Crop seeds may be treated with pesticide prior to drilling in order to protect the growing plant during early developmental stages from pests and diseases. Treated seed may be attractive to farmland birds as a food source and as such these uses are subject to an ecotoxicological risk assessment prior to approval, under European Union Regulation (EC) 1107/2009. In temperate zones, spring-sown crops are likely to coincide with bird breeding seasons, and there is thus a potential dietary exposure of reproductively active birds to pesticide.
We modelled the reproductive success of four bird species (rook, skylark, linnet and yellowhammer) exposed to pesticides through consumption of spring drilled treated seed. The higher bodyweight of rooks should make them less vulnerable to pesticide as larger bodied birds consume less food, and thus less contaminant, relative to smaller bodied birds. Our result show, however, that the rook may be ecologically vulnerable, due to an earlier breeding habit which coincides with the drilling of spring crops, and due to breeding only once per year. Other birds breed later, and may make further breeding attempts. We also compared individual level risk quotients to population level effects measures, which may relate more directly to the relevant protection goals. Highlights include:
Crop drilling and breeding calendars affect modelled breeding success.
Individual risk quotients may not translate into measures of population growth rate.
Bird life history can drive ecological vulnerability to pesticides during breeding.
Rooks were more ecologically vulnerable to pesticides than smaller bodied birds.
This work was presented at the SETAC Europe Annual Meeting in Brussels this year (May 2017). The slides are available here.
Our journal article on this same topic has now been published https://www.ncbi.nlm.nih.gov/pubmed/28841527.
In addition to this topic, CEA also presented 7 posters and 2 other platform presentations at SETAC Brussels. These are available for download here.
For further information, please contact Alan.Lawrence@cea-res.co.uk.