We constructed bioenergetic and economic models to estimate the potential impact of Red‐winged Blackbirds (Agelaius phoeniceus), Common Grackles (Quiscalus quiscula), and Yellow‐headed Blackbirds (Xanthocephalus xanthocephalus) on production yields of sunflower in the northern Great Plains of North America. The amount of sunflower consumed annually by males and females, after considering field metabolic rates, energy value and moisture content of achenes, and percentage of sunflower in diets was, respectively: Red‐winged Blackbirds 277 g and 168 g; Common Grackles 267 g and 230 g; and Yellow‐headed Blackbirds 248 g and 139 g. The per capita annual economic damage was: male Red‐winged Blackbirds $0.09 (U.S. dollars), females $0.05; male Common Grackles $0.09, females $0.07; and male Yellow‐headed Blackbirds $0.08, females $0.05. Annual loss was $5.4 ± 1.3 × 106 for all three species in aggregate, with Red‐winged Blackbirds accounting for 52% of the loss. Blackbird damage represented 1.7% of the dollar value of the 1999 sunflower harvest in the northern Great Plains. This loss would be inconsequential if damage were distributed evenly; however, bird damage is often localized around wetlands and can be economically debilitating to individual producers. Although our model was based on regional population estimates, it should perform well at local scales, provided that a local population can be defined, accurately estimated, and remains stable in size over the six‐week length of the damage period. Because of the large numbers of blackbirds that congregate in the region during August and September prior to migration, sunflower producers should expect some crop losses. The solution to the conflict appears to be one that focuses not on eliminating all damage, but on preventing it from exceeding 5% per field. Corresponding Editor: S. J. Hannon.

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The prevalence of Escherichia coli, Salmonella spp., and Mycobacterium avium subsp.paratuberculosis isolated from the feces of wild European starlings (Sturnus vulgaris) humanely trapped at a feedlot in central Kansas was assessed. All E. coli and Salmonellaisolates recovered were tested for antimicrobial susceptibility using National Antimicrobial Resistance Monitoring System panels and the E. coli isolates were classified as to their content of genes associated with pathogenic E. coli of birds and cattle, including cvaC, iroN2, ompTp, hlyF2, eitC, iss, iutA, ireA, papC, stxI, stxII, sta, K99, F41, and eae.Escherichia coli O157:H7 and Mycobacterium avium subsp. paratuberculosis were not detected and Salmonella was isolated from only three samples, two of which displayed antimicrobial resistance. Approximately half of the E. coli isolates were resistant to antimicrobial agents with 96% showing resistance to tetracycline. Only one isolate was positive for a single gene associated with bovine pathogenic E. coli. An interesting finding of this study was that 5% of the E. coli isolates tested met the criteria established for identification as avian pathogenic E. coli (APEC). Thus these findings suggest that starlings are not a significant source of Salmonella spp., Mycobacterium avium subsp.paratuberculosis, E. coli O157, or other shiga toxin-producing E. coli in this feedlot. However, they may have the potential to spread APEC, an important pathogen of poultry and a potential pathogen to human beings. SUMMARY. The prevalence of Escherichia coli, Salmonella spp., and Mycobacterium avium subsp. paratuberculosis isolated from the feces of wild European starlings (Sturnus vulgaris) humanely trapped at a feedlot in central Kansas was assessed. All E. coli and Salmonella isolates recovered were tested for antimicrobial susceptibility using National Antimicrobial Resistance Monitoring System panels and the E. coli isolates were classified as to their content of genes associated with pathogenic E. coli of birds and cattle, including cvaC, iroN2, ompTp, hlyF2, eitC, iss, iutA, ireA, papC, stxI, stxII, sta, K99, F41, and eae. Escherichia coli O157:H7 and Mycobacterium avium subsp. paratuberculosis were not detected and Salmonella was isolated from only three samples, two of which displayed antimicrobial resistance. Approximately half of the E. coli isolates were resistant to antimicrobial agents with 96% showing resistance to tetracycline. Only one isolate was positive for a single gene associated with bovine pathogenic E. coli. An interesting finding of this study was that 5% of the E. coli isolates tested met the criteria established for identification as avian pathogenic E. coli (APEC). Thus these findings suggest that starlings are not a significant source of Salmonella spp., Mycobacterium avium subsp. paratuberculosis, E. coli O157, or other shiga toxin-producing E. coli in this feedlot. However, they may have the potential to spread APEC, an important pathogen of poultry and a potential pathogen to human being...

Even though avian damage to sunflower (Helianthus annuus L.) is a worldwide economic issue, several of the current methods used to reduce sunflower damage were developed and tested in the Prairie Pothole Region of the United States. An intensive research program was conducted in that area because of the regionalized concentration of sunflower production and the severe incidences of blackbird (Icteridae) depredation. During the past 40 years, federal and university scientists tested chemical and physical frightening agents, aversive repellents, bird-resistant sunflowers, decoy crops, habitat management, population management, and cultural modifications in cropping. Some of these techniques have broad applicability and may be useful in depredation scenarios involving other bird species and crops. Population suppression is intuitively appealing, but it typically fails beyond local scales because of avian mobility, population dynamics, and public antipathy. Scare devices, repellents, habitat management, and decoy crops are more likely to meet the test of predictable efficacy and practicality.

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