American Kestrel

Yes. American kestrels are the smallest falcon in North America and the most colorful raptor in North Louisiana, and they are disappearing for reasons that nobody has definitively identified despite decades of research. paulus), which includes North Louisiana's breeding population, has declined an estimated 82 percent since 1940.

A falcon that once perched reliably on every other power line, hunted grasshoppers from every other fence post, and nested in every available cavity across North Louisiana's open landscapes has become measurably and undeniably less common with each passing decade across North Louisiana and the broader Southeast, and the cause of the continent-wide decline remains, in the words of the raptor biologists who study the species most intensively, largely unknown.

American kestrels are small, compact falcons — 8.7 to 12.2 inches long, with a wingspan of 20 to 24 inches and a weight of 2.8 to 5.8 ounces, with females averaging larger than males in a size dimorphism typical of falcons. Both sexes display bold facial markings: two vertical black "sideburn" stripes on each side of a white or buffy face, creating a distinctive facial pattern shared by no other North Louisiana raptor. The crown is blue-gray in males, rufous in females. Males are the showpieces of North Louisiana's raptor community: rufous back with bold black barring, blue-gray wings with black spotting, rufous tail with a broad black subterminal band and white tip, buffy-cream underparts with scattered black spotting, and a blue-gray head crowned with a distinctive rufous cap. Females wear more subdued plumage: rufous-brown back, wings, and tail all barred with black, and streaked underparts that provide better camouflage during nesting.

Yet no single factor — habitat loss, pesticide exposure, increased predation by Cooper's hawks, nest-site competition from European starlings, climate change effects on insect prey populations — has been conclusively identified as the primary driver responsible for the continent-wide pattern.

The habit of perching in the open — tail pumping, head bobbing, scanning the ground below for prey — makes kestrels one of the most visible raptors in agricultural and suburban landscapes, and the colorful plumage visible at surprisingly long range makes identification straightforward for any observer who learns the basic pattern: small, colorful falcon on a wire, pumping its tail.

Kestrels hunt from two primary strategies: perch-hunting (sitting on a wire or fence post and scanning the ground, then dropping on prey spotted below) and hover-hunting (flying over open ground, stopping in midair to hover on rapidly beating wings while scanning the ground, then plunging feet-first onto prey).

Nesting

Kestrels are cavity nesters that cannot excavate their own cavities — a dependence on existing holes that ties the species' breeding success directly to the availability of dead trees, abandoned woodpecker holes (particularly northern flicker cavities, which provide the right entrance diameter), natural tree hollows, nest boxes, building crevices, and any other enclosed space with an entrance hole large enough to admit a small falcon but small enough to exclude larger competitors.

No nesting material is added to the cavity; eggs are laid directly on whatever substrate the cavity floor provides — wood chips, dirt, old debris from a previous occupant. Nest-site availability is considered one of the most significant limiting factors for kestrel populations, and the systematic removal of dead trees from agricultural landscapes, suburban developments, and managed forests reduces the number of available nesting sites in habitat that otherwise contains abundant prey and ideal hunting conditions.

Nest box programs have been implemented across North America to supplement natural cavity availability and test whether providing artificial nest sites can sustain local kestrel populations. Some programs have demonstrated that kestrels readily adopt nest boxes mounted on fence posts or poles in open agricultural land, and that box-nesting populations can maintain stable or even increasing numbers where natural cavities have declined.

In North Louisiana, landowners who install kestrel nest boxes — a simple wooden box with a 3-inch entrance hole, mounted 10 to 30 feet high on a pole or post overlooking open grassland or agricultural fields — can attract breeding pairs to habitat that contains everything a kestrel needs except the cavity.

Breeding season in North Louisiana extends from March through June, with courtship beginning in late February as day length increases and hormonal changes trigger territorial behavior. Males court females through spectacular aerial displays — steep climbs, power dives, fluttering flights — combined with food deliveries and cavity presentations in which the male leads the female to prospective nest sites, enters the cavity, and performs ritualized head-bobbing at the entrance while calling.

Once the pair selects a site, the female lays 3 to 7 eggs (typically 4 to 5), heavily marked with brown and cinnamon, and incubates for approximately 30 days with the male providing most of the food during incubation.

Both parents feed nestlings on a diet that shifts from insects early in the nestling period to larger prey (mice, lizards, small birds) as the nestlings grow and demand increasing food volume. Young kestrels fledge at about 30 days — leaving the cavity entrance and making their first flights within a day or two of departure in a burst of uncoordinated aerial effort that gets progressively more competent over the following week.

Post-fledging dependency lasts several weeks, during which the parents continue providing food while the young learn to hover-hunt and perch-hunt independently through a trial-and-error process that involves many missed strikes before the young falcon's aim improves.