What's the deal with Kenya's rare polka-dot zebra?

Stripes may still be a hot look in 2019, but one plains zebra in Kenya's Maasai Mara National Reserve dared to be different. A foal, sporting a unique brown coat accented with a smattering of white polka dots, was recently spotted by Maasai guide Antony Tira.

Word of the spotty zebra – given the name "Tira" by the guide who first found him – quickly got around and photographers and tourists in the area rushed to catch a glimpse of the unusual animal. “At first glance he looked like a different species altogether," photographer Frank Liu told National Geographic. While Tira may look like he's been crossed with an okapi, he actually owes his unique colouration to a rare genetic condition called pseudomelanism.

Skin and hair colour in mammals comes from a pigment protein called melanin which is produced by specialised cells called melanocytes. In humans, melanin acts as a natural sunscreen, darkening the skin to help protect it from harmful UV rays."There are a variety of mutations that can disturb the process of melanin synthesis, and in all of those disorders, the melanocytes are believed to be normally distributed, but the melanin they make is abnormal,” Greg Barsh, a geneticist at the HudsonAlpha Institute for Biotechnology, explained to National Geographic.

Under their striped coats, zebras have uniformly black skin as a result of melanocytes being evenly distributed across their bodies. According to Barsh, pseudomelanistic zebras like Tira have all of their melanocytes in place, but the melanin produced does not result in stripes, for unexplained reasons.

Zebras with unusual colour patterns are rare, but not unheard of. In 2014, a black zebra was photographed in Botswana's Okavango Delta, while a 'blonde' individual showed up in the Serengeti earlier this year. Unusual colouration is likely to put the animals at greater risk of falling victim to predators, according to University of California biologist Dr Tim Caro. "Some predators choose members of herds that stand out because it may signal that they are not so good at fleeing," he explained to us via email.

This does not necessarily mean that stripes are effective at deterring predators, he adds. In fact, Caro's research indicates that zebra stripes could have evolved to aid in repelling disease-carrying flies. Field experiments show that horse flies are less likely to land on striped surfaces, which puts darker animals like Tira at increased risk of contracting trypanosomiasis, African horse sickness and equine influenza, all of which are spread by biting flies.

Although Tira's sensational polka dots make him stand out in the herd, it's unlikely that his strange colouring will result in rejection from other zebras. Field studies in South Africa found two cases of zebras with atypical colouring that were able to form normal relationships with other herd members. Provided Tira can make it to adulthood, he should be able to fit right in.