Take Their Own Photographs?

These graphics demonstrate a typical camera trap set-up. The wildlife biologist will choose a likely spot along a well traveled, narrow path, such as the base of a cliff or along a narrow valley floor. How does the biologist know the path is used by snow leopards? Perhaps there will be feces (poop), or perhaps there will be a “scrape”. A scrape is a place where the snow leopard has marked its territory by scratching with its hind legs on loose sand or soil. In the photo above, the biologist has chosen a spot where snow leopards have scent marked a boulder. Snow leopards spray boulders with a pungent liquid from scent glands located under the base the tail. They also spread scent by cheek-rubbing on rocks or trees. In the photo, you can see the scent mark as a discoloration on the under side of the rock that the leopard appears to be looking at.

Scents help leopards to identify one another, or merely let one cat know that another has been there. Scent marks can mean “keep out,” where males wish to identify the boundaries of their home ranges. Usually a male cat’s range will include that of one or more females, but the ranges of more than one male may overlap. Scent marks help males and females find each other in the breeding season, and possibly also ensure that the genes of dominant males prevail. Snow leopards pay very close attention to these marks.

At the spot that the wildlife biologist has chosen, rocks are stacked to form a cairn, which is a fancy way to say “a rock pile”. The cairn is used to hide the camera and support it and the infrared triggering mechanism. The equipment is set up so that the infrared beam is snow leopard height – so that a snow leopard will interrupt it as it walks along the path. The interrupted infrared beam acts to trigger the camera shutter.

In the bottom illustration you see a typical placement for two cameras. Wildlife biologists prefer to use two cameras because they can get photos of both sides of the snow leopard making pelage patterns easier to identify. And that is why biologists use cameras in the first place. By carefully placing camera traps over a portion of snow leopard habitat and then monitoring them over an extended period, say a winter season, the biologist can get a very good idea of the number of cats in the study area. All of us get to see some very interesting photos of wild snow leopards.

So, the snow leopard walks along the trail, minding its own business. It interrupts the infrared beam and... presto! Without ever saying “cheese”, the snow leopard has taken its self-portrait.

In these three camera-trap photographs a wild snow leopard notices a scent mark on a nearby rock and investigates. The two photos at the top of the page were taken at the same instant by a two-camera trap. The photo on the left was taken by the camera hidden in the cairn you see at the bottom right corner of the photo on the right. Likewise, the photo on the right was taken by a camera hidden in the cairn you see in the photo on the left. Notice how well camoflaged this snow leopard is; it’s hard to distinguish it from the rocky background even at this short distance, isn’t it?

In the bottom photo, which was taken almost a month after the others, the same cat has returned to investigate the scent-marked rock. Scent marks and scrapes are ways in which snow leopards keep track of who’s who and who’s where.