It’s tempting to call cats lazy, since they spend most of their day either sleeping or looking like they’re about to fall asleep. The snow leopard is no exception here – this rare mountain creature can spend up to 18 hours a day resting or sleeping.
However, for the snow leopard, sleeping is not a choice, it’s a survival strategy.
The snow leopard has very substantial energy needs: an adult male consumes around one ibex or argali sheep per week, more than twice its own body weight.
Hunting this much food would be a challenging task even in an environment where prey is abundant and readily available. In the barren, steep and dry high altitude landscapes the snow leopard roams, it’s downright daunting. Wild sheep and goats are far and few in between in these mountains, and each hunt is a rollercoaster ride of steep cliffs, precipitous falls and desperate lunges. Each failed hunt costs precious energy the cat can ill afford to waste.
Even its choice of resting places follows that same logic. “Last fall, we visited all the resting places our three GPS-collared cats in Mongolia had used in the previous couple of days”, says Gustaf Samelius, the Snow Leopard Trust’s Assistant Director of Science. “One pattern emerged very quickly. It appears that snow leopards like to hang out in panoramic spots with sweeping views over the valley, especially during the daylight hours. Though it’s probably not for the scenery, but rather for the strategic advantage of being able to detect potential prey while taking a rest, and for protection from interference by wolves or humans.”
When a hungry cat does indeed spot a suitable prey, it will carefully make its way down from its lofty perch, try to sneak up on the unsuspecting animal, and try to pounce on it before it can escape. “Most of the kill sites we’ve seen were in narrow ravines and valleys. Presumably, it’s easier for the cat to corner its prey in such a terrain’, Gustaf Samelius says.
So, apart from extended naps and observations, how does a typical day in the life of a snow leopard look? To find out, Gustaf and his colleagues programmed the GPS collars on two cats to log a position every hour, giving them the most complete picture yet of how a snow leopard moves through the landscape. “The hourly GPS data points show us where a cat has gone, and how long it spent in a specific location. From this, we can stitch together an entire itinerary of an individual snow leopard, over one day or several days.”
Usually, GPS collars on snow leopards only send a position to the satellite every 5 hours, which preserves the collar’s battery life. “That’s enough to answer broader questions on how these cats use space, and how frequently they take down large prey such as ibex. But there are these five-hour gaps, where we have no idea what the cats are up to. So, to make sure we’re not missing anything crucial, like for instance a kill of a smaller animal, we’ve deliberately programmed these collars a bit differently during two three-week periods”, Gustaf says.
Technology helps us better understand the snow leopard – but at the end of the day, it takes old-fashioned human effort to make sense of the data. “We visited a total of 62 so-called cluster sites – places where a cat had spent several hours – in two weeks”, Gustaf recalls. “That may not be much for a snow leopard, but for a mere human, it was a lot of hiking – especially since these cats like to hang out near the top of mountains, not at the base.”
So far, it looks like the hard work has paid off. “As far as we can tell from our cluster visits, we haven’t been missing anything crucial in those five-hour gaps”, Gustaf says.