Food habits of American Kestrels in the Southern High Plains of Texas

Journal of Raptor Research
By: , and 

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Abstract

The American Kestrel (Falco sparverius) is in general decline across its North American distribution. In contrast to widespread patterns of decline, kestrel populations appear stable in the southern Great Plains region. Historically, this region had a very low occurrence of kestrels, and their current abundance is highly likely due to vegetation and structures associated with settlement by people of European descent. To determine prey use by breeding kestrels, we placed motion-activated video cameras at preexisting kestrel nest boxes located in the Southern High Plains in 2017. We recorded over 4200 prey deliveries during 1748 hr of observation at five nests over the 4-wk brood-rearing period. On basis of frequency, these deliveries were dominated by reptiles (74.8%), with invertebrates (18.2%), mammals (4.4%), birds (2.9%), and unidentified (1.2%) prey used to lesser extents. Prey delivery rates were high relative to other studies; across the brood-rearing period we recorded an average of 2.3 deliveries/hr, equating to an average of 0.49 deliveries and 3.85 g of prey/nestling/hr. Because invertebrates dominate the diet reported in most kestrel food habit studies, the volume of reptiles captured as prey was unexpected. Even more unanticipated was the number of large prey captured, including juvenile eastern cottontails (Sylvilagus floridanus) and ground squirrels (Ictidomys tridecemlineatus, Xerospermophilus spilosoma). We suspect the proportion of vertebrate prey captured during the nesting season may explain the local high rates of nesting success and number of young fledged.

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Publication type Article
Publication Subtype Journal Article
Title Food habits of American Kestrels in the Southern High Plains of Texas
Series title Journal of Raptor Research
DOI 10.3356/JRR-20-75
Volume 55
Issue 4
Year Published 2021
Language English
Publisher BioOne
Contributing office(s) Coop Res Unit Atlanta
Description 10 p.
First page 574
Last page 583
Country United States
State Texas
Other Geospatial Southern High Plains
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