New research from the British Trust for Ornithology (BTO) has provided clues as to how to conserve one of our best-loved but declining species – the Curlew.
With their distinctive long, downturned beaks and evocative cry, Curlews have inspired many writers, poets and artists, but sadly these well-loved birds are becoming harder to find. Curlew numbers in the UK fell by 48% between 1995 and 2018, and this species is classified globally as Near Threatened. The UK holds between a fifth and a quarter of the global Curlew population, meaning that any effective means of combatting this species’ decline could make a real difference on a global scale.
This new study by the British Trust for Ornithology (BTO), published in the journal Biological Conservation, used data from 15,000 Curlew fitted with individual leg rings by volunteers taking part in the British and Irish Bird Ringing Scheme. The results of the study show that Curlew declines are being driven by poor breeding success. Curlew pairs breed once a year and normally lay four eggs in each clutch. The results of the study suggest that, on average, Curlew pairs only successfully raise 0.25 chicks per breeding attempt. If we are to stabilise and reverse Curlew declines, then this number would need to be increased to 0.43 chicks per breeding attempt. Once young Curlews get past the vulnerable chick stage, the research found that the survival rates of adult birds are high.
Lead author of the study, Dr Aonghais Cook, said, “Our study shows that Curlews have high annual survival rates, so the decline that we have seen in their populations will have been driven predominantly by factors affecting breeding success rather than adult survival. If we want to reverse these declines then we need to focus our conservation efforts on improving breeding success.”
Breeding Curlew are likely to benefit from the wader-friendly management of land, including restoration of wet features within fields and delays in cutting vegetation. The use of fencing to prevent predators from accessing nests is another approach that can help. Other tried and tested interventions to improve Curlew breeding success include headstarting, where eggs are taken from vulnerable nests and the chicks raised in protected enclosures until they are ready for release.
The study also highlighted the role of cold weather and habitat availability on survival during the winter. Dr Cook added, “As migratory species, Curlews face a range of pressures over the course of a year. Whilst improving breeding success is key to reversing declines, we must ensure the habitat they use outside the breeding season is protected as well, otherwise these efforts are likely to be insufficient.”
With focused conservation efforts to target Curlew breeding success, perhaps the Curlew’s cry can become widely heard and appreciated once more and for generations to come.
Read the study at: https://www.sciencedirect.com/science/article/pii/S0006320721002500?dgcid=author or request a copy of the manuscript from firstname.lastname@example.org
Header image: Philip Croft.