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Spot Check!

Why do giraffes have different spot patterns?

May/June 2019

By Jeanette Ferrara

Giraffes have a brown-and-white pattern that’s easy to recognize. But look closely and you’ll notice the spots are not exactly the same from giraffe to giraffe. Spots can be dark or pale, smooth-edged or jagged, large or small.

Each giraffe’s coat is unique—just like a human fingerprint, says Derek Lee. He’s a biologist at Penn State University who studies giraffes. Scientists like Lee use the animals’ distinctive patterns to identify individuals in the wild.

Back in 2011, Lee wanted to know why spot patterns varied among giraffes of the same species. He suspected that a giraffe’s spot pattern is an inherited trait. That’s a characteristic determined by DNA, material inside cells passed down from parents to offspring.

To figure out if he was correct, Lee needed to observe giraffe families in the wild. So he and his research partner, Monica Bond, traveled to a place that’s home to thousands of giraffes: the East African country of Tanzania.

Giraffes have a brown-and-white pattern. It’s easy to recognize. But look closely. You’ll notice the spots aren’t exactly the same from giraffe to giraffe. Spots can be dark or pale. They can be smooth-edged or jagged. They can be large or small.

Each giraffe’s coat is unique. It’s just like a human fingerprint, says Derek Lee. He’s a biologist who studies giraffes. He works at Penn State University. Scientists like Lee use the animals’ patterns to identify individuals in the wild.

Lee had a question about spot patterns back in 2011. He wanted to know why they differed among giraffes of the same species. He thought a giraffe’s spot pattern might be an inherited trait. That’s a feature produced by a creature’s DNA. It’s the material inside cells passed down from parents to their children.

Lee needed to observe giraffes in the wild to see if he was right. He teamed up with another researcher, Monica Bond. They traveled to Tanzania. It’s a country in East Africa. It’s home to thousands of giraffes.

Passing Down Patterns

Scientists studied 31 mother giraffes and their calves. Here are patterns from two of those pairs.

Think: What traits are similar between each mother and calf?

Passing Down Patterns

Scientists studied 31 mother giraffes and their calves. Here are patterns from two of those pairs.

Think: What traits are similar between each mother and calf?

Pictures of Patterns

Lee and Bond spent eight years observing wild giraffes. Every four months, the scientists would travel by car across northern Tanzania, taking photos of giraffes. “The main tools we used are the ‘three C’s,’” says Lee. “A car, a camera, and a computer.”

Animals inherit traits from both parents. Lee and Bond focused on 31 mother giraffes and their calves. (Giraffe fathers don’t raise calves, so they could not be studied.)

The scientists collected thousands of giraffe photos. They used a computer program to analyze each giraffe’s spot pattern. “We couldn’t have done our project without this special software,” says Lee.

Lee and Bond spent eight years studying wild giraffes. The scientists would travel by car every four months. They’d cross northern Tanzania. They’d take photos of giraffes. “The main tools we used are the three C’s,” says Lee. “A car, a camera, and a computer.”

Animals inherit traits from both parents. Lee and Bond focused on 31 mother giraffes and their calves. (Giraffe fathers don’t raise calves. So they could not be studied.)

The scientists collected thousands of giraffe photos. They used a computer program. It analyzed each giraffe’s spot pattern. “We couldn’t have done our project without this special software,” says Lee.

Fur in the Family

Lee and Bond compared the patterns of giraffe mothers to those of their calves. The spots had two traits in common: their roundness and the smoothness of their edges. Those similarities suggested that giraffes inherit spot patterns from their mothers. Lee’s hypothesis was correct!

Certain patterns also seem to help giraffes survive. During the study, calves with large, round, and asymmetrical spots were more likely to avoid predators and poachers. The scientists aren’t sure why.

Lee continues to study giraffes, which face many threats. “We need to learn more about these awesome creatures so we can save them,” he says.

Lee and Bond looked at the patterns of giraffe mothers. They compared them with those of their calves. They found the moms and their calves shared two traits in common. The traits were the spots’ roundness and the smoothness of their edges. That suggested that giraffes inherit spot patterns from their mothers. Lee’s hypothesis was correct!

Certain patterns also seem to help giraffes survive. Some calves have large, round, and uneven spots. They’re more likely to avoid hunters and animals trying to eat them. The scientists aren’t sure why.

Lee continues to study giraffes. They face many threats. “We need to learn more about these awesome creatures so we can save them,” he says.