Thousands of birds, commonly called seagulls, have made a rare migration south to roost at Pittsburgh’s North Shore.
Bob Mulvihill, an ornithologist at the National Aviary said the gulls ("seagull" is actually a colloquial term, he explained), normally roost at the Great Lakes this time of year, but the extreme cold from the polar vortex has frozen the surfaces.
He said these gulls have chosen Pittsburgh for its three rivers — which are much cleaner than they used to be — as well as for a variety of aquatic life and the safety of ice-floats.
“They like to roost out on the rivers, ”Mulvihill said. “When the Great Lakes freeze, not only does the food become unavailable to them, but they are then accessible to four footed predators that can walk out on the ice, and get them while they’re roosting at night.”
While this mass of birds flying across Pittsburgh’s skyline can be beautiful to behold, they’ve also invited a bit of a mess. Hundreds of chicken wings litter the banks of the Allegheny River, as well as piles of gull feathers, a rare sight for the tidy River Walk area near Heinz Field.
“I don’t know for sure whether they have been finding the chicken wings on their own,” Mulvihill said, “or whether someone has thought that they should be bringing the chicken bones to this location for the gulls.”
But the bones aren’t dangerous for the gulls. Mulvihill said because they’re omnivores, gulls can and will eat anything that’s organic — emphasis on "anything."
“Anything that’s edible will go in a gull’s gullet, and they will find fish alive or dead along the river” Mulvihill said, referring to them as nature’s clean up crew.
In addition to gulls, Pittsburgh birders, or "Pitts-birders," according to Mulvihill, have sighted and charted a variety of other bird species normally found at the Great Lakes, including diving ducks such as white-winged scoters and long-tailed ducks, as well as rare red necked grebe and red throated loons.
Clarification: The post has been updated to clarify that "seagull" is a colloquial term for the gulls currently nesting in Pittsburgh.