In the United States, blackbirds are abundant and widely distributed. with their winter populations estimated to be between 500 million and 1 billion. Annual damage to grain, fruit, and berry crops from blackbirds exceeds $100 million in direct costs. Additional costs, not estimated, include those spent to prevent human health and safety hazards and those from damage abatement efforts. The U.S. Department of Agriculture\u27s Wildlife Services (WS) is charged with reducing the magnitude of health. safety, nuisance, agriculture, and feedlot/dairy problems caused by these birds. WS\u27 goal is to improve profitability to agricultural producers, enhance the human health and safety, and protect the environment through the development of new or improved management strategies. In this paper, we outline WS research and operational needs to resolve the health, safety, nuisance, and agricultural problems caused by blackbirds. We also discuss needs and actions to protect desirable migratory birds from the negative impacts of blackbirds

Homan, H. Jeffrey

Linz, George M.

Mastrangelo, Philip

Penry, Linda B.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln USDA National Wildlife Research Center - Staff Publications U.S. Department of Agriculture: Animal and Plant Health Inspection Service November 2003 REDUCING BLACKBIRD-HUMAN CONFLICTS IN AGRICULTURE AND FEEDLOTS: NEW METHODS FOR AN INTEGRATED MANAGEMENT APPROACH George M. Linz USDA/APHIS/WS National Wildlife Research Center, george.m.linz@aphis.usda.gov H. Jeffrey Homan USDA/APHIS/WS National Wildlife Research Center Linda B. Penry USDA/APHIS/WS National Wildlife Research Center Philip Mastrangelo USDA/APHIS/WS National Wildlife Research Center Follow this and additional works at: https://digitalcommons.unl.edu/icwdm_usdanwrc  Part of the Environmental Sciences Commons Linz, George M.; Homan, H. Jeffrey; Penry, Linda B.; and Mastrangelo, Philip, "REDUCING BLACKBIRD-HUMAN CONFLICTS IN AGRICULTURE AND FEEDLOTS: NEW METHODS FOR AN INTEGRATED MANAGEMENT APPROACH" (2003). USDA National Wildlife Research Center - Staff Publications. 241. https://digitalcommons.unl.edu/icwdm_usdanwrc/241 This Article is brought to you for free and open access by the U.S. Department of Agriculture: Animal and Plant Health Inspection Service at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in USDA National Wildlife Research Center - Staff Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. REDUCING BLACKBIRD-HUMAN CONFLICTS IN AGRICULTURE AND FEEDLOTS: NEW METHODS FOR AN INTEGRATED MANAGEMENT APPROACH GEORGE M. LINZ, USDA-APHIS-WS, National Wildlife Research Center, Great Plains Field Station, 2110 Miriam Circle, Bismarck, North Dakota 58501 H. JEFFREY HOMAN, USDA-APHIS-WS, National Wildlife Research Center, Great Plains Field Station, 2110 Miriam Circle, Bismarck, North Dakota 58501 M D A  5. PENRY, USDA-APHIS-WS, National Wildlife Research Center, Great Plains Field Station, 2110 Miriam Circle, Bismarck, North Dakota 58501 PHILIP MASTRANGELO, USDA-APHIS North DakotaISouth Dakota Wildlife Services, 2110 Miriam Circle, Bismarck, North Dakota 58501 Abstracl: In the Unitcd Statcs, hlackhirds are abundant and widcly distrihutcd. with their winter populations estimated to bc bctwern 500 million and 1 billion. Annual damage to grain, fruit, and bcrry crops from blackbirds exceeds $100 million in dircct costs Addltiund costs, not rstim~ted, include thusc sprnt to prrvrnt human hralth and safety hazards and those from d~mage abaremcnt cfforts The U. S Drpartmcnt of Agriculture's Wildlifc Scrviccs (WS) is charged with rcducing the magnitudr of hcalth. safety, nuisdncc. agriculturd, and feedlor/dairy prublcms caused by these birds. WS' goal is to improve profitability to agricultural producrrh. cnhancr the human health and safety, and protcct thr rnvironmrnt through thr development of new or improved management strategies. In this paper. we outline WS rrsearch and operational needs to resolve the health, safety, nuisance, and agricultural problcms causcd by blackbirds We also discuss nerds and actions to protect desirable migratory birds from the negative impacts of blackbirds. Key words: avicides, birds, blackbirds, DRC~l j39.  