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Stephanie Lindsell opened the cardboard box and gently removed a female great horned owl, which immediately spread her wings and flew off, staying low to the ground and settling down about 100 yards away to survey her surroundings at the Valle de Oro National Wildlife Refuge.
The owl, given the designation 20-964 rather than a name, eventually made her way to the nearby heavily-treed bosque along the Rio Grande.
The Tuesday flight was short, but the journey to get there took two years.
The injured owl was reported to the nonprofit Hawks Aloft, which recovered the bird in November 2020 from along Interstate 25, south of Albuquerque, and subsequently handed it over to the Española-based Wildlife Center. The owl was apparently hit by a vehicle – possibly while feeding on rodents or other prey that was attracted to discarded food thrown from a vehicle, said Lindsell, wildlife rehabilitation manager with the New Mexico Wildlife Center.
“Our veterinarian found some scarring in her eyes and her feathers were in really, really bad condition – very brittle and broken – all of which indicates that she probably had a prior infection, most likely West Nile virus,” she said.
While broken wing bones usually heal well, the condition of the bird’s feathers complicated the recovery. The normal treatment is to take donor feathers lost during molting from another great horned owl, trim them and insert the shaft portion of the feather into the remaining hollow feather shaft of the recipient bird.
“But we can only do that if the recipient feather shaft is healthy,” Lindsell said. In this case, the bird’s feathers were split, ripped and frayed. “We had to wait for her to molt naturally, and great horned owls have a two-year molt cycle, so all we could do is wait.”
The poor condition of her feathers also meant that her flight ability was severely limited, particularly her ability to fly silently as she swooped down to capture prey.
As the female owl recovered, she was moved to ever larger flight enclosures – from 20 feet long to 50 feet and most recently 100 feet – and she successfully passed “prey school” in which the bird’s hunting abilities were tested, Lindsell said. “So she’s very ready to go.”
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While great horned owls are common throughout North America and are not an endangered species, they do have a high first year mortality rate, as do many bird species.
Prey birds in particular have a difficult time as inexperienced members often hunt near roads, where they are killed or injured by passing vehicles. In addition, rodents and rabbits, among their main sources of food, are often tainted with rodenticides, which get transferred into the owls that prey upon them, said Laura Siegel, also a New Mexico Wildlife Center rehabilitator and the organization’s resident owl expert.
In the wild, great horned owls generally live from 10 to 12 years, she said. In human care they can live well into their 20s and 30s, with the record for the longest lived member at 50 years.
Nocturnal creatures, they are particularly active hunters around dawn and dusk. They have excellent night vision and even better hearing, which they use to locate and capture prey, Siegel said. Although their eyes don’t move in their sockets, they can swivel their heads 270 degrees.
Great horned owls have an average weight range of 2½ to 3½ pounds and an average wingspan range of 3½ to 4½feet. The females of the species are generally larger than the males.
“The colors and patterns of their feathers provide really good camouflage against the trees and other sorts of natural landscapes,” Siegel said. “They’re one of the most adaptable animal species.”