Why do tigers have stripes?

Stripes as disruptive camouflage

A tiger hunts by stalking to within a short distance of its prey and then rushing it, so the most important thing is not to be noticed first. Camouflage that breaks up an animal's outline is called disruptive colouration. In vegetation full of vertical stems and long shadows, bold vertical stripes make it harder to pick out the shape of a tiger's body against the background, especially in the low light of dawn and dusk when tigers are often active.

Tigers are the only cats with stripes. Other big cats achieve a similar effect with spots and rosettes, which suit the dappled light of woodland and forest.

Why is a tiger orange, not green?

To a human eye, a bright orange animal seems like poor camouflage in a green forest. The answer lies in who is looking. Humans are trichromats, with three types of colour sensitive cone cell. Most mammals, including deer, are dichromats, and they cannot reliably tell orange and green apart.

A 2019 study by Fennell and colleagues at the University of Bristol, published in the Journal of the Royal Society Interface, modelled how detectable different colours are to human like and dichromat observers in natural scenes. Their simulations showed that, viewed by a dichromat, a tiger's colour is very effective camouflage. They point out that deer are dichromats, so to them most predators like tigers appear green, and there is little evolutionary pressure for tigers to actually become green. They also note that making a green coat would require a major change to mammal biochemistry, since mammal fur colours come from just two pigment types, eumelanin (black and brown) and phaeomelanin (yellow to red).

Is every tiger's stripe pattern unique?

Yes. According to the IUCN Cat Specialist Group, stripe patterns vary between individuals in the number, width and shape of stripes, and whether they split or break into spots. The pattern on a tiger's left side is also different from its right side. This is enormously useful for conservation: scientists set camera traps in pairs on opposite sides of a trail so they photograph both flanks, then identify individual tigers from their stripes. Repeated detections of known animals let them estimate population size using capture recapture statistics, which underpins many national tiger surveys.

Are tigers striped under the fur?

The stripe pattern is set in the skin where the hairs grow, so shaved tiger skin shows the pattern as darker and lighter areas. The stripes are not painted on the fur alone.

What about white tigers?

White tigers still have stripes, which are ash grey to brown rather than black, on a white coat, usually with blue eyes. They are a rare colour variant, not a separate species or subspecies. The IUCN Cat Specialist Group notes that the last documented white tiger in the wild was shot in Bihar, India, in 1958. A white coat would make camouflage harder in most tiger habitats, which may help explain why the variant is so rare in the wild.

Do stripes do anything else?

Camouflage is the main accepted function. Other markings may carry signals at close range; for example, tigers have a conspicuous white spot on the back of each ear, which researchers have suggested may help communication, such as cubs following their mother, but this is a hypothesis rather than an established fact. How exactly the stripe pattern forms during development in tigers is still being studied.

Key takeaways

• Stripes break up the tiger's outline in grass and forest, helping it ambush prey.
• Orange looks similar to green to deer and other dichromatic mammals.
• Each tiger's stripes are unique, and left and right sides differ.
• Scientists count wild tigers by photographing stripe patterns with camera traps.

More in our tiger facts guide.