As Kestrels are approximately the size between a sparrow and a robin, they may often be mistaken for a large songbird or a mourning dove. Kestrels are 1 of 3 raptor species that are sexually dimorphic in plumage, color, and size. Both males and females display dark brown eyes that are enhanced with a black, teardrop stripe that outlines the face. These dark lines are known as a “mustache” and a “sideburn”, in comparison to peregrine falcons, they just have one “sideburn”. They both have a capped, blue-grey crown and forehead with a reddish-brown spot on top. Kestrels are also one of the only North American raptors with circular nostrils and have yellow anisodactyl, scutellated feet, and short toes. Kestrels will acquire sexually dimorphic plumages before they fledge.

Adult Male, Photo: Parisa Ardekani, WA

The adult male has a thick black subterminal bar that marks the end of his tail feathers. The coverts on his wings are dusty blue-gray with charcoal primaries. He has separate rufous-brown back with black peppered spots. Males typically have a white belly with small dark dots that reach to his flanks.

Adult Female, Photo: Bob Haney, WA

The adult female shares similar features with the male that includes head features, as well as black the male’s blue-grayish color, but encompasses peppered brown blurry dots on her belly and dots on her coverts, and overall cinnamon and deep orange hue.

Distribution of the American Kestrel – Birds of North America, Cornell Lab of Ornithology

The range expands all over North America, towards central & west Alaska, and will breed across Canada (summer) and south towards Mexico, typically when nonbreeding. Kestrels will migrate through Panama when reaching South America.

The American Kestrel is a widely distributed and is an ecologically adaptable species. They can thrive in intense conditions from alpine zones to desert habitats, yet they prefer savanna-like prairies and open land with short vegetation. Kestrels can be also be found in city parks, suburbs, and farmlands. This is because Kestrels prefer to hunt on open terrains for insects and small vertebrates, which inhabits minimum habitat needs. Perch sites such as telephone poles and second cavity nests also influence the Kestrels distribution.

Photo: Parisa Ardekani, WA

Courtship displays start around late February to early March. The male kestrel will select a nesting cavity before the females arrive to select a mate. Kestrels prefer secondary cavities, meaning that they do not create their own. Cavities can include abandoned nests that were excavated and once used by woodpeckers, man-made nest boxes, barn crevices, or holes in dead trees. Once the male has found the perfect nest site, he then proceeds to find a mate. Vocalizations, passing food to one another and aerial displays are some of the essentials of courtship behavior, which can take several weeks. During this process, the male will lure the female with food to his site, and the female will inspect to see if it is suitable for nesting. The female can lay up to 4-6 eggs, 1 brood from April until June. Both parents bring food for their fledglings post-hatch.

The Kestrel has great eyesight with an additional advantage, they can see ultraviolet light. When prey is spotted from its perch, the Kestrel will plunge down to attack with their talons, and carry it back to its perch. The kestrel will continue to eat in safety while keeping a lookout. Kestrels will also hover like a hummingbird, using its fan-like tail to steer themselves, flapping against the wind to scan over fields. The Kestrel can see up to several hundred times better than the human eye, as well as additional colors.

Video: Parisa Ardekani, Delphi Road 2/25/2019, 47.0128, -122.9625 14:24

The broad diet of the Kestrel can include grasshoppers, crickets, cicadas, beetles, dragonflies, butterflies, moths, small birds, mice, voles, frogs, lizards, and snakes.

2/25/2019, 14:24

Stationary observation, Duration 32 minutes.

2892-2780 Delphi Rd SW, Olympia, WA 98512

47°01’27.5″N 122°59’46.0″W (47.024306, -122.996111)

Habitat: Open fields and plains, with overhanging long powerlines that run through and over livestock fields of cows and horses. (Describe trees)

I scan the landscape in 360 turns with my binoculars, ready with my digiscope to hopefully capture some footage. About 13 minutes in of searching, I find a male kestrel perched on the far top branch of what looks like an apple or plum tree southwest of my observation spot. The excessive tail pumping and head bobbing confirmed the identification of the small falcon. The male’s head bobbed suddenly, then dives into the long grass and was out of sight for about 3 minutes. I then found him on a nearby tree not too far from his original perch with what looks like a field mouse in his feet. The male then proceeds to rip and tear his catch as if to check if it’s still alive. The male then flies north with prey still intact. No calls were heard during the session.

Blue Circle: Observation spot

Red Circle: Male Kestrel

 (Google Earth)

3/5/2019, 14:06

Stationary observation, Duration 12 minutes

2892-2780 Delphi Rd SW, Olympia, WA 98512

47°01’27.5″N 122°59’46.0″W (47.024306, -122.996111)

Recording done by Parisa Ardekani, March 5th 2019, Delphi road, WA 14:06 (47.0128, -122.9625) .

Farmer, C. J., & Smith, J. P. (2009). Migration monitoring indicates widespread declines of American Kestrels (Falco sparverius) in North America. Journal of Raptor Research, 43(4), 263-274.

The American Kestrel has faced a significant decline in populations of North America and is still currently under research. This map shows some trends across the Country. The dark black arrows facing downwards represent population declines, striped arrows facing up are increases, and the size of the arrow indicates the quantity of that trend. Some examples may be pesticides, collisions, and an increase in the population of coopers hawks. The cause that stands out the most is the loss of habitat and land for nesting and roosting. Logging and removal of dead trees containing natural nest cavities decrease the habitat.

Nest box programs have been a significant help for Kestrel populations as they respond progressively to the boxes provided.

Photo: Dendroica Cerulea https://flic.kr/p/oohxpA

Bardo, L., & Bird, D. M. (2009). The use of captive American Kestrels (Falco sparverius) as wildlife models: a review. Journal of Raptor Research, 43(4), 345-365.

Hawks, Eagles & Falcons of North America: Biology and Natural History, by Paul A. Johnsgard, Smithsonian Institution, 2001, pp. 276–284.

Miller, T. A., & Lanzone, M. J. (2015). Gregarious winter roosting and early morning perching Behavior of American Kestrels (Falco sparverius) in the Imperial Valley, California. Journal of Raptor Research, 49(4), 526-529.

Smallwood, J. A., Causey, M. F., Mossop, D. H., Klucsarits, J. R., Robertson, B., Robertson, S., … & Bortolotti, G. R. (2009). Why are American Kestrel (Falco sparverius) populations declining in North America? Evidence from nest-box programs. Journal of Raptor Research, 43(4), 274-283.

Watson, K. A., & Ritchison, G. (2018). Effect of variation in nestling hunger levels on the begging behaviour of nestlings and the provisioning behaviour of adult American Kestrels. Avian Biology Research, 11(1), 35-43.

Farmer, C. J., & Smith, J. P. (2009). Migration monitoring indicates widespread declines of American Kestrels (Falco sparverius) in North America. Journal of Raptor Research, 43(4), 263-274.

Smallwood, J. A., & Collopy, M. W. (2009). Southeastern American Kestrels respond to an increase in the availability of nest cavities in north-central Florida. Journal of Raptor Research, 43(4), 291-301.

Sockman, K. W., Schwabl, H., & Sharp, P. J. (2000). The role of prolactin in the regulation of clutch size and onset of incubation behavior in the American kestrel. Hormones and Behavior, 38(3), 168-176.

Parisa Ardekani is a third-year student at The Evergreen State College studying Wildlife Biology.