In World War II, did people with bird feeders have substantially different chirping friends than we see today?

Probably not, but a group of researchers warns than 2075 might look a lot less like then, or even 1975, or today. The distribution of birds in the United States could change a lot.

A new U.S. Geological Survey study in PLOS ONE predicts where 50 bird species will breed, feed and live in the conterminous U.S. by 2075. While some types of birds, like the Baird's sparrow, could lose a significant amount of their current U.S. range, other ranges could nearly double.    

Climate change could cause average temperatures to change by three degrees or even up to seven degrees Fahrenheit by 2075, depending upon scenario, which will drive changes to breeding ranges for many species to the north. Precipitation will increase in some regions and decline in others, resulting in substantial impacts on local and regional habitat.

Habitats for birds currently breeding in the far southern U.S., such as the desert-dwelling Gambel's quail and cactus wren, will expand greatly by 2075 in the conterminous U.S. as a warming climate moves the overall range to the north. The chestnut-collared longspur, sharp-tailed grouse and gray partridge could all lose over 25 percent of their suitable breeding range in the northern U.S. as climate becomes more suitable in Canada for these species. The Baird's sparrow may lose almost all of its current U.S. range.

The new study used climate and landscape data to create and compare U.S. distribution maps of 50 bird species in 2001 and 2075. The maps for each species are available online.

The species that will either gain or lose more than 20 percent of their conterminous U.S. ranges as compared to 2001 are:

Gambel's quail: 61.8 percent gain

Cactus wren: 54.1 percent gain

Scissor-tailed flycatcher: 46.4 percent gain

Gray vireo: 44.9 percent gain

Painted bunting: 38.5 percent gain

Anna's hummingbird: 27.2 percent gain

Black-capped chickadee: 21 percent loss

Ferruginous hawk: 21.2 percent loss

Sora: 22.8 percent loss

Northern harrier: 24.7 percent loss

Bobolink: 24.9 percent loss

Short-eared owl: 26.2 percent loss

Vesper sparrow: 26.4 percent loss

Savannah sparrow: 27.2 percent loss

Sedge wren: 29 percent loss

Gray partridge: 35.6 percent loss

Sharp-tailed grouse: 44.8 percent loss

Chestnut-collared longspur: 54.1 percent loss

Baird's sparrow: 90.8 percent loss

Landscape changes resulting largely from human activity, including land use and land cover changes, will also significantly affect future U.S. bird distributions. The effects of landscape change will be more scattered, with very high loss of habitat at local and regional scales.

"Changing landscape patterns such as deforestation and urban growth are likely to have at least as large of an impact on future bird ranges as climate change for many species," said  "Habitat loss is a strong predictor of bird extinction at local and regional scales," said Terry Sohl, a USGS scientist and the author of the report. 

Source: United States Geological Survey