Wednesday, August 4, 2010 - 1:30 PM

COS 66-1: Reintroducing threatened falcons into vineyards reduces bird-damage to wine grapes

Sara M. Kross, Jason M. Tylianakis, and Ximena J. Nelson. University of Canterbury

Background/Question/Methods

Land use intensification is driving range reduction and even extinction of many iconic species, despite the potential ecosystem services provided by these species. Although it is well documented that conserving natural enemies of insect pests may provide direct biological control benefits, comparatively little research has examined the benefits of protecting natural enemies of vertebrate pests. In vineyards, pest birds directly reduce yield by feeding on grapes, and reduce wine quality through increased fungal infection on pecked bunches. In order to assess a joint conservation/ pest management project that reintroduced the threatened New Zealand falcon, Falco novaeseelandiae, into vineyards, we estimated pest bird abundance and quantified grape damage in vineyards containing resident falcons and vineyards without falcons. 

Results/Conclusions

We found that falcon presence significantly decreased the number of grape-removing introduced European pest species, and hence the incidence of grape removal and overall pest bird damage. Falcons did not affect the number of native silvereyes, Zosterops lateralis, which peck grapes and cause fungal infection, but falcons did reduce the amount of pecking found on grapes. Our results indicate that reintroducing native birds of prey into vineyards can reduce both pest bird abundance and grape damage, resulting in considerable savings for the vineyards while protecting an endemic species.