Large predators are difficult to study because they’re relatively uncommon and they roam widely, so I was thrilled when I heard two good news stories about big predators.
Back in November 2006, Dr. Todd Katzner, Director of Conservation and Field Research at the National Aviary in Pittsburgh, and biologists from the Pennsylvania Game Commission and Powdermill Avian Research Center captured two golden eagles in western Pennsylvania and outfitted them with solar-powered satellite telemetry devices.
For years birders have been seeing golden eagles pass through Pennsylvania in spring and fall, but no one knew where they were going or where they originated. This effort was an attempt to understand the movements of eastern golden eagles.
One of these eagles, number 39, spent that first winter in southern West Virginia, near Beckley, then moved to northern Quebec in the spring, presumably to nest. Unfortunately, its transmitter went quiet in June 2007.
Then, about five weeks ago, a biologist with the West Virginia Division of Natural Resources, Jeff Hajenga, set up some motion-activated trail cameras on mountaintop clearings. The day after setting up the cameras, he had an image of a golden eagle feeding on road-killed deer, which had been used as bait.
Hajenga alerted Tricia Miller at Powdermill and soon her husband, Mike Lanzone, an ornithologist at Powdermill, traveled to southern West Virginia and set up a cannon-propelled net. Before long, Lanzone captured a golden eagle, and it was number 39.
Lanzone examined the bird, determined it was healthy, attached a new transmitter, and released it. Soon it will join other golden eagles as they head north through Pennsylvania on their way to breeding grounds in remote areas of northeastern Canada.
According to Katzner, “We now have about 10 golden eagles fitted with transmitters in Pennsylvania and West Virginia, and another five or six in Canada. We haven’t yet confirmed the birds are nesting in Quebec, but based on their limited movements during the nesting season, we suspect they are.”
The other big predator story comes from southwest of Tucson, Ariz.
On Feb. 18, biologists inadvertently trapped a healthy, 118-pound male jaguar during a study of mountain lions and black bears.
“While we didn’t set out to collar a jaguar as part of the mountain lion and bear research project, we took advantage of an important opportunity,” says Terry Johnson, endangered species coordinator for the Arizona Game and Fish Department.
“More than 10 years ago we tried to collar a jaguar with no success. Since then, we established handling protocols in case we inadvertently captured a jaguar in the course of one of our other wildlife management activities.”
Jaguars are big cats that once roamed from southern South America as far north as the southwest U.S., but none had ever been captured in Arizona.
Females breed year-round and have litters of one to four young that require maternal care for nearly two years.
By the late 1900s, jaguars were thought to be extinct in the U.S., until two independent observations in Arizona and New Mexico in 1996 confirmed their presence.
For the last 10 years, the Jaguar Conservation Team has been working with biologists in Mexico because they recognize that U.S. jaguars depend on a healthy population south of the border.
Arizona biologists have confirmed that the cat is “Macho B,” an individual that has been photographed intermittently by trail cameras over the last 13 years. He is the oldest known wild jaguar.
The jaguar was fitted with a GPS tracking collar and released. The collar provides location data every three hours so biologists can determine the cat’s home range and habitat use. And it’s programmed to send a special signal if it crosses the Mexican border.
Experts agree that tracking collars should weigh no more than three to five percent of an animal’s body weight. At less than two pounds, Macho B’s collar weighs less than two percent of his body weight, so he should be able to move normally and capture prey.
After the first week, the cat had traveled about 3 miles from the trap site and is doing well in very rugged terrain. Johnson confirms that Macho B is, “… doing well and has recovered from his capture and collaring.”
The wild jaguar southwest of Tucson was fitted with a GPS collar so its activities could be monitored. After two weeks, the jaguar began moving erratically, so biologists relocated and recaptured it. Veterinarians at the Phoenix Zoo determined it to be in, “severe and unrecoverable kidney failure,” according to Bill Van Pelt, nongame birds and mammals manager for the Arizona Game and Fish Department.
Kidney failure is a common illness among older big cats, so it was euthanized March 2. The jaguar, nicknamed Macho B after being photographed a number of times by motion-activated cameras over a 13-year period, was the first ever captured in Arizona and was approximately 15 years old.