Proposed as the most urgent conservation priority in the UK as a result of a decline in its breeding population, numbers of this iconic bird are also falling in the winter, despite an influx of continental birds. Latest research from the British Trust for Ornithology investigates the likely causes and asks where conservation efforts should be directed.
It is estimated that 58,000 pairs of Curlew breed in the UK; during the winter months numbers increase slightly to around 120,000 individuals, with most of these wintering birds being found in our estuarine habitats. While wintering numbers increased during the 1980s and 1990s they have been in decline since then, and we need to understand why.
To understand what might be driving these changes, scientists at the BTO have looked at the role of both local and more widespread factors. If local factors (such as disturbance from recreation uses, localised pollution events and new developments) influence what is happening at individual sites, then it should be possible to identify those sites at which these local factors are an issue and to then direct conservation action towards them. However, if the changing numbers are instead influenced by factors (such as climate change, sea level rise, and national policy changes) that have an impact across many sites, action may be needed across a much broader geographical scale.
We also need to understand to what extent factors operating during the winter months influence the wider fortunes of UK Curlew populations. If, for example, such factors only exert limited impact on Curlew survival rates, and hence both wintering and breeding numbers, then the focus of conservation action for Curlew populations should target the breeding grounds.
Ian Woodward, Research Ecologist at BTO and Lead Author on the paper said, “Whilst we would expect to see an increase in Curlew numbers, or at least stability, as a result of milder winters, numbers are falling due to the decline in the breeding populations and factors operating during the summer months. Although conservation action therefore needs to be targeted at the breeding population, protection of wintering sites will still be important, ensuring the Curlew does not face added pressures during winter months.”
Posted On: 21/04/2022