1998) and so likely play less of a role as a pest in the west compared to the east.
Understanding the behavioral ecology of pest species is another key component of wildlife damage-management efforts (Dolbeer et al. 1994, Tracey et al. 2007). When, how, and where species forage will determine differences in crop impacts and provide information about which management strategies should be tested (Tracey et al. 2007). For example, bird damage may be greater at field edges than interiors, indicating that management efforts should be concentrated at edges (Somers & Morris 2002). Birds foraging in groups often cause greater losses than birds foraging alone; effective management strategoes for flocking species versus solitary foragers will likely differ (Tracey et al. 2007).
4. Information on landscape effects on bird damage. We commonly hear anecdotal information about the influence of landscape context on fruit damage, usually that isolated orchards, i.e. those surrounded by non-orchard land covers, experience greater damage than orchards surrounded by other orchards. Grapefruit groves farther from other groves showed greater bird damage than groves close to other groves (Johnson et al. 1989) and studies in non-orchard settings demonstrate landscape effects on fruit removal (Manuel Herrera & Garcia 2010) There is increasing awareness of the importance of landscape context to agricultural systems (Robertson et al. 2007) yet no work to date has systematically investigated landscape effects on bird damage across a range of crops. Investigating these effects is important to understanding mechanisms leading to bird damage and directing management strategies. For example, if isolated orchards experience greater bird damage than orchards in landscapes with many other orchards, this indicates that management strategies must include planning at the landscape scale, including cooperation among producers and information dissemination to producers about where and where not to cultivate.
5. Information on potential impacts of bird management on consumer choices.
Bird damage-management strategies have the potential to influence sales of specialty crops. Consumer interest in the practices embodied in food production is rising, as evidenced by the exponential growth of eco-labels such as “organic” and “fair trade” (Howard 2010). Knowledge of damage-management strategies embodied in production practices may increase or decrease willingness to buy a product, or even willingness to pay an additional premium for a product. Bird damage-management strategies may have larger market impacts than those employed for other pests (e.g. insects), due to the greater charismatic appeal of birds (Sergio et al. 2006); 21% of the US population engages in birdwatching as a recreational activity (Carver 2009). It is important to provide fruit producers and marketers with accurate information about the potential marketing impacts of bird damage-management strategies when they are making decisions about whether or not to adopt them.
Researchers are beginning to measure consumer preferences and willingness to pay for foods that embody specific production practices, such as use/avoidance of genetically engineered organisms (Costa-Font et al. 2008) and organic standards (Batte et al. 2007). Nothing is known about the potential consumer response to bird management strategies, however. In the short-term, identifying strategies that receive positive consumer interest may help foster niche markets, and possibly garner price premiums, for participating producers. This knowledge may encourage more producers to adopt such management techniques. Incorporating management techniques into a third-party certified eco-label is beyond the scope of this project; in the long-term, however, better understanding of consumer preferences for these techniques will inform efforts to broaden the appeal of existing or new “wildlife-friendly” eco-labels (Treves & Jones 2010).
6. Well-replicated, controlled studies to systematically test the effectiveness of bird management strategies. Testing bird management strategies is challenging in that birds are more mobile than many other types of pests and use large areas. Previous work has often been limited by a lack of a replication and appropriate controls (Bomford & O’Brien 1990). Despite the technical and economic challenges, large-scale well-replicated field trials of management strategies are critical.
We believe that by addressing the issues above, progress toward providing producers with effective, sustainable management strategies will occur much more quickly than with the current ad hoc, piecemeal efforts.
Participants in meeting
Brandon Darin (Dave Camp office)
Brandon Fewins (Debbie Stabenow office)
Gabe Schneider (Carl Levin office)
Other growers/managers whose farms we visited
Lenny Ligon, Ligon Farms, Old Mission Peninsula
Don Coe, Managing Partner, Black Star Farms, Suttons Bay, MI
Participants who gave oral presentations
Allyn Anthony, Michigan State Horticultural Society, 63806 90th Ave., Hartford, MI 49057, 269-424-3990, email@example.com.
