Extreme sports become extra extreme when you add bears ...

Mountain biker Arben Kuqi was cruising down a stretch of single track in the Sharr Mountains near Kosovo recently when he very nearly collided with a pair of brown bear cubs as they darted across the trail in front of him. Mama bear was just ahead of the fleeing cubs and, according to Kuqi, put on an aggressive display to see off the perceived threat (crank the sound up and you can hear her growl at Kuqi as he races past).

Kuqi uploaded footage of the close encounter to YouTube last month where it has been viewed over 100,000 times. Shortly after the incident, the second rider seen in the clip took a tumble and (wisely) abandoned his bike. The two were forced to ride tandem down the trail to build some distance between themselves and the protective mother bear.

There is a relatively healthy population of brown bears in the Balkans, so it is not entirely surprising that cyclists exploring trails in southeastern Europe do occasionally encounter them. While there have been a handful of attacks by bears on humans in the area, serious incidents are uncommon. Staring down a sow defending her cubs, however, is certainly not a situation any mountain biker wants to find themselves in.

If you look closely you can see the mother bear peeking her head out from the tall grass.

review following a fatal attack in 2016 in Montana suggested that mountain bikers on backcountry trails could be inherently more vulnerable to run-ins with bears than hikers. The report noted, "Mountain biking is a quiet and fast activity that may cause you to get much too close to a bear before either you or the bear knows it, resulting in a surprise encounter and a defence attack by a surprised bear."

Some of the recommendations for bear-safe mountain-biking practices include carrying bear spray and avoiding riding in the dawn, dusk and nighttime hours when bruins tend to be more active.