Emeritus Professor Colin Townsend (72) retired to Wanaka to play his drums at birthday parties and make greenstone pendants for his friends.

He ended up rewriting a massive book, Ecology: From Individuals to Ecosystems, which he and co-authors Michael Begon and John Harper first published in 1986.

The fifth edition of the 884-page academic tome was recently released by the scientists’ UK publishers, Wiley Blackwell.

It features a cover illustration of people painting over rock art, a concept developed by the publisher’s artists after Prof Townsend saw a Banksy work showing art being waterblasted off a wall.

The London-born academic is a former head of Otago University’s Zoology Department and retired about seven years ago.

‘‘I wasn’t going to do it. I had retired to play drums in a rock band and do greenstone carving,’’ he said.

He described his 35-year labour of love over five editions of the book as ‘‘one of the greatest pleasures of my academic life’’.

‘‘After the third edition, a reviewer said we would need a wheelbarrow to get it around.’’

The fifth edition actually has 32 pages fewer than the first edition, but the page size has grown somewhat, making the word count similar.

Prof Townsend said the authors, all Royal Society Fellows who specialised in ecology, had tried to edit it down.

‘‘We added 1000 new references, so it never got any smaller,’’ he said.

The British scientists had not met until selected by the publisher to write the critically acclaimed book.

Prof Townsend moved to New Zealand to work at Otago University in 1989 and worked on rewrites in 1990, 1996 and 2006.

The book has been translated into several languages and has won the British Ecological Society’s Exceptional Lifetime Achievement Award.

Dr Harper died in 2009 and Profs Townsend and Begon had not planned a fifth edition.

‘‘But, rather to our own surprise [we] realised in 2015 that we were ready to embark on a fifth edition. It has been even more pleasure than the earlier editions for me, because having retired, I didn’t have to juggle departmental and professorial duties with my writing,’’ Prof Townsend said.

The book was aimed at thirdyear and postgraduate students. A simpler version, The Essentials of Ecology has been produced (in four editions) for first and second-year university students.

Rock art was a recurring front cover theme for all editions, ‘‘because from very early times people have had to be ecologists of a sort, to know about food and hunting . . . the idea is that Homo sapiens has been destroying ecosystems at a very fast rate,’’ he said.

‘‘But there is something else hardwired into us. A lot of people enjoy going into nature. . .a lot of change is happening. With the biodiversity crisis, a lot more effort is being put in [to stop destruction],’’ he said.

Prof Townsend said while the planet had big problems and it was important for scientists to communicate what they knew, ‘‘I am not a doom and gloom merchant myself’’.

‘‘It is essential to contribute to [social and political] debate but I am not going to tell other people how to live . . .though I agree, the polluter should pay from an economic and ecological argument.’’

Writing the fifth edition had been challenging and required new research.

‘‘Building it together is an art. Writing satisfies a different part of your brain, and even when you have finished there is probably a year where you have to go through the proofs . . .I must have read that book a hundred times. Imagine sitting down and reading that whole book,’’ he said.

Fortunately, members of the local branch of the Royal Society probably can imagine that.

‘‘Wanaka is just a big, busy branch. I am not sure there is any other like it in New Zealand. It is impressive to give talks to 200 people or more,’’ he said.

Now the book is done, all Prof Townsend wants to do is continue greenstone carving, which he took up about five years ago, and make more music with his Doubtful Sounz bandmates Graham Walmisley, John Parr and Bob Fellows.

‘‘I was in a rock band when I was 17 and joined this when I was 70, so there is sort of symmetry about it. I am the oldest. We have not done many gigs but we are not too bad.’’