Earlier this month, we brought you some adorable photos of a mountain lion family in California in the US enjoying a nice meal of freshly killed deer. At the time the photos were taken, brother P-32 and sister P-33 were still with their mother, P-19. But at 15 months old, they were just on the precipice of leaving their mother's care and setting off on their own. 

Because each of the cats is outfitted with GPS collars, US National Park Service (NPS) researchers verified recently that the two youngsters had indeed gone their separate ways. And in a surprising turn of events, P-33 has turned up on the opposite side of a busy eight-lane freeway – the California state highway 101!

National Park Service researchers have been observing the mountain lions of the Santa Monica Mountains National Recreation Area for some thirteen years, but this is only the second time they have recorded evidence of a mountain lion crossing that particular freeway. Over the years, the study has followed 35 mountain lions. Their movements, tracked by the GPS collars, have given the researchers evidence of mountain lions in more than 90,000 locations throughout the Los Angeles area's natural landscape.

"As far as we're concerned, it’s a 100% increase in the number of times mountain lions have crossed the 101 in terms of ones we've been radio tracking," says NPS researcher Seth Riley, who is also an adjunct assistant professor at University of California, Los Angeles (UCLA)

It's also fairly remarkable that it was a female mountain lion that made the crossing. While both males and females leave their mothers' territories once they're old enough, males tend to venture much farther away. "It's certainly not unusual for females to disperse, but it's true that it's not as common as in males," says Riley. 

While P-33's successful crossing is cause for celebration, it's worth remembering just how rare it is for mountain lions to survive such risky attempts. In 2013, a car hit and killed a young male lion as he tried to cross the 101 freeway. That's why conservationists and mountain lion advocates are thrilled that a substantial government grant has been allocated to build a wildlife crossing over one of the world's busiest freeways, a crucial link that would provide safe passage for mountain lions and other wildlife, allowing the animals to find more space, food and mates on the other side.