Powdermill Avian Research Center documents bird species year round
The parade of birds heralding the arrival of spring are nesting earlier as climate change brings warmer weather and earlier plant budding, according to the Powdermill Avian Research Center in Rector.
An outpost of the Carnegie Museum of Natural History, Powdermill has the longest-running bird banding program in the country, established full time in 1962.
With extensive, long-lived data documenting bird species year round, the research center has tracked trends like birds migrating northward earlier, riding the wave of the greening countryside.
The bird banding program's most recent study examines whether the earlier spring and bird migration are changing when birds decide to nest.
Apparently they are, at least with some birds.
“What this study does is provide us with a richer story to tell about how birds in eastern North America are responding year to year in long term changes in the climate,” says Dr. Wesley M. Hochachka, assistant director of bird population studies at Cornell Lab of Ornithology in Ithaca, N.Y.
The Powdermill study is authoritative as it looks at more than one species over time, Hochachka says.
“Data sets that go that far back are rare,” he says.
The researchers and volunteers at Powdermill may have changed over its more than five decades, but they still arrive before dawn at the Laurel Highlands site to set their mist nests, as airy as a spider web, for catching birds on the wing. The rows of nets are stretched between banks of vegetation shorn to keep the brushy habitat appealing to birds.
A number of long-term studies have documented that temperature change is causing plants to bud a month earlier than a century ago and that is profound, says Luke DeGroote, ecologist and Powdermill bird banding program coordinator.
Over 50 years, Powdermill researchers looked in their own backyard and found lilacs were budding two to three weeks earlier. But the program's other research documented that the migrating springs birds were arriving only about a week earlier during the same time frame.
“We saw the mismatch between leafing out and birds migrating, so we wanted to know what the timing of breeding looked like,” DeGroote says.
Powdermill's most recent study found the birds were breeding earlier — two to three weeks over the same 50-year time span.
Birds migrate thousands of miles from South and Central America just to nest here in the spring. The researchers know the timing of nesting because of their year-round bird banding records: They document when they catch young birds hatched that season and when the breeding females lose their breast feathers as their bellies prepare to incubate eggs.
“The take home message is a lot of birds, three-quarters are responding to climate change and only a quarter are doing worse (having fewer young),” DeGroote says.
Powdermill will continue to follow these migration trends.
Mary Ann Thomas is a Tribune-Review staff writer.