The Western Pennsylvania Conservancy: Saving the Places We Care About™: Membership

July 1st Peregrine Banding Signals Successful Ending
to a Dramatic 13th Nesting Season
at Pittsburgh's Gulf Tower

If you're one of those people who like to check out the Pittsburgh skyline on your way to work, or if you're something of a birdwatcher, you're going to see considerably more activity at the top of the Gulf Tower in a week or so. Four new peregrine falcon chicks, hatched last month, will be testing their wings as they learn to fly and take the first flaps toward making a life of their own.

With their flying days looming, the four chicks were banded on Tuesday, July 1st at 10 a.m. on the 37th floor of the Gulf Tower. Below is a slideshow of the day's events (with photos by WPC Member and Volunteer Maureen Carr).

Sorry, your browser doesn't support Java(tm).

Beth Fife, a wildlife conservation officer from the Pennsylvania Game Commission, and Charles Bier, director of the Natural Heritage Program at Western Pennsylvania Conservancy will be present to answer questions about the birds. Banding involves placing identifying bands on the legs of the chicks. Peregrine falcons are a protected species in Pennsylvania and are especially important because of their endangered status.

A Matter of Life and Death on the Ledge at Gulf

Viewers of Western Pennsylvania Conservancy's live Web cam saw not only the beginning of the peregrine life cycle, but, sadly, the end as well. In April the original male, who began nesting at the Gulf site when WPC built it in 1991, was killed. WPC scientists believe he was probably killed by another peregrine, and possibly by a young male falcon, hatched on Mother's Day last year at the Cathedral of Learning. This one-year-old male remains a prime suspect since he has subsequently assumed the older male's role at Gulf. The first six eggs laid at the site this year were abandoned and, a few weeks later, the female and the new male began courting. She laid four new eggs, all of which hatched and can be viewed at www.paconserve.org.

This is the 13th year that Western Pennsylvania Conservancy, the Pennsylvania Game Commission and Gulf Tower building management have collaborated to provide a safe nesting site for the falcon pair on the ledge of the 37th floor. The nest box, built by volunteers, is filled with round pea-size gravel that peregrines need to ensure their eggs do not roll off of the ledge. In the wild, falcons nest on cliffs, but in urban settings, they seek a private spot on a tall building. When a pair of this endangered species first took up nesting at the Gulf Tower in 1991, it was the first nesting in western Pennsylvania in 40 years. The Gulf Tower is the first known urban nest site in Pennsylvania, since the decline of these birds of prey. By the 1960s, there were so few successful nesters that the species was in danger of extinction. The birds have made a remarkable recovery, thanks in part to the creation of urban nesting sites and to restriction on the use of certain pesticides, which impacted peregrine eggshells.

This spring, Pennsylvania Game Commission biologist Dan Brauning confirmed that a pair of peregrine falcons was nesting on a cliff in northcentral Pennsylvania overlooking the west branch of the Susquehanna River. A follow-up visit to the new nesting site led to the banding of the first peregrine chick hatched outside of a major Pennsylvania city since 1957, when five nesting sites were active in the state.

Continual monitoring at the Gulf Tower occurs through the dedication of WPC volunteer Water Sadauskas, who visits the peregrine nest and tracks the birds via live pictures seen on a television monitor in the window at the LL Cool Beans coffee shop, which is at street level of the Gulf Tower. The video is provided through the generosity of Edgar Snyder and Associates.

Two of last year's Gulf brood were outfitted with satellite telemetry devices and are presently making their way in and above the Philadelphia and New York City areas.

A CHRONOLOGICAL SUMMARY
OF GULF TOWER PEREGRINE EVENTS, 2003

The first egg of the 2003 season was observed in the nest on March 9th.
After a week-long pause in laying, a second egg was observed on March 16th. Normally, eggs are laid only a couple of days apart.
Nearly two more weeks passed with no new eggs and very infrequent incubation.
On March 29, egg laying resumed and followed the standard pattern: four new eggs were laid over the course of the next week.
The bird that laid the four later eggs was a different female from the one who was observed at the nest early in the season. The original resident female is banded; no bands could be seen on the new female.
The new female began regular incubation of all six eggs, but incubation became sporadic after a few days.
On Friday, April 11th, a male peregrine was found dead at the nest box. He appeared to have been killed by another peregrine in a dispute over the nest. His leg bands identify him as the male who has nested at the Gulf Tower since 1991.
Since the death of the original male, a pair has been observed courting at the Gulf Tower nest box. The female was identified as the female who has nested at the Gulf Tower since 1998 and who probably laid the first two eggs there in 2003. The male is banded; however, at present no one has been able to clearly read the band code to identify him.
The six unincubated eggs were removed from nest by the Pennsylvania Game Commission; they were no longer considered to be viable.

Prior to the death of the original male, incubation of the six eggs had become erratic, perhaps because the nesting pair was preoccupied defending their nest from another pair. Because the eggs had gone unincubated for such long stretches of time, they were not considered to be viable and were removed from the nest by the Pennsylvania Game Commission. Although it is now getting late in the season for laying eggs, it is possible that the current pair will successfully breed and raise young this year. They have now been observed in courtship at the nest site.

The male that was killed had been nesting at the Gulf Tower since 1991 and originally arrived in the city in 1990 from a release site in Tennessee. He was 14 years old this year and produced nearly 40 offspring in the course of his life. While it is unfortunate to have lost the "founding father" of Pittsburgh peregrines, his death is the result of what is becoming more normal falcon behavior and interactions in city environments. In 2002, an unidentified pair tried to take over a new nest site WPC placed at the University of Pittsburgh's Cathedral of Learning in the Oakland section of Pittsburgh. The resident peregrines would not yield. These disputes over nest sites are a sign that peregrine numbers continue to be on the rise and that nesting sites are limited. As cliff-nesting birds, peregrines instinctively look for nest sites that allow the female to sculpt a depression where the eggs will be laid and incubated without rolling away. The pea-size gravel in the WPC-constructed nest-trays provides this feature, as well as cushioning for the eggs. Because even natural nesting sites, such as cliff ledges, have always been scarce, these falcons have developed a highly territorial and competitive behavior.

The conservation challenge at this point is ensuring that there are suitable nesting sites available so that pairs do not have to compete. There are currently about a dozen known pairs of peregrine falcons nesting in Pennsylvania, all on buildings and bridges in urban settings. No peregrines are known to have returned to the 40+ historic nest sites in the wild that these birds once inhabited, which raises questions about the overall recovery success of this species, which is still listed as endangered in the state. Western Pennsylvania Conservancy is now considering the establishment of additional nest sites in the Pittsburgh area.

WPC biologists and volunteers will continue to monitor the two nests to see how events unfold. The public is invited to track the progress of both the Gulf Tower and the University of Pittsburgh nest sites at the Conservancy's website: www.paconserve.org
Click here to view the Gulf Tower site. Please allow about thirty seconds for the camera images to upload.

Click here to view the Pitt site.