Wednesday, July 29, 2009

Almost Wordless Wednesday: American Kestrel

American Kestrel

American Kestrel

American Kestrel

Kestrel parent-offspring interaction
Click images for larger versions.

Meet the American Kestrel
  • Scientific name: Falco sparverius.
  • Formerly known as Sparrow Hawk.
  • The smallest, most numerous, and most widespread North American falcon.
  • The only kestrel species that occurs in the Western Hemisphere.
  • Contains seventeen recognized subspecies.
  • Sexually dichromatic, meaning males and females have different plumages. Males have blue-gray wings, females have rufous wings. Tails also differ, the male showing a rufous tail with a black subterminal band, females show a rufous tail with black bars across the length of the tail.
  • Often seen in open areas with short ground vegetation.
  • Hunts by perching on limbs, fences, or wires or hovering if perch sites are limited.
  • Captures arthropods and small mammals on the ground, insects and small birds in flight.
  • Nests in natural cavities or those made by woodpeckers. Availability of suitable cavities may limit numbers in certain areas of breeding range; they will readily take to nest boxes.
Source: The Birds of North America Online



Anonymous said...

They are awesome little birds! Unfortunately, suburban development in our area (S. Calif) has contributed to much reduced numbers in the past 30 years. We enjoy a few more during the winter.

noflickster said...

@Anonymous - They really are amazing birds! Their declining numbers is interesting. The BNA-Online states, "The kestrel is attracted to human-modified habitats, such as pastures and parkland, and often is found near areas of human activity, including some heavily developed urban areas."

But there's an interesting article at about the decline, declaring they certainly are declining, but to answer why is complicated.

The author, Ernesto Ruelas Inzunza, cites four main hypotheses that are emerging:

1. Contamination (e.g., DDT or other sources),
2. Forest succession (loss of preferred habitat, particularly in the east),
3. Increased predation, and
4. West Nile Virus.

As Ernesto states, it'll take some effort to fully understand what's going on.

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