The Birding Club of Delaware County (BCDC) proudly supports the third Pennsylvania Bird Atlas (PBA3). In this expansive, 5-year effort – January 1, 2024 through early 2029 – birders, ornithologists, engagement specialists, and state scientists collaborate to document breeding and overwintering birds across the Commonwealth. Everyone is welcome and encouraged to get involved! Note updates below, and subscribe to the BCDC e-newsletter for timely news and information. Debbie Beer is serving as Delaware County Coordinator for the PBA3 – contact Debbie directly with any questions.
Update April 2026:
April marks the beginning of breeding bird activity for a number of species in our region. We invite everyone to get involved and submit data to the PA Bird Atlas during this 3rd season of the project. Remember to keep atlas checklists within 1 hour and 1 mile, and use personal locations instead of hotspots. Apply the most appropriate code during the right timeframe, and do not use any codes for non-breeding birds. For a refresher on protocols, review the PA Bird Atlas website.
Click below for the PA Bird Atlas program (PDF) presented by BCDC member Ethan Kang in March 2026 – full of great information and inspiration!
Update March 2026:
Spring migration brings thousands of birds to our region. Some are passing through to more northerly breeding grounds, while others stop here to follow age-old instincts to reproduce. March is a month of transition, with so many species on the move. Waterfowl are still present, along with Snow Geese and Tundra Swans. Overwintering species like White-throated Sparrow, Winter Wren, Yellow-bellied Sapsucker, kinglets, and creepers will linger into April.
The earliest migrants appear this month, including Osprey, Tree Swallows, and Eastern Phoebes. These species get a headstart on finding mates and securing breeding territories before others arrive later in spring. American Woodcocks have been displaying for weeks, twirling over open fields near wet woodlands at sunset. Raptors are building nests. Many of these can be documented for the PA Bird Atlas. If you haven’t already, it’s time to set your eBird account to the PA Bird Atlas project, start looking for breeding evidence of some species, and plan atlasing goals for this season.
Protocols for the 3rd Pennsylvania Bird Atlas (PBA3) involve a matrix of breeding behaviors and timeframes for each species. Essentially, it’s important to apply the right code during the right timeframe, and don’t use any codes for non-breeding birds. It can be confusing, but there are good tools to assist birders in submitting checklists that provide the most valuable information for the project. The PA Bird Atlas website provides myriad resources.
For this season, we are hoping for additional atlas efforts in Marcus Hook CE, Marcus Hook CW, Lansdowne NW, Bridgeport NW and a few other Blocks. These areas may lack expansive green spaces or have little public access, but scouring small pocket parks, recreational fields, church yards, and cemeteries may yield important results. If you can spare an hour to explore a bit, please help out with atlasing!
Update January 2026:
With about 4 weeks remaining before the Winter Atlas period closes on February 28, 2026, we encourage everyone to bundle up and get out to log a few more hours in Delaware county. It’s easy and fun for everyone to get involved. Simply set your eBird app to the Pennsylvania Bird Atlas project and follow a few protocols that are similar to the spring/summer breeding survey. Stay within Block boundaries, use personal spots instead of hotspots, and don’t apply any breeding codes (except for winter breeders like eagles, owls, etc). Stay warm and safe during frigid winter conditions.
Thanks to everyone who has submitted Atlas checklists, especially in the Valley Forge SE Block which is a priority for this winter 2025-2026 season. This season’s Winter Atlas runs December 1, 2025 to February 28, 2026 – click here for details. On March 1, the project will pivot to the halfway point – the 3rd breeding season of the PBA3.
Update December 2025:
The second season of Pennsylvania’s first Winter Bird Atlas is underway! We know that winter is a critical time of year for bird populations because food and cover can be limiting, and severe winter weather events can result in high mortality. Coupled with a changing climate and habitat loss, winter can be a huge struggle for birds. Yet avian distribution and abundance in the winter season have historically been far less studied than in the spring breeding season. This is changing, with the state’s first Winter Bird Atlas being conducted as part of the 5-year Pennsylvania Bird Atlas (PBA3) project. Thanks to many dedicated Atlasers, we are now learning a lot about species that overwinter in our area, gathering important data to inform conservation decisions. Organized by Hawk Mountain Sanctuary and the Pennsylvania Game Commission, the project relies upon hundreds of volunteers as well as staff and material resources to keep the Atlas going strong all year long. Click here for more details about the PBA3.
We encourage everyone to get involved in the Winter Atlas! The protocols are similar to the spring/summer breeding survey, but no breeding codes should be applied (except for winter breeders like eagles, owls, etc). Simply set your eBird app to the Pennsylvania Bird Atlas project, stay within Block boundaries, use personal spots instead of hotspots, and go birding December 1 to February 28! Details here: Winter Atlas – Pennsylvania Bird Atlas.
Winter atlasing in ALL blocks is highly encouraged every year of the PBA3! However, a focus on Priority Blocks helps maximize coverage. Out of 4,938 Atlas Blocks in the state, every 6th one – Blocks ending in “SE” (southeast) – is designated as Priority. Delaware County has 4 Priority Blocks – outlined in Brown in the map image below. Each winter a subset of Priority Blocks are tapped to be a focus. This winter 2025-26 the “Valley Forge SE” Block is a Priority focus. There are good habitats here, including Newtown Meadows Preserve, the Willows and Skunk Hollow Preserves, Chanticleer Garden, and more. There is no Principal assigned to this Block, so birders are especially encouraged to submit Winter Atlas checklists within Block boundaries to help achieve project goals.
