This post was created with valuable insights and information provided by Dave Brooke, Friends of Harrison Hills Park 

The nine Allegheny County Parks are home to well known features, including beautifully landscaped fields, natural forests, rugged hiking trails and abundant recreational facilities. Beyond these well-known attractions, each park offers something uniquely its own. While many people associate North Park with birdwatching, it’s Harrison Hills Park that has a particularly special relationship with birds. In fact, Harrison Hills is home to the only colony of Purple Martins in the entire county park system, and one of the few publicly accessible colonies in the region.

Purple Martins are native songbirds in the swallow family. They have long been one of America’s favorite birds, loved for their beautiful song, graceful flight, social antics and insect-eating habits.  Purple Martins nest in groups called colonies and, amazingly, migrate to the Brazilian Amazon and return north to the same colony site every year.

Purple Martins are considered secondary cavity nesters, meaning they use cavities that are already created, either by other animals or in natural cavities of cliffs and rock formations.  Traditionally, Purple Martins nested in natural cavities such as old woodpecker holes, on rock ledges, or in dead trees.  However, thousands of years ago, people began providing man-made housing for the Purple Martins in the form of dried, hollow gourds. Over time, the successful nesting of Martins in these man-made homes, paired with the decline of natural cavities, led to a complete behavior shift within the Eastern species so that they only nest in man-made structures.

The Purple Martin Colony at Harrison Hills Park was created by and continues to be maintained by Natrona Heights resident Ken Kostka. Ken Kostka has dedicated much of his life to bringing Purple Martins back to the region, a mission sparked by childhood curiosity and fueled by decades of determination. After the birds vanished from western Pennsylvania following Tropical Storm Agnes in 1972, Kostka made it his goal to re-establish a colony in his hometown of Natrona Heights. His efforts eventually extended to Harrison Hills Park, where he installed an elaborate Amish-made Martin house, played recorded dawn songs and used decoys to entice the birds – with permission and approval from Allegheny County. In 2015, his work paid off when three pairs of Purple Martins chose to nest in the park – an unusually strong start for a new colony. Ken continues to monitor and support the birds, which has grown to over 40 nesting pairs, aiming to grow the site into a thriving population that will help repopulate the surrounding area.

Kostka’s success at Harrison Hills was made possible with the support of the Friends of Harrison Hills, a volunteer-led group founded by Patrick Kopnicky. The group, already active in maintaining and mapping 30 bluebird boxes throughout the park, embraced Ken’s vision and helped make the site a welcoming home for the Martins. Their ongoing collaboration exemplifies how grassroots conservation and community leadership can come together to support native species and strengthen local ecosystems.

Thanks to dedicated volunteers and Allegheny County Parks staff, the Purple Martin colony at Harrison Hills continues to thrive, offering visitors a rare glimpse into the lives of these remarkable birds. Whether you’re an avid birder or interested in learning more, a visit to Harrison Hills Park in the early summer is a chance to witness something truly special. Visitors are encouraged to observe the birds from a distance, never touching the birds or their housing, while always being respectful of this sensitive habitat.

The Friends of Harrison Hills Park group invites you to learn more about Purple Martins and see the colony on June 15, 2025 at 1:00 pm. Ken Kostka will first lead a presentation on the Purple Martins, then invite the group over to the birdhouses where visitors can see nests with eggs and hatchlings up close. Please gather at the Environmental Learning Center and RSVP to the Friends of Harrison Hills Park to participate.