Which animal's stripes are unique to the individual, like a fingerprint?

Both zebras and tigers carry patterns no two individuals share, and researchers use them the way police use fingerprints - photographing flanks and matching them by software to track populations without tagging anything.

A tiger's stripes are in its skin as well as its coat, so a shaved tiger is still striped. A zebra's are the opposite of the popular framing: the animal is black with white stripes, since the underlying skin is dark and the white is where pigment is switched off.

Why zebras have them at all was argued over for a century. Camouflage and predator confusion were the favoured answers, and the evidence for them turned out to be weak. The current best-supported explanation is flies: horseflies fail to land properly on striped surfaces, aborting their approach at the last moment, and experiments putting striped coats on plain horses reproduced the effect. Africa's biting flies carry diseases fatal to horses, and zebras are unusually vulnerable, having thin coats. The most famous pattern in nature may be insect repellent.