Great blue herons return to Alcoa nests
Iva Butler | (email@example.com)
The great blue herons that nested in Alcoa last year have returned and are using the same nests.
In February 2012, eight pairs of great blue herons built nests about 200 yards south of the Alcoa pedestrian bridge over the U.S. 129 Bypass in a single hardwood tree on the banks of Culton Creek.
On Tuesday afternoon four of the large birds could be seen nesting just off the Bypass.
Instead of looking toward the trees in the area or at Culton Creek, the birds were all watching the traffic on the Bypass.
Last year, Dr. Cheryl Greenacre, associate professor of avian and zoological medicine at UT College of Veterinary Medicine, said “it is unusual for them to nest so close to a bypass. I would think they would want more privacy, but as we encroach on their environment they may be used to humans.”
Tennessee Ornithologist Scott Somershoe said there should be not problem with the site “as long as the birds are not disturbed.”
Repeated human intrusion often results in the herons abandoning the nests.He estimated there are 300 to 400 small colonies of nesting blue herons across the state.
This is the largest type of herons found in North America.
They nest mainly in trees and bushes close to lakes or in wetlands, according to the U.S. Fish and Wildlife Service website.
They are seen all over the area, fishing below the Greenbelt Lake Dam, in Little River at Rockford and in the numerous creeks and lakes in the area. Being near water is a must, since they mainly eat fish.
The males gather twigs and the females build the large nests. Nest size varies with newer nests being 1½ feet in diameter.
The nest size grows because great blue herons use the same nests year after year, adding fresh sticks each year. They line the interior of the nests with finer twigs, leaves, grass, pine needles, moss, reeds or dry grass, according to the website.
The wings of great blue herons span 6 feet, they weigh 2½ to 5½ pounds and measure between 38 and 54 inches from head to tail.
Adults have a blue-gray back and wings and a belly with a white crown and face.
Take turns sitting
Both females and males take turns sitting on the nest to keep the eggs warm, with females incubating mostly at night and males during the day, according to the Michigan Natural Features Inventory. Eggs are incubated for about 28 days and hatch over a period of several days.
Somershoe said if they are sitting in the nests they already have eggs.
While their main diet is fish, they will eat crabs, aquatic insects, rodents and other small mammals, frogs, turtles, reptiles and small birds.
They take advantage of having long legs, fishing in shallow water, standing very still until a fish swims past. They kill with their thick yellow beaks as they wade slowly in search of food.
Normally they hunt alone. “Once the chicks can fly and leave the nests, their parents stick with them for quite a while teaching them where to find food and roosting together at night,” Greenacre said.
Resident Joe Pope noticed the birds were back on Tuesday.
He said last year, when he rode his bike along the adjacent Greenway Trail, “I would look over there and see those big nests, which are not hard to see.”