‘Citizen scientists’ watch for songbird facing extinction
HADLEY — When wildlife biologist Randy Dettmers goes into the field looking for birds, often his sights are set on creatures he has little chance of spotting.
That was true for several outings in March when the focus was the rusty blackbird, whose population in North America is estimated to have declined by 85 to 99 percent over the last 40 years. But there have been some sightings. Dettmers, who works with the U.S. Fish and Wildlife Service in its Hadley office, is helping the International Rusty Blackbird Working Group, which has mobilized “citizen scientists” to feed it data on where those are occurring.
The aim is to solve the mystery of why the number of these birds, once commonly seen songbirds, has crashed so dramatically.
Judith Scarl is the international coordinator for the rusty blackbird spring migration blitz. She is asking experienced birders as well as novices with an interest in nature in 38 states and most of Canada to spend a few hours outdoors along the rusty blackbird migration routes looking and listening for these small black or grayish-brown birds distinguished by rust-colored fringes along the tips of some of their feathers and their pale yellow eyes.
“It doesn’t take a super experienced birder” to join the ranks of citizen scientists, Dettmers said, just a willingness to learn what the bird looks like and to create an account at www.eBird.org to log information.
“Once you know how to identify a rusty blackbird, pretty much anyone can participate,” Scarl said.
Dettmers said his expeditions, including trips to the Lawrence Swamp in Amherst, in which he didn’t see any rusty blackbirds, provided important data nevertheless. He is planning more outings to agricultural fields in Hadley, Northampton and Hatfield where they might be foraging.
Why the blitz?
The population of rusty blackbirds has been in steady decline for a century, plummeting in the last four decades, Scarl said. But scientists didn’t really take notice until the 1990s. Still, they are stumped, she said.
The number of rusty blackbirds alive today is thought to be anywhere from 158,000 to 2 million, Scarl said. The uncertainty is due to the fact that breeding grounds in Canada and northern New England are hard to get to, making it difficult to count them.
The spring migration blitz is meant to identify where they congregate during their annual trek from the Carolinas, Georgia and the Mississippi Valley. By collecting data from birders, Scarl hopes to identify “hot spots” where the rusty blackbirds are seen.
More blitzes are scheduled for next year and the year after. They will be fine-tuned by asking people to go to areas where sightings occurred this year and also to places that weren’t visited in this round.
One of the goals, Scarl said, is to see if the resting places these birds seek out have common characteristics.
“Ultimately we are going to use the data for conservation,” she said. “Once we figure out where the hotspots are we can assess whether or not they are protected and what actions we can take to make sure they are protected.”
Another goal is simply to bring the rusty blackbird to wider attention.
“This bird is a fascinating mystery,” Scarl said. “It has undergone one of the steepest population crashes of any once common land bird.”
Dettmers, who specializes in studying declining bird species, said the rusty blackbird’s demise could be a warning sign of broader issues.
“It’s not a particularly showy species that people were paying attention to, but they are a pretty good biological indicator of overall wetland health and the degree to which contaminants might be impacting important ecological systems,” he said.
Culprits for the population crash are also being sought in rusty blackbird wintering grounds in the South, where forested areas they favor are being converted to agricultural use, and in their northern breeding grounds.
This year’s blitz is “the beginning of getting a basic understanding of what the spring migration looks like,” Dettmers said.
Tools like www.eBird.org, created 12 years ago by the Cornell Lab of Ornithology and the National Audubon Society, have helped wildlife biologists by allowing citizen science, sometimes also called “crowd sourced science,” or “networked science,” to gather and channel large amounts of data in a meaningful way.
“There is a whole cadre of people who really know all the mathematical and statistical techniques and they are poring over this stuff every day trying to figure out how we can get the most information out of it,” Dettmers said. “We have a better idea of migratory information for different species, which is something we didn’t have really good information on before eBird.”
Scarl said the initial results of her efforts to coordinate broad participation in tracking rusty blackbird habits are promising. Last March entries on eBird checklists that included sightings of the bird numbered 2,376. This March they were up to 3,613.
“That’s a great indicator that we’re getting the word out there,” she said.
A special section on eBird is now available devoted specifically to the spring migration blitz, which will continue to mid June. The majority of the sightings in western Massachusetts are expected in April.
“Citizen science is amazing,” said Scarl, who is also a conservation biologist at the Vermont Center for Ecostudies. “You can collect data over an enormous range at very little cost.”
An added benefit is that “you can get people excited about conservation and really bring science home to them.”