Deep inside a field of thornscrubs in southern Texas, only when the sun goes down, the ocelots begin to roam. Not even 100 remain of the endangered wildcats, not to mention they can’t be easily spotted in their habitat. In fact Melissa Grigione, USF professor of environmental science and policy, relied on radio telemetry to locate the cats for a documentary.

In December, Earth Justice, a firm in Washington, D.C., selected Grigione to film a documentary on the ocelots and how changes in the Endangered Species Act will affect them. The ocelots, which resembles a leopard or a jaguar with its spotted fur, is more closely related to a margay and oncilla. The ocelots are the only remaining species in the United States that Grigione has been studying, along with the jaguar and jaguarandi, and all three are in danger of becoming extinct.

“The purpose is so Earth Justice can take (the documentary) to Capitol Hill and educate people in the Senate and the House of Representatives,” Grigione said.

For two days, Grigione observed the ocelots at the Laguna Atascosa in Rio Hondo, Texas. Remote cameras were set up along trails to take photos of the ocelots and the only sure way to know where the ocelots stood was through radio telemetry provided through the collars that had been previously been put on the cats.

“The vegetation is so thick that it conceals them so well,” Grigione said. “They live in thornscrubs and in order to walk through you have to lay down and crawl.”

Grigione said because of the vegetation, she was only able to get within about 200 feet of an ocelot. But relying on the radio telemetry she mapped the ocelots’ movements by location and time.

“Then we were able to ask questions like ‘Why are they in that habitat?’ Then we could understand how they were acting,” Grigione said. “At that point we could go on our knees and crawl to see if there was a cub.”

For about 15 years, biologist Linda Lack had been collecting data on the ocelots in a similar way and trapped the ocelots to put collars on them for tracking purposes. Before filming the documentary, Grigione had experience tracking cats with her team called the Bordercats. Grigione said the group of scientists meet once a year for about three days to review each of the 25 members’ research and collaborate.

A majority of Grigione’s research takes place along the United States and Mexican border, where she has seen the population of ocelots shrink as the cats migrate to Mexico.

“Unless we begin to conserve that habitat it will continue to shrink,” Grigione said.

At the border of Mexico, Grigione said, there is little habitat because of the commerce, and highways surrounding the Laguna Atascosa refuge, so more ocelots are being killed.

“We’re working on setting aside a habitat with corridors to protect the ocelots and to connect the U.S. and Mexico,” Grigione said. “We’re working with private landowners to provide incentives so they don’t kill the ocelots because right now, for them, a good cat is a dead cat.”

The landowners fear the ocelots will attack their cattle. Grigione said she can’t blame them, but it’s important to work with the landowners because the last remaining ocelots remain around their land near the refuge.

Grigione, who has been a professor at USF for three years and previously taught at the University of Connecticut, said this was the first documentary she has filmed.

The documentary mainly focuses on the ocelots because the jaguar and jaguarandi are more difficult to locate. Grigione said there are less than 10 jaguars remaining and there is not definite number on how many jaguarandi exist today.