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Although they're often revered for their beautiful appearance, butterflies might not be as enchanting as you think. They regularly congregate around mud, dung and even decaying corpses.

Ah yes, the butterfly. A beloved cultural icon, celebrated in ancient artworks and revered as a symbol of everything from love to rebirth. But these delicate insects might not be quite as enchanting as you think. Naturalist and butterfly expert Andre Coetze gives us the lowdown on the butterfly's dirty little secret...

Ever had the desire to grab your camera and get up close to a pile of fresh dung? How about lying flat on a sand bank where animals urinate? While most photographers would rather snap wildlife from the comfort of their cars, for anyone with an interest in butterflies, smelly mud and stinky excretions often lead to the best shots…

Butterflies and moths regularly congregate around mud, dung and even blood, tears or decaying flesh! Little is known about this behaviour, but there are a couple of interesting observations that may help explain the icky phenomenon.

For starters, the majority of specimens found near mud are males and quite often, while the butterfly blokes are drinking from the mud, fluids are pumped out of their abdomens. The male Gluphisia septentrionis moth even goes so far as to shoot the fluids in forced anal jets ... charming. Butterflies also seem to be pretty selective about the spots where they settle down for a drink. So why don't females get in on the action? And what's with the abdomen secretions? These factors combined seem to indicate that the butterflies are probably not there simply to absorb water, but rather to look for something else.

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It is believed that butterflies congregate on mud and the other such substances primarily for salts.

In fact, it is believed that butterflies congregate on mud and other such substances primarily for salts. The salts and amino acids absorbed during mud-puddling play various roles in butterfly ecology, ethology and physiology. Males seem to benefit more from the sodium uptake as it aids in reproductive success, with the precious nutrients often transferred to the female during mating. This extra nutrition helps ensure that the eggs survive.

A slightly strange experiment can be performed to test the 'salt theory' (it's best performed when no one else is around). Firstly, find a sandy bank or a muddy patch situated in direct sunlight where there are plenty of butterflies. Next, pour a salt mixture over a wet, but butterfly-free, patch (in the less civilised version of this experiment you can replace salt with urine – butterflies are attracted to the sodium and ammonium ions). You can return to the spot later, when it is still warm outside, but before the moisture in the area has evaporated, and, if all goes well, you can photograph or observe the butterflies on your newly created “mud-puddling” spot.

Although this experiment can be very effective, it's sometimes necessary to place a dummy butterfly on the patch as well to coax others in the area to join in. This dummy can be anything from a roadkill butterfly found stuck to the grill of your car, to a fake paper specimen. Keep in mind that all butterflies do not go to mud, so your best bet is something that is either white, resembling a butterfly from the family Pieridae, or black like the underside of a swallowtail butterfly from the Papilionidae family.

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Not all butterflies species gather at mud puddles and it is a behaviour that is still not fully understood.

And just in case the photos aren't evidence enough, our film crews have captured footage of mud-puddling butterflies in Thailand: