Soaring high: Volunteers track raptor migration across the Chesapeake Bay
Ospreys, falcons and eagles are among the species of raptors that fly through the Chesapeake Bay region as they migrate.
And in our latest Chesapeake: A Journalism Collaborative story we learn that as they do - a group of volunteers is taking note.
Delaware Public Media’s Katie Peikes tells us they’re part the Hawk Watch initiative - an international effort to study raptors during their migratory period.
It’s common this time of year to see and hear flocks of birds flying south for the winter.
But not all birds travel in flocks. Many birds of prey or “raptors” move in smaller groups, or fly solo, and their flight is being tracked by a group of volunteer hawk watchers.
On a cloudy, windy September morning at Cape Henlopen State Park, Jen Ottinger stared at the sky through binoculars looking for raptors.
“We don’t get nearly the number of birds that Cape May does and part of that is just geographically they are set up to funnel the birds down to Cape May Point where they get a lot of birds,” Ottinger said. “Here on the Delaware coast we don’t have that funneling activity…”
She paused, to point out a merlin darting across the sky.
Ottinger has participated in the Hawk Watch, an international network dedicated to raptor conservation and research, since 1995. She said during the watch - which runs from Sept. 1 to Nov. 30 - she can see hundreds to thousands of birds in a single day, including raptors.
“I’m a total raptor enthusiast; I love studying raptors. I’ve been all over the U.S. doing raptor surveys,” Ottinger said. “And migration is amazing because you can see 15 different species of raptor in one day.”
The hawk watchers' primary focus is to record the number and types of raptors, such as ospreys, falcons and eagles, passing through the region. They feed the information into a universal population database.
So, Ottinger looks for specific things as she scans the sky: Wing shape, size and flapping style are all clues to which raptor she sees flying above.
Volunteers also help identify trends as they log two defined pathways in the Chesapeake region: coastal migration and ridge migration.
For example, while adult raptors tend take the ridge path through the mountains in Western Maryland, the majority of raptors passing through the coastal track are younger. Maryland Department of Natural Resources Central Regional Ecologist Dave Brinker explains why those younger, inexperienced raptors - typically less than a year old - tend to drift.
“The young birds doing migration for the first time don’t know the geography as well, even though migration is hardwired into them genetically,” Brinker said, “and what happens is they get blown away from the best places to migrate like the mountain ridges, and they drift onto the coastal plain.”
While ecologists may understand why young raptors head toward the coast, Brinker said they don’t know the precise path these raptors are taking; they turn again to hawk watchers spread throughout the region.
Coastal Virginia Wildlife Observatory president Brian Taber heads up the Kiptopeke Hawk Watch on Virginia’s Eastern Shore. He said over the years, the data they gather, combined with data from other watch groups, will help define those paths and inform future conservation management decisions.
“You can’t have a big database if you only just have a few sites,” Taber said. “And the more sites, the better. The more data points, the better, and when you have statisticians take all that data to try to analyze it, the more you have, the more accurate your information is going to be.”
Observing these young raptors on their coastal path may also be valuable down the road if states examine building offshore wind farms. NRG Bluewater Wind had a plan on the table to develop one off the Delaware coast. Delaware Wildlife Biologist Kate Fleming said before that project fizzed in 2011 due to lack of funding, hawk watchers started collecting data to determine if raptors and wind turbines could easily co-exist.
“One of the questions that came up was ‘how could this new technology potentially interact with raptors?’” Fleming said. “So we started collecting flight height information to help answer that question.”
They didn’t collect enough information to draw any conclusions, but Fleming said they learned tracking flight height is difficult. It could take years to gather enough data to fully understand the potential impact of wind turbines on raptor migration, she said.
But it is information that may be needed, should NRG Bluewater Wind try again on the federal wind farm lease it still holds off the Delaware coast, or as US Wind moves to put a $2.5 billion dollar wind project off Ocean City, Maryland “in service” by 2020.
The good news is the Hawk Watch volunteers plan to keep heading out each fall to gather this kind of information, as they enjoy watching their feathered friends in flight.
The Chesapeake: A Journalism Collaborative is funded by the participating stations with grant support from the Clayton Baker Trust, The Bancroft Foundation, Michael and Ann Hankin, The Jim and Patty Rouse Foundation, The Rob and Elizabeth Tyler Foundation, and the Mid-Shore Community Foundation.