Dorothy, the age-defying and possibly record-tying peregrine falcon on the University of Pittsburgh’s Cathedral of Learning in Oakland, celebrated Mother's Day by becoming a mom for the 43rd time.
Dorothy’s first, and so far only, chick this year poked through its shell at 4:53 a.m., Sunday. The best place to view photos of the nestling is on the birding blog of Kate St. John, “Outside My Window,” at at http://www.wqed.org/birdblog/
A live view of Dorothy’s 40th floor nest, with occasional glimpses of the new nestling and, as of Monday evening, her three remaining unhatched eggs, is available at post-gazette.com/wildlifecams.
“It was a nicely timed hatching” said Robert Mulvihill, a National Aviary ornithologist. “I wasn’t surprised. It was exactly on the money at 33 days after she began incubation.”
Dorothy, now 16 years old, laid her first eggs on the 40th floor ledge at the Cathedral in 2001, and fledged birds each year until 2014, when the one egg she managed to lay did not hatch. In 2013, Dorothy laid five eggs, but only two chicks hatched and one of those had deformities and did not survive a week.
Ms. St. John said that given Dorothy’s problems hatching an egg last year and her declining rate of successful fledging, she is “surprised one egg hatched and would be shocked if all four do.”
“We recognize that she has a history of reduced fertility, and having less than all of them hatch would not be unexpected,” Mr. Mulvihill said.“It’s not past time. It can take two days for chicks to hatch, so we’ll have to wait another day to see what will happen. But she’s already ahead of the game compared to last year.”
Given that the average lifespan of peregrines in the wild is 13 years, Dorothy’s fertility is remarkable.
“Sixteen years old is very old for a falcon of either sex in the wild,” said Art McMorris, the peregrine falcon coordinator for the Pennsylvania Game Commission. “When she started laying we were thrilled and when the one hatched we were even more thrilled.
If the single nestling lives long enough to fly, or "fledge," which occurs 40 to 45 days from birth, Dorothy will have matched the record set in 2003 by Meg, a peregrine that, according to a Canadian Wildlife Federation Web page, nested for 16 years on the North Central Life Tower in St. Paul, Minn., and also fledged 43 offspring. If one or more of Dorothy’s remaining three eggs hatch and the bird or birds fledge, she would hold the mothering record alone.
The most productive male known to date was Kato, who nested for 14 years on the Colonade Building in Minneapolis, fathering a total of 47 young, according to a 2015 Audubon Dakota Web page entry.
”Either way, Dorothy is a member of a club with relatively few members, a small group of elderly peregrine falcon females that are still breeding at the maximum tail end of their reproductive life,“ Mr. Mulvihill said.
Peregrines, the best-known of the 58 birds in the falcon family, nearly became extinct in the early 1970s due to the use of the now banned pesticide DDT, and were placed on the endangered species list in 1972.
The species continues to recover. Mr. McMorris said there were 43 nesting pairs of peregrines in Pennsylvania last year, the most since the DDT era. Eggs were laid in 35 of those nests and 24 of those nests were successful in fledging at least one bird.
”That’s on the low side of normal,“ he said, ”but still above 50 percent which is considered healthy and successful and producing a growing population.“
Don Hopey: dhopey@post-gazette.com or 412-263-1983. Twitter: @donhopey
First Published: May 11, 2015, 12:51 a.m.
Updated: May 11, 2015, 11:38 p.m.
