Bird use of organic apple orchards: Frugivory, pest control and implications for production

PLoS One. 2017 Sep 14;12(9):e0183405. doi: 10.1371/journal.pone.0183405. eCollection 2017.

Abstract

As the largest terrestrial biomes, crop and pasturelands can have very large positive or negative impacts on biodiversity and human well-being. Understanding how animals use and impact agroecosystems is important for making informed decisions that achieve conservation and production outcomes. Yet, few studies examine the tradeoffs associated with wildlife in agricultural systems. We examined bird use of organic apple orchards as well as how birds influence fruit production positively through control of an economically important insect pest (codling moth (Cydia pomonella)) and negatively through fruit damage. We conducted transect surveys, observed bird frugivory and assessed bird and insect damage with an exclosure experiment in small organic farms in western Colorado. We found that organic apple orchards in this region provide habitat for a large number of both human-adapted and human-sensitive species and that the species in orchards were relatively similar to adjacent hedgerow habitats. Habitat use did not vary as a function of orchard characteristics, and apple damage by both birds and C. pomonella was consistent within and across apple blocks that varied in size. A small subset of bird species was observed foraging on apples yet the effect of birds as agents of fruit damage appeared rather minor and birds did not reduce C. pomonella damage. Our results demonstrate that organic apple orchards have the potential to provide habitat for diverse bird communities, including species typically sensitive to human activities, with little apparent effect on production.

MeSH terms

  • Agriculture / methods
  • Animals
  • Biodiversity
  • Birds / physiology*
  • Feeding Behavior
  • Insect Control / methods*
  • Malus
  • Moths / physiology*
  • Organic Agriculture

Grants and funding

This project was funded in part by the National Wildlife Research Center, a unit within the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services (https://www.aphis.usda.gov/aphis/ourfocus/wildlifedamage/programs/nwrc) and by Arkion® Life Sciences (http://www.arkionls.com/). The Colorado State University Center for Collaborative Conservation (www.collaborativeconservation.org/ccc-fellows-program-overview) and the Colorado Field Ornithologists (http://cobirds.org/CFO/Grants/) also contributed small grants to AMM to support this research. Corporate collaborations do not imply endorsement by the United States Department of Agriculture. Co-authors at the National Wildlife Research Center and Colorado State University had input on the study design, data collection, analysis, writing and submission of this paper.