Biologists in California got a holiday surprise last December—a pair of brand-new, blue-eyed mountain lion kittens peeking out of a den.
The team stumbled upon the youngsters—whose picture was recently released by the National Park Service—while keeping tabs on a female named P-19 in the Santa Monica Mountains. Since 2002, the scientists have been using tracking devices, such as GPS collars, to study the behavior and movements of big cats living on the outskirts of Los Angeles.
While newborns are always cause for celebration, the kittens could be particularly important, depending on who the father is, says Jeff Sikich, biologist for Santa Monica Mountains National Recreation Area.
P-19’s previous two litters were both sired by her father, P-12, which he says is inbreeding of the first order. This reduces the genetic diversity—and ultimately future survival—of the region's small mountain lion population.
But if the new kittens—a female and male named P-46 and P-47—are the offspring of a new male (perhaps a newcomer named P-45) it could mean a crucial infusion of fresh genes, Sikich says.
“Our mountain lions have some of the lowest genetic diversity of any lion population studied on the west coast, outside that of the Florida panther,” says Sikich.
"Island of Habitat"
A paternity test—determined by blood samples from the kittens—will reveal the father sometime in the next few weeks, Sikich says.
But even with hardier genes, the cubs will face many challenges.
For one, the Santa Monica Mountains National Recreation Area is about 650 square kilometres of protected land, only enough space to support a maximum of 15 of the wide-ranging species at any given time—only one or two of which can be adult males.
“I like to think of it as an island of habitat,” he says.
Fights over territory, food, and breeding rights are also troublesome—especially for male kittens.
“So, you have lions killing lions,” says Sikich. “The young males run into the adult in the mountains and gets killed.”
In October, a collared male from the research study entered a den and ate kittens fathered by another male.
Tough Road Ahead
The lions’ home is hemmed in by agricultural fields and development to the west, the Pacific Ocean to the south, and freeways to the north and east.
Getting struck by a vehicle while crossing a road is one of the biggest threats to the Los Angeles area’s lions, especially when they get too old to keep living with mom.
That's what happened to P-32, the 21-month-old male who became the first known lion to leave the Santa Monica Mountains. P-32 crossed four major highways on his journey north—an amazing accomplishment—before being struck down by a truck on the interstate highway near Castaic, California.
“Lions can persist in these near urban environments,” Sikich says, “but only if we can ensure that there are large blocks of interconnected habitat.”
“We have to protect our remaining natural areas and ensure that there are corridors connecting them,” he says.
A Mother’s Love
The good news for kittens P-46 and P-47 is that their mother has already proven herself to be a good parent.
Several of her previous kittens are still alive and being actively tracked by Sikich and his colleagues. Some even have kittens of their own. In fact, the highway crosser, P-32, was one of P-19’s sons.
Furthermore, new kittens are also good news for the fate of other cougars in the area.
“It’s definitely a good indication," says Sikich, "that our females are still reproducing in the Santa Monica Mountains.”
By Jason Bittel