Giraffe spots are weird. They seem to vary from animal to animal, with their true purpose being somewhat of a mystery. But now we might know how they get them.
According to a study led by Penn State University, published in the journal PeerJ, giraffes may inherit the pattern of their spots from their mother. And the pattern of the spots may be crucial to their survival from predators early in their life.
"Giraffe spot patterns are complex and can be quite different among individuals, but we don't really know their purpose in the wild," Dr Derek Lee, lead author on the paper, said in a statement.
"Complex markings can help animals evade predators, regulate their temperature, or recognize family or individuals, all of which can affect their ability to survive and reproduce.”
In their research, the scientists studied Masai giraffes, native to East Africa and the largest subspecies of giraffe. They looked at photos of spots on the giraffes, and also analyzed their survival records.
They found that newborn giraffes that had larger and more irregular spots were 7.5 percent more likely to survive in their first months, possibly due to being camouflaged better. Other factors like temperature regulation and communication could also have played a part.
Spots on a giraffe, which come in a variety of shapes and colors on top of their dark grey skin, do not change as they age. So the researchers could also identify different individuals based on their patterns.
In particular, they found that two traits of spot patterns seemed to be passed from mothers to calves. These were the circularity of the spots, how close they were to forming a perfect circle, and how smooth their edges were – known as solidity.
The previous best look at giraffe spots dated back 49 years ago to 1968, when an expert called Dr Anne Innis Dagg also found evidence that some spot traits were hereditary. Her research was done with a small zoo population though, notes National Geographic, and not a wild population like Dr Lee’s study.
It should be noted, though, that the sample size for hereditary spots in Dr Lee’s study was fairly small. They looked at 31 mother-calf pairs from 2012 to 2016, using imaging software to analyze their patterns. They used a larger sample of 258 calves when studying survival rates.
Still, it looks like we’re getting closer to answering the bigger questions of why giraffes have spots, and how they get them.
“There are likely many reasons for why giraffes have spots,” Dr Lee told Quartz. “This is how science works, by building up evidence over time. It just took us a long time to catch up to Dr Dagg’s thinking.”