Falcons reduce pre-harvest food safety risks and crop damage from wild birds

Foodborne illness outbreaks have heightened pressures on growers to
improve food safety, including mitigating possible threats from wildlife.
Among wildlife, birds are particularly challenging to deter, and the risks
they pose to pre-harvest food safety remain unclear. Further, deterrence
efforts can jeopardize conservation and biological control, necessitating
strategies that effectively lead to co-management of farmlands for
conservation, pest control, and pre-harvest food safety. Promotion of
birds of prey with nest boxes may be one promising strategy to promote
species of conservation concern that can deter pest birds that damage
crops and introduce foodborne pathogens. Here, we evaluate if the American
kestrel (Falco sparverius), a small falcon, can concurrently reduce crop
damage and pre-harvest food safety risks from birds in sweet cherry
orchards in Michigan, USA. In orchards with and without active kestrel
nest boxes, we conducted avian transect surveys, estimated the percentage
of cherries with bird damage, and estimated the percentage of branches and
cherries with feces. We collected fecal samples directly from birds and
crop surfaces. We tested feces for Campylobacter, the most common
foodborne pathogen in birds, using both culturing and PCR. Fewer birds
were present in fields with nest boxes, which translated into reduced bird
damage (0.47% vs. 2.50%) and fewer branches with feces (2.33% vs. 6.88%).
Feces on individual cherries were rare (4/15,890 [0.025%] cherries across
all sites). We detected one or more species of Campylobacter using
culturing and/or PCR in 10.65% (33/310) of bird feces collected from crops
and in 19.67% (24/122) of samples collected directly from birds. Detection
rates were similar in fields with and without nest boxes. Despite the
somewhat high overall detection, cultivable Campylobacter were only
detected in 0.97% of feces collected from crops. Pre-harvest food safety
and wildlife conservation are often thought to be in conflict, and produce
growers have few tools to effectively manage birds. However, our findings
suggest that the promotion of birds of prey using nest boxes may be one
way for growers to conserve a declining species, reduce crop damage, and
reduce in-field fecal contamination that could cause foodborne illness.