Summary1. Characterizing and mitigating the disease risks associated with wildlife use of concentrated animal feeding operations (CAFOs) can reduce the spread of micro-organisms throughout the environment while increasing agricultural productivity. To better understand the disease risks associated with bird use of CAFOs, we assessed the capacity of European starlings Sturnus vulgaris to spread Salmonella enterica to cattle, their feed and water. 2. We sampled starlings, cattle feed, cattle water and cattle faeces from 10 CAFOs in Texas, USA. Samples were screened for Salmonella enterica to investigate: (i) the prevalence of S. enterica in starlings using CAFOs, (ii) whether there was a relationship between cattle infections and starling numbers, and (iii) if S. enterica contamination of cattle feed and water was related to numbers of starlings observed on CAFOs. 3. We used generalized linear mixed logistic regression models to assess the importance of starlings, cattle stocking, facility management and environmental variables in the transmission of S. enterica to cattle, feed troughs and water troughs in CAFOs. 4. Starling gastrointestinal tract samples tested positive for S. enterica (2AE5% prevalence; 95% CI = 0AE3%, 8AE6%) and starlings were retained as model covariates in the best supported logistic regression models for S. enterica contamination within cattle feed, water and faeces. 5. Salmonella enterica contamination of both cattle feed troughs and water troughs is significantly related to numbers of starlings. Contamination in cattle feed increased as more starlings entered feed troughs. Contamination in water troughs increased asymptotically as numbers of starlings on CAFOs increased. Starling variables in the cattle faecal shedding model were not significant. 6. Synthesis and applications. The numbers of European starlings better explained S. enterica contamination of cattle feed and water than other variables including cattle stocking, facility management and environmental variables. This suggests that starlings are a source of S. enterica contamination in CAFOs. Thus, starling management tools such as population control, habitat management, exclusionary devises and bird repellents may be used to reduce the amplification and spread of disease within livestock production systems.

a b s t r a c tNon-lethal alternatives are needed to manage bird damage to confectionery and oilseed sunflower crops (Helianthus annuus). Ring-necked pheasants (Phasianus colchicus) can cause localized damage to newly planted sunflower, and blackbirds (Icterids) damage ripening sunflower annually in the United States of America. We conducted seed germination experiments, a repellent efficacy study with ring-necked pheasants and Avipel ® repellent (a.i. 50% 9,10-anthraquinone), and laboratory and field efficacy studies with common grackles (Quiscalus quiscula) and Avipel ® -treated confectionery sunflower. Compared to the germination of seeds not treated with anthraquinone, we observed no negative effects of up to 12,223 ppm, 14,104 ppm, and 11,569 ppm anthraquinone seed treatments for germination of confectionery sunflower, oilseed sunflower, and canola seeds, respectively. Pheasants avoided emergent sunflower seedlings (12 days post-planting) from 15,800 ppm anthraquinone seed treatments during a caged preference test (P = 0.045). We observed a positive concentration-response relationship (P = 0.001) and predicted a threshold concentration (i.e., 80% repellency) of 9200 ppm anthraquinone for common grackles offered Avipel ® -treated confectionery sunflower seeds. Grackles also reliably discriminated between untreated sunflower and seeds treated with 1300 ppm anthraquinone in captivity (P < 0.001). During our field efficacy study for ripening confectionery sunflower, we observed 18% damage among anthraquinone-treated enclosures and 64% damage among untreated enclosures populated with common grackles (P < 0.001). Harvested seed mass averaged 2.54 kg (dry weight) among treated enclosures and 1.24 kg among untreated enclosures (P < 0.001). Our laboratory and field efficacy data provide a reliable basis for planning future field applications of anthraquinone-based repellents for protection of sunflower crops. Supplemental field efficacy studies are necessary for development of an effective avian repellent and management of avian depredation of ripening agricultural crops, including oilseed sunflower.Published by Elsevier B.V.

effect of an ultraviolet feeding cue for an avianrepellent and protection of agricultural crops" (2014).