Study: Climate change could make dozens of bird species extinct in Pennsylvania
Pennsylvania’s state bird, the ruffed grouse, could go extinct in the state along with dozens of other bird species because of climate change, according to a National Audubon Society study released Thursday.
It’s more bad bird news.
Last month, the journal Science reported the loss of 3 billion birds since the 1970s. Now the National Audubon’s study fast-forwards the fate of birds and finds that 64% of North American bird species could go extinct by the end of the century because of climate change.
The report, “Survival by Degrees: 389 Species on the Brink,” provides state and county data on the species most at risk.
Pennsylvania’s 30 highly vulnerable species are a who’s who of some of the most beautiful and intriguing birds: the ruffed grouse, wood thrush, brown thrasher, bobolink, yellow-bellied sapsucker, red-headed woodpecker, white-throated sparrow, eastern whip-poor-will, eastern towhee, dark-eyed junco and a number of warblers.
“Birds have long been seen as messengers, and they’re definitely telling us something now,” said Jim Bonner, executive director of the Audubon Society of Western Pennsylvania, which is among the top five largest chapters in the country.
“It’s frightening that two-thirds of our bird species are at risk of extinction or at the very least having to move from their current habitats in order to survive,” Bonner said. “The good news is that if we take action now, we can help many of them. Even better, we know what needs to be done.”
The report, which draws on more than 70 data sources and more than 140 million bird records, advocates reducing the amount of carbon released into the atmosphere.
Bonner said Pennsylvania’s temperatures are predicted to rise higher than the global average used in the report by the end of the century, increasing an estimated 11 degrees on average in summer months and 8 degrees in winter months by the end of the century.
While having a warmer winter might sound good, Bonner said the predicted 8-degree increase could mean the difference between something freezing or not, upsetting insect populations that won’t die-off over the winter. The fruit of some berry trees that must freeze and thaw several times won’t be palatable to some birds, including the cedar waxwing that relies on berries in the winter.
Although the predicted temperature change will be dramatic, different bird species will be impacted while others won’t, according to Bonner.
The ruffed grouse is expected to vanish if the state sees temperatures rise 5.4 degrees or more by the end of the century. Rising temperatures and shifting weather patterns would affect its ability to find food and reproduce, according to the report.
When stressed, the Pennsylvania birds won’t be able to successfully breed and the population here will eventually die off, Bonner said.
Another at-risk bird is the wood thrush, which sings that throaty, metallic and melodic song often heard in the summer woods.
“They will lose about 57% of their current range, while the new colonizing range is 20%,” Bonner said.
“As it gets warmer, they don’t do well in the warmer, drier climate,” Bonner said. “They like it cooler and wetter for the food they eat.”
How climate change is affecting PA birds, according to Bonner:
• False spring: “This is when you hear people talk about their lilacs coming out too early, then a frost hits and kills the flowers,” Bonner said. For the birds that travel thousands of miles from Central and South America, a false spring impacts the plants that attract the insects they eat, perhaps severely diminishing their food supply. These birds arrive tired and hungry. “Hummingbirds feed on certain plants for fuel,” Bonner said. “If they bloom too early before the birds arrive, they can’t have their nectar.”
• Heavy rains: Lots of heavy rain means less foraging time for birds to find food, which can become perilous for their young. Heavy rains also can wipe out a number of nests.
• Extreme heat: Extreme heat is forecasted every three years instead of much longer intervals, stressing the birds just like people. “You see on the webcam with the bald eagles with the parents shading the young,” Bonner said.
Mary Ann Thomas is a Tribune-Review staff writer. You can contact Mary at 724-226-4691, [email protected] or via Twitter .