hahitat use. red-wingcd blackbirds. spring migration. sunflower. HISTORICAL PERSPECTIVE A few blackbirds' rise from thc suntlowcr field as the grower drives down the county road. The growrr is happy becausc she knows that this number of  black^ birds is manageable and they are only eating weed seeds and insects. Oh yes, she had heard tales of growers losing entire fields to blackbirds but that was before an integrated blackbird management plan was developed and implemented. Gone are the days of firing thousands of rounds of shot shells, using rapid-fire high-caliber rifles, low-flying hazing aircraft, iffy repellents, and the scare device of the year. She also knows that her rice, fruit and watermelon farms are protected as well. In h c t ,  thc birds arc so effective at controlling weeds and insccts that her pesticide costs wcrc rcduccd 50% ovcr the  previous year Yrs, life was good in the Farm indus- try these days but her father says it was not always this way. In the bad old days there was a myriad of ineffec- tive and partially effective management tools, but the corn. sunflower. rice, fruit, and feedlots industries were still losing more than $100 million dollars to blackbirds rach yCAr in the 1960s and 1970s, agrncy and univer~ sity scientists focused on improving repcllcnts, dcvrl- oping birdhesistant hybrids, conducting taste-aversion studies. recommending alternate-cropping practices, developing lure-cropping strategies, and testing scare- crows and distress calls (Linz and Hanzel 1997, Linz and Homan 1998). Additionally, some resources were spent on learning more about the basic ecology of blackbirds. Despite these efforts; the same tired advice was being given to growers such as, avoid planting fields near  cat^ tail-choked wetlands, synchronize sunflower plantings. provide access lanes in large fields, and plant alternate foods (Arnctt 1984) Littlc wondcr that industry rcprc- sentativcs doubted that current methods were effective and that reducing the blackbird populations would be ' ~ h r  term blackblrli rcfcrs I" rcd-wlngcd b~nckblrdr, ~pu i~ i iu iph .e ,~~ -  more appropriate. ceui, common gracklrr, Quircnlus yuiiculu, hr0wnhe:idrd cowbird$. Uoluihrur vrrr tircwc<r birckblrdr. E u p h q ~ u  qaizocephnlur, and In the  1980s, scientists gathered data on migra- , c I I < , w ~ c ~ ~ c ~  hlrikblrds. X ~ ~ ~ L ~ O L ~ ~ ~ U I U . ~  U ~ I ~ O C ~ ~ ~ O I U S  tion patterns and roosting habits using a paint~tagging method and found that red-winged blackbirds funnel from staging areas in northwestern Missouri and east- ern South Dakota to sunflower growing areas in the Dakotas. Minnesota, and Canada (Knittle et al. 1996). These data suggested that suppressing spring migratory blackbirds at these staging areas might help reduce the number of fall-migrating blackbirds and, in turn; reduce sunflower damage. However. the agency-in-charge did not intend to follow up with an operational program because of possible environmental safety issues and philosophical divisions within the agency. Concur- rently. researchers began quantifying the relationship among blackbirds. cattail-choked wetlands, and sun- flower damage (Otis and Kilburn 1988). Besser and Otis (1980)fioted a significant decline in the number of red- winged blackbirds between the 1960s and 1980s and attributed the decline to drought and large machinery that could plow the drier portions of the  wetlands that wcre used by nesting red-winged blackbirds. In 1986; the blackbird issue, along with other wildlife damage management problems, was transferred to the Animal and Plant Health Inspection Service (APHIS) of the U S .  Department of Agriculture (USDA). With the transfer came the possibility of developing an avicide to reduce blackbird numbers. The use of DRC- 1??9~treated ricc baits was initiatcd to rcducc blackbird numbers feeding on sprouting rice though managers warned that clearance for an aerially-applied avicide would be costly in time and money. hleanwhilr, an acrial hazing program was started despite some misgiv- ings regarding safety and efficacy On another front, resource managers advised that, while cattails are perfect for blackbird nesting and roosting, they are not conducive for propagating ducks. Growers were urged to manage cattailkhoked wetlands to reduce blackbird roosting habitat and thus disperse the birds. This technique was considered cost-effective and environmentally friendly by mainstream rcsourcc biologists (McEnroe 1992). However thc subjcct of developing an avicide did not abate despite lJSDA offi- cials reminding growers the blackbird problem would never be eliminated if the crop and birds coexisted. CURRENT STATUS We recognize that as the human population grows. the number and severity of bird-human conflicts will continue to rise. This was indicated in USDA-APHIS Wildlife Services program surveys that were conducted in 1990, 1996, and 2001. In the surveys, respondents across the nation placed a high priority on undcrstand- ing and finding solutions to blackbird 2nd starling damage to agriculture. We also are awarr that even the most environmentally benign damage abatement meth- ods can be subject to much public debate. Realizing this, we developed a plan to tackle the issue of black- bird and starling damage with the following premises: 1. Blackbirds will continue to be abundant and widely distributed. 