Bobcat Den Discovery Halts Project

Caltrans crews preparing to set off explosives along a section of the Antelope Valley Freeway were stopped in their tracks Tuesday morning when workers discovered what appeared to be a bobcat den in the mountainside along the highway.

The rock blasting is part of a $31-million road-widening project, which includes construction of a carpool lane between Agua Dulce Canyon and Escondido Canyon roads in the Santa Clarita Valley.

Although not legally obligated to safeguard the den, Caltrans was taking steps to avoid harming any bobcats.

During a routine final walk-through of the blasting site at 7 a.m., Caltrans environmentalists discovered what appeared to be a bobcat den nestled in the craggy rock. Although no bobcats were found, transportation officials halted the operation as a precaution.

“It is a common practice to make sure that everything has been checked thoroughly one last time,” said Margie Tiritilli, a Caltrans spokeswoman. “If the environmental people find anything in question, they halt the job until a determination can be made. There was no way of knowing if it was an active den or if it had been there a long time.”

Caltrans officials planned to consult with state Department of Fish and Wildlife environmentalists to determine if the den is active and, if so, how best to relocate the bobcats, Tiritilli said.

Bobcats make their dens in rocky hillsides where they hollow out holes often 3 to 6 feet deep, said Michael Grima, deputy chief of the Wildlife Protection Division, the fish and wildlife department’s law enforcement branch.

Wildlife biologists use miniature cameras to peer into holes to determine whether a den is active, Grima said. If newborn bobcats are found, the den remains undisturbed until the animals are old enough to survive being moved, he said. Smoke canisters are deployed to force older bobcats out of a den.

Because bobcats are not an endangered species, there is no need for Caltrans officials to obtain permission to move the den, Grima said.

“It is hard to move every common animal along the course of a large project and find a way to move them to a suitable habitat,” he said. “Most likely [Caltrans] would call to see if we had any concerns, just as a courtesy.”

Caltrans officials had not determined late Tuesday when work would resume on that section of the project, Tiritilli said. The cost of the one-day delay was about $2,000, she said.

The price of relocating the bobcats is nowhere near the $1 million Caltrans spent to replace ecologically sensitive wetlands along the Arroyo Simi when it connected the Simi Valley and Moorpark freeways. A new, larger patch of wetlands was created out of nearby pasture land to make up for the six acres of grasses and cottonwood trees lost to the highway project.

“This delay is nothing like that at all,” Tiritilli said. “This is just one isolated den and it is 50 feet to 100 feet from the blast area.”

A Traffic-Stopper

The discovery of an empty den prompted Caltrans to postpone using dynamite near the Antelope Valley Freeway in a $31-million road-widening project. Although not legally obligated to safeguard the den--bobcats are not an endangered species--Caltrans took steps to avoid harming any of the felines. Delay costs about $2,000 per day.

Bobcat Stats

Length: 25-30 inches

Weight: 15-35 lbs.

Features: short tail with black tip and shot ear tufts.

Habitat: Rimrock and chaparral areas in the west; Dens are usually in rock crevices, hollow logs, etc.

Habits: Mostly solitary and nocturanl. Preys on small mammals and birds. Litter consists of 2-4 young.

Size Comparison

Domestic cat, Bobcat, Mountain Lion

Domestic cat track: 1 in.

Bobcat track: 2 in.

Mountain lion track: 4 in.

Source: Peterson Field Guides