If you have visited Hilltop Park recently, you may have noticed our latest additions to the Park’s offerings.  In March, eight Eastern Bluebird houses were installed at the eastern end of the park as well as a Purple Martin condominium outside Hilltop House. These 9 bird houses were recommended to Easttown Township when PA Game Commission visited the park last fall.  Dan Mummer of PA Game Commission said the large, open meadow with separation from the woods, but nearby perching locations was conducive to Eastern Bluebird houses.  Purple Martins also prefer open clearings away from the woods, but proximity to humans. Mummer’s recommendations to the Township were provided to the EAC, who decided to act upon his suggestions this spring offering an educational birding opportunity to Easttown residents as another way of getting to know our natural neighbors.

For those unfamiliar with Eastern Bluebirds, they are beautiful, small birds native to North America, east of the Rocky Mountains. Males have bright blue plumage, a warm orange belly, and white lower belly. Females are gray, with bluish wings and tails and orange-brown bellies. Juveniles of both sexes are gray in color with blue tinted wings and tail feathers. They are secondary cavity dwellers, meaning they must nest in holes in trees and cavities that have already been made by other species ex. Woodpeckers.  The removal of dead trees and snags has greatly reduced their breeding habitat making them increasingly reliant on humans for nesting sites.

Purple Martins are another American songbird with beautiful, deep purple plumage, cheery songs and great aerial tricks. Trees with multiple woodpecker holes that would have been the ancient nesting sites of these colonial nesting birds, have disappeared as forests have been cut down to build houses and other buildings. Since the early 1800s, and perhaps even prior to Europeans settling here, humans in the eastern US have provided the housing that purple martins require for nesting. According to the Purple Martin Conservation Association, their population has declined over 24% in the past 50 years due to habitat loss and competition with European House sparrows and Starlings. 

The unique relationship between humans and Purple Martins appears to be mutually beneficial- martins were valued by people for eating insects that eat crops (some studies show they can eat upwards of 260 billion insects a year!) and because they chased crop eating birds away from farmland.  At one time, many farms across eastern and southern states had purple martin houses, but the tradition has declined as farmlands have been lost.

While they too are found in the spring and summer east of the Rocky Mountains, they leave in early fall for a balmy winter in Brazil. When they arrive back home, they are similarly reliant on humans for nesting habitat. Purple Martins prefer to next in colonies where they can be close together (and close to humans, as they are social birds)!  After speaking with several other local Purple Martin colony managers, the EAC selected a house/gourd hybrid condominium structure on a pulley system for easier nest monitoring. Purple Martins like to nest high in the air, and in sites previously colonized, hence the pulley system for raising and lowering houses for monitoring and cleaning, and decoys on the roof to encourage martins to check out the space.

A handy Easttown Resident volunteered to build us several bluebird houses at no cost, offering us 4 beautiful homes; the other 4 houses were sourced and installed by Willistown Conservation Trust and their Bluebird monitoring program.

Following installation, resident volunteers attended complimentary training through an online Bird Town PA workshop, as well as an in-person training with Blake Goll of Willistown Conservation Trust. Resident volunteers can now sign up to monitor bird houses on a weekly basis using provided equipment and monitoring logs.  As of early May, our volunteers have seen two Eastern Bluebird nests started in the houses along with several Sparrow nests. Purple Martins are just beginning to arrive back from their winters in Brazil and have been sighted around the houses. Colonies may take several years to develop but once established can last decades as Purple Martins practice “site fidelity,” returning to the same colony year after year.

We hope you enjoy seeing the increased bird activity surrounding Hilltop Park’s newest bird houses and learning more about these beautiful North American birds.