Volunteer birdwatchers have been keeping tabs on the birds in Europe for decades, but they have been noticing some disturbing changes in bird populations. According to a press release from Eurekalert, changes to Europe’s climate have proven beneficial to some species, but other birds more suited to colder regions may be in serious trouble.

The study found that warm winters offer a benefit for bird species that remain in Europe year-round, like the short-toed treecreeper and the collared dove. The warmer and earlier springs make the trip easy for migratory birds like the goldfinch and the woodlark, and gives them a larger window of opportunity to successfully mate.

The data was collected across 18 different European countries, and the findings were published in the journal Global Change Biology by researchers from the Center for Macroecology, Evolution, and Climate at the University of Copenhagen, in cooperation with BirdLife International and the European Bird Census.

According to the study’s lead author, Peter Sogaard Jorgensen, “We found benefits from conditions observed under climate change for both resident birds, short-distance migrants and long distance-migrants, but at very different times of the year that complement their breeding season. So if we are to predict what the future bird community may look like in Europe, we need to understand how the conditions during breeding will change.”

Birds like the house sparrow and the carrion crow, however, which are more adapted to the colder regions of Europe, are expected to become less abundant. Migratory birds that spend their summers in Europe will likely have a better time with the increase in temperature.

While not all birds will be affected equally, climate change is set to create winners and losers in Europe and across the globe.