A large wildlife book, start to finish, could take one to two years, but then I would expect to get several good (nature) magazine features off the back of this, plus of course a lot of stock.
“Foolish men imagine that because judgment for an evil thing is delayed, there is no justice; but only accident here below. Judgment for an evil thing is many times delayed some day or two, some century or two, but it is sure as life, it is sure as death.”
“Short-story writing requires an exquisite sense of balance. Novelists, frankly, can get away with more. A novel can have a dull spot or two, because the reader has made a different commitment.”