Not so long ago, there was a fun party at Zoo Atlanta: their gorilla Anaka celebrated her 6th birthday. To commemorate the joyous occasion, the employees at the facility snapped a couple of pics of the big girl and shared them on Facebook. People started sending their best wishes. However, while congratulating Anaka, those who were more observant noticed an interesting detail.

The gorilla has a unique patch of pigment on her hand. In the close-up picture of the pink patch, it even looks remarkably human-like. Which is understandable, considering that gorillas have opposable thumbs. Interestingly, like all primates, they also have individualized fingerprints and toeprints, which sometimes may be used for identification purposes. Unlike most animals we’re used to seeing, primates have fingernails and toenails rather than claws. They are used for opening and scraping things, cleaning, and scratching.

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Image credits: Zoo Atlanta

According to the zoo, not only is Anaka’s skin unique, but her personality is as well. “[She’s] often barking at her mom and others to get a prime spot for food and juice,” they wrote on their website. “She is often seen riding piggyback on her brother and sisters.”

Image credits: Zoo Atlanta

Image credits: Zoo Atlanta

Some people were thinking Anaka has vitiligo, a long-term skin condition characterized by patches of the skin losing their pigment. But Morena Lale commented that she wrote to the zoo about it and they didn’t confirm it, “I asked this question … and this is their reply: ‘Well, her skin pigment has always been like that and hasn’t changed over the years, so we think it’s just a cool birthmark.'” To learn more about Anaka’s distinctive feature, Bored Panda has reached out to Zoo Atlanta as well.

Image credits: Zoo Atlanta

Image credits: Zoo Atlanta

Image credits: Zoo Atlanta

Image credits: Zoo Atlanta

Image credits: Zoo Atlanta

Here’s what people said about Anaka and her unique feature