For example, one very recent major study shows for the first time that common bird populations are responding to climate change in a similar pronounced way in both Europe and the USA. The exceptionally large data set comprises information collected by more than 50,000 birdwatchers around Europe and USA for nearly three decades.
According to Academy Research Fellow Aleksi Lehikoinen, the study also speaks to the power of citizen science.
Lehikoinen’s research group is generating significant research results from material collected by volunteers. It has found that the numbers of birds considered typical of Finnish forests, such as the wood warbler common in older leafy forests, are decreasing as climate change progresses and the exploitation of forests intensifies.
– If we increase the exploitation of our forests, as has been suggested by the current Finnish government, this will most likely lead to further decreases in the number and diversity of forest birds, says Lehikoinen.
Aquatic birds now winter in Finland
The group also established that with the warmer winters, growing numbers of European aquatic bird varieties now spend the winter in our country. Thus Finland has an increasing responsibility to protect these birds.
However, Finnish and European nature conservation areas have, despite their shortcomings, proven to be effective in helping aquatic birds adapt to climate change. The quality of the habitats in conservation areas is better than that of habitats outside them, which may help species spread to new areas in the north as southern areas become inhospitable in terms of climate.
Bad news for northern birds
If Finland’s bird populations were following changes in temperature in a straightforward manner, they would be moving north-east in Southern and Central Finland. In Lapland, their direction would be north-west, towards the coldest temperatures. However, research conducted by Lehikoinen's group indicates that there are considerable differences in the directions of migration between different populations. Birds accustomed to life on the fells, such as the rock ptarmigan, are in the worst trouble. Their only options are to migrate higher towards the top of the fell, or to higher fells across the border in Norway or Sweden.
At the same time, it has become apparent that small bird species which winter in Finland react to global warming more severely and that their territories have moved more rapidly northwards than those of larger and/or migratory species. Migratory birds change their behaviours throughout the year, and a rapid move north may not be the best solution for them.
Finland- and Europe-wide data sets require constant cooperation with both Finnish and European research institutes as well as ornithological associations.
Academy Research Fellow Aleksi Lehikoinen leads the Helsinki Lab of Ornithology at the Finnish Museum of Natural History Luomus. The group members involved in the above-mentioned studies include doctoral students Sara Fraixedas Nuñez, Kalle Meller and Diego Pavon Jordan as well as postdoctoral researcher Kaisa Välimäki. Finnish partners of the research group are the Finnish Environment Institute and the Novia University of Applied Sciences.
However, volunteer birdwatchers are owed the greatest gratitude for their tireless data collection which has made these studies possible.
Links to the articles:
- Strong effects of climate change on common bird populations in both Europe and the USA
- Abstract of Kalle Meller´s thesis: The impacts of temperature on the long-term variation in migration and breeding performance of birds
- Continent-scale global change attribution in European birds - combining annual and decadal time scales
- Population trends of common breeding forest birds in southern Finland are consistent with trends in forest management and climate change (pdf)
- Inter-annual variation and long-term trends in proportions of resident individuals in partially migratory birds
- Climate-driven changes in winter abundance of a migratory waterbird in relation to EU protected areas
- North by north-west: climate change and directions of density shifts in birds
- Velocity of density shifts in Finnish landbird species depends on their migration ecology and body mass