Terri Irwin comments on Robert Irwin's career: 'Steve never took his shirt off for wildlife'

Terri Irwin has commented on her son Robert's career and how it differs from his father's.

The mother and son attended the Steve Irwin Gala in Las Vegas on May 2, where they reflected on what it's been like to carry Steve Irwin's legacy on as a family.

"Everything started so small," Terri, 61, recalled of the beginning of Australia Zoo. "It was two acres, it was a few animals, and it was no filming. And so to see where we've gone, and to have Steve embrace that, was so impressive."

She told how, after Steve died in 2006 after being stung by a stingray barb, "It was a lot of work, it was a lot of grief. There were times of great joy. And to be able to have shared that with him was incredibly special - and carry it on."

She added, jokingly, "But I will say the one thing that Robert's got that Steve didn't - Steve never took his shirt off for wildlife."

Robert, 22, responded by insisting he's simply been doing "whatever gets the job done." He told how his late dad will always serve as his "greatest inspiration."

"He would really exemplify what it is to give everything 100 per cent," Robert said. "And that's what I take into everything I do. You know, if you have a passion, you really owe it to yourself to give it everything."