A scientific paper, just published in the journal Bird Study, shows that rates of declines in breeding Whinchat in the UK since the mid-1990s have varied with habitat and other environmental conditions. Conservation Scientist Andrew Stanbury explains.
Over the last century, Whinchat have been lost as a breeding species from most of the UK lowlands due to changes in grassland management as a result of agricultural intensification, with declines continuing over recent decades (Figure 1). Whinchat are now on the Red list of Birds of Conservation Concern in the UK.
With the exception of a notable population on Salisbury Plain in Wiltshire, The Whinchat that remain are now largely confined to open unenclosed upland habitats, particularly around its fringes. Due to their lower intensity management, these areas have offered, at least, a partial refuge for the species.
Figure 1: Whinchat abundance has declined by 57% in the UK between 1994 and 2022 Source: BTO/JNCC/RSPB Breeding Bird Survey. Green dots are the annual population index estimates, the green line is the smoothed population trend, and the shaded band is the 85% confident intervals around the smoothed trend.
The aim of this study was to fill a knowledge gap and investigate fine-scale relationships between changes in Whinchat abundance, collected as part of the BTO/JNCC/RSPB Breeding Bird Survey, and habitat across the UK.
We found that rates of decline in Whinchat abundance varied by habitat type, with steeper rates of decline noted within human sites (parks, golf courses and recreational areas), woodland and enclosed farmland, compared to unenclosed open semi-natural habitats. Many of these relationships were to be expected, as these are the habitats that have been impacted most by grassland intensification, and young plantations become unsuitable for Whinchat as trees mature.
More notable, was the fact that within unenclosed open semi-natural habitats, declines were lower in grass-dominated relative to heather-dominated habitats. It is currently unclear what factors are driving these differences, but Whinchat has been described as a grassland specialist and these results suggest that grass-dominated habitats are of key importance to breeding Whinchat in the UK.
Whinchat (c) Sergey Yeliseev (Flickr - CC BY-NC-ND 2.0 DEED)
Whinchat also appear to be faring better within upland valley systems, close to areas of Bracken and at mid-elevations (c300m). Whinchat do show a preference for sheltered, warmer micro-climates; favour south and east facing aspects and steeper slopes, and it is plausible that valley systems offer similar warm micro-climates.
The positive association between Whinchat and Bracken in the UK uplands is well documented and probably relates to the vegetation structure and perches it offers. It is, however, worth noting that a mosaic of vegetation types, rather than large solid stands of Bracken, appears to be important as other studies have shown that Whinchat mostly forage away from areas of high Bracken cover.
The finding of this study also supports a paper by Calladine and Bray who suggested that Whinchat are constrained at lower altitudes (where a large proportion of the population historically bred) by modern agriculture practices and at higher elevation by environmental restrictions on their breeding biology, potentially linked to climate.
What does this mean for Whinchat conservation?
As a long-distance Afro-palearctic migrant, Whinchat are exposed to many potential pressures during their annual migratory cycle; however, current evidence suggests that the large-scale decline seen across Europe over recent decades has been driven by a lack of recruitment into the breeding population, e.g., low breeding success/first year survival, rather than conditions on their sub-Saharan non-breeding grounds.
Whinchat habitat in the upland valleys of the Cheviots in Northumberland (c) Andrew Stanbury
This study highlights the importance of semi-natural grassland and other unenclosed habitats for breeding Whinchat in the UK, particularly upland valley systems with a patchwork of Bracken. These areas are likely to offer the greatest opportunities to conserve the species here. Where maintenance of Whinchat populations is desired, these habitats should be protected from management practices that might have a detrimental impact on habitat quality, such as inappropriate grazing pressure and afforestation.
Future work could test whether important habitat and environmental variables can be influenced to help increase Whinchat breeding success and first-year survival. However, in the meantime, it is important to use available evidence to help protect their key breeding habitats and promote and target conservation measures that are likely to benefit Whinchat.
Acknowledgements
Finally, the authors would like to thank the many volunteers who have taken part in the BTO, JNCC, RSPB Breeding Bird Survey, without whom, such comparison studies would not be possible. We also thank Dartmoor National Park Authority, Exmoor National Park Authority and the Exmoor Society/MacEwen Trust for their financial contributions.
Continue reading
Would you like to be kept up to date with our latest science news? Email with the heading 'enewsletter' to be added to our quarterly enewsletter.
Want our blogs emailed to you automatically? Click the cog in the top right of this page and select 'turn blog notifications on' (if you have an RSPB blog account) or 'subscribe by email'.