Birders take off for Global Big Day

For millennia people had no idea where birds went when they migrated or how long they lived. In the 1800s, scientists began studying bird migration by wrapping metal bands inscribed with numbers around birds’ legs. The numbers corresponded with data about the bird. In the late 1950s, bird banding centers began forming an international network.

With more than 50 years of experience, the Carnegie Museum of Natural History’s Powdermill Nature Reserve in Westmoreland County is among the longest continually operating bird banding centers in North America. Nearly 13,000 migrating birds are live-captured every year at the Powdermill Avian Research Center. By 2001, more than 500,000 birds of more than 200 species had been banded. Data on the bands includes the bird’s size, weight, date of banding, banding location and other details.

“Banding, or more precisely the recovery of banded birds, could yield useful information,” said Jim Bonner, executive director of the Audubon Society of Western Pennsylvania. “The downside is that the birds usually have to be caught again — or picked up, if dead — to be able to read the band. The recovery rate is very low.”

Powdermill staff live-catch birds in delicate mist nests. Sometimes researchers are able to note band numbers through spotting scopes, but more bands are recovered when members of the public find dead birds and when hunters report band data following the harvest of migratory fowl. The information is collected by the U.S. Geological Survey and used to study ways that water, habitat and other factors influence migratory bird populations and how the birds impact their environment.

“New electronic devices are making not just the identification of the birds possible but also their actions between trapping,” said Mr. Bonner. “Some can identify a bird remotely and do not require the bird to be trapped. Although they cost more, they yield a tremendous amount of good information, making it less important to band as many birds.”

Backyard birders can contribute to migratory science on May 13. Designated Global Big Day by the Cornell Lab of Ornithology, it’s one big international bird count. On a single day participants record every bird species they see. During last year’s Global Big Day, more than 17,500 birders from 154 countries logged data on 60 percent of known bird species. In 2015 and 2016, backto-back records were set for the most bird species seen in a single day. Get details at www.eBird.org.

“Anyone can participate at whatever level they feel comfortable,” said Mr. Bonner. “The only criteria for participating is submitting your observations to eBird. That could be one bird or hundreds.”