2. The estimated annual damage to grain. fruit; and berry crops from blackbirds will continue to exceed $100 million in direct costs. 3. The use of avicidcs will continue to be controversial and lack general public acceptance. 4. A major constrain6 to the development of chemical repellents is the lack of profit incentives for private companies that see limited markets for ncw bird control products. 5. Every new wildlife damage management method will undergo public scrutiny through the Kational Environmental Policy Act. This paper outlines research and operational needs to resolve the health, safety. nuisance, agricul~ ture: and feedlot problems caused by blackbirds. The needs and actions to protect desirable migratory birds from negative impacts of blackbirds are also consid- ered. Our goal is to improve profitability to agricultural producers, enhance the Iiealth and safety of urban dwellcrs, and protect the environmcnt through devcl~ opment of new or improved managemcnt strategies, while implementing nrw or improved n,ildlifc damage management methods and expanding partnerships among producers, commodity groups, research boards, universities, and state and federal agencies. Development of Repe1le~zts.-New repellents are needed to augment currently available hird  manage^ ment tools and enhance the effectiveness of a  manage^ ment program based on integrated pest management concepts. The rice industries rely heavily on the use of an avicide and habitat managcment to protect sprouting rice and ripening sunflower, respectively. Even so, both thc ricc and sunflower industrics suffer annual losses of $4 to $11 million (Rcsscr 1985, Hothem ct 11. 1988). The brrry, nut, and fruit industries also have limited bird management tools for protecting their crops from  black^ birds, costing them millions of dollars (Besser 1985). Because food producers do not have a consistently effi- cacious repellent, they must rely on hird management techniques that are labor intensive. sporadically effec~ rive, sometimes environmentally hazardous, occasion- ally dangerous, and nearly always expensive. The feedlot industry relies on the use of an avicide that some groups find unaccept~ble, especially when thc avicide is used near urban centers. Fccd losscs. livestock hcalth prohlcms, and watcr trough maintenance can cost feedlots >$7,000.000 annually (Besser 1985). Economic losses caused by birds are a result of feed and contamination, accelerated corrosion of fencing. corrals. and other infrastructure materi- als due to fecal mattcr, threats of discascs, and loss of business for custom feeder operations due to customer perceptions or beliefs about the effect on  weight gain and disease problems caused by the presence of large numbers of birds (Clark and McLean. In Press). Thus. repellents placed in livestock feed or sprayed as an aero sol would be highly desirable. Cities in the southeastern part of the United States harbor large concentrations of wintering black- birds. These birds foul sidewalks. playgrounds, and other private and public areas and can harbor diseases. A repellent would be ideal for moving birds out of the city to more rural arcas. Development of Biological Agentsfor Cattail Control-Agriculturists, state and federal resource agencies, and private groups currently rely on a rela- tively expensive aquatic herbicide. A new environmen- tally safe method is needed to manage invasive hybrid cattails that attract blackbirds and are detrimental to biodiversity (Kantrud 1986). We propose to cooperate with APHIS' Plant Protection and Quarantine unit and universities to pursue the development of cost-benefi- cial, environmentally safc biological agent(s) for manag~ ing invasive wetland vegetation. This research effort will require a conlmitmcnt of significant rcsourccs becausc the proccsscs of discovery, devclopmcnt, deployment and monitoring an cnvironmcntally safe and cost-effective biological agent is likely to be long- term. However, development of biological agents for controlling other species of invasive plants including leafy spurge and purple loosestrife have been success- ful, reducing the need for herbicides. Development of Cost-Benefit .Models.