Oak Openings Breeding Raptor Monitoring Project

Monitoring raptor populations is important because raptors are sensitive bioindicators at the tops of food chains, and changes in the numbers of raptors reflect changes in the health of the environment.” www.hawkmountain.org

 The Oak Openings Region is composed of a wide range of habitats that support a diverse breeding raptor population. Twelve species of raptors are known to have successfully nested in this area since 1978. Currently, nine species of raptors can be found during the breeding season: Cooper’s hawk (COHA), Red-shouldered hawk (RSHA), Red-tailed hawk (RTHA), Broad-winged Hawk (BWHA), American Kestrel (AMKE), Eastern Screech Owl (EASO), Bald eagle (BAEA), Great-horned owl (GHOW), and Barred owl (BDOW). The Northern harrier was probably the most common raptor that nested in the region during the first half of the 20th century, but due to habitat loss, it is no longer found breeding here. There is also evidence that Northern saw-whet owls and Sharp-shinned Hawks have attempted to nest in this area in the past.

Raptors as a group, have been identified as key indicators of ecosystem health. They are an essential component to healthy, functioning ecosystems and a valued biological resource. As regulators of natural systems, raptors are crucial to maintaining a balance within the stable and healthy ecosystems upon which we all depend. Through monitoring these birds over many years’ time with the help of many volunteers, Metroparks hopes to be able to document the nesting success of the raptor species found in the Oak Openings Region; gain a better understanding of the habitats that breeding raptors use for nesting in Northwest Ohio; inform the community about the importance of preserving the unique biodiversity of the Oak Openings Region---a globally threatened ecosystem; and contribute nesting information to the Ohio Breeding Bird Atlas II (2006-2010).

This annual program starts in February after an annual volunteer orientation. Walking surveys in various habitats typically start in mid-March and are completed by mid-June at Oak Openings Preserve Metropark, Wildwood Preserve and Secor Metropark, as well as portions of Irwin Prairie State Nature Preserve, Kitty Todd Preserve and Maumee State Forest. Driving surveys are conducted by a few individuals in some remote areas, as well as residential sites within the mapped areas of the region. Priority is placed on covering areas occupied by raptors in previous seasons. Data is collected any time of the day using binoculars and/or a spotting scope and noted on a survey data card. Information captured includes: date, time of day, species, adult/juvenile, sex, type of contact (visual, heard, nest, sign), nest success/number fledged and description of the activities/location. As nests are confirmed, the type of tree used, nearest distance to water, GPS reading, nearest distance to structures and roads/trails are noted in the Metroparks database. In addition, other nest locations have been added by following up on injured raptor nestlings from the Oak Openings region that were taken to Nature’s Nursery Wildlife Rehabilitation Center.

Since 2006, the data gathered through this study has been added to the 2005-2010 Ohio Breeding Bird Atlas (where applicable). Information has also been presented at the 2008 Lake Erie Raptor Symposium, the Oak Openings Forum (annually), the Midwest Oak Savanna and Woodland Conference, and the Huron-Clinton Metroparks Hawkfest program (bi-annually). Red-shouldered Hawk data was also shared with staff from Raptor Research Foundation, Cincinnati, OH in regard to their suburban Red-shouldered Hawk study.