Hungarian researchers found that zebras’ stripes do not help stay cool

According to borsonline.hu, several theories exist as to why zebras have stripes. Some believe that they help them with camouflage, others that they help them to deal with the heat. A Hungarian research team set out to discover the truth.

Existing theories about zebra stripes

The debate about the reason zebras have stripes has been going on for a long time. Charles Darwin and Alfred Wallace argued about this back in 1870, and at least 18 new theories have popped up since then. One of them was that the stripes create air currents that help the animals cool down. However, Hungarian researches invested four months of experimentation into this theory, and they succeeded in disproving it.

Hungarian experiment
Photo: nature.com/articles/s41598-018-27637-1

Researchers from the Hungarian University of Veterinary Medicine, from Eötvös Loránd University’s Faculty of Science and the Swedish Lund University, published their findings in the Scientific Reports, refuting the theories that have persisted over the years.

Gábor Horváth, the associate professor of the Faculty of Science at Eötvös Loránd University who is also the leader of the research said that

“One of the most well-known theories that we managed to refute is over seventy years old. This says that sunlight makes the black stripes warmer, creating ascending air currents, while the white ones are less affected by heat, creating descending air currents.

These result in small eddies in the air that cool the body. Those familiar with Physics thought this to be a viable explanation.”

Hungarian research

Gábor Horváth and his colleagues started working on the project last year. They received money for the research and made sure to get thermometers, automatic meteorological devices, black, white and grey horse skins as well as cattle and zebra skins. They also got some barrels, covered them with the skins, filled them up with water and thus began the experiment.

“We experimented in Göd, over a four-month period, with the measurements being recorded every 5 minutes.

It turns out that the white skin got the least warm while the black one got the hottest, but there was no difference between the grey and the striped skins”

– revealed the proud Gábor Horváth.

Zebra stripes protecting against horseflies

The research team has been fascinated by the stripes for years. A few years ago, their focus was on finding out whether the stripes serve as protection against horseflies, considering these insects tend to attack horses the most. They draw the blood of horses to help their eggs grow.

It turns out that they were right and, in 2016, their work was awarded an Ig Nobel Prize in the Physics Studies category, an award which is assigned to amusing but interesting research materials.

Their findings brought both practical and economic success, as zebra-striped horse blankets are now sold in several equestrian supplies shops, for a sum of 37 thousand HUF (113.25 EUR).

Further research

The associate professor revealed that they will not stop with the research now. “We have four years to research zebras, so we will continue the work. We will look at the temperature-relationship between them and horseflies.

Horseflies tend to go for the black animals. They see the different coloured animals with seemingly equally good blood, yet they opt for the black ones.

This is most probably due to heat-related reasons, but we do not know yet what exactly. And another thing we would be interested in is the origin of the possible eddies in the air.”

For more animal-related news, check out this article about Hungarian researches claiming dogs understand what we say!

Source: borsonline.hu