for National Geographic News
In southern Arizona, just north of the U.S.-Mexico border, a heat- sensitive remote surveillance camera was recently triggered by a warm body. But it wasn't an illegal immigrant in search of a job, or a courier in the drug trade. It was a jaguar (Panthera onca).
The photograph, taken on August 7, represents the second time in three years that the big cat has been imaged in the U.S. and it raises an intriguing question: Are jaguars seeking U.S. residency?
The southwestern U.S. as far north as the Grand Canyon in Arizona is part of the jaguar's historic range, but since the 1960s sightings of the big cats have occurred at a rate of only about once every ten years.
Wildlife biologists and conservationists believe jaguars largely abandoned the U.S. owing to increased pressure from sprawling development and killing by ranchers seeking to protect their livestock.
"But in last seven years we've had three animals documented here in Arizona, one photographed twice" said Bill Van Pelt, a biologist with the Arizona Game and Fish Department in Phoenix.
In 1996, two hunters independently reported jaguar sightings, which led to development of the Jaguar Conservation Team, a group composed of state wildlife agencies, ranchers, and conservationists interested in the cat's U.S. presence.
"Those two sightings woke a need for some conservation measures, and since then we've been actively looking for them," said Jack Childs, a wildlife researcher in Tucson, Arizona, who sighted one of the jaguars in 1996.
One of the first tasks undertaken by the group was setting up the surveillance cameras, which are triggered when they sense the heat of a body. One of the cameras photographed a jaguar in 2001, providing the first photographic proof that the big cats have a presence in the U.S.
According to a comparison of spots on the jaguar's coat, which serve as a sort of fingerprint, Van Pelt said that the jaguar imaged in August of this year appears to be the same animal imaged in 2001.
"Before no one made a concerted effort at monitoring the border for the presence of jaguars," said Van Pelt. "Perhaps what we are doing is documenting that we have an animal that lives here in Arizona. That is the question we are looking at now."
The closest known population of jaguars to the U.S. lies 135 miles (220 kilometers) south of the border in Mexico's Sierra Madre Mountains. The cats spotted in the U.S. are believed to originate from this population.
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