A first-of-its-kind study published by the U.S. Fish and Wildlife Service has found the leading causes of death among Albuquerque’s urban raptor populations.
The research, which analyzed 10 years of Cooper’s hawk observations, recently won “best paper” in the Journal of Raptor Research.
The Cooper’s hawk is a familiar sight across the continental United States, where countless backyard seed feeders have unnaturally boosted their primary prey: small birds.
“They eat the rodents, they eat the birds. They love pigeons and doves, man. I mean, they'll eat all birds,” Kristin Madden, one of the head authors of the study told KUNM. She is an Albuquerque resident and the migratory bird program chief for the Southwest region of the U.S. Fish and Wildlife Service.
Because of the virtually endless supply of food and shelter offered by modern urban environments, these top predators have learned to prefer the city life – essentially becoming year-round residents.
“But there are unique challenges in a city like cars and windows, electrical poles, the availability of pigeons and doves that have been eating poisoned bait,” Madden said.
Tracking these birds throughout their life-span using GPS technology, Madden and her team found that human infrastructure is the No. 1 reason for Cooper’s hawk deaths, such as collisions with fences, electrical lines, windows, and vehicles.
“You name it, they'll run into it,” Madden said.
The study, which Madden calls “groundbreaking,” avoids a “biased” picture of hawk deaths. She said dead birds are usually found by chance, either when they are hit by a car or when they’re found in a backyard.
By meticulously keeping tabs on these birds, researchers were able to find dead birds where they would likely go unnoticed; like in air conditioning systems or those who were illegally shot and bludgeoned to death, despite broad federal protections.
Major studies show that urban areas are expanding rapidly, so much so that they are expected to house 68% of the world’s entire population by 2050. And with development, comes the inevitable destruction or encroachment of animal habitat.
While it’s hard to remove the fencing around houses or the utility electrical power lines overhead, Madden stressed there are little things people can do to prevent collisions.
This can be as simple as moving bird feeders away from buildings, creating shaded areas, putting stickers on glass windows, or using small noisemakers.
Madden said their research has already been used to understand eagle population trends and could just as easily be mapped onto similar raptor species – like red-tailed hawks or the American kestrel.
As it happens, the summer is a time when people are most likely to encounter raptor hatchlings as they grow and learn to leave the nest. With this often comes momma and poppa hawks that might show aggressive behavior in order to protect their kiddos.
Madden said that raptors, especially the Cooper’s hawk, are not as problematic nor dangerous as people might believe.
In order to reduce conflict and impacts on young birds, she said it's important to pay attention to raptor vocal cues and keep a responsible distance from nesting sites. If a nest can’t be avoided, walking with an umbrella can help.
Other resources and information about raptors
- Collision prevention: Bird Collision Prevention Alliance
- Living with birds in urban areas: Raptor rapport | U.S. Fish & Wildlife Service
- Rescue, rehab, local information: The Santa Fe Raptor Center, Hawks Aloft, Wildlife Rescue Inc.