Jay Boulanger, Cornell University, Department of Natural Resources, 111 Rice Hall, Ithaca, NY 14853, 607-227-5444, firstname.lastname@example.org
Pete Butchko, USDA-Wildlife Services, 2803 Jolly Rd., Ste. 100, Okemos, MI 48864, 517-336-1928, email@example.com.
Juliet Carroll, New York State IPM Program, 630 West North Street, Geneva, NY 14456, 315-787-2430, firstname.lastname@example.org.
Rachael Eaton, Michigan State University, Department of Zoology, 203 Natural Science Bldg., East Lansing, MI 48823, email@example.com
John Eisemann, USDA APHIS Wildlife Services, National Wildlife Research Center, 4101 Laporte Avenue, Fort Collins, CO 80521, 970-266-6158, John.D.Eisemann@aphis.usda.gov.
Cathy Heidenreich, Cornell University, Department of Horticulture, 134A Plant Science Bldg., Ithaca, NY 14853, 315-787-2367, firstname.lastname@example.org.
Philip H. Howard, Michigan State University, Department of Community, Agriculture, Recreation and Resource Studies, 316 Natural Resources, East Lansing, MI 48823, 517-355-8431, email@example.com.
Catherine Lindell, Michigan State University, Department of Zoology/Center for Global Change and Earth Observations, 1405 S. Harrison Rd., East Lansing, MI 48823, 517-884-1241, firstname.lastname@example.org.
George M. Linz, USDA-Wildlife Services, National Wildlife Research Center, 2110 Miriam Circle, Suite B., Bismarck, ND 58501. 701-250-4469, email@example.com.
Erin Lizotte, NW MI Hort. Research Station, Michigan State University, 6686 S. Center Highway, Traverse City, MI 49684, 231-946-1510, firstname.lastname@example.org.
Nikki Rothwell, NW MI Hort. Research Station, Michigan State University, 6686 S. Center Highway, Traverse City, MI 49684, 231-946-1510, email@example.com.
Stephanie Shwiff, USDA/APHIS/WS National Wildlife Research Center, 4101 LaPorte Ave., Fort Collins, CO 80521, 970-266-6190, Stephanie.A.Shwiff@aphis.usda.gov.
Karen M.M. Steensma, Trinity Western University, Department of Biology/Environmental Studies Program, 7600 Glover Road, Langley, British Columbia, Canada. 604-888-7511, firstname.lastname@example.org.
John C Wise, Michigan State University, Entomology Dept., Applied Insecticide Toxicology Lab, 206 CIPS, East Lansing, MI 48824, 517-432-2668, email@example.com
Proposal Summary (Submitted to SCRI, Jan. 31, 2011)
Title: Limiting bird damage in fruit crops: integrating economic, biological, and consumer information to develop sustainable, long-term solutions.
Summary: Fruit producers have identified bird damage as a critical issue that has received limited attention from researchers. A USDA study estimated that birds cost producers in seven states tens of millions of dollars through fruit loss and management efforts. Despite these costs, research has been uncoordinated and piecemeal, leaving producers with few affordable management options. Our transdisciplinary, multi-state team will address bird damage to blueberries, cherries, wine grapes, and ‘‘Honeycrisp’’ apples with a systems approach. Our long-term goal is to provide producers with cost-effective, environmentally sustainable bird management strategies. To achieve this goal we will: 1) quantify economic consequences of bird damage for producers, consumers, and regional economies, 2) determine how bird damage varies within and across spatial scales (orchard, landscape, region), 3) identify amounts of damage attributable to specific bird species across crops and regions, 4) investigate consumer responses to management strategies and potential effects on marketing, and 5) test management strategies for efficacy. We will use the information generated by addressing objectives 1-4 in a systems framework to determine management strategies to be tested in different crops and regions (objective 5). By coordinating activities among researchers in New York, Michigan, and the Pacific Northwest, and from different disciplines, we will maximize efficiency in addressing this issue on a national scale while providing individual producers with region-specific information to guide their bird management efforts. This Standard Research and Extension Project addresses SCRI emphases on identifying and addressing threats from crop pests and improving long-term production efficiency, productivity, and profitability.
