This book would be best for a beginning birder, or someone who enjoys nature. For those who have read other birding books (Weidensaul, Bernd Heinrich, Zickefoose, Marina Richie etc) this book may not offer much new content.
Most of the content here I am very familiar with as an experienced expert birder, but I still enjoyed the book. Although the writing wanders off on tangents a bit and is sometimes repetitive, Mr. Dunne tells about adaptations of birds for winter survival. He covers (briefly) feathers, other cold-defying behaviors such as roosting, camouflage, food strategy, etc. Most essays are brief and sometimes stray from the subject of winter. In the largest section, he covers selected species: Arctic Tern, Northern Wheatear, Bar-tailed Godwit (long-distance migrants), American Black Duck, Harlequin Duck, Rock Ptarmigan, American Goshawk, Rough-legged Hawk, Purple Sandpiper, Northern Gannet, Common Poorwill, Anna's Hummingbird, Virginia Rail, Downy Woodpecker, Brown Creeper, Winter Wren, American Dipper, Canada Jay, Golden-crowned Kinglet, Hermit Thrush, American Robin, Yellow-rumped Warbler, McKay's bunting, Red-winged Blackbird, Black-capped Chickadee (other chickadees covered in this section), Sparrows including white-crowned, juncos, American tree, towhees, and finally house sparrow (which is actually a weaver finch). This section often repeats the material he covered earlier in the book, and much of the material is of course covered in any book about bird behaviors.
An appendix classifies 671 species according to resident/migrant. A one page bibliography includes websites (allaboutbirds.org) and Peterson's 1934 field guide! An epilogue outlines his June 21, 2001 visit to Eclipse Sound, Qukiktaaluk north of Baffin Island as thousands of eiders and ducks waited for the late spring to thaw.