By Katherine Gould
This article appeared in the Summer 1998 edition of Zoo View. It is posted here with permission from the Greater Los Angeles Zoo Association. For more information about the Los Angeles, please visit their website at www.lazoo.org.
Each day at the World of Birds show, Abe, an Abyssinian ground hornbill and one of the stars of the show, walks onto stage, catches grapes, "kills" a rubber snake, forages in the ground for worms, shows off his beautiful black plumage and red and blue wattle, then runs offstage. This very intelligent bird's performance shows off many behaviors he would exhibit in the wild, but it is one of these behaviors that has landed Abe in the hospital more than once.
Ground hornbills find much of their food by foraging in the ground for grubs and worms. In doing this, they often pick up small rocks along with their food. Evolution made a benefit of this habit, lodging the rocks in the bird's gizzard where they help to grind up food as it passes through on its way to the stomach. Every once in a while, the bird's crop gets too full of little rocks and things, and the bird regurgitates the foreign objects -- a normal event called casting.
So far so good.
Enter Abe, who doesn't simply forage, but eats everything in his path. Before the show, keepers lead Abe from the large flight pen that is his home, to a smaller cage -- a green room, if you will -- behind the stage. Abe has been known to pause along the way and eat whatever he finds -- including nails, which are unfortunate but unavoidable debris in an area adjacent to a major construction project.
In late 1995, keepers called the animal hospital because Abe had been acting lethargic, was not casting as he should, and hadn't eaten in a day. An X-ray showed nothing unusual, but a blood test showed increased lead levels, suggesting that Abe had already digested some lead-containing metal he swallowed. Abe was treated with chelation therapy, a drug treatment that binds the lead so it won't be absorbed by the body. Before long, he was back to his usually cheerful self.
Then in June 1997, keepers noticed a mass on Abe's breastbone. The bird was taken to the hospital again to have the mass removed. It turned out to be a benign tumor that had not spread, but an X-ray revealed a nail and a nut in Abe's gizzard. Although he hadn't shown any symptoms, he had already partially digested the hardware.
"They took X-rays because they know he's a junk food eater," says Dr. Cynthia Stringfield, one of the Zoo's veterinarians. Although Abe's lead levels were fine, his blood was high in zinc, which is also toxic. Once again, Abe received chelation therapy, but he had to stay in the hospital for a while.
"Keepers are always concerned when he's up here because he gets bored easily," Stringfield says.
Those keepers visited regularly in an effort to keep Abe entertained, but without his regular stage appearances, Abe grew restless. His medical chart shows a request from one of the keepers: "Can Abe go back to work ? He's bored." Fully healed, his weight back up to normal, Abe was given clearance to return to his starring role in the show.
"People have mixed feelings about birds being trained and being in shows," Stringfield says. "But for certain birds, especailly the intelligent ones, it's great. For Abe, it gives him a chance to get out and do stuff, he has to think about things, which is good, because when he's not working, he's looking for trouble."