Mr Whitehead, who lives in Hampden, will celebrate the century with a party at the local bowling club.
"A small boy’s dream," Mr Whitehead says of his life.
He also survived two plane crashes during active service in World War 2 and an encounter with man-eating lions in Africa.
For his birthday, Mr Whitehead’s only daughter, Anne Harrison, of Moeraki, is throwing him a "wee party" that will be attended by about 30 people.
Mr Whitehead settled in New Zealand, in the coastal village of Hampden, about seven years ago to be closer to his daughter.
He was not sure he knew the secret to a long life.
"I had nothing to do with it.
"I just get up and keep going," he said.
He was born in Shanghai, China, in 1923, to British parents.
He does not remember much about his early childhood "except for falling in a septic tank and going to school and swimming in pools ... and living a very comfortable life".
When he was only 14, he made his way to Australia, determined to become a stockman.
His love of horses and wildlife had him living in Australia before and after the war, first as a stockman and then breaking in and training horses in northwest New South Wales.
Those equine skills proved invaluable when, in the first two years of the war, he was part of a manpower group that broke in 7000 horses for the Australian Army.
"The genes for horses was passed down," he said, referring to his grandfather who was a horse trader in Scotland.
With a "desire" to go to Africa, he started his travels in Nigeria and went down to Northern Rhodesia (now Zambia), Tanganyika (now Tanzania), on to Kenya and then to Mozambique and Ethiopia.
Hunting, wildlife and farming were his passions.
After the first flush of excitement hunting lions in Africa, Mr Whitehead realised he had found another passion.
"I didn’t get enthusiastic about the hunting of them, as I was for the conservation of them," Mr Whitehead said.
Being a game ranger was a "fantastic life", but one suited to a single person.
In 1961, Mr Whitehead married Lorna Swynnerton.
Their daughter was born in Kenya and the couple were married for 41 years.
Mrs Whitehead died 21 years ago.
Mr Whitehead’s involvement on the film set of Born Free was serendipitous.
In 1964, he was in Nairobi, Kenya, when his appendix burst.
"It was very unpleasant" and he went to recover at his brother-in-law’s farm.
The British drama film was being filmed nearby, and he was hired to take care of the animals on set.
Settled in his Hampden bach, where he lives alone with his blue cattle dog, Mr Whitehead described with pride his grandchildren following in his footsteps, into wildlife conservation.
His grandson is a marine biologist who works as a protection officer in Denham, Western Australia, while his granddaughter is completing her doctorate in marine biology.
