Blackbird Population Management to Protect Sunflower: A History

Sunflower (Helianthus annuus) growers in North Dakota and South Dakota harvested 593,522 ha in 2012, valued at $US600 million. Blackbirds, numbering about 75 million, annually damage 2 to 3% of the crop. Damage tends to be clumped around cattail (Typha spp.) dominated wetlands with standing water. In an attempt to reduce sunflower damage, three general population management strategies have been tested over the past three decades. One potential strategy was to reduce blackbird numbers during winter in the southern U.S. A second strategy was to use an avicide at spring roost sites in eastern South Dakota. A third approach was to reduce local blackbird populations that were doing or about to damage ripening sunflower. All three schemes largely relied on the use of DRC-1339 (3-chloro-4-methylaniline hydrochloride) and related compounds and all failed because of logistics, cost-effectiveness, environmental risks and societal concerns. In this paper, I chronicle significant research efforts to implement these strategies

State of Bird Damage Management

This is the letter from George M. Linz, associate editor for the special issue on bird damage management in Human–Wildlife Interactions

Modeling Migratory Nongame Birds: A Plea for Data

The Bird Damage Management Conference held February 10–13, 2020 in Salt Lake City, Utah, USA provided a forum for professionals from across the United States to discuss and share management approaches, research strategies, policy, and messaging regarding the management of blackbirds (Icteridae), starlings (Sturnus vulgaris), corvids (Corvidae), and vultures (Cathartidae). Mathematical models were presented at the conference and subsequently discussed in a special issue of Human–Wildlife Interactions. Rapidly changing landscape variables point to the need for detailed systematic population monitoring programs with specific objectives. Nationwide periodic monitoring would provide data about changes not only in bird populations due to changing landscapes but also could be used to assess management activities

Birds

Sunflower, due to the easy accessibility and high nutritional value of its seed, is particularly vulnerable to damage by birds (Figure 101). Seeds are exposed and the large head serves as a perch during feeding. Sunflower seed is a preferred bird food because the seed contains many proteins and fats essential to their growth, molt, fat storage and weight maintenance processes. Although many species of birds feed in maturing sunflower fields, the greatest losses are caused by migrating flocks of red-winged blackbirds, yellow- headed blackbirds and common grackles (Figure 102). Significant losses can occur in fields near cattail marshes

Blackbird Damage is an Important Agronomic Factor Influencing Sunflower Production

From 2001 to 2013 (except 2004), the National Sunflower Association sponsored a comprehensive production survey of physiologically mature sunflower (Helianthus annuus) fields in the Canadian province of Manitoba and eight states in the United States. Trained teams of surveyors randomly stopped at one sunflower field for every 4,047 – 6,070 ha (10,000-15,000 acres). Each team evaluated plant stand, yield potential, disease, insect, weed, and bird damage for each field. We pooled data gathered during the most recent 5-years (2009 to 2013) of the survey and found that sunflower damage caused by blackbirds and plant lodging ranked fifth (behind plant spacing, disease, drought and weeds) as the most limiting factors on production. We found that overall annual economic losses from blackbird damage averaged $US13.5 million and$US4.9 million for oilseed hybrids and confectionery hybrids, respectively. We suggest elements of a multi-faceted bird management plan that might help reduce damage

Birds

Sunflower, due to the easy accessibility and high nutritional value of its seed, is particularly vulnerable to damage by birds (Figure 101). Seeds are exposed and the large head serves as a perch during feeding. Sunflower seed is a preferred bird food because the seed contains many proteins and fats essential to their growth, molt, fat storage and weight maintenance processes. Although many species of birds feed in maturing sunflower fields, the greatest losses are caused by migrating flocks of red-winged blackbirds, yellow- headed blackbirds and common grackles (Figure 102). Significant losses can occur in fields near cattail marshes

Blackbirds

The term blackbird loosely refers to a diverse group of about 10 species of North American birds that belong to the avian family Icteridae. The most common species include: Red-winged blackbird (Agelaius phoeniceus) Common grackle (Quiscalus quiscula) Great-tailed grackle (Quiscalus mexicanus) Brown-headed cowbird (Molothrus ater) Yellow-headed blackbird (Xanthocephalus xanthocephalus) Brewer’s blackbird (Euphagus cyanocephalus) Rusty blackbird (Euphagus carolinus) In addition to blackbirds, this family includes orioles, meadowlarks, and bobolinks. Human-Wildlife Conflicts 1 Damage Identification 3 Management Methods 4 Economics 7 Species Overview 8 Legal Status 11 Glossary & Key Words 12 Resources 13 Appendices Damage Prevention and Control Methods for Blackbirds. Range Maps of Common Blackbird Species. Characteristics of Selected Blackbird Species

Sunflower Bird Pests

Sunflower (Helianthus annuus L.) is annually planted on approximately 26 million hectares in Australia, China, Europe, India, North America, Paldstan, Russia, South America, and Ukraine (National Sunflower Association, 2014). Flocks of granivorous birds, ranging in size from a few to millions, can be found in every sunflower growing region and have been documented to cause serious economic losses (Linz et al., 2011) (Figure 7.1). Avian species that damage sunflower generally belong to the parakeet (Psittacldae), dove (Columbidae), cockatoo (Cacatuidae), sparrow (Passeridae), crow (Corvidae), and blackbird (Icterinae) families (De Grazio, 1989; Linz and Hanzel, 1997; Linz et al., 2011; Rodriquez et al., 1995; van Niekerk, 2009)

Aerial Mass Color - Marking of Blackbird Roosts

We use mass color-marhng to track the local and regional movements of large roosts of blackbirds (Icteridae). Several marhngs have been done by National Wildlife Research Center scientists, including marhng of spring roosts in northeastern Missouri and eastern South Dakota (Knittle et al. 1987, Knittle et al. 1996, Homan et al. 2004), fall roosts in central North Dakota (Linz et al. 1991, Homan et al. 2005), and winter roosts in the southern U.S. (Harsch 1995). Here, we provide a description of the process and methodology of aerial mass color-marhng with fluorescent particles

TRACING THE HISTORY OF BLACKBIRD RESEARCH THROUGH AN INDUSTRY\u27S LOOKING GLASS: THE SUNFLOWER MAGAZINE

The Sunflower magazine, the voice of the National Sunflower Organization, featured articles in January 1978 and December 1996 that began with these words, If Old King Cole was a merry old soul, it was probably because he had only four and twenty blackbirds to contend with, and they were all out of commission! This quotation captures the sentiments of sunflower growers, who have identified blackbirds as a major production problem since the 1960s. The National (formerly Denver) Wildlife Research Center, a unit within the U.S. Department of Agriculture\u27s Animal and Plant Health Inspection Service Wildlife Services, is charged with both improving and developing new methods for managing blackbird damage to sunflower. The Sunflower has chronicled these research efforts championing studies with clear objectives and opposing studies, sometimes vehemently, that use resources for seemingly esoteric research. In this paper, the history of blackbird research in the northern Great Plains is traced through The Sunflower