A perfect blend of science and poetry.
Going by the alternative name (why do they do that?) A Year on the Wing: Four Seasons in a Life with Birds in the USA, Tim Dee's The Running Sky is set to become a classic. Although each chapter covers a different month in the birdwatching year, this is not an account of one year's birdwatching. Instead, Dee reminisces about encounters with birds over 40 years that he associates with the month in question.
The writing is pretty amazing: almost poetic in place. As Dee himself states:
Science makes discoveries when it admits to not knowing, poetry endures if it looks hard at real things. Nature writing, if such a thing exists, lives in this territory where science and poetry meet. It must be made of both; it needs truth and beauty.
Dee clearly demonstrates that Nature writing does indeed exist. He has written a very truthful and beautiful book.