Interview: Zoe Saldana, actress

Last year, she appears to have propped up the American film industry with the $3 billion success of Avatar, and the enthusiastic business generated by her Kirk-resistant Uhura in the rebooted Star Trek.

Starring as the blue warrior princess in the most profitable movie of all time has brought her fame, though unfortunately not a share of the gross. "If it had," she quips, "I'd have my own studio. But I can afford to pay the bills for the next two or three years."

Despite the success, Saldana still feels she may have something to prove. Avatar was a showcase for director James Cameron's swaggering 3D visuals, with the actors coming a distant second.

Although the film was nominated for best picture and best director, the performers were excluded from consideration in the relevant categories on the grounds that their work was digitally manipulated. "We worked just as hard as other actors", she points out. "But some people didn't see it."

The preparations were certainly authentic. Avatar dominated her life for the best part of two years, including a six-month training regime and a camp-out with Cameron, Sam Worthington and Sigourney Weaver in the Hawaiian rainforest where the director instructed them to build fires and go barefoot.

A few steps into her jungle adventure, she trod on something unfamiliar and realised she was standing on the half-eaten corpse of a rat. "I screamed," admits Saldana. "It had no head! And Jim just cried laughing."

No longer 10 feet tall nor bright blue, Saldana now seems to be in everything these days.

Earlier this summer she saved The Losers from becoming a muscle-flexing Esquire love-in by striding across the screen firing off bullets or applying a well-shod foot to an evil forehead.

She even manages to bring toughness to her slinky decorative role in the upcoming Takers, by trading up in movie terms from a boyfriend who casually showers her with unprintable epithets to one who lavishes her with diamonds. In between times she popped up as an imperious mourner in the farce Death At A Funeral (and can volunteer an uncanny impersonation of co-star Chris Rock).

Strength of character is something that has preoccupied Saldana, who has been offered her share of damsels in distress.

"Hollywood has made a living out of portraying women as needing to be rescued all the time because we're so incompetent," she sniffs, and it seems unlikely we'll see her clucking helplessly under Gerard Butler's gaze any time soon. "I'd rather quit this business than constantly play the girlfriend of the action hero," she says. "Because in reality, if Spider-Man was always coming to my rescue, I'd get to the point of saying, 'Come on, man, I can do it myself!'"

Even her latest job as the face - and body - of Envy, a new Calvin Klein range of underwear, combines sultriness with assertiveness after Saldana took a hand in scripting the commercials.

"I can be tough," Saldana purrs in her black bra and knickers. "I learned to ride a dirtbike when I was nine, and I can be deadly with a bow and arrow. Don't mess with me."

All true, according to the 32-year-old. James Cameron insisted she learn to shoot her Avatar bow left-handed, like him, and she still hit the targets. The dirtbike lessons in the Dominican Republic: Saldana, her mother and sister moved there from New York after her father died in a traffic accident.

"Women were the caretakers and the soldiers," she says. "Our way of thinking was very masculine." It was also unafraid to buck tradition: Saldana and her family used to celebrate Christmas in March because her mother reasoned that December wasn't the true birth month of Jesus. It was also Mrs Saldana who pushed her daughter towards acting when she announced she didn't want to go to university.

"My mother said, 'Well, you'd better do something,'" Saldana recalls. "So I said, 'OK, I'll try acting." At 17 she returned to the US and made her first film appearance as a stroppy diva in 2000's Center Stage, and went on to bust Johnny Depp's cannonballs as a swashbucklerette in the first Pirates of the Caribbean. More often than not, she opts for roles that make her a rare female face in rather blokey adventures. "I like being around men," she agrees. "I figure I can hold my own."

More accessible than Angelina Jolie, tougher than Julia Roberts and smarter than Katherine Heigl, Saldana's choices have contributed to her being named Face of the Future at the recent Women In Film awards. In the rather cheesy context of film award acceptances, there appeared to be nothing exceptional about her little speech except that she left her boyfriend of ten years Keith Britton red-faced by paying tribute to a relationship she usually refuses to discuss.

"I have to thank that one special person who always gets buried and overlooked," she told her audience. "I tend to confuse privacy with not saying thank you - and he has to pick me up and put me to bed. Try doing that for ten years with somebody who has, like, five personalities."

Saldana and Britton have since added fiance to the list of personas, by announcing their engagement.

Meanwhile, there are another couple of engagements in the offing. The next Star Trek starts shooting in 2011, and at some future point she also anticipates a return to Pandora.

"That could take ten years," she laughs "But when it does, I know the second Avatar will be as great as the first one. I'll just need some advance warning because it takes about six months to get into that character. You just can't show up and shout, 'Hey, I'm here'."

Takers is released 1 October

This article was first published in Scotland On Sunday on Sunday, 5 September, 2010