A recent study in the journal Environmental Pollution is the first to show that chronic exposure to pesticides reduces fitness and reproduction of birds. Populations of farmland birds have been declining across North America and Europe. While many studies have looked at the effects of long-term chemical exposure on the decline of other types of biodiversity such as insects and reptiles, less attention has been paid to this exposure on the decline of farmland birds. This study used an experimental approach and fed partridge birds either organic (untreated) grain or grain from conventional farms for 26 weeks and then measured behavioral and physiological traits known to affect population dynamics such as immune system response and reproductive effort. Researchers found that ingesting small of amounts of pesticide over long period of time caused the birds to have lower immunity, increased parasite loads, and reduced investment in breeding. They suggest that these effects on important life history traits paired with the scale of chemical use in today’s conventional agriculture will negatively impact farmland bird populations, and that chronic exposure to sublethal amounts of pesticides should no longer be ignored in future research.

Photo: Partridge amongst grains. Credit:  Dana Davis; unsplash.com

Banner Photo Credit: Alfred Kenneally; unsplash.com