Do Big Cats Like Catnip?
Or: What’s a cat sex hormone doing in a plant?
Ever wondered if ocelots, leopards, lions, and tigers dig catnip the same way domestic kitties do? Watch and see.
Ok, I’m intrigued. Obviously this catnip connection reaches further back in the evolutionary timeline than just domestic cats — it looks as though, with the exception of mister King of the Jungle there, no feline animal can escape the wiles of catnip.
What makes catnip work? According to veterinarian Ramona Turner writing for Scientific American, catnip contains a chemical called Nepetalactone which happens to bind to protein receptors in a cat’s olfactory system exactly like a chemical found in the urine of a dominant female cat in heat.
When cats smell catnip they exhibit several behaviors common to queens in season (females in heat): They may rub their heads and body on the herb or jump, roll around, vocalize and salivate.
In other words, kitty’s not seeing double-rainbows; kitty thinks she or another female is in heat.
The effects seem to wear off within 10 minutes, and the cat in question won’t respond to catnip again until another 30 minutes have gone by. (Sensory adaptation?) Roughly 75% of felines are genetically wired to respond to catnip in this way; for the remaining 25%, it’s just not their cup of mint tea.
Ok, but WHY?
The plants that belong to the catnip family are indigenous only to the Old World, and yet, members of the feline family that respond to catnip are found in both the Old World and the New World. So, if you think about the catnip response from an evolutionary standpoint, it seems clear that some species of cats have acquired the ability to display the catnip response even though the natural source of nepetalactone was not present to influence the evolution of this behavioral response. (Yet another fun fact that adds to the overall mystique of the feline).
But this is actually a great argument for total arbitrariness: cats around the world react to this chemical that happens to grow only in certain parts of the world, so the idea certain cats somehow having evolutionarily “acquired the catnip response” is a futile line of inquiry.
Far from constituting another example of “feline mystique”, the easiest and best explanation would be that a common ancestor of all cats had this nepetalactone response as a vital part of the feline sexual cycle — and the presence of the chemical in the plant is mere coincidence. Does the presence of theobromine in chocolate, a mood-altering stimulant, tell us something useful about human evolution?
So what is a cat sex hormone doing in a plant?
Nepatalactone may have evolved as a honeybee attractant and perhaps also as an unwanted-insect repellant. The chemical is also mildly antibacterial, according to Wikipedia.
Of those possibilities, the honeybee attractant theory makes the most sense. Catnip doesn’t have much to fear from mosquitoes and cockroaches, the only bugs that seem to react negatively to the chemical, and the antibacterial quality doesn’t tend to do a whole lot for plants, whose cellulose structures are more susceptible to fungus than anything else.
Does that mean that letting your ocelot go into heat and pee all over your garden will bring honeybees to your flowers?
Sure, maybe. Try that out and let me know how it goes.