It's a bird. But is it a plain or is it a super bird?
That's the flapping question about an unusual bird that has returned for the fourth year to Canonsburg Lake in Peters and North Strabane, Washington County.
Is the long-necked, long-beaked character a great blue heron with unusual coloration, or a previously undocumented hybrid of great blue heron and great egret?
The rare bird has egged on discussion among birders internationally ever since its official discovery March 25, 2004, although there have been reports of its existence since 2002.
The bird features characteristics and coloration from each species, prompting most birders to date to conclude it's a hybrid.
But such a creature would be rare: No such hybrid has ever before been documented in birding literature, ornithologists said.
While great blue herons and great egrets belong to the same avian family, they are different genera, much the way moose, elk and deer are members of the same family of mammals but never interbreed.
"I've opened this up for discussion with people all over the world and everyone agreed it's a hybrid," said Geoff Malosh, a Moon birder and wildlife photographer who's photographed the bird and placed his photos and descriptions on his own Web site: home.earthlink.net/~pomarine/index.html.
"Based on all the features, the way it looks, the way it acts, all the evidence points to the fact it's a hybrid," he said.
While Mr. Malosh's theory has many backers, it's not a universal opinion.
"One possibility is that the bird is a small-sized great blue heron with albinism that gives its head and neck the same appearance as an egret," Dr. Kevin McGowan, an ornithologist at the Cornell University Laboratory of Ornithology in Ithaca, N.Y., said upon viewing Mr. Malosh's photographs.
Lack of plumage and head feathers and the white head and neck create an argument for an egret hybrid. Dr. McGowan said the bird's anatomy appears to be that of a great blue heron, but the photographs are not conclusive.
"I won't rule either out," Dr. McGowan said. "It's an interesting animal."
Albinism in a great blue heron alone would make it a rare find, he said. And the possibility remains that "a great blue heron got a bit out of range and ended up mating with an egret."
Even if it is a hybrid, it would not create the stir generated by reported rediscovery of the ivory-billed woodpecker in the Big Woods of eastern Arkansas. Those reports prompted a massive search as birders try to verify the existence of a bird thought to be extinct.
But the bird at Canonsburg Lake is generating its own buzz from birders claiming it's a once-in-a-lifetime find.
"To some of us with a deep interest in birds, it is very, very exciting," said Paul Hess of Natrona Heights, who writes a column for "Birding" published by the American Birding Association. "It's not a normal bird."
Great blue herons are heavier by half than egrets, have grayish head feathers and plumage on the neck during mating season and feature overall bluish gray coloring.
In Florida, however, there's a variation of the great blue heron that's white.
Great egrets pass through this area during migration, but are not known to reside here for long. Great blue herons do settle in the area and nest in rookeries. Some remain year around, while others head south for winter, birders say.
While the bird at Canonsburg Lake has many heron characteristics and colors, its smaller size and its white head and neck typify the egret, Mr. Hess and Mr. Malosh said.
Mr. Malosh also said the bird also has egret qualities of being light-footed with an ability to hop across the water to fish.
Stephen Rogers, collection manager of birds at the Carnegie Museum of Natural History said he's heard some buzz about the bird. But looking at one of Mr. Malosh's photos, he said he would side with Dr. McGowan.
"Everyone would say it's a curious bird," he said, noting he's skinned 100 to 150 great blue herons for study. "But I would probably say it's a great blue heron. Some things are not heron-like, but there is so much more that looks like a great blue heron."
Mark Vass, a birder from Ambridge, was first to document the bird's existence May 25, 2004. Another birder had reported seeing the odd bird in 2002 in the nest of a Chartiers Creek heron rookery not far from the lake.
Mr. Vass shared information with fellow birder Mr. Malosh, who tracked down the bird a month later and took a series of photographs that he's circulated worldwide for comment.
When Mr. Malosh posted its photographs on his Web site, it received 2,500 hits, revealing the level of excitement among bird enthusiasts.
A heron-egret hybrid "is unheard of in ornithology," Mr. Malosh said. "In all my research, no one has found evidence of a hybrid of a great blue heron and a great egret."
Hybrids commonly occur in other bird species, said Dr. McGowan, but noting he never heard of a heron-egret mix.
An article published June 2004 in "The Peregrine: Three Rivers Birding Club Newsletter" outlined Mr. Malosh's efforts to determine the bird's genus.
He submitted photographs and descriptions to Ed Kwater, former chairman of the Pennsylvania Ornithological Records Committee, and Bill Pranty, field observations chairman of the Florida Ornithological Society.
Both men agreed it most likely was a hybrid, the article states.
Mr. Malosh also posted photos on an international forum where experts discussed its identification. Again there was general agreement it was a hybrid.
But the only way to prove that point would be to capture the bird, take a blood sample and have its DNA analyzed, Dr. McGowan said. There are no plans to do such testing.
But until that happens, birders and ornithologists will continue winging it.
"Here is a bird that you can look at and not identify what it is," Mr. Hess said. "It's very unusual. No one has ever before seen a bird that looks exactly like this."
David Templeton can be reached at firstname.lastname@example.org or 412-263-1578.