Document Type
Article
Publication Date
4-24-2023
Journal / Book Title
Journal of Raptor Research
Abstract
We analyzed long-term datasets from nest box programs, Breeding Bird Surveys run by the US Geological Survey, Christmas Bird Counts run by the National Audubon Society, and counts from two key fall migration watch sites, Hawk Mountain Sanctuary and Cape May Hawkwatch. We found that populations of American Kestrels (Falco sparverius) in North America are generally still declining, albeit with some caveats. Some populations are actually increasing, while others are remaining stable. Overall, the magnitude of annual change appears to be decreasing slightly during recent years. To understand potential causes of the decline, we recommend the following courses of action in no particular order: (1) determine whether the increase in Cooper’s Hawk (Accipiter cooperii) populations is restricting kestrel distributions by the mere presence of the larger raptor; (2) study the effects of habitat loss and/or degradation on the falcon’s wintering range; (3) further investigate on a broader spatial scale whether within-season habitat alterations are creating ecological traps for breeding kestrels; (4) determine the importance of arthropods in the diet of kestrels, especially the long-term population trends and timing of emergence of grasshoppers in relation to kestrel breeding chronology; (5) discover whether rodenticides pose a serious risk to American Kestrels across North America; (6) learn more about possible effects, both direct and indirect, that the use of neonicotinoids may have on kestrels; and (7) continue ongoing studies of the effect of climate change on these birds.
DOI
10.3356/JRR-22-35
Montclair State University Digital Commons Citation
Bird, David M. and Smallwood, John A., "Evidence of Continuing Downward Trends in American Kestrel Populations and Recommendations for Research into Causal Factors" (2023). Department of Biology Faculty Scholarship and Creative Works. 545.
https://digitalcommons.montclair.edu/biology-facpubs/545
Rights
© 2023 The Raptor Research Foundation, Inc. This article is made available under an Open Access license by the publisher.
Published Citation
Bird, D. M., & Smallwood, J. A. (2023). Evidence of continuing downward trends in American Kestrel populations and recommendations for research into causal factors. Journal of Raptor Research, 57(2), 131-145.