Read Time: 4 min

By Amy Markarian, Senior Copywriter

Captain David Cushman Preserve, in Duxbury, hopes to introduce a few new inhabitants this summer, and they are sure to be a welcome addition to the neighborhood! In March 2022, Wildlands Trust began the implementation of a habitat management plan developed by Land Steward for Wildlife & Habitat Mitch Hennings, to attract and support Eastern Bluebirds. While the birds were once abundant in this area, their habitat is in decline and the shortage of nesting opportunities has reduced the species’ population. Wildlands’ plan serves to both increase the Eastern Bluebird population and provide the valuable service of nuisance pest management for the inhabited area.  

According to Mitch, “The management plan looks to improve the environment through affordable and creative means that provide habitat for birds and an ecological service for the community.” The addition of cavity nesting birds into specific environments for the purpose of insect management dates back to the 14th century, with some research showing as many as 75-90% of harmful insects being consumed by the birds. And, neighbors of the preserve may be pleased to know that mosquitos are among the Eastern Bluebird’s dietary preferences! 

Secondary cavity nesting birds, including Eastern Bluebirds, build nests in abandoned hollows left by woodpeckers and other wildlife in dead or dying trees, known as snags, along forested edges of farms and managed fields. Eastern Bluebirds are typically seen in open environments with low ground growth and intermittent shrubs that offer cover for hunting. In the mid-1900s, such landscapes—like clearcut woodlots, managed farmland, and meadows—provided ample habitat for the birds. However, urban sprawl and the increasing tendency for landowners to remove suitable snags for aesthetic or other reasons, along with the succession of former meadows into woodland (due to fewer burn events or other land disturbances that prevent regrowth) have decreased the prevalence of nesting opportunities for the birds.

Wildlands’ Captain David Cushman Preserve is a 27.37-acre property in Duxbury that was selected to pilot this habitat management plan for several reasons. Its early successional meadow is mowed annually, providing the required disturbance for Eastern Bluebird habitat. Its open field is proximal to both a saltmarsh and mud flat, and is surrounded by deciduous trees, a combination that’s appealing to the birds. And, it is one of Wildlands’ smaller fields, which helps to simplify project management and data collection for this new initiative.

This spring, nesting boxes were introduced around the edge of the field, with artificial snags added throughout the center of the meadow. Special attention was given to both the distance between and the orientation of the nesting boxes, to maximize productivity and minimize potential territorial conflicts among the birds. Secondary cavity nesting birds utilize these nesting boxes in the same way that they would use naturally occurring snags, and the strategy has demonstrated effectiveness in promoting bird species abundance. In addition to supporting Eastern Bluebirds, the nesting boxes also attract Tree Swallows, another bird species that provides similar benefit to the environment without interfering with Eastern Bluebird activity. 

Since the inception of Wildlands’ habitat management plan in Duxbury, Mitch has conducted weekly monitoring visits to the preserve, systematically recording findings from each of the boxes at the site and addressing any issues of concern. Such continual attention is important, not only to gather data on the effectiveness of the program, but also to ensure that predation of the Eastern Bluebirds by other species does not occur. He reports that many of the boxes are currently occupied by Carolina Wrens, but says this is not counterproductive to the plan’s goals thus far. He also observed that one early Eastern Bluebird nest failed this spring, but recent activity has him hopeful for some hatchlings in the near future! For the safety and well-being of the birds we aim to support, please do not approach or disturb the nesting boxes. But, if you visit Captain David Cushman Preserve this summer, keep your eye on the sky for some new blue inhabitants!