The young orangutan reaches his hand through the cage and rubs his knuckles over an iPad, drawing wide colors across the screen with his favorite app.

A few minutes later, Mahal presses his face up against the mesh, stretches out his long tongue and taps the screen to make it light up and play his favorite song, 'Twinkle, Twinkle Little Star'.

Soon Mahal and the two other orangutans at the Milwaukee, Wisconsin county zoo will be able to use their iPad for something even more exciting: "play dates" with orangutans at other zoos and wildlife preserves.

They're already fascinated by videos of orangutans they've watched on the tablet. Their keepers are hoping a live video feed will be even more engaging.

"We're excited to see where that goes," said Trish Kahn, the zoo's primate coordinator.

"It could be they don't care at all, but, from what I understand of them, I think they're definitely going to be able to understand this is real time and they're looking at another orangutan."

Nearly a year after the zoo introduced iPads as a form of enrichment, the primate building is being rewired for wifi so the orangutans can have their play dates and the public can watch them on a webcam.

Several other zoos have also introduced tablets to primates with the help of the non-profit Orangutan Outreach, which launched the 'Apps for Apes' campaign after seeing how much the Milwaukee orangutans enjoyed playing with the iPads.

The goal is twofold: to bring a powerful new enrichment activity to the orangutans and to get zoo visitors engaged in the fight to protect an endangered species.

"It's really important for the public to connect with these animals because we're losing them in the wild -- they're facing extinction," Kahn said.

"For me the most important thing is for people to recognize these are sentient beings that are so incredible, that have all these wonderful adaptations and a profound brain."

So in addition to the playtime in their private feeding area, the zoo also offers iPad enrichment in the public viewing area, where volunteer Scott Engel shows them videos through the thick glass.

'They can brighten your day'

Crowds of people are drawn to Engel and pepper him with questions about the orangutans and the iPad.

They laugh when he tells them that Mahal likes to watch penguin videos while his adoptive mother MJ hankers for BBC nature shows by David Attenborough.

They lean in to take pictures when MJ taps on the glass to get Engel to start the next video.

And they listen when he tells them how orangutans are losing their natural habits as rainforests in Indonesia are burned to make way for palm oil plantations.

Engel, a freelance photographer who has been visiting the zoo to hone his craft for years, got the program going as a bit of a lark after a doctored photo of a gorilla playing with an iPad made the rounds online.

He made contact with the Milwaukee zoo's gorilla keeper over Facebook and offered to donate his old iPad after he upgraded to the iPad 3.

Now, he's coming to the zoo several times a week to show the orangutans videos -- many of which he shoots himself.

"It's just amazing to make a connection with an animal," Engel said. "They can brighten your day."

Mahal will raise his hands and clap when he sees Engel and likes to play peek-a-boo by bending under the window frame.

MJ taps her forehead to get Engel to show her the top of his head, or points to her eyes to get him to wipe his face for her.

The most special moments, Engel said, come when the zoo's introverted and somewhat anxious 30-year-old male orangutan comes out of his corner to say hello.

Tommy used to spend most of his days out of sight or with his back to the window.

But he's excited about the iPad, and having Engel stand outside his window seems to have made Tommy more interested in watching other people as they lean in to get a look at his long orange fur and flat black face.

"To see him out and about and engaging and not hiding in his corner is wonderful to us," Kahn said. "He's incredible, and we want people to see him."