When Brian Shema began taking part in the Audubon Society’s annual Christmas Bird Count more than two decades ago, red-bellied woodpeckers were a very rare sight.
The red-headed bird’s historical range was the central and southern states. They’re not suppose to be here, traditionally speaking.
But these days, Shema said about 250 red-bellied woodpeckers — which actually have the most red on their heads, not their bellies — are spotted each year in the 15-mile Pittsburgh count circle.
“Its range has expanded from the south, and through the CBC data, we’re able to watch and map, over the course of 30 to 40 years, the march of that species into and beyond Pittsburgh.”
That and other small-but-significant changes are part of why groups like the Audubon Society, the Cornell Lab of Ornithology and the American Bird Conservancy are always looking for more “citizen scientists” to volunteer, count their local birds and help create an even-more-complete data picture.
The American Bird Conservancy attributes the expanded range of the red-bellied woodpecker, and other species, to the more-moderate winters in areas like southwestern Pennsylvania, as well as the increased availability of backyard bird feeders in winter.
Another change in the local data is the continued appearance of gray catbirds, which Shema said are always plentiful in the summer, but should be largely gone from the area by late December, even though they only migrate a short distance.
“But we’re finding catbirds every winter,” he said. “It’s almost like the birds are balancing the risk of migration against the risk of surviving the winter, when a lot of the food they need can still be found around here.”
Southwestern Pennsylvania has had more than its share of mild winter in recent years. Going back to 2000, the average December temperature has ranged from just over 23 degrees in 2000 to 44.5 degrees in 2015, according to the National Weather Service. Over that time span, eight of the 10 warmest Decembers have come in the past decade.
January and February temperatures going back to 2000 have generally stayed between the mid-20s and upper 30s.
That, combined with a lack of snowfall makes it easier for birds to overwinter at home instead of migrating.
“We have chipping sparrows that nest in people’s backyards every summer,” Shema said. “They’d normally have gone to Virginia by now, but we’ve seen then in seven of the last 10 counts. Usually it’s only a couple, but in 2020 we recorded eight. I expect it to continue as long as our winters aren’t as harsh.”