Researcher lives his life with egrets
07/01/2012 8:44 AM
07/01/2012 8:44 AM
Many know the white birds around local waterways are egrets.
Those with a little birding experience know they come in three sizes and species – smallish cattle egrets, medium-sized snowy egrets and the appropriately-named great egrets.
But few in America know as much about the birds as Alan Maccarone.
“I’ve been studying egrets for most of my adult life,” said Maccarone, a Friends University professor. “This is what I do in my summers.”
Raised in New York and educated on the east coast, he researched egrets in graduate school.
He’s continued his quest to study the white birds since coming to Friends in 1990.
As he did last year, this spring and summer he’s studying the movements of great egrets, using telemetry equipment to track the birds.
“We’re always trying to answer some kind of question about energetics,” Maccarone said of this year’s study. “That’s calories in and calories out. We’re trying to define how great egrets acquire their energy and how they use it.”
In late May, he and helpers trapped five birds using plastic flamingos painted white for decoys. Light-springed leg-hold traps held the birds so a small transmitter and antenna could be attached.
Most days he’s out and about by about 5:30 a.m., waiting for birds to leave a popular breeding colony near I-235 and Zoo Boulevard, and at resting roost at Twin Lakes, at 21st and Amidon.
The birds tend to be predictable in their daily patterns.
“Once they establish a routine it’s pretty much like a milk run, the same place day after day,” Maccarone said as he drove along the Arkansas River on Wednesday morning, a tracking antenna attached to the top of his car.
A little later he predicted, almost to the exact branch, where a bird would be perched in a tree on the far side of the river.
Though each bird is predictable in daily movements, Maccarone’s research has shown some great variances from bird to bird.
Some birds congregate at the low dams along Wichita’s rivers, where big schools of fish are blocked from moving upstream.
“The trade-off is that there’s usually a lot of competition from other birds at those places,” Maccarone said. “We had 72 birds feeding by the Keeper of the Plains at once.”
Such crowds often lead to birds losing a lot of time to chasing and posturing for prime fishing spots.
Others take a more private approach.
Beeps on his telemetry system, which can find birds up to two miles away, took Maccarone as far south as the 47th Street South Bridge over the Arkansas River.
“A bird down here isn’t going to deal with much competition,” he said. “But there aren’t as many fish and it takes quite a bit of flying time, too.”
Last summer, he and fellow researcher, John Brzorad of North Carolina’s Lenoir-Rhyne University, tracked an egret about 22 miles from its roost to West Emma Creek in Harvey County. Records show that was a 58-minute flight, each way.
The bird and a collection of other egrets were working their way up the stream.
“The creek was just a few puddles and they’d go to one, clean it out, then move on to the next one,” Maccarone said.
Rather than just noting locations, distances from roosting areas and feeding times, the research is studying birds’ diets. At the dams, egrets feed heavily on gizzard shad. On open creeks and rivers their diet is more varied.
“Shiners, sunfish, catfish, I don’t think they discriminate,” Maccarone said. “If something swims by, they’re going to grab it.”
Through hundreds of hours with spotting scopes, the researchers have identified, counted and judged the size of each eaten fish.
Fisheries charts tell them about how much each fish should weigh.
Maccarone said some egrets may eat 40 to 50 fish before returning to feed the nest. Young egrets often stick the heads well into a parent’s throat to gather food.
On average they return to the fledglings about every three hours, though he’s seen them feed up to eight hours before heading to the nest.
This summer’s research will end when this spring’s chicks leave the nests, and all are eventually off toward wintering grounds along the Gulf of Mexico or Central America.
Later this year, Maccarone and Brzorad will write up their great egret research from the past two summers for a scientific publication.
Sometime they’ll discuss the topic of their next research project.
One thing’s for sure: “It will probably be about egrets,” Maccarone said.