Cavity Nesting Birds

Cavity Nesting Birds

Since 1988, Metroparks has participated in cavity nesting bird conservation, and volunteers within the parks have been conducting nest box monitoring activities. The purpose of the Metroparks Cavity Nesting Monitoring program is to sustain and increase the cavity nesting bird numbers in the Metroparks through providing suitable boxes, managing natural habitat, and monitoring their success. Eastern Bluebird populations in particular have been threatened by introduced species and habitat modifications since the 1950’s, but long-term efforts to restore habitat have contributed to their increased numbers. Since the Oak Openings Region has always been a “stronghold” for the Eastern Bluebird, Metroparks maintains the largest percentage of boxes in managed and restored “openings” in this region. As a secondary cavity 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 suburban areas. Native cavity nesting species like bluebirds can often be “out-competed” not only by these non-native birds, but also by other native cavity nesters, such as woodpeckers and Great-crested Flycatchers. Most of the nest boxes (>100 total) are located and monitored in Oak Openings Preserve Metropark with the remainder of the boxes at Secor, Wildwood Preserve, Swan Creek Preserve, Side Cut, Middlegrounds, and Howard Marsh.

This program originally focused on providing boxes/habitat for the breeding Eastern Bluebird population in the Metroparks. Currently, however, Metroparks monitors all native songbird species that inhabit nest boxes in and adjacent to open managed areas, including Eastern Bluebird, House Wren, Tree Swallow, Tufted Titmouse, White-breasted Nuthatch, and Black-capped Chickadee.

The data collected from each nest box includes the presence or absence of nests, species occupying nest boxes, number of eggs present, young present, and number of young fledged. These data have been used to track changes in rates of eggs fledged over the years.

In addition to our songbird nest box program, Metroparks staff also maintain and monitor a number of Wood Duck nest boxes in wetlands and flooded forest habitat in several parks, including Howard Marsh, Pearson, Manhattan Marsh, and Side Cut.