Firstly, what is it? Bendiocarb is “an acutely toxic carbamate insecticide used in public health and agriculture and is effective against a wide range of nuisance and disease vector insects” (it is used in malaria control, for example). Pure bendiocarb is highly toxic to birds such as ducks and quail, and to honey bees.

It is so toxic that it has been banned in Scotland since 2005 and even possession is considered a serious offence. In England, bendiocarb is licenced for (diluted) use as an ingredient in a number of products, but they are intended for the indoor control of certain insects such as ants and wasps.

So how do raptors end up ingesting it?

By feeding on poisoned baits – often pheasant or rabbit carcasses split open and dosed with poison – left in the open to attract raptors.

The laying of poison baits in the open countryside has been illegal for over 100 years, but as the RSPB’s Guy Shorrock wrote in November 2021, “we are still a long way from removing the cancer of illegal poisoning from our countryside“, adding that bendiocarb “has increasingly become the poisoner’s weapon of choice”.

Recent incidents involving the illegal use of bendiocarb to kill birds of prey include

– a Red Kite poisoned in North Yorkshire in March 2019 with Bendiocarb and Isofenphos (Northern England Raptor Forum)

– a Red Kite found poisoned near Scarmpston, North Yorkshire in April 2020: tests found a combination of Brodifacoum and Bendiocarb. (Northern England Raptor Forum)

– a Buzzard killed in Nidderdale by a combination of pesticides including Bendiocarb (three were found in the buzzard’s gizzard and crop with a fourth pesticide detected in its kidney).

– an adult Peregrine found dead on top of the remains of a wood pigeon in May 2020 on National Trust land in the Upper Derwent Valley (Peregrine poisoned in Peak District National Park).

– a young Peregrine found poisoned near Barnsley in July 2020 (RSPB Community Our Work).

– a young White-tailed Eagle from the Isle of Wight reintroduction scheme found dead on a shooting estate in West Sussex in October 2021.

– two young White-tailed Eagles found poisoned in Northern Ireland in May 2023.