On a hillside in Hays, the third bald eagle egg is in the process of hatching. This morning a series of pips -- pecks from the inside -- was visible on the egg. The eaglet is expected to completely emerge by this evening
Watch it happen live at www.post-gazette.com/baldeagles.
"Audubon confirmed a 'star pip' -- the beginning of the hatching process -- on the third Hays egg yesterday, so a hatch should happen today," said Rachel Handel, communications director of the Audubon Society of Western Pennsylvania.
"I predict a hatching by late today, before night anyway, right on schedule," said Bob Mulvihill, an ornithologist at the National Aviary.
Two grey, fuzzy, baseball-sized eaglets and the third egg with pip marks are visible when the 5-year-old female shifts position or feeds the young with tiny pieces of fish from a carcass brought by the male.
The live view inside the nest is provided via a wildlife camera and video feed paid for and managed by the PixController security camera company in collaboration with the state Game Commission.
Confirmation of life within the third egg resolves a biological question posed last week when the first egg to hatch opened two days late by bald eagle standards, leading to speculation that the first laid may have died. It now appears certain the first egg laid was the first to hatch.
The next sequence of events visible in the nest may not be so warm and fuzzy. Bald eagle suffer a 50 percent mortality rate in their first year, but nestling mortality is substantially higher and the risk is highest for the last eaglet hatched from a clutch of eggs.
"It's a reproductive strategy called 'brood reduction,' " said Mr. Mulvihill. "The eggs hatch asynchronously. The first eaglets to hatch grow quickly and are bigger than the last eaglet. In competition for food they'll win out. In years when there's a shortage of food, the last to hatch, the least developed chick, will be allowed to die to insure that the first to hatch will live. It's not a fun or smiley story, but that's the way it is."
Nevertheless, Mr. Mulvihill said the Hays eagle pair, which fledged one eaglet in 2013, have worked well together. Food, primarily fish from the nearby Monongahela River, has been plentiful.
"My feeling is barring predation or some terrible weather event, the third chick should probably survive," he said.
With no cameras on Pittsburgh’s other bald eagle nests, it’s more difficult to assess nesting status.
Audubon reports that bald eagles in Harmar are exhibiting incubation behavior which suggests they’re sitting on at least one egg. On private property in Crescent, where Allegheny County’s first bald eagle pair fledged three eaglets in 2013, a new family seems to be forming.
“It looks like we’re going to have young ones,” said Gary Fujak, Game Commission Wildlife Conservation Officer. “All indications are that they are successfully hatching or brooding eaglets, but I can’t give you any specifics.”
A previous version of this story gave an incorrect age for the female eagle.
John Hayes: 412-263-1991, email@example.com