Zebra Stripes: Not Just for Camouflage?
The Mystery of Zebra Stripes
For centuries, scientists have debated the purpose of zebra stripes. Some have argued that they provide camouflage, while others have suggested they serve a social or thermoregulatory function.
Camouflage or Not?
The traditional view has been that zebra stripes help the animals hide from predators. However, a recent study published in the journal PLOS One challenges this theory.
Researchers used digital images of zebras in Tanzania to simulate how the animals would appear to different predators, such as lions, hyenas, and other zebras. They found that while humans could spot zebras at distances of up to 50 meters during the day and 30 meters at twilight, predators could not see them as far away.
In well-lit conditions, humans could spot zebra stripes at distances 2.6 times greater than zebras, 4.5 times greater than lions, and 7.5 times longer than hyenas. This suggests that at least at far distances, the stripes do not act as effective camouflage.
The researchers also found that predators could see the zebras’ outlines just as well as other prey at close distances. Zebras were also bad at seeing one another at wide distances, suggesting that there is no real social advantage to stripes.
Alternative Theories
If zebra stripes are not primarily for camouflage, what other purposes might they serve? Several alternative theories have been proposed:
- Tree Trunk Mimicry: Some scientists have suggested that zebra stripes mimic tree trunks, confusing predators in wooded areas.
- Background Blending: Others have proposed that the stripes help zebras blend in with their surroundings, making them less conspicuous to predators.
- Biting Fly Deterrence: Another theory is that zebra stripes deter biting flies. However, a recent study published in Royal Society Open Science found no evidence to support this theory.
Multifactorial Origins
The researchers behind the PLOS One study suggest that the selective agents driving zebra striping are likely “multifarious and complex.” In other words, zebra stripes may have evolved for a combination of reasons, including camouflage, social signaling, and thermoregulation.
Conclusion
The debate about the purpose of zebra stripes is far from over. However, the latest research suggests that the traditional view of stripes as camouflage may not be entirely accurate. Further research is needed to fully understand the evolutionary origins and functions of this iconic animal pattern.