Catherine Lindell, Associate Professor, Michigan State University, Zoology Dept. and Center for Global Change and Earth Observations, 1405 S. Harrison Rd, East Lansing, MI 48823, firstname.lastname@example.org (PD)
Dr. Stephanie Shwiff, Research Economist, USDA-APHIS, National Wildlife Research Center, 4101 LaPorte Ave, Fort Collins, CO 80521, Stephanie.email@example.com (Co-PD/PI)
Dr. Paul Curtis, Associate Professor and Extension Wildlife Specialist, Cornell Cooperative Extension Department of Natural Resources, Cornell University, 114 Fernow Hall, Ithaca, NY 1485, firstname.lastname@example.org (Co-PD/PI)
Dr. Philip Howard, Assistant Professor, Department of Community, Agriculture, Recreation and Resource Studies, Michigan State University, 316 Natural Resources, East Lansing, MI 48824, email@example.com (Co-PD/PI)
Karen Steensma, Assistant Professor and Co-Director of Environmental Studies, Biology Department, Trinity Western University, 7600 Glover Rd, Langley, BC, CA V2Y 1Y1, Steensma@twu.ca, (Co-PD/PI)
Dr. George Linz, Supervisory Research Wildlife Biologist, Leader of WS-NWRC ND Field Station Leader and Adjunct Professor, USDA-APHIS Agriculture and Resource Protection Program and North Dakota State University, National Wildlife Research Center, 2110 Miriam Circle, Suite B, Bismarck, ND 58501, George.firstname.lastname@example.org (Co-PD/PI)
Erin Lizotte, IFP/IPM District Educator, Michigan State University Extension, Northwest Michigan Horticultural Research Station, 6686 S. Center Hwy, Traverse City, MI 49684, email@example.com (Co-PD/PI)
Dr. Jay Boulanger, Extension Associate, Department of Natural Resources, Cornell University, 111 Rice Hall, Ithaca, NY 14853, firstname.lastname@example.org (Co-PD/PI)
Dr. Nikki Rothwell, District Extension Horticulturalist and Station Director, Michigan State University Extension, Northwest Michigan Horticultural Research Station, 6686 S. Center Hwy, Traverse City, MI 49684, email@example.com (Co-PD/PI)
Dr. Juliet Carroll, Fruit IPM Coordinator and Senior Extension Associate
and Joint Faculty, New York State IPM Program and Department of Plant Pathology, Cornell University, NYASAES 630 W. North St, Geneva, NY 14456, firstname.lastname@example.org (Co-PD/PI)
Dr. Chi-Ok Oh, Assistant Professor, Department of Community, Agriculture, Recreation and Resource Studies, Michigan State University, 313 Natural Resources Building, East Lansing, MI 48824, email@example.com (Co-PD/PI)
Colleen Burrows, Program Coordinator, Washington State University Whatcom County Extension, 1000 N Forest St, Suite 201, Bellingham, WA 98225, firstname.lastname@example.org (Co-PD/PI)
Mark Longstroth, Southwest Michigan District Extension Fruit Educator and Van Buren County Extension, Michigan State University Extension, 219 Paw Paw St, Suite 201, Paw Paw, MI 49079 email@example.com (Co-I)
Dr. Clive Kaiser, Assistant Professor, Department of Horticulture, Oregon State University, 418 N Main St, Milton Freewater, OR 97862 firstname.lastname@example.org (Co-PD/PI)
Dr. Dave Lusch, Senior Research Specialist, Remote Sensing and Geographic Information Science Research and Outreach Services , Department of Geography, Michigan State University, 212 Geography Building, East Lansing, MI 48824 email@example.com (Co-I)