-We propose to expand cooperation with lcading wildlife resource economists within land-grant universities to identify cost-beneficial methods of managing blackbird- human contlicts. Insufficient data are available on the costs and bencfits of protecting individual crops from blackbirds. In particular, models integrating population, bioenergetic and economic data are needed to estimate economic impacts of blackbirds. Development of Reproductive Inhibitors.-We propose to investigate the feasibility of species-specific reproductive inhibition techniques for managing black- bird populations. These techniques would supplement already established programs based on avicides,  repel^ lents, and habitat management. CONCLUSION Although Wildlife Scrviccs m d  its methods~dcvcl- opment branch, the National Wildlife Research Cmtcr. have made progress in addressing these problems. the dvnamic nature of human-bird conflicts is complex, and new environmentally safe, cost.effcctivc damagc abatement methods arc ncedcd. To date, 1 avicide. 2 repellmts. several scare devices. and 1 habitat man- agement technique are available as tools for managing troublesome blackbird and starling populations. All of these techniques have limited application because of problems related to efficacy, cost, and environmental safety. Additionally, the use of avicides is contro\,ersial and lacks general public acceptance. Rather than wring our hands in despair. we look forward to the challenge of finding new environmentally safe methods of rcduc~ ing blackbird damage to grain crops and feedlots. ACKNOWLEDGMENTS M. Axry, J. Cummings, D. LeBlanc, and K. Gustad commented on earlier drafts of the manuscript. LITERATURE CITED ARSETT, G. R. 1184. Blackbird control in sunflower. The Sunflower 10:37. BESSER. J. F. 1985. A grower's guide to reducing bird damage to U.S. agricultural crops. U.S. Fish and Wildlife Scrvice, Denver Wildlife Research Center Uird Damagc Research Report No. 340. Riissm. J., ANLI D. OTIS. 1980. Dakofa drought speeds blackbird dccline The Sunflower 6:42.  CLARK. L , AND R. E.  MCLEAIC. 2003. A review of pathogens of agricultural and human hcalth intsrest found in blackbirds. In G. M. Linz, editor. Management of North American blackbirds. National Wildlife Research Center, Fort Collins, Colorado. In Press. HOTHEM, H.L., R. W DEHAVEU. AN,) S. D. FAIRAIZL. 1988. Bird damagc to sunflower in North Dakota, South Dakota, and Minnesota, 1979.1981 U.  S. Fish and Wildlife Service Technical Report 15. KAPII.RUD, H .  A. 1986. Effects of vcgefation manipulation on breeding waterfonrl in prairie wetlands - a literature review. U.S. Fish and Wildlife Scrvice Technical Report 3. KSIITLL, C. E.,  (;. M. LINZ, J .  L. CUMMIXCIS, J .  E.  DAVIS, IR., B. E.  Josrs. A D J .  F. UESSER. 1996 Spring migration patterns of male red-winged blackbirds (Agelaius phoeniceus) from two migratory roosts in South Dakota and Minnesota. American Midland Natu- ralist 136134-142. Llsz. G. M.,  AKII J .  J .  HASZEL. 1997. Birds and sunflow- ers. Pages 381-394 in Sunflower technology and production. .Monograpt~ 35: Americ~n Society of Agronomy Crop Science Society of America, Soil Science Society of America, Madison. Wisconsin, USA. Lwr. G. M.. AND H. J. HOMX 1998. Tracing thc history of agcment Symposium. Denver W-ildlife Research blackbird rrsearch through in industry's looking Center. Denver; Colorado and C.  S. Fish and Wild- glass: The Sunflower magazine. Proceedings of life Service. Fargo; North Dakota. LSA. the Vertebrate Pest Conference 18:3i-42. OTIS, D. I., ASD C. M. KILRCRK. 1988. Influence of MSENR~E. M  R. 1992. Catf~il  management: views of the environmental factors on blackbird damage to U S .  Fish and Wildlife Service. Pages 42-44 in G. sunflower. U. S. Fish and Wildlife Service Fish and M.  Linz editor. Proceedings of the Cattail Man- U'ildlife Technical Report 16. 2003. G .  M. Linz, editor. Management of North American Blackbirds (Proceedings of a special symposium of the Wildlife Society 9Ih ~ n n u a l  Conference. Bismarck, North Dakota, September 27, 2002). 24 

REDUCING BLACKBIRD-HUMAN CONFLICTS IN AGRICULTURE AND FEEDLOTS: NEW METHODS FOR AN INTEGRATED MANAGEMENT APPROACH

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REDUCING BLACKBIRD-HUMAN CONFLICTS IN AGRICULTURE AND FEEDLOTS: NEW METHODS FOR AN INTEGRATED MANAGEMENT APPROACH

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