If you live in England and venture out on the roads after dark, there's a chance you'll spot a fox or a badger going about its nightly business.
In California, however, motorists were recently greeted by an altogether more exotic and dangerous sight.
Just a few days ago a mountain lion was seen walking across the 101 freeway - only the fourth successful crossing by the species since the National Parks Service began its mountain lion study 15 years ago.
The lion also crossed two other major thoroughfares before ending up in the Santa Susana Mountains, having apparently begun its trek in search of love.
Were it an isolated incident, such a story would probably warrant an 'and finally' slot in the news agenda, a bit of light relief from talk of North Korea, acid attacks and Isis. But this big cat odyssey is evidence of a wider problem, the ever-growing proximity of human and mountain lion in California - a trend which could have dire consequencies for both sides.
For those who aren't well-up on the big cat family, or the flora and fauna of our transatlantic cousins, a mountain lion has nothing to do with a regular lion, apart from being part of the same broad family. It's actually another name for a cougar, and the animal can be found all the way down the Americas, from Canada to the Andes. But it's particularly prevalent in California; in fact more than half the state is a mountain lion habitat.
It's in the mountain lion's nature to avoid humans. Despite this recent reports seem to suggest that mountain lions are being forced into human areas in search of food. The California Department of Fish and Wildlife warns that although mountain lions like to eat deer, they will also eat livestock and pets, and the latter are available in plentiful quantities in the wealthy California suburbs.
However the females were eating closer to more developed areas. Researchers believe this is due to the risk of them or their cubs being killed by aggressive males is less in this area and there is also more deer for them to kill.
This has inevitably resulted in increased contact with humans. Last month, a mountain lion ran into a bowling alley in the town of Colusa before crashing into the bedroom of a nearby home, apparently thinking the window was the entrance to a cave. Although it sustained cuts and bruises from the window, the animal apparently avoided serious injury and was allowed out by the startled woman.
The mountain lion seen on a rampage through Colusa
There have been a spate of other sightings over the summer months, mainly on California's hiker trails. Although none of these close encounters has resulted in an attack, such an event is not impossible; indeed on August 1 an officer was forced to shoot and kill a mountain lion which attacked him in the nearby state of Utah.
This incident also demonstrates the huge danger posed to mountain lions by their increasing contact with their human neighbours. A mountain lion which attacks a human is certain to be killed, either by the person it attacks or by investigators afterwards. The human might survive the encounter, but the animal won't.
Furthermore, as the mountain lions venture further from their rural habitats in search of prey, the dense grid of highways and freeways which criss-cross California can separate the cats from one another, as they become disorientated by these huge, noisy barriers. Cut off from their wider networks, the animals may be forced to breed with their own direct relatives, reducing their genetic diversity and making more susceptible to extinction. Alternatively the road network may leave young males trapped in rival territory - a mistake which inevitably ends in death.
The risks to the mountain lion population are immediate and real. Researchers using National Park Service data to analyse the population found that if an "inbreeding depression" happens, there will be a 99.7% chance of mountain lion extinction within 50 years.
There have been moves to curb the risk. Researchers have suggested installing wildlife crossings across freeways to allow the animals to travel more, thereby reducing the risk of fighting while allowing new breeding opportunities.
Yet so far nothing has been done about this new and rather troubling problem. As California's cities continue to expand outwards, it's an issue that's only going to become more prevalent in the years ahead, and could soon have deadly consequences - for both sides.