Sir David Attenborough has undergone surgery to insert a pacemaker. The 87-year-old broadcaster was forced to cancel a sell-out speaking tour of Australia because of the urgent procedure

A spokesman for the naturalist said doctors believed he was doing well. He said: "Sir David has now had the operation and his doctors are satisfied with his progress."

Before the operation he said the naturalist behind landmark television series such as Life on Earth, The Blue Planet and The Life of Birds was still his "lively self".

"It's a minor procedure but it meant that he cannot go on a 27-hour flight to Australia," he said.

"He's very disappointed that he can't fulfil the tour but it's nothing to be alarmed about."

BBC director of television Danny Cohen sent a message of support, saying: "We all wish Sir David a full and strong recovery."

Attenborough, whose programmes have also included Planet Earth and Frozen Planet, recently narrated and presented the hit BBC1 series Africa.

He is also presenting a new BBC Radio 4 series, Tweet Of The Day, devoted to birdsong.

The wildlife star said recently that he had no intention of doing less, saying: "I've been broadcasting for 60 years. I don't want to slow down. Retirement would be so boring."

Asked about his plans earlier this year, he said: "I'm going to China to see some very interesting fossils. In 2012, I went to the Galapagos, to Africa, north America and Australia.

"I've no idea how many days I was away."