Bird Migration Shifts
Climate change has been ongoing for decades, and as average temperatures around the world and in the oceans increase, plant and animal life is being affected. Several new studies have documented some of ways that climate change is altering animal behavior, migration, and characteristics.
Reporting in the journal Ornithology, scientists tracked Lesser Goldfinches with birdwatching data that was collected from 2012 to 2022 in two efforts run by Cornell University: Project FeederWatch and eBird.
Normally, these birds are found in the Southwest US. But their range is going northward into the Pacific Northwest. The study showed that the numbers of Lesser Goldfinch increased dramatically in Washington state by 110.5%, in Idaho by 66.3%, and to a lesser extent, in Oregon as well, which saw a 16.9% increase in that decade.
Rivers were found to be a crucial part of this movement; the waterways can also move seeds and certain plants, the researchers noted. As the goldfinches moved, they also appeared to settle down and form stable populations in their new areas. The investigators also confirmed that Lesser Goldfinch populations are declining in the Southwest.
Another study published in The Wilson Journal of Ornithology has determined that a small, grey bird known as the Least Flycatcher is now migrating an average of 14 days earlier, compared to the same birds 32 years ago. They move from Alberta to Central America, and their numbers are in decline.
Tree Rings Illuminate Snowpack Decline
In another study, scientists used tree rings to learn more about climate change. This work, which was reported the Journal of Hydrology: Regional Studies, showed that snowpack in a region of Quebec known as Gaspesie has been decline for nine decades. The mountains here are at the northern end of the Appalachian range, and the tree ring data went back to 1822. As such, the scientists were able to reconstruct historical data that goes far beyond official record-keeping.
Thinner tree rings indicate a spring season with snow cover that persisted late, while thicker rings indicate years in which snow and ice thawed earlier. Not only was snowpack in decline, but young forests also seem to be moving further upslope.
Caribou Migration is Shrinking
Research published in Global Change Biology has recently shown that the migration areas of caribou are shrinking. Over 35 years of tracking tagged animals with GPS devices, investigators found that the duration, distance, or elevation of migrating caribou were getting smaller. These animals are losing the areas that they can move freely. And these losses are not due to climate change, however, but to other human activity.
Pregnant female caribou might move anywhere from 200 to 500 kilometers every years between their seasonal ranges. But humans are disturbing the landscape, whether by oil and gas drilling, logging, or development. The researchers noted that this is a major reason for declines in caribou populations, and significant efforts will be needed to manage the landscape and conserve these creatures.
Sources: Ornithology, The Wilson Journal of Ornithology, The Journal of Hydrology: Regional Studies, Global Change Biology
