PHENOLOGICAL RELATIONSHIPS OF NESTING BARN SWALLOWS IN A SWALLOW-FLY-CATTLE SYSTEM AND THEIR POTENTIAL ROLE IN SUPPRESSION OF PEST FLIES IN A WARMING CLIMATE

Conservation efforts for birds that provide ecosystem services in agricultural systems require management approaches that cross disciplines. This information is communicated through a variety of outlets but rarely in ways that interface effectively with normal management approaches. The disconnect between agriculture and wildlife conservation reduces the likelihood that ecosystem service benefits will be realized. One understudied ecosystem service provided by birds such as barn swallows (Hirundo rustica) is their role in suppression of flies that are pests to livestock. Climate change, however, may differentially affect flies that respond largely to temperature, and swallows that migrate and respond to photoperiod and other local variables. Chapter two uses barn swallow nesting records from citizen science databases, and growing degree-days (GDD) to assess swallow nest initiation in relation to published GDD for fly emergence. Survival analysis indicates that GDD are a stronger indicator of when barn swallows nest than is day-of-year. Our day-of-year and GDD data provide no evidence to indicate that timing of barn swallow nest initiation has changed over time and nest initiation appears to be still in synchrony with fly resources. The use of GDD allows more precise tracking of swallow nesting and, as a common measurement tool, facilitates comparisons with fly emergence that can be used to elucidate interactions and management options across the swallow-fly-cattle system. To better understand the feasibility of incorporating barn swallows into an integrated pest management approach, it is important to consider the audience that will be implementing the technique. Chapter three documents perspectives of cattle organization leaders across the United States using an online questionnaire. Overall response rate from the 320 leaders contacted was 48.8%. Follow-up phone interviews with a subsample of 25 leaders provided additional clarity and understanding. Our results suggest that cattle organization leaders favorably view barn swallows and the potential benefits that barn swallow management might contribute to help reduce pest fly populations. Continued communication is needed as research is conducted toward development of sound management strategies that benefit swallow conservation and livestock producers