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June 11, 2015

Things are looking up for CL’s peregrine chick

A few weeks has made a world of difference for the peregrine falcon chick at the Cathedral of Learning nest. At its May 29 medical exam, the chick was found to be anemic and was treated for parasites. Since the treatment, the chick’s development has accelerated.

Could a simple flea and tick treatment have provided the boost Pitt’s baby peregrine needed to catch up to other birds its age?

Health concerns over this season’s lone peregrine chick in the Cathedral of Learning nest appear to be subsiding following a May 29 veterinary exam that found delays in development but no apparent abnormalities.

Wildlife experts had left open the possibility of taking the bird to a wildlife rehabilitation center, if they deemed it would be unable to survive in the wild.

In this June 9 falconcam screen shot, the young bird is active and vocal. Brown feathers are displacing its down and it is expected to fledge later this month.

In this June 9 falconcam screen shot, the young bird is active and vocal. Brown feathers are displacing its down and it is expected to fledge later this month.

“Because of his continuing progress, we are no longer contemplating removing him from the nest,” F. Arthur McMorris, the Pennsylvania Game Commission Bureau of Wildlife Management’s peregrine falcon coordinator, told the University Times this week.

Pitt veterinarian Robert Wagner said the bird is developing normal feathers and its strength, coordination and attentiveness all appear to be improving. “The chick’s development seems to be catching up to what is normal for this age,” he said.

When Wagner examined the bird on banding day, it wasn’t noisy and aggressive as most chicks are. It needed support to stand. And while its feet appeared normal, its grip was weak.

He and the game commission experts opted to watch and wait, returning the chick to the nest to be cared for by its parents. “We made the right decision,” he told the University Times.

At the May 29 banding, McMorris estimated the 19-day-old bird’s development to be more like that of a 14-day-old bird.

Although McMorris used male pronouns, the bird’s gender — typically revealed through a weigh-in — could not be determined with certainty. It weighed in at 550 grams — less than the 580 grams typical for a male of its age, and much less than females, which would weigh 650-750 grams, he said.

Initial bloodwork found the chick to be anemic, probably due to an infestation of blood-sucking parasites. Treatment — including an over-the-counter parasite remedy — seems to be helping the nestling gain strength and catch up on its development, McMorris said.

“On June 5, when he was 26 days old, he stood up on his feet, rather than resting on his tarsi, and took a few steps, albeit clumsily. That is the age when the average peregrine falcon chick is able to stand and walk on its feet, rather than relying on its tarsi for balance and support, so that was a very positive sign,” said McMorris.

That the Cathedral’s nesting peregrines Dorothy and E2 produced an offspring this year came as a surprise to many. At 16, Dorothy is “ancient” for a peregrine in the wild, where surviving to 10 or 12 is a ripe old age, McMorris said.

Since she began nesting at the Cathedral of Learning in 2002, Dorothy typically has laid four or five eggs each year.

She and her previous mate, Erie, raised 22 chicks over seven years. In 2008, Erie disappeared and was replaced by E2, with whom Dorothy has fledged an additional 20 chicks. Recently, the success of her nests has declined, as might be expected for a bird that is hormonally past her peak.

As female birds age, fertility declines and the incidence of birth defects in their offspring increases, McMorris said.

Older mother birds also may lay eggs with less nutritious yolks, which feed the embryo. Wagner posited that this, in tandem with parasites, could have contributed to the current nestling’s developmental delays.

Dorothy indeed is showing her age. Last year, she laid one egg, which did not hatch. Two years ago, her clutch of five eggs produced just two live chicks. One appeared abnormal and died in the nest. The other fledged, but was killed in traffic on Forbes Avenue.

Dorothy laid four eggs this year. One broke to reveal an underdeveloped chick; two others did not hatch. The sole chick, born May 10 — Mother’s Day — displayed abnormal behavior early on, falling over and pedaling its legs, unable to right itself.

Its condition worried many falcon webcam viewers — with some, upset by what they were seeing, demanding that the bird be rescued from the nest. The drama prompted the National Aviary to temporarily suspend its live webcam feed and ask PixController, which operates the camera, to cut the site’s chat feature.

It also resulted in a more thorough exam than is typical on banding day, the one time each year when experts intrude on peregrines’ nests to place ID bands on the young birds before they’re able to fly.

The human interventions aim to reverse the human-caused damage wrought by the use of the pesticide DDT, which wiped out peregrine populations. Although peregrine falcons are no longer on the federal endangered species list, their numbers are still rebounding in the eastern United States, McMorris said.

“Everything we’re doing here is to help the peregrine falcon population recover here in Pennsylvania,” he said, explaining that the state’s peregrines are the descendants of birds born in captivity and released into the wild.

Once peregrines are removed from the state’s endangered list, interventions will end in order to “let nature run by its own rules,” he said.

In the meantime, banding day serves several purposes:

The ID bands that are placed on the birds’ legs enable wildlife officials to track peregrines’ life-spans, migrations and family tree. It’s how we know that Dorothy was born in Wisconsin and that E2 hails from the Gulf Tower nest Downtown.

Banding also lets wildlife officials learn nest results and provide health checks to the chicks. Most peregrine nests aren’t equipped with webcams, so the number of chicks remains a mystery until banding day. The baby birds are examined for diseases and parasites and treated if necessary. In “extreme cases,” — for example, a broken wing that experts deem would never properly heal, McMorris said — a chick could be removed to a wildlife rehabilitation center either temporarily or permanently.

The prime determinant is what is best for the birds, he said. “That is what we’re here for.”

Despite the positive news for the Pitt peregrine chick, perils remain.  Half to three-quarters of peregrines die before they reach one year of age, McMorris said.

Fledging, which for peregrines typically comes at about 40-45 days old, is a dangerous time. Until the young birds gain strength in their wings, they are vulnerable to predators and traffic dangers. Some, like one of Dorothy’s 2012 brood, collide with windows and are killed.

To boost the young peregrines’ odds, local birdwatchers arrange “fledge watches” in which trained volunteers stand ready to watch for accidents and rescue birds in trouble.

Given the Pitt peregrine’s delayed development, birdwatchers are relying on the webcam to determine when it is ready to fledge.
Watches are scheduled to begin Downtown on June 20 for three chicks that are expected to fledge from a nest near Fifth Avenue and Grant Street.

Fledge watch information is posted on local bird expert Kate St. John’s blog at www.wqed.org/birdblog/.

One fledgling from a nest of four chicks banded May 29 at the I-79 Neville Island bridge already has succumbed, apparently to a predator, according to a June 7 post on the blog.

During the Neville Island banding, it was discovered that the father bird at that nest is among Dorothy and E2’s progeny, born at the Cathedral of Learning nest in 2010.

—Kimberly K. Barlow