Bushwise Field Guides

Zebras are quite unique in their appearance, especially taking into consideration that they are related to horses that show no such elaborate and strange colouration.

There are currently 3 recognised species of Zebra:

  1. Plains zebra – Equus quagga,
  2. Mountain zebra- Equus zebra and
  3. Grevy’s zebra- Equus grevyi .

They all have the black and white striped patterns but the patterns are different in each species.

Photo by Gina Ferguson

 

The question often asked is why do they have this strange colouration.

There are a few popular hypotheses:

The stripes are there to:

  • dazzle predators and make it more difficult to single out an individual,
  • deter biting flies like tsetse flies,
  • create micro air currents to help cool down the animal,
  • help the zebras to recognise each other.

Photo by Ellie Schwartz

 

These are all just theories that try to explain the reason why they have these stripes but none is scientifically proven. The most popular hypothesis is that the stripes make it difficult for predators to single out an individual but a recent scientific study in 2016 showed that this is in fact not true at all. The stripes may only have such a dazzling effect if the predator is less than 9 meters away from its quarry and by that time the predator can already hear and smell its prey.

There are also a few counter arguments about the theory of biting flies. Tsetse flies do not occur in many areas where zebras do occur so it asks the question of why Zebras need the stripes? The study that was done to make the claims about the biting flies was apparently not done on Zebras but on painted surfaces making any findings not really scientific. Another counter argument is that there are many other animals that occur in areas where biting insects are present so why do more animals not have these stripes?

Photo by Gina Ferguson

 

The idea of the stripes causing a cooling effect is also questioned as such micro air currents will become inefficient when there are natural breezes and when the zebras are on the move. Another question is that there are many animals that live in such hot climates and still none of them display this pattern to help them maintain their homeostasis.

If they use these patterns to identify each other is also possible but horses and donkeys get along very well without any stripes.

 

It is clear that humans do not really know the answer to why Zebras have these strange patterns.  Maybe we must look  for the answers somewhere else or maybe there is someone who speaks Zebra that can just go and ask them this question.

Bushwise field guide students can also try and figure the answers out for themselves while on course. We see plains zebras here on many an occasion.

Sources:

Blog by Gerhard van Niekerk