April 27, 2017
By DAVID RAINER
Alabama Department of Conservation and Natural Resources
Alabama’s coastal environment along the Fort Morgan peninsula and Dauphin Island provides critical habitat for a wide variety of birds en route to their summer breeding grounds.
Some of the birds make journeys that may be more than 1,000 miles to reach their preferred nesting grounds, and the coastal areas untouched by development give the birds a place to rest and replenish their drained energy and fat reserves.
To understand how important coastal Alabama is to the migrating species, the bird banding effort championed by the late Bob Sargent and his wife, Martha, has been reborn.
Birmingham Audubon teamed with the Alabama Department of Conservation and Natural Resources (ADCNR), Mississippi State University, Alabama Gulf Coast Visitors Bureau, the Alabama Historical Commission and Mobile Bay Audubon Society to conduct a five-day banding program at historic Fort Morgan, which connects to one tract of the Bon Secour National Wildlife Refuge on the peninsula.
The bird banding project has been dormant since Bob’s death in 2013, but Scott Rush of Mississippi State University examined Sargent’s historical data and determined it was too valuable to let the banding station remain dormant.
Rush and Eric Soehren of the ADCNR’s State Lands Division led the data-gathering effort at the banding station and paid homage to the Sargents.
Sargent was the founder of the Hummer/Bird Study Group. An electrician by trade, Sargent learned banding from renowned ornithologist Tom Imhof, who authored Alabama Birds in the ’60s and updated it in the ’70s.
When he retired in the ’80s, Sargent started banding birds on Fort Morgan at the site where the 2017 effort was located.
“Bob was a people person and could communicate effectively,” said Soehren, who manages the State Land Division’s Wehle Nature Center in Bullock County. “He had strong convictions toward bird conservation. He really got the Fort Morgan station going. He saw the value of education through science. He was banding until 2013, right up to his death.”
After his death, there was some question as to what would happen to Sargent’s data. Rush requested the data, and after analyzing it, found some interesting trends.
“What we found was that some of the birds are shifting the timing of their migration,” said Rush, an assistant professor in Wildlife Ecology and Management at MSU. “A lot of times in the spring, those long-distance migrants are arriving earlier. Depending on what’s going on in the Southern Hemisphere, where some of these birds are migrating from, that can influence when they are arriving. The concern is that if the birds arrive a few days or weeks early that there may be a mismatch of the resources they need, like the caterpillars or the fruits.
“When they fly across the Gulf of Mexico and they’re having trouble on that last leg, if they’re out of resources when they get here and can’t get any here, then it’s not good. They could starve to death.”
Soehren added, “When Dr. Rush started diving into the data, we saw some interesting trend changes and saw a need to get this station back up and add to the existing dataset.”
The research team set fine mesh nets to catch the birds, which are carefully removed and handled. The team records species, sex and weight and then applies a band.
Common species, like the gray catbird, are caught, as well as multiple species of warblers, a yellow-bellied sapsucker (not making that up), great crested flycatcher and a yellow-billed cuckoo.
“Migrants are quite diverse,” Soehren said. “All the species that are trans-Gulf migrants are expected to show up here. Those include the warblers, tanagers, buntings, cuckoos, thrushes, swallows and so forth. Because we’re collecting in a forested area, we’re getting more forest species than grass species. They’re seeking cover. They’re seeking to rest and replenish fat reserves so they can continue their migration north.”
Rush said it’s hard to know where the birds captured on Fort Morgan started their journey north.
“We have a general idea for each species,” Rush said. “Some species of birds may be leaving South America and coming all the way up into Canada. It’s not unheard of for a bird to leave South America and the first land it sees is the Fort Morgan peninsula. That’s a significant distance.”
Soehren added, “The key thing about this is places like the Fort Morgan peninsula, Dauphin Island and other coastal barrier islands are areas referred to as migrant traps. They consolidate birds. The birds see it as first land on their single flight from the Yucatan (Mexico), roughly 600 miles. These areas are just as important in the fall. It’s the last staging area before the flight back down to the tropics.
“Some of these birds will pack on twice the amount of their normal body weight just so they can metabolize that fat to make that trip across,” Soehren said. “It’s a perilous journey, and condition is everything. That ties into the quality of habitat. If you have high-quality habitat with a good diversity of plants, a good diversity of bugs and berries, then they can condition themselves better for the migration.”
One of the birds banded last week at Fort Morgan was a blackpoll warbler, which makes an epic migration, according to Rush.
“In the fall, it’s not unheard for them to leave southern Ontario (Canada) or Maine or New Hampshire and fly out to sea before heading all the way to South America,” Rush said. “Imagine a bird that weighs about 12 grams making a flight like that. I forget the exact analogy, but it’s something like us getting 500,000 miles per gallon of fuel if you convert that into energy.”
Soehren and Rush said banding is the most viable tool to track bird migrations. Whether the bird is recaptured at another banding station somewhere else in the U.S. or flies into the net again on Fort Morgan, the researchers gather important data.
“We’ve caught some birds that we banded earlier in the week, and we can look at how much their mass has changed between the time we first banded them and when they were recaptured,” Rush said. “We can see if they are building fat or whether they might be burning more energy while they’re here. Ultimately, if you collect enough of that information, you can look at differences between species and between sexes and ages.”
Rush said through work at other banding stations, scientists can determine migration routes and marvel at how the birds travel with pinpoint accuracy.
“We’ve got data on birds that travel thousands of miles and they come back to a location the size of a football field year after year after year,” he said. “Something that small flying up in the atmosphere can get buffeted by the winds. Somehow they’re correcting for that and they’re homing in on a particular location. We’re not sure how they do it. We think they are using redundant systems. They are probably navigating by the stars. When it’s cloudy, they’re using landmarks. It works a lot better than our GPS (Global Positioning System), so that’s pretty wild.”
One interesting aspect of the Fort Morgan banding program is that it is open to the public, and the interest in birding continues to thrive.
“This is the only banding program open to the public, that we’re aware of, on the Gulf Coast,” said Chandra Wright with Alabama Gulf Coast Tourism. “This is the only chance for people to see banding up close, so this is a great education event.
“With the Sargents starting this back in 1989, 25 years of doing it in the spring and fall, this was something the public looked forward to. We have tons of visitors who visit the Gulf Coast between Memorial Day and Labor Day, so the interest in the bird banding program is great for us. People are coming and spending their lodging dollars and eating in our restaurants, shopping and buying gas. And it’s very important that we educate people about the value of this habitat so we don’t lose it.”
Soehren hopes the revived Fort Morgan banding will attract other scientists and skilled bird-banders to the effort.
“That way we can get it back to what the Sargents had,” Soehren said. “They did two weeks in the spring and two weeks in the fall right here on Fort Morgan.”
Rush said the Sargents’ banding efforts have advanced the education of the public about migratory birds and inspired many to pursue the field.
“So many careers have been launched here, and so much interest has been created here that it’s great to keep it going,” Rush said.
PHOTOS: (Billy Pope) A yellow-billed cuckoo make a quick exit after being banded recently on Fort Morgan. Eric Soehren of the Alabama State Lands Division, left, and Scott Rush of Mississippi State University give attendees at the bird banding project a few facts about the great crested flycatcher. Emilie and Jacob Rice of Fairhope release a northern waterthrush, a bird that makes an annual migration from forest swamps and bogs to the Boreal Forest region in Canada to breed. Another northern waterthrush is released by Birmingham Audubon's Suzanne Langley.