An unprecedented number of great egrets — large, white wading birds from the South — have descended upon Lake Ontelaunee within the past week.
Rudy Keller of District Township, who compiles the Berks bird records for the local Baird Ornithological Club and for the state ornithological committee, has been birding at the lake since the 1960s and has never encountered a concentration of these waders of this magnitude before.
“It’s the biggest movement I’ve ever seen here,” Keller said after he drove around the lake and tallied 134 of the waders, many of which can be seen from the West Shore Drive bridge, now known as the Graffiti Bridge.
“I mean, you can go to Bombay Hook (in Smyrna, Del.) and get tired of counting egrets as you go around the dikes,” he continued, “but I’ve never outside coastal areas seen a concentration this big here inland, certainly not here in Berks County.”
Mid-July is typically the time when egrets that nest in colonies in the South will disperse and wander north, what’s called a post-breeding dispersal, Keller said.
Great egrets can show up anywhere along the Schuylkill River, streams and even small farm ponds.
Keller found one at Gotwal’s Pond in Oley on Wednesday.
Ed Barrell of Bern Township found several great egrets in the last week at Blue Marsh, but not in the numbers at Lake Ontelaunee.
“I was out kayaking and found the egrets in some of the backwater areas,” Barrell said. “They tend not to like Blue Marsh because of the boating.”
Boating is not allowed at Lake Ontelaunee.
The floodgates opened Tuesday, when birder Andy Wlasniewski reported another southern rarity, a little blue heron, at Lake Ontelaunee along with 71 great egrets.
The little blue heron occasionally occurs in Berks during the post-breeding dispersal and is noted for its all-white juvenile plumage, the form in which it is most often seen in the county. The little blue heron can be distinguished from the great egret by its smaller size and greyish legs and bill as contrasted with the yellow bill and black legs of the great egret, which is the general size of a great blue heron.
The number of great egrets has been building all week.
Historically, the great egret was first recorded in Berks along the Maiden Creek in 1920, found again in 1923 and 1925 and has been seen in the county every year since, according to records kept by the Baird club, but not in numbers approaching this occurrence.
One high count of 49 occurred at the lake on Sept. 16, 1995, when the water level was low due to drought conditions.
The conditions at Lake Ontelaunee right now, particularly along the west shore, are conducive to attracting these long-legged wading birds, Keller said.
An invasive aquatic plant and native lily pads have created a matting that the birds can walk on, but the water is also shallow at that spot due to silt that has accumulated at the head of the lake, Keller noted.
Great egrets in post-breeding dispersal usually stay through the late summer with birds occasionally remaining into October, he said.
“They’re probably scattered all over the place in Berks, as they usually are,” Keller said, “but that number at the lake is enormous, in my experience, certainly.
“It’s like looking over the Everglades.”
Source: Berkshire mont