STUDENT NEWS

Caballero with one of Rosie’s chicks, freshly tagged.

Doctoral Student Studies the Peregrine Falcons of University Hall

Elvis has left the building.  So says the DNA that Isabel Caballero has extracted from the falcon chicks living on a ledge atop University Hall.  The former mate of Rosie—the chicks’ mom—Elvis apparently was replaced by another male bird five years ago.  That bird is not banded, but after looking at five years’ worth of hatchlings, "I know from DNA that he’s the same guy," Caballero says.  Unfortunately Elvis probably is, like his namesake, dead.  Peregrine falcons mate for life and Elvis hasn’t been around for quite some time.

Rosie’s latest hatchlings were born sometime during the weekend of May 9, 2009.  A month later, Caballero, along with Mary Hennen, the Field Museum-based director of the Chicago Peregrine Program, and Mary Ashley, professor of biological sciences and Caballero’s graduate advisor, banded the two male chicks.  They also drew blood for health and genetic information. 

Caballero is studying the birds is for her doctorate in population genetics. She is gathering data from about 500 peregrines around the world—from nests in Argentina, Chile, Ecuador, Peru, Sweden, Spain, Italy, the United Kingdom, Kenya, South Africa, Mozambique, Zimbabwe and Madagascar besides the Chicago area.  She can’t get to all those places herself—who could?—but collects DNA samples from far-flung collaborators, fellow members of the Raptor Research Foundation.

Caballero and Mary Hennen tag one of Rosie’s chicks.

Not that Caballero limits her personal sampling to the 23 falcon sites in the Chicago area. Along with a veterinarian and two other researchers, she is currently visiting bird homes in remote areas of Argentina and Chile as well as dropping in to her own home to spend Christmas with her family in Buenos Aires.

Sometimes penetrating bureaucracy can be as challenging as reaching a nest on a windswept cliff. Getting samples from Madagascar requires piles of paperwork because the falcon is an endangered species there.  At the other end of the scale, securing DNA from falcon skins in a museum collection can be a breeze.  "It’s a short cut to get samples," Caballero says. "You don’t need an expedition."  Though Caballero is prepared for anything her research might throw at her—including rock climbing.  In addition to taking a course in rock climbing, Caballero works out on the three-story climbing wall at the UIC Student Recreation Facility.

Peregrines of the Northern Hemisphere breed at home but fly south for the winter; peregrines of the Southern Hemisphere stay where they are.  Through genetic mutations, "(w)e want to know which population was established first, and how they moved around the world," Caballero says.

A closer look at the tagging

In a study focusing on the Chicago area birds, Caballero is also examining their fidelity to nesting sites and to each other. It seems that though they’re generally monogamous, peregrines of both sexes occasionally engage in what’s known as extra-pair copulations.  She is also looking at the area birds’ dispersal—where they decide to settle down.  "Males tend to stay close to the place they were born," she says.  "Females may go out of state or to different cities."  Rosie, for example, is from Wisconsin and other area females were born in Indiana and Ohio. 

Caballero is ready for her own migration—she plans to join her husband at Texas A&M at the end of this academic year.  There, she will do post-doc work—including a project on prairie falcons.  "I’ve been at UIC since 2004," she says. "It’s time for me to leave the nest."

Adapted from a UIC News article by Gary Wisby, June 24, 2009.