Quantification of potential exposure of gray partridge (Perdix perdix) to pesticide active substances in farmlands

Abstract

Estimating exposure of wild birds to plant protection products is of key importance in the risk assessment process evaluating their harmful potential. In this paper, we propose an ecologically-relevant methodology to estimate potential exposure to active substances (ASs) of a farmland focal bird, the gray partridge Perdix perdix. It is based on bird habitat use of fields at the time of pesticide applications. It accounts for spatio-temporal heterogeneity at population and landscape scales. We identify and quantify the potential exposure to 179 ASs of 140 clutches during pre-laying, laying, and incubation phases, and of 75 coveys. The data come from a large scale field study combining radiotelemetry and a farmer survey. They were collected in 12 different representative sites. The proportion of clutches potentially exposed to a given chemical was ≥5% for 32 ASs; prothioconazole and epoxiconazole ranking first. 71% of clutches were potentially exposed to ≥1 AS and 67% to ≥2 ASs. Mixtures involved 2 to 22 ASs. They emerged from commercial formulations, tank mixtures, bird habitat use, and combinations. ASs were fungicides (53%), herbicides (25%), and insecticides (16%) used on a variety of crops in April-June, when ground-nesting birds are breeding. The European Food Safety Authority conclusions report a long-term first-tier toxicity-to-exposure ratio (TERlt) <5 for 11 out of 19 documented ASs, and higher-tier TERlt <5 for 5 out of 10 ASs. This suggests a potential risk for bird reproduction in farmlands. Globally 13% of coveys were potentially exposed to 18 ASs during the first month (1-4 coveys per AS). The use of our field data in future research and risk assessment is discussed.

Residues of plant protection products in grey partridge eggs in French cereal ecosystems

“…We collected failed eggs from hatched, destroyed and deserted clutches of radiotagged grey partridge females (Bro et al 2015 ). They were put in quail egg boxes and stored in the dark at −20 °C.…”

“…Of the ASs we listed as used by the farmers in our 12 study sites in spring and summer 2010–2011, 85.5 % were measured (Online Resource 2 , Bro et al 2015 ). The remaining ASs were not measured either because they were not proposed in routine by the laboratory or because they needed costly specific analyses.…”

“…20–30 days. Thus, all of them are not likely to be exposed to an AS following its application (see Bro et al 2015 ). As a consequence, a non-positive result obtained on one egg cannot be extrapolated to the whole clutch.…”

“…Clutches and eggs were selected following three “strategies”: Eggs displaying worst cases with regards to several endpoints (eggshell thickness, embryo deformity), Failed eggs of successful clutches with lowest egg hatching rates, Eggs of clutches potentially exposed to specific ASs (ASs that have been commonly used but that would need further consideration with regards to risk assessment for avian reproduction (first-tier toxicity-exposure ratio (TER lt ) < 5; Bro et al 2015 ; EFSA 2009 )). …”

“…Eggs of clutches potentially exposed to specific ASs (ASs that have been commonly used but that would need further consideration with regards to risk assessment for avian reproduction (first-tier toxicity-exposure ratio (TER lt ) < 5; Bro et al 2015 ; EFSA 2009 )).…”