Two Hawk Deaths at Cornell Illustrate Hazards Faced by Urban Birds

By Miyoko Chu, Senior Director of Communications, Cornell Lab
September 9, 2013
Hunting juvenile Red-tailed Hawk Surviving Red-tailed Hawk fledgling D2 on the hunt. Photo by Christine Bogdanowicz.

UPDATE: In August 2014, DNA analysis revealed surprising new information about the young hawks described in this post. For the full story, see DNA Tests Determine Whether 2013’s Injured Hawks Came From Bird Cams Nest.

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On the morning of August 9, 2013, a Cornell University mechanic found a dead hawk on the sidewalk near Bradfield Hall on campus. The bird was on its back, its feathers wet from heavy rains. After contacting the Animal Health Diagnostic Center at the Cornell College of Veterinary Medicine, he carefully placed the hawk in a bag and brought it to them.

That same morning, Dr. John Parks at the Cornell Raptor Program received a call. A passerby had spotted an injured hawk on a nearby road half a mile away from Bradfield Hall. Dr. Parks, a licensed rehabilitator, brought the injured bird to the wildlife health center in the Cornell College of Veterinary Medicine.

News spread quickly to the Cornell Lab, where we learned that both hawks were juveniles. Based on their locations, we knew there was a good chance that they were the young of Big Red and Ezra, the Red-tailed Hawks featured on our live Bird Cams. For the past two years, more than three million people around the world have witnessed the hawks building their nest high above campus, watched as Big Red laid her eggs, and waited with anticipation as the chicks inside began cracking their way out of the shell. These chicks, nicknamed D1, D2, and D3, grew up and fledged before our very eyes. And though participants in the live chat often worried about the fledglings, knowing that more than half of red-tails typically do not survive beyond their first year—it was hard to imagine losing even one of these young hawks that we knew so well.

It was enough of a blow that one was found injured and another dead on the same day—but even sadder to realize that the causes were probably related to their urban environment. The diagnostic center reported that the hawk by Bradfield Hall had died from blunt force trauma. We’ll never know the exact cause, but it probably collided with a building or a vehicle. At the wildlife health center, the veterinarians treated the other hawk for severe injuries to his feet and legs, but had to euthanize him several days later because the injuries were too extensive to allow recovery and quality of life. The nature of the injuries suggested that the hawk’s feet and legs may have become caught in something human-made such as a gutter or piece of machinery.

Meanwhile, the cams community responded with an outpouring of Facebook posts and email messages—people sharing their good memories of the hawks, sadness over the losses, appreciation for the veterinary team that cared for the injured one, and thoughts about how to make the world a safer place for birds. Though we don’t know whether the hawks’ injuries occurred on campus or nearby areas, the Cornell facilities team has looked at photos we’ve sent of the hawks’ favorite perches. They plan to inspect gutters, fans, and other possible hazards when they do annual maintenance, with hawk safety in mind. Local observers are looking into whether wildlife crossing signs could be added along the state highway where Ezra often hunts.

The Cornell hawks are lucky to have so many people looking out after them. But what about all the places a young hawk might travel when it disperses from its home here at Cornell? What about the adjacent family of red-tails on the golf course, or the pair that nests in the Falls Creek Gorge—or the hawks in your own neighborhood? All across North America, there are red-tails like Big Red and Ezra, with their own families, their own stories and challenges. And there are hundreds of other bird species, some of which suffer even greater tolls on their populations than the adaptable Red-tailed Hawk.

Aside from habitat loss and destruction, which is a leading cause of declines in birds, direct mortality from human-related causes is estimated to be more than one billion birds each year in the United States. According to a USDA Forest Service study published in 2005 (available as a PDF), collisions with structures may kill 550 million birds each year, power lines 130 million, and vehicles 80 million. A 2013 study published in Nature Communications estimated that cats alone kill 1.4 billion to 3.7 billion birds each year.

Estimating these numbers is challenging because people find and report only a fraction of dead birds (experimental studies have shown that other animals scavenge most dead birds within 24 hours), but even these best estimates are staggering. Sadly, stories of other beloved raptors from around the country, like that of the Cornell hawks, reflect the ubiquitous hazards that birds encounter, on a more personal level. This year, two young hawks from the Franklin Institute’s cam struck windows and died. A third was hit by a car, rehabilitated, and released. In 2012, two young Bald Eagles, D12 and D14, from the Decorah, Iowa, cam were electrocuted on power poles. In New York City that same year, three Red-tailed Hawks including Lima, the mate of the famed Pale Male, died from rodenticides after eating poisoned prey. The year before that, the female Bald Eagle from the Norfolk Botanical Garden cam in Virginia died after being struck by an airplane.

The statistics can be so numbing that people sometimes despair that the dangers to birds are too pervasive to tackle. But something powerful happens when we follow the fates of individual birds. They cause us to care so much that our hearts ache, and we feel that we can and should do something to help. In New York City, citizens successfully lobbied to stop the use of rodenticides in Washington Square Park. In Decorah, eagle enthusiasts worked with local energy companies to create safer perches near the nest site. At the Franklin Institute, the college plans to install banners featuring student work in certain windows to prevent future collisions.

What if each of the millions of people who watch bird cams did something to make their own neighborhood a little safer for birds? Would it matter if we could save a few more birds? If you think of Big Red, Ezra, and the young hawks we watched fly out into the world, perhaps you agree that the answer is yes. Maybe collectively we could save even more than a few.

What are some of the ways?

  • To reduce window collisions, place your bird feeder far enough from windows that birds won’t scatter into them if startled. Or move them to within one or two feet of windows so that collisions won’t be as forceful. If you work in an office building, turn off lights at night to avoid attracting and confusing migrating birds. For more tips on making windows safer at home and at work, visit the Fatal Light Awareness Program website.
  • To reduce collisions with vehicles, keep within the speed limit. Even an extra second or two can help you avoid colliding with birds and other wildlife, making it safer for them and for you. Slower speeds can also result in better gas mileage and reduce greenhouse gases.
  • Cats are one of the leading causes of mortality for birds, and people can make a big difference here. Keep your cats indoors, speak up in your community to prevent feral cat colonies from becoming established, and help your neighbors understand how cats affect bird populations. Keeping cats indoors is safer for cats, too. For more information, visit the American Bird Conservancy’s Cats Indoors web page.
  • Concerned about whether power lines in your area might cause electrocution or collision risks for birds? The Avian Power Line Interaction Committee website offers information and protection plans.
  • Avoid using anticoagulant rodenticides around your home. Inquire with your city park to find out what they are using. Hawks that eat poisoned prey may die from hemorrhaging. To learn more about these rodenticides, visit the New York State Department of Environmental Conservation website.
  • Please support the work of land trusts and conservation organizations, including the Cornell Lab of Ornithology’s efforts to improve the appreciation and protection of birds through science, education, and conservation.
  • Share a bird cam with a friend.

Please share more ideas and let us know what you’ve found works best around your home or in your community to make the world a safer place for birds.