New giraffe study: More species and more at risk than we thought

There are few living animals as iconic as the giraffe. Yet despite their fame, giraffes are not often the subjects of scientific research, and that means many mysteries still surround these towering mammals. Now, a new study has found that they're deserving of at least four times the attention they've been getting.

Giraffes are spread out across several countries in Africa, but they're classified as one species: Giraffa camelopardalis. Most scientists have generally agreed that the various populations scattered across the continent represent nine different subspecies. But when Julian Fennessy of the Giraffe Conservation Foundation and his team examined the genetics of these groups, they found a lot more variation than they expected.

There are nine recognised subspecies of giraffe, each with distinguishable coat markings. The new study, however, suggests the giraffe family tree looks a little different.

To analyse giraffe genes, the researchers took DNA from skin biopsies of nearly 200 giraffes from all nine subspecies, making this the most inclusive such study ever performed. Instead of nine closely related genetic groupings, the results revealed four very distinct groups, each as different from the next as a grizzly is from a polar bear. This degree of genetic distance reveals that these groups aren't doing much breeding with each other, so the scientists suggest they be considered four separate species.

"We were extremely surprised, because the morphological and coat pattern differences between giraffe are limited," said co-author Axel Janke in a press release. This sort of surprise is why genetic studies are so important: DNA often holds hidden secrets we can't see from the outside.

You might think it would be hard for giraffes to keep such big secrets from science – they seem pretty unlikely to slide under the radar, literally and figuratively! – and yet they've received little attention compared to other African mammals like elephants, rhinos or lions. And this is a shame, because these "forgotten giants", as Fennessy calls them, are in dire need of our help.

Giraffes browsing near the Ngorongoro Crater in Tanzania. Populations across Africa have fallen by 40% over the past two decades. Image: butforthesky.com, Flickr

According to the Giraffe Conservation Foundation, populations have fallen 40% over the past two decades, with fewer than 100,000 individuals remaining today. In fact, the animals have already disappeared from several African countries. "The world assumes they are everywhere," Fennessy told me in an email. "Relatively little education, awareness and conservation action has been focused on or around them to date."

The results of his study tell us that Africa may not be home to just one giraffe species with low numbers, but to four species, each with perilously small populations. "As an example," Fennessy said in the press release, "northern giraffe number less than 4,750 in wild, reticulated less than 8700, making them some of the most endangered large mammals in the world."

The science of categorising species is called taxonomy, and such studies are often the subject of scientific disagreement, but the researchers are quite certain of their findings. "The data are very solid, so I do not expect a hot debate," Janke said via email.

Instead, the scientists are hoping these results will spark conversations about how best to protect these four endangered species. "With now four distinct species, the conservation status of each of these can be better defined and in turn added to the IUCN Red List," said Fennessy. "Hopefully the study will create discussion – and importantly, help to support giraffe conservation."