How many pairs of [insert bird species here] nest in Philadelphia, and how are they distributed?
These were the questions that led my friend Tony Croasdale and I to organize the very first Philadelphia Breeding Bird Census (PBBC) in June 2016. We are so thankful to our birding friends, and proud to have collectively completed over 70 surveys within the Philadelphia city limits, each beginning before 7:00 AM! These surveys covered nearly all of the park spaces within 5 km of City Hall, as well as the entire Wissahickon Valley Park, the entire Cobbs Creek and Tacony Creek corridors, and various other sites as far north as Benjamin Rush State Park. We also gathered breeding evidence (e.g., locating nests, taking note of food and material carries, etc.) for as many species as possible. In short, these surveys will give us an unprecedented understanding of Philadelphia’s breeding birds and how they are distributed, that will serve as a baseline of data for future monitoring efforts.
It will be some time before a complete report of the PBBC is available, but in the meantime I took a few minutes to summarize my own survey effort. I completed 18 surveys that began before 6:30 AM, including almost all of Fairmount Park west of the Schuylkill River. That accounts for about 25% of the total PBBC surveys, and so can offer some insight into the enormity of the total effort. I meandered through each survey block, intentionally avoiding the same area twice so as not to double count the birds, and so covered a straight-line distance of 72 miles (116 km). I counted 4127 birds during 58 survey hours. I found 145 nests of 17 species, of which 78 (54%) were active and 67 (46%) were used this breeding season, but no longer active when I found them (see Table 1). By the way, there are many species that nested in Philadelphia in 2016 of which I personally did not observe any nesting behavior, but that were documented by other PBBC contributors. These details will be in the forthcoming report.
Some PBBC highlights include the discovery by Annie Reeves of an Osprey nest along the Delaware River that had been previously overlooked by our birding community. George Armistead located a singing male Blue Grosbeak at the Philadelphia Navy Yard, which is an interesting breeding season record even though we have no evidence that it was a breeder. A surprising absence from the PBBC results was the Louisiana Waterthrush, which has bred in small numbers in recent years in the Wissahickon, but of which there was only 1 report during the month of June. Other interesting finds included a Hooded Warbler singing in the Houston Meadow (Tony Croasdale), and Pine Warblers at Hermit Lane (Keith Russell) and Cresheim Woods (myself).
Once again, thank you to all of the volunteers! Abundance surveys and supplemental observations were submitted by Cindy Ahearn, Scott Ahearn, George Armistead, Anne Bekker, Erica Brendel, Peter Burns, Rich Conroy, Tony Croasdale, Martin Dellwo, Morgan Evans, Gregg Gorton, Barbara Granger, Matthew Halley, Cliff Hence, Robin Irizarry, Ken Januski, Sandra Keller, Daniel Kobza, Peter Kurtz, Holger Pflicke, Elizabeth Porter, Katrina Rakowski, Bill Reaume, Annie Reeves, Keith Russell, Navin Sasikumar, Martin Selzer, Michael Sonkowsky, and Geoff Veith. Special thanks to the Schuylkill Center for Environmental Education and Pennypack Environmental Center, for sharing their breeding bird data for 2016 and previous years.
We can all be proud of our accomplishment, because we are leaving a legacy of data for future generations of Philadelphia birders!