Thanks to everyone who has donated to the ‘Beyond the maps’ appeal so far.
We have just £11,000 more to raise to fund this ‘Beyond the maps’ research. Can you help us to reach it by making a donation? With over one third of breeding species showing range contractions, there’s a pressing need to understand what’s driving changes.
BTO scientists have started working on two of the most pressing issues for our bird populations – climate change and upland bird declines - using Bird Atlas data.
Climate change impacts
There is growing evidence that species are extending their breeding distributions to the north, most likely in response to rising temperatures. Previous research shows that our bird populations shifted, on average, around 20 km north between 1968–72 and 1988–91. Bird Atlas 2007–11 data suggest this trend has continued, with an additional shift of around 15 km.
Our work suggests this is a rather simplistic summary, and in fact some species are shifting to the northwest or northeast rather than directly north. This is an important finding because it could mean that other aspects of climate change than warming (e.g. changes in rainfall) are affecting some species more than others.
There is some concern that if species differ in the speed they can move to track climate warming then the communities of species, and the interactions among them, might become disconnected. That might be important for how ecosystems function, including how predators and prey interact. This may be doubly important if, as our results suggest, species also go in different directions.
Upland bird research
A disproportionate number of species associated with the uplands have shown range contractions and abundance declines since 1988–91 so we really want to understand how and why upland bird communities are changing.
Our work has started by looking at the mix of species found in uplands, and the elevations at which different species occur. Everyone thinks of Ptarmigan and Dotterel as upland species but it appears there are other species that might now be classed as upland birds. For example, for the Cuckoo, major declines in the lowlands of the south combined with increases in the upland northwest mean that the proportion of the British Cuckoo population that breeds within the uplands has increased from 28% two decades ago to around 50% today.
A similar trend for the Willow Warbler means that the average elevation at which you might see breeding warblers has increased by around 100 m. We see a similar uphill shift for Goldfinch and Greenfinch. The question now is to understand why and whether these are trends we should welcome or be concerned about. Uphill shifts can be another sign that climate change is affecting species, perhaps allowing them to breed at elevations that were formerly too cold. This could explain the finch shifts, but are their different explanations for the warbler and the Cuckoo in lowlands and uplands?
We’re delighted that the data everyone worked so hard to collect are now being used by us, and other institutions, to inform conservation. In addition to these BTO-led projects we are working in collaboration with institutes with complementary skills and data:
- With the University of Exeter who are investigating the role birds play in different ecosystem services, whether in controlling pests or contributing to a better environment in urban areas.
- With the University of York/Biological Records Centre who are testing how different species groups are responding to climate warming. Knowing which species groups are struggling to adapt will help us to manage landscapes, for instance by providing the right sorts of habitats as corridors or stepping stones to enable dispersal.
Please help us to do even more and reach our target by making a donation to the 'Beyond the maps' appeal.