Cavity Nesting Bird Monitoring

This volunteer monitoring program started in 1988 and has continued annually since that time. The program originally focused on providing boxes/habitat for the breeding eastern bluebird population in the Metroparks. At one time (1950’s-1970’s), this species was rapidly declining, so many nest box programs started up for bird conservation. Currently, however, Metroparks monitors all native songbird species that inhabit nesting boxes in and adjacent to open, managed areas (Eastern Bluebird, House Wren, Tree Swallow, Tufted Titmouse, White-breasted Nuthatch, Black-capped Chickadee).

The main purpose of the Metroparks Cavity Nesting Monitoring program is to maintain the eastern bluebird population in the Metroparks through providing desirable nesting boxes, managing suitable habitat, and monitoring the success of other native, cavity nesting bird species. Currently, monitors are also documenting signs of nest, egg, or hatchling predation.

Since the Oak Openings Region has always been a “stronghold” for the eastern bluebird, it is important to keep the largest percentage of boxes in managed and restored “openings.” As a secondary nester, the eastern bluebird relies on abandoned cavities in open areas previously created by woodpeckers. Many of those cavities have the potential to become occupied by non-native species such as starlings and house sparrows---mostly, in urban and some suburban areas. Bluebirds can also be “out-competed” not only by non-native birds, but also by other native, cavity nesters, such as woodpeckers and great-crested flycatchers. Bluebirds absolutely need open areas to hunt insect prey. They will not live in thickets or wooded areas.

Most of the nest boxes are located in Oak Openings Preserve Metropark (59), with the remainder of the boxes in Secor Metropark (10), Wildwood Preserve Metropark (7), and Swan Creek Preserve Metropark (9).

Boxes are monitored/checked from mid-March (depending on the weather) until late August or until nesting is completed. Each monitor is asked to check the boxes on a weekly to bi-weekly basis (depending on the stages of nestlings)---ideally, three times a month. Nest boxes must be cleaned after each brood.  Data such as: species building nest; number of eggs; number of young; known or presumed fledged, and evidence of predation is noted on a card and then submitted. Boxes are checked by removing the nail or screw and opening up the front door. Volunteers are trained according to a standard set of monitoring guidelines/instructions that are updated annually.