Report: Climate Change Threatens Dozens of Missouri Birds | St. Louis Public Radio

Report: Climate Change Threatens Dozens of Missouri Birds

Sep 19, 2014

The White-Throated Sparrow is commonly seen in the St. Louis area during fall and winter, but a new report says climate change could reduce its breeding habitat.
Credit Dave Inman, Flickr Creative Commons

A recent report finds climate change is threatening dozens of birds that call Missouri home.

The National Audubon Society says more than half of the 588 North American bird species studied over the course of seven years are at risk. About 50 species common to Missouri are identified in the report as being threatened.

"Climate change is here and we’re seeing an impact on our natural areas and our natural species, in particular birds. We’re seeing them respond directly to the effects of a warming climate. That requires, demands and needs our attention right now," said Mitch Leachman, executive director of the St. Louis Audubon Society.

Studying suitability

Using 30 years of citizen-scientist observations and surveys, Audubon scientists identified the "climatic suitability" for each bird species - essentially what temperatures, levels of rainfall and seasonal variations at which a bird can live.

The report shows changes to species' livable ranges over the course of three time periods: 2020, 2050 and 2080.
Credit National Audubon Society website

Scientists then mapped those factors against "internationally recognized greenhouse gas emission scenarios" to show how temperatures may change across the continent and where birds would move as a result, according to the report. The resulting maps show how birds' ranges change over the course of three time periods: 2020, 2050 and 2080.

"The center of their ranges are moving north, very broadly, and unfortunately the single biggest concern with that is, while bird are mobile, they might not find suitable habitat when they move north," Leachman said.

Local birds affected

In general, the maps show that, if global warming continues at the present rate, 314 bird species in North America will lose more than 50 percent of their current ranges, or where they can suitably live, by 2080. Of those, 126 "climate endangered" species will lose more than half of their ranges in only about 35 years.

Leachman said affected species include the Purple Finch, the Tree Swallow, and the White-Breasted Nuthatch. These species, as well as many others, breed here in the summer months and fly south for winter. But Leachman said if summers get "too warm and inhospitable," the birds will move farther north to breed.

That's a particular problem for one local species, the White-throated Sparrow, a common sight in St. Louis during the autumn. The bird likes colder climates, so it summers in Canada and winters in the St. Louis region.

But the report's projections show climate change may reduce its summer breeding grounds in Canada. 

"In the summer, if this bird is breeding so far north in Canada, well, at some point you run out of continent," he said.

If there's less summer habitat, fewer sparrows would be able to successfully breed, and that means fewer sparrows would return south to the St. Louis area, he said. 

"So that's a big reason we think some of these birds actually will go extinct because they will run out of space to move to."

The White-Breasted Nuthatch is common to the St. Louis area, but if climate change makes Missouri summers too warm, it could move out of the state to breed.
Credit Matt MacGillivray, Flickr Creative Commons

Moving from current habitats

The report says that even those birds that don't lose much of or even expand their ranges are not necessarily safe from the effects of climate change because the maps do not take into consideration specific habitat needs.

"If they are a forest dwelling bird, but the warming climate pushes them north, they might not find the right and the same type of forest when they get to that appropriate temperature regime," Leachman said, noting that loss of habitat could lead to the extinction of some species.

Leachman says such a big impact on so many species of one kind of animal should cause people to take pay attention to climate changes' impacts.

"Birds are pretty, I love birds. There are all kinds of other reasons I could give you to care, but ultimately it should be a very selfish, very practical reason to take notice and go, 'Oh, we're altering the processes of the planet.' That has to be a concern," he said.