Close Calls: In Fight For Survival, Predator Falls Victim To Her Prey

By Mónica Ortiz Uribe
July 14, 2014
Kate Sheehy
Sonora is a four-year-old red tailed hawk who survived a severe rattlesnake bite this spring.

At the Arizona-Sonora Living Desert Museum outside Tucson, one of the top attractions is the raptor free flight. Visitors watch as birds of prey swoop and soar in the open desert.

There are falcons, owls and hawks —all trained performance animals. A volunteer narrates the program while the audience gasps in awe.

On a recent afternoon, trainer Wally Hestermann showed off a sand-colored bird that lives at the museum. She has dark wings and fierce eyes.

"This is Sonora, she's a four-year-old red tailed hawk," he said.

Red tailed hawks can be choosy about their meals. This spring Sonora decided she liked the taste of rattlesnakes.  

"One day she went after an adult, a really, really big one," Hestermann said. "We saw her go down on it and by the time I found her, the head was already eaten and I saw two puncture marks on her foot. She was hobbling around like it was really bothering her."

Sonora was in trouble. Her trainers rushed her to Audrey Siegrist, the veterinarian on duty that day.

At the moment Siegrist was getting ready to head home early, as she was feeling the early stages of the flu.

"I had just finished my day and I thought, 'Oh boy, these things have a tendency to happen when you're least prepared,'" she said.

As a vet, Siegrist has seen her share of oddball cases. She one rehabilitated a paralyzed tarantula. She's treated rattlesnake bites in dogs and cats, even on a goat and a coyote. But she'd never treated a bird. So she went online to search a veterinary medicine network.

"I typed in 'rattlesnake envenomation of birds' and basically they said, 'Never seen one. Never been able to treat it. They're dead by the time they present, but I would use antivenom if I could'," Siegrist said.

Unfortunately the museum clinic had no antivenom in stock. The medication is expensive and can have a short shelf life. Getting it to the museum would take two hours to transport from a supplier in Tucson. Meanwhile Sonora arrived at the clinic, looking weak and unresponsive.  

"I saw that her eyes were oscillating back and forth," Siegrist said. "Her heart rate was about 350 beats per minute, when normally she's around 160 or 190. I knew she was starting to go into shock."

Kate Sheehy
Audrey Siegrist is a veterinarian at the Arizona-Sonora Living Desert Museum outside Tucson. She helped save the life of a red tailed hawk who was bitten by a rattlesnake.

Siegrist ordered the antivenom. She switched on a ventilator and placed an air mask on Sonora in an effort to stabilize her vitals. Then she picked up the phone and called her friend in Tucson, Dr. Leslie Boyer.

"I was sitting in my office for one of those rare occasions when I'm at the phone and took the call," Boyer said.

Boyer is a pediatrician. She's also a toxicologist who specializes in treating venomous bites and stings. Since this was a new situation for both doctors, Boyer decided to improvise.

"I said, 'We're just gonna pretend that we are in a rural clinic in Africa and this is a tiny child for whom we are, if you will, winging it, trying to come up with the best possible treatment,'" she said.

Over the phone Boyer recommended doing a simple blood test to check for snake venom. If it was present the blood would not clot. The test turned out positive. But before they got the results, Sonora went into respiratory arrest.

"And I thought, 'Oh, let her go, let her go. Hang up the phone, it's over'," Boyer said. "And I hung up the phone confident that you had a dead bird."

As Boyer sat mourning in her office, Siegrist scrambled to put a breathing tube in Sonora's airway.

"We couldn't get that antivenom fast enough, because she was starting to die," Siegrist said.

Finally the antivenom arrived. Siegrist called Boyer back, who was astonished Sonora was still alive. But the toughest part was yet to come. Boyer knew using antivenom was risky.   

"This particular type of antivenom is well known for sometimes very dangerous allergic reactions," Boyer said.

So in case that happened, she recommended Siegrist have a shot of adrenaline ready. Siegrist slowly injected four milliliters of antivenom into Sonora's wing. Then she had to hang up the phone again.  

"All of a sudden her heart rate went completely erratic and it was too fast to count," she said. "And I thought, we're losing her."  

It was the allergic reaction they had feared. So in went the adrenaline shot.

"And about a half hour of struggling to keep her stable and bringing her back from the dead, she lived," Siegrist said. "She actually started to look good."

Two hours later, Siegrist took Sonora off the ventilator and removed the breathing tube. When the tube was out, Sonora proceeded to regurgitate the head of the rattlesnake she swallowed earlier. After that her condition only improved.

"She stood on both of her feet without a problem," Siegrist said. "She was gripping with both feet, like nothing ever happened. We were absolutely thrilled."

Siegrist got Boyer back on the phone to share the good news. The museum staff celebrated.

Curator Will Bruner said Sonora has an important job, teaching humans about animals.

“If you have that connection with that animal then you are going to do more to help that animal in the wild," he said. "Or you are going to think about things that you do in your normal life that impact animals because you have formed a connection, just like you would with another person.”

Since the bite back in April, Sonora is doing well. She'll spend most of the summer in a cage while she molts. In the fall she'll be back out hunting. When she does, the big question is — will she go for another rattlesnake?