HEARTS were aflutter at the Australian Butterfly Sanctuary on the weekend after they had a surprise visit from a famous wildlife warrior.

Bindi Irwin popped in to check out the colourful butterflies at the Kuranda tourist attraction on Sunday, en route to Cape York.

Sanctuary staff remarked how friendly and relaxed the young TV star appeared.

Irwin, the 19-year-old daughter of Steve "The Crocodile Hunter" Irwin, was heading to the Wenlock River with her family for the annual Australia Zoo-sponsored crocodile research trip, 80km northwest of Weipa.

The family is joined each August at the Steve Irwin Wildlife Reserve on the Wenlock River by a team of scientists, conservationists, media and other guests to conduct research on crocs.

Previous trips to the Cape reserve had helped unlock secrets about crocs, including that they can spend seven hours underwater.

Last year, Bindi took her boyfriend, US wakeboard Chandler Powell, to the Steve Irwin Wildlife Reserve, where the young couple were photographed wrestling crocodiles together, in the name of science.