American Kestrels (Falco sparverius) are North America’s smallest falcon and range extensively throughout the Americas. They tend to occupy open areas both in rural and urban environments, and require some sort of cavity for nesting and roosting, such as in a tree, a shallow cave in a cliff, a hole in a building or some other man-made structure. Their willingness to use nest boxes has been well documented.
Despite the generalist nature of this species, counts of long-term Breeding Bird Surveys, Christmas Bird Counts, migration data, and even nest box programs are showing regional population declines throughout the continent over the last century. Concerned investigators have hypothesized various causes of this decline but empirical support is unfortunately lacking. Our primary goals for this project are two-fold;
1) to develop student and citizen science based long-term research and monitoring efforts to better understand local and regional American Kestrel biology, especially in terms of conservation and population decline
2) provide nest boxes as a management strategy to increase cavity availability for nesting and roosting of the American Kestrel.
The Iowa Raptor Project (University of Iowa and Kirkwood Community College) and Brandon MacDougall, a doctoral student with the University of Iowa’s Department of Geographical and Sustainability Sciences, are partnering to develop a research project that focuses on nest box placement in an urbanized setting of the American midwest. The primary scientific objectives are to place nest boxes for the American Kestrel within open spaces along an urban-rural gradient, in order to compare occupancy, reproductive success, long-term demographic parameters of survivorship and dispersal, and possible long-term changes in life-history; such as sex ratios differences, as well as differences or changes in egg and chick size morphology. Local landscape attributes, such as the degree of canopy cover, land-cover type (i.e. Medium-density residential), or distance to water can be calculated and may play an important role in the selection of viable nesting habitat for the American Kestrel.
This first year will focus on identifying locations within and adjacent to the Iowa City metro area to compare the various types of open space habitat landscapes that are present. Approximately 40 boxes were built and donated by a local contributor and another ten were donated through a local Eagle Boy Scout. The goal is to continue to expand the number of nest boxes in the research project to include another 150-200. This increase will allow for greater statistical comparisons, as well as student and citizen science volunteer participation through the building and monitoring of the nest boxes.
Volunteers will be recruited and trained to observe clusters of nest boxes in order to identify and monitor those that are active. Monitoring will be done on a weekly basis. In the beginning, volunteers will monitor from a distance with binoculars. Iowa Raptor Project (IRP) Director, Shawn Hawks, will determine when it is safe for volunteers to check inside the box to get an egg (or clutch) count. American Kestrels are most prone to abandon during laying or early in the incubation stage, but the longer birds incubate, the more devoted they become to the nest. IRP volunteers will climb ladders to gain access to the nest after it is deemed appropriate. At approximately 20 days old, during the nestling stage, we wish to band the young. Another goal is to also band the adults. This project has been approved by the University of Iowa International Animal Care and Use Committee (IACUC) and the necessary permits for banding have been obtained from the state and the federal government. Monitoring will continue until the young have fledged; boxes will be cleaned in February of each year to allow for a new pair of American Kestrels each spring.
The data collected will be incorporated into Brandon’s doctoral work, but we plan to continue the project and collect data past his tenure. Thus, we hope to use the research data to help publish multiple papers in both gray literature reports and peer-reviewed articles, as well as keep the public updated through local social media, newspaper articles, and talk radio. We also expect to share this research with the international American Kestrel Partnership sponsored by the Peregrine Fund Inc. based in Boise, Idaho. We really appreciate your cooperation with this exciting project!
Shawn Hawks, Director, Iowa Raptor Project
Brandon MacDougall, PhD. Student, Dept. of Geographical and Sustainability Sciences