Dr Karl › Dr Karl's Great Moments In Science

Jaguars trapped by perfume obsession

Choosing the right men's cologne could save your life in the Nicaraguan jungle. Dr Karl's sniffs out a connection between jaguars and Calvin Klein's Obsession for Men.

Now this is not a problem that most of us have. Even so, let me lay it on you. How would you attract a jaguar to your camera trap?

Let's look at the jaguar. This solitary, nocturnal animal is smaller than lions or tigers and so it's the third largest cat in the world.

The female's territory ranges from 25 to 40 square kilometres, while the male's is twice the size. Today, jaguars are found only in the Americas, from the southwest of the USA across the equator and down to northern Argentina.

Second, what is a camera trap? It's a remote hidden camera that silently takes photographs when an animal passes in front of the lens and triggers some kind of sensor. It has many advantages.

First, you learn about the animal's natural behaviour without the confounding affects of a human presence. Most animals can't sense infrared radiation so infrared flashes are widely used to take the photos.

Second, a camera trap lets you collect data continuously, whereas a human operator would need to sleep.

Third, camera traps have given us both evidence of rare species in the wild and rare behaviour, such as an eagle attacking a deer.

Fourth, it's a lot cheaper to set up a whole bunch of camera traps than to pay many field assistants.

And fifth, camera traps are a much kinder and less invasive way of getting information about animals than the traditional method of trapping, studying and finally releasing them.

So, how do you get a jaguar to visit your camera trap? Well according to Miguel Ordeñana a biologist from the Natural History Museum of Los Angeles you spray a men's cologne — that's right Calvin Klein Obsession for Men on a tree branch near the centre of your camera's field of view.

Now, this odd preference was discovered by a researcher at the Bronx Zoo in New York who tried a whole bunch of different scents and found that the jaguars really, really liked Obsession.

Why? Well we're not really sure. But the best guess is related to the fact that Obsession contains two chemicals: civetone and vanilla extract. Perhaps the vanilla triggers the curiosity of the jaguar — we really don't know. But we know a lot more about civetone, one of the oldest-known perfume ingredients.

It's a musky chemical collected by glands near the anus of the civet, and it's widely used as a fragrance and stabilising chemical in perfumes. The poor animal that supplies the much valued civetone is the civet, a mostly nocturnal animal from tropical Africa and Asia. It looks like a cat but it's more closely related to a mongoose. They're not very large, being about 43 to 71 centimetres long with a weight between 1.4 and 4.5 kilograms.

Why would a jaguar be interested in civetone? Well, jaguars like to mark out their territory, and the civetone probably smells like the territorial marker of a potential invader. So the jaguar responds by rubbing its own scent on top of the cologne Calvin Klein Obsession for Men and bingo, it unknowlingly gets photographed.

By the way, there's another twist to this tale. The most expensive coffee in the world, up to $700 per kilogram is made from coffee beans that have passed through the gut of a civet. The civet eats the so-called 'coffee cherry', digests the plump fruit and excretes the indigestible coffee bean covered in civet poo.

This coffee is variously claimed to be "smooth, chocolately and devoid of any bitter after-taste" or having a "smooth, caramel-like taste or a rich, almost full-bodied syrupy quality". Certainly, research by food chemist Massimo Marcone found that the digestive enzymes inside the civet's gut attacked some of the proteins in the coffee bean. This snipped some of the longer proteins into shorter ones and actually generated lots of free amino acids. Did it actually improve the flavour? Well, according to the coffee connoisseurs: "no". Civet coffee is pretty universally reckoned to be an expensive and rare novelty item rather than the prince of coffees.

But one thing you should know is: if you are on a bushwalk through the jungles of Nicaragua you might be better off not wearing Calvin Klein Obsession for Men …

^ to top