The sky's the limit for Indiana’s peregrine falcon population

Posted at 5:30 AM, Jul 08, 2021
and last updated 2021-07-08 05:30:05-04

INDIANAPOLIS — Wildlife biologist John Castrale scanned the Indianapolis skyline from the roof of the Indiana National Bank tower in Sept. 1990.

“That one has some good potential for nesting ledges right on the side there.”

Castrale was on the hunt for the perfect place to release 15 young peregrine falcons the following year.

“By releasing 15 individuals, survivorship should be such that at least one pair will make it to about three years of age when they’re ready to nest,” Castrale told former WRTV reporter Angela Cain.

The venture was part of the Indiana Department of Natural Resources’ effort to restore the peregrine falcon population. The birds of prey were considered an endangered species at the time.

“We have a moral obligation to try to save species that man has had a direct impact on negatively. The use of DDT and other harmful chemicals have reduced those populations, illegal shooting has played a part,” said Castrale.

“We’re hoping they’ll come back to Indianapolis or other urban areas, industrial areas, and then reproduce from then on and maintain a population in Indianapolis.”

Falcons take flight

One day after our Independence Day, July 5, 1991, was the first day of independence for seven peregrine falcons atop the Blue Cross building, now the Indianapolis Hilton, in downtown Indianapolis.

Amos, Augustus, Faraday, Lazer, Thunderbolt, Tokata and Zoomer had been perched inside boxes on the roof of the building for about a week before the doors were finally removed.

Observers spent 16 hours every day watching the birds and cataloging their actions.

“We have volunteers on the ground, on parking garages in the downtown area, so we can keep track of these birds almost all of the time if we can,” Castrale told former WRTV reporter Linda Lupear.

Faraday, who earned a reputation for being the most aggressive falcon, was the first to fly the coop.

Peregrine falcons today

The peregrine falcon is no longer considered an endangered species.

The Indianapolis releases were the beginning of a regional effort to restore the species. Peregrine falcons were released in several Indiana cities the following three years including in Fort Wayne in 1992, South Bend in 1993, and Evansville in 1994.

Despite a historical population of around 60 pairs, Castrale says the Midwestern peregrine population has grown to 200-250 pairs.

"This is one of the most successful wildlife conservation stories with a species that was extirpated or greatly reduced over much of their worldwide range by the early 1970s to a current population in the Midwest and other places that is multiple times greater than what they were historically."

Indiana saw a high of 18 nesting pairs in 2012, but that number has since leveled out to 11-13 pairs according to Castrale.

A pair of peregrine falcons have been nesting in Indianapolis since 1995. The south side of the city saw an additional pair in 2001. Both raised young this year says Castrale.

One pair calls a nest box on the Market Tower home and the other pair resides at the AES Indiana Harding Street power plant. AES has a dedicated peregrine falcon page.

Castrale says successful peregrine nesting is dependent on cooperation from industries like power plants and steel mills. Though peregrine falcons are adaptable, the placement of undisturbed nest boxes at these sites is crucial.

Peregrine falcon facts from the Indiana DNR:

  • The Peregrine falcon is 15-20 inches tall with a 38-44 inch wingspan, about the size of a crow.
  • Adults have a distinctive dark hood and "side burns" running down from the eyes. The back and wings are blue-gray, the throat white, and the breast is white to buff with gray barring.
  • Immatures are dark brown in color with a buffy feather edging. The hood and moustache are less distinctive than in the adult. The breast is brown with heavy streaking.
  • Peregrine falcons feed on medium-sized birds including pigeons, doves, blue jays, and starlings.
  • Many peregrine falcons in the Midwest, including the chicks, are equipped with identification bands on their legs. One leg band is purple or silver, while the other is black and green, black and red, or black and blue, with a unique letter/number combination