'She was in awe:' 28-year-old chimp freed from cage sees blue sky for the first time in viral video

In a moment caught on-camera warming the hearts of thousands around the globe, a look of awe visibly crosses the face of Vanilla, a 28-year-old chimpanzee, after catching a glimpse of open sky for the first time after a life she had previously spent caged.

Vanilla, along with four other chimps named Shake, Magic, Jeff, and Ernesta arrived last year at Save the Chimps, one of the world's largest chimpanzee sanctuaries located in Fort Pierce, FL.

In a move to integrate the new arrivals into a larger chimpanzee family roaming freely on the sanctuary's 3-acre island, the moment the chimps saw blue sky for the first time was captured on camera by staffers, and quickly went viral.

Shake appeared to show no sign of hesitation, while Vanilla was more apprehensive when the door opened to a world she had never experienced before. She sat in the doorway until Dwight, the alpha male, encouraged her to join him.

"She leaped into his arms, and he engulfed her in a big hug — a special moment caught on camera. As she gained the courage to go farther, she was in awe, gazing up at the open and vast sky above her for the first time in her life," the organization shared in a press release.

In an update following the release, the organization says both Vanilla and Shake have been regulars on the island, soaking up sunshine and exploring the outdoor space.

Is it harmful keeping chimpanzees in captivity?

Reasearch has shown that many chimpanzees housed in enclosures or zoos exhibit abnormal behaviour observers liken to mental illness, a PLoS One study conducted during 2011 reveals.

The authors documented behaviours that included self-mutilation, repetitive rocking and consumption of feces — behaviours they say is not commonly found among wild chimpanzees.

"Absolutely abnormal behavior and possible mental health issues are most commonly associated with lab chimps," co-author Nicholas Newton-Fisher told Discovery News. "This is one of the reasons we were surprised to see the levels of abnormal behavior that we did — in chimpanzees living in good zoos."

The study documented the behaviours of 40 chimpanzees at six zoos across the U.S. and the U.K. covering a two-year period combining a total of thousands of hours of research.

"We conclude that the chimpanzee mind might have difficulties dealing with captivity," Newton-Fisher, who is a primate behavioral ecologist at the University of Kent's School of Anthropology & Conservation added.

"Efforts to improve captive welfare in apes have focused upon the need for social companions, adequate cage space, fresh fruits and vegetables, variety in the diet, and some type of enrichment."

Viral video warms viewers' hearts

It is safe to say gauging social reaction many hearts were warmed at Vanilla's pure look of awe at her first glimpse of blue sky.

Many of the users in the comment section reported the video brought them to tears.

Others pointed out just how evident her emotions in those moments were — raw and unfiltered.