Update June 2025:
Atlasing is in full swing for the 2nd season, with 124 species coded Possible, Probable, or Confirmed breeding, including 86 Confirmed in the 23 Blocks of Delaware county. The current stats reflect 1 more coded species (123 in last Atlas), but we’ll need more time to Confirm breeders (95 in last Atlas).
The general goals to complete a Block are as follows:
– 70 species coded as Possible, Probable, or Confirmed. This number may not be feasible for Blocks that are heavily developed, lack access to natural-habitat areas, or are reduced in size due to border with New Jersey or Delaware. Principal Atlasers should strive for a number similar to the previous PBA2 Atlas.
– Less than 25% species coded Possible; the goal is to elevate them to Probable or Confirmed status
– At least 25% species coded Confirmed status.
Two (2) Blocks have already met the criteria for Complete: Lansdowne SE (91 species coded, 64 confirmed) and Wilmington North NE (74 coded, 53 confirmed). Congratulations and many thanks to the Principal Atlasers and everyone involved in many hours of effort in these areas! The Lansdowne Block encompasses John Heinz National Wildlife Refuge – one of the most popular birding locations in the state – where more than 2,200 birding hours have been dedicated to the PBA3!
The Atlas project website contains a wealth of information – click here for the County overview. From that webpage, click on the Block tab near the top, to see stats for each Block. Continue clicking to drill-down for details. Note that species Observed are listed in addition to the other 3 status codes. Observed indicates that the species was included on a PBA3 project ebird checklist but was not tagged with any breeding behavior. Observed species do not count towards Block stats. Some of these species are not local breeders, while others require more effort to document breeding.
For this second season, atlasers are encouraged to spend time in Blocks that have few coded species. Focus less on confirming breeders, and more on getting species onto the board with Possible, Probable, or Confirmed behavior codes in Blocks with low totals – in Delaware county or across the state. June is the ideal month to get out and see nesters in action, enjoy warm weather, and explore new places. Happy summer birding!
Update May 2025:
PBA3 organizers released a list for each county, of breeding bird species detected in the prior atlases which took place 20 years ago, and 40 years ago. The Delaware County list reflects interesting changes over the past four decades, with 123 species documented in the last Atlas, and 120 in the first Atlas. Bald Eagle and Osprey were unreported 40 years ago, before being confirmed breeders 20 years ago. Yellow-throated Warbler was unreported 40 years ago, then a probable breeder 20 years ago; they have since been breeding in Ridley Creek State Park since 2019 or 2020. Mute Swan was not reported 20 years ago but are now, unfortunately, well established. Pine Siskin was confirmed as breeding 20 years ago. Grasshopper Sparrow was a probable breeder 40 years ago, and now very rare even in migration.
Note that for the Breeding Bird Atlas, “Delaware County” is defined as all 3×3 square-mile Blocks whose geographic center is within Delco. Thus, the PBA entity does not align with official political county boundaries, as multiple Atlas Blocks span two counties. Notably, the entire 1,000-acre John Heinz National Wildlife Refuge falls under Delaware County, hosting Least Bittern, Sora, Virginia Rail, Common Gallinule, and other species that are rare or absent elsewhere in the county.
Update February 2025:
After more than a year of diligent effort, atlasers in Delaware county have submitted data for 118 species, confirming breeding for 85 species. Thanks to everyone who contributed to this excellent first-year effort! We still have 4 more breeding seasons to flesh-out breeding bird data.
General Info about the PBA3:
All birders are welcome and encouraged to participate in the PBA3 – we need many eyes and ears in the field to document avian activity. Utilize the Pennsylvania Bird Atlas eBird project at www.ebird.org/atlaspa for resources, information, and submitting sightings for the Atlas. Thanks to everyone who submits data to the project, spending thousands of hours in the field to document breeding bird behaviors!
There are 23 Blocks in the Delaware County area (map image below), each covering 9 square miles (3×3 miles). The Pennsylvania Bird Atlas Map centered on Delaware County can be found here: Pennsylvania Bird Atlas Map (arcgis.com). Use this map site to view Atlas blocks and priority blocks, and glean block information including: Principal Atlaser assigned to the block, the county and regional Coordinators for the block, and Species Summaries for the block from PA Bird Atlas 1 and 2.
BCDC posts tips and guidelines for the PBA3 in our “Wingbeats” e-newsletter. Sign-up for the BCDC newsletter to receive this information, or check our Newsletter archive on this website.
The PBA3 relies upon thousands of volunteer birders submitting eBird data in 4,938 Blocks across the state. In the last Atlas, 2004-2009, birders submitted 854,773 records, documenting 218 species (plus two hybrids) statewide, of which 190 were considered breeding. The results of the new PBA3 will help detect population and distributional changes for the birds of PA – information that is critical for designating species of conservation concern and informing land management and protection.
The five-year project is funded by the Pennsylvania Game Commission and headquartered at Hawk Mountain Sanctuary where project coordinator Amber Wiewel is managing volunteer regional and county coordinators, honing training materials, giving presentations, and providing support for this amazing initiative!
For more details about the project and how you can participate, review this webinar presented by Amber on November 28, 2023.
