One of our favorite nature study writers has not one! - but two books on sale right now, in Kindle format. I don't know how long this price will last, but at only 99c a piece, they are well worth their price.
Beautiful books visually, and superbly written! Just had to let you know :)
(A third book by the same author, A Seed is Sleepy, is also on sale right now, for $4.99. Yes, I *had* to purchase all three!)