For Farley Mowat, writing is like breathing.

The 87-year-old icon of Canadian literature has been going strong for 50 years, writing dozens of books, both fiction and non-fiction, and articles, as well as living a life of activism and advocacy for the natural world.

But though Mowat tells CTV.ca he will keep writing "as long as I can continue to hit the keys on my typewriter," he says his new memoir "Otherwise" will likely be his last published work.

"Writing is my function -- it's the only function I've got that really works and has worked for the last 50 years," Mowat says.

"I would be a fool to give it up, so I will continue to write, but whether I publish or not, it remains very much in the air. I am not anxious at all to publish any more books.

"Otherwise" deals with the years of Mowat's life between 1937 and 1948. The book, based largely on the meticulous journals Mowat has kept through much of his life, is part of an "autobiographical experiment" to retrace those formative years that helped determine the path his life would take.

"I've gone back and relived my life through my journals mostly, and what memories are still available to me in my antiquated state, in an attempt to discover who and what I was and why I lived the life I have," Mowat says.

Much of the book focuses on the period after he returned from war in Europe and was attempting to re-establish his footing in the world.

"And this I was helped to achieve by the animals I was encountering," Mowat says. "I went to the Arctic and I was meeting wolves and caribou and all sorts of other animals and they helped me find myself -- re-establish a feeling of worthiness of existence, and that's really what the book is all about."

The beginning of a lifelong obsession

"Otherwise" is a fascinating read, providing insight into the influences and experiences that galvanized Mowat's obsession with animals and other inhabitants of the untainted natural world -- what he terms "The Others."

That obsession begins with an expedition to the Canadian Arctic to collect bird's eggs with his larger-than-life great-uncle Frank Mowat -- an experience that seemed to point him on his chosen path.

It also includes hilarious anecdotes, such as the time he became, as he describes it, the first person to be "treed" by a loon.

The book also provides background and context to Mowat's books "Never Cry Wolf," "People of the Deer" and "The Desperate People", which focused on his study of life in Canada's Arctic and advocacy for the wolf population and the Inuit people.

If the book, which Mowat says in the introduction "may well be my last hurrah," is in fact his final published work, it will cap a long and successful career that has been highlighted by a Governor General's Award, the Order of Canada and numerous literary prizes.

Conservation activism

But Mowat's proudest achievement has little to do with his books.

At the top of the list, he said, is the fact that the Sea Shepherd Conservation Society has named their ship -- one which intervenes to protect seals and whales from illegal hunting -- after him.

Mowat has even bailed the crew out of jail when their action's caused friction with maritime law enforcement.

"She single-handedly, with her crew of volunteers, engages the whole of the commercial whaling fleet of the world and has done for 20 years," Mowat says.

"She engages those who are trying to exploit the seal populations and she fights for the survival of life in the seas, and to have my name on the bow and stern is one of, if not the greatest, compliment ever paid to me."

Mowat and his wife Claire spend their winters in Port Hope, Ont. and their summers in River Bourgeois, N.S.