Overall, between 2002 and 2014, a total of 14 mountain-specialist bird species showed declines in their numbers.
Europe’s mountain bird populations have declined significantly over the past two decades, partly as a result of warming temperatures, a new study has found.
Birds that specialize in living at higher altitudes on the continent have also been losing out to deforestation and land conversion. In the face of these threats, they have been moving further uphill where their habitats are inevitably reduced, a team of researchers from the University of Helsinki says.
A study conducted by the researchers with the help of monitoring schemes around Europe looked at 44 bird species from four major European mountain regions, covering a dozen nations: Fennoscandia, the United Kingdom, the Iberian peninsula, and the Alps. Overall, between 2002 and 2014, a total of 14 mountain-specialist bird species showed declines in their numbers with eight of them showing dramatic drops of around 10%, although not uniformly across all their ranges.
“On average, population decline among the species studied was 7% over the 13-year research period, making the situation of mountain birds distinctly worse compared to, for example, European forest birds, whose numbers did not change during the same period,” notes Aleksi Lehikoinen, a research fellow at the Finnish Museum of Natural History Luomus, who headed the study.
The worst-affected have been avian “mountain specialists” that live only in mountain regions and are unable to survive in other environments. These species saw their numbers dwindle by up to 10% during the monitored period. The numbers of mountain birds have plummeted especially in Finland, Sweden and Norway, as well as on the Iberian Peninsula. In Great Britain and the Alps, however, the populations remained more stable.
“Alpine habitats are highly vulnerable to climate change, and this is certainly one of the main drivers of mountain bird population trends,” the researchers explain. “However, observed declines can also be partly linked with local land use practices. More efforts should be undertaken to identify the causes of decline and to increase conservation efforts for these populations.”
Yet it isn’t just a changing climate that is endangering alpine birds. “In addition to climate change, an abundance of mountain birds are affected by human land use,” says Päivi Sirkiä, a research coordinator. “For example, on the Iberian Peninsula the reduction of grazing on mountain fields may result in afforestation, which in turn will lead to a decline among mountain species inhabiting open terrain.”