Two rare peregrine falcon chicks born on Worcester Cathedral this spring died from ingesting poison, laboratory tests have confirmed. The chicks were among three that hatched from eggs laid by adult birds Peter and Peggy, but all three died between 6 and 15 May.
The cathedral's biodiversity adviser, Chris Dobbs, said the results would be shared with West Mercia Police and the British Trust for Ornithology. He described the deaths as "terribly sad", noting that the nesting pair had successfully fledged four chicks in each of the previous three years.
Post-mortem examinations on two of the chicks found internal bleeding consistent with poisoning. It is thought the adults may have brought contaminated prey to the nest, unaware the small animals had been killed by rodenticide. The first chick to die was removed from the nest by Peggy, while the other two were recovered and sent for analysis.
West Mercia Police confirmed they received a report about the suspected poisonings on 20 October and spoke to the RSPB, but the investigation has since been closed due to "evidential difficulties". Both adult birds appear fit and healthy and will continue to be monitored.
The Peregrine Falcons in Worcester team, which runs a live stream of the nest, said the carcasses were initially sent to DEFRA, which ruled out avian influenza, before further analysis by a university researching raptor mortality. They added that the adults are behaving normally, and the team do not plan to speculate on the cause until further details emerge.
