American Birding Podcast



What Lies Beneath?

A review by Donna Schulman

The Unfeathered Bird by Katrina van Grouw

Princeton University Press, 2013

304 pages, $49.95—hardcover

ABA Sales / Buteo Books 13698


Remember those crinkly transparent overlays in the anatomy articles of your childhood encyclopedia? The blood vessels, then the muscles, then the organs. Or maybe it was the other way around. Eventually came the bones, and that was the best part, because bones were supposed to be scary—but those diagrams were strangely beautiful.

I felt the same combination of wonder and mystery when I examined the illustrations in The Unfeathered Bird, a unique book on anatomy and art and birds. As an art student in Great Britain twenty-five years ago, Katrina van Grouw conceived the mission of creating a volume that would combine the authority of an ornithological text with the visual beauty of nineteenth-century scientific illustration. The result is a large and  elegant book, well designed and well produced, printed on thick cream-colored paper and composed in typefaces that echo those of pre-industrial times. At the heart of The Unfeathered Bird are the book’s more than 300 drawings: They are simply beautiful, in spite of the  fact—because of the fact—that they depict bones and muscles.

The book is divided into two parts. The first, “Generic,” presents the blueprint for avian flight. Here we learn the basics of bird anatomy, especially the adaptations—a rigid trunk, a lightweight skeleton, and a flexible neck—that enable a bird to fly. The second, much longer part, “Specific,” comprises forty-one chapters devoted to taxonomic groups, mostly orders and families, and focuses on the anatomical variations, some familiar, some bizarre, that have evolved over the ages.

Buy It Now!These “specific” chapters are grouped into six sections, corresponding to the Linnaean orders Accipitres, Picae, Anseres, Grallae, Gallinae, and Passeres. Van Grouw’s use of an eighteenth-century taxonomy “concerned only with outward structural appearances” allows her to indulge her fascination with convergent evolution, the process by which creatures that are only remotely related develop the same traits independently. For example, cranes, storks, and herons, neatly separated in modern classifications, have all developed long legs and long necks; hornbills and  toucans, groups only distantly related to one other, have evolved huge bills. The Linnaean sequence lets van Grouw and her readers examine such similarities in appearance and adaptation unencumbered by the niceties of modern taxonomy. Not, of course, that van Grouw is anything less than familiar herself with the latest research, as her discussions in the text reveal; but it seems to me that she also feels an affinity for the older system, as concrete and solid as the bones she has embraced.

There is a lot going on under a bird’s skin, and van Grouw draws back the feathered veil layer by layer, showing birds with their skin removed, birds reduced to skeletons, bird skulls furnished with bills large and small, and bird feet with and without their scaly skin. Sepia-toned, cross-hatched, and finely detailed, her Mallards, Gentoo Penguins, and Great Spotted Woodpeckers, to name a few, do indeed have a nineteenth-century quality. (In an interview, van Grouw cites among her inspirations Thomas Eyton’s 1867 Osteologia Avium.) Pencil is used to delineate the edge and curve of bone, shadowing gives the muscles and feet substance, and a slight tilt of the skull makes the skeletons seem almost
alive. The unclothed birds fly and swim and prance across the pages, much in the manner of the dead birds John James Audubon posed for his paintings. And like Audubon’s paintings, these illustrations embody a strong sense of design. The Northern Lapwing raises the bones that are its wings in sweeping diagonals; the skeleton of the Great Hornbill zigzags up from its perch, its great crescent bill stretching across the corner of the page.

The book is also full of drawings of parts of birds, mostly skulls and feet but also breastbones, wings, windpipes, and tongues. Skulls and feet are often shown in groups, revealing their striking range of sizes and shapes. It’s amazing how much easier it is to see the differences among the Darwin’s finches when you take away the feathers!

Barn owl heads

Similarly, drawings of one species in different stages of “undress,” such as this Barn Owl—its feathers, skin, and muscles removed one after the other to reveal the structure of its ear flap—function as visual lectures in ornithological biology.

Unexpectedly, domestic birds—waterfowl, fowl, and pigeons—are also unfeathered here. It turns out that the history of selective breeding over the centuries reveals a great deal about anatomical possibilities and limits. The description and drawing of the skull of the crested duck, an ornamental Mallard with a pouf on the top of its head, is heartbreaking: This bird has been bred for a genetic defect, a hole in its skull, which makes it look cute but often results in the growth of bone tendrils into the brain.

Rock Pigeons have also been bred into bizarre-looking types. This bird that so many birders love to hate is lavishly illustrated in a number of its most extreme domestic manifestations, including the African Owl, with its extremely small bill, and the Fantail, with its concave back. Van Grouw reminds us that Charles Darwin bred pigeons, the fancier the better, and found in them eloquent examples of mutability.

There is a surprising amount of text in The Unfeathered Bird, and it is worth the reading. Thanks to a background in taxidermy and seven years spent as curator of the ornithological collections at London’s Natural History Museum, Katrina van Grouw is conversant with what seems like every single bone in every single bird species, and she exhibits a notable talent for graceful explanations uncluttered by scientific jargon.


Here she is on the woodpecker’s tail:

Now a tail is not just a convenient bundle of feathers to lean on. It takes muscle power to function effectively as a brace, and large muscles need large bony surfaces to anchor to. The tail vertebrae of a woodpecker do not diminish in size toward the tip, and the  final bone—called the pygostyle—is enormous, with a broad flattened underside for the muscles to really pull those tail feathers against the tree.

With the same appealing clarity, she explains why Anhingas have an extra bone in their neck, how hummingbirds’ wings are attached to their bodies by a ball and socket joint that allows them to fly like helicopters, and what nightjars have—a tapetum lucidum—that owls don’t that allows them to truly see in the dark.

The highly detailed descriptions of bones and eyelids and toe pads and mandibles never get boring, because all of those details are ultimately related to bird behavior. Toucans are able to nest in cramped tree cavities because their tails flip forward. Storm-petrels’ well-developed sense of smell allows them to return to their breeding sites at night. The occasionally overwhelming density of the materials would make this a hard book to read in one sitting, but it is a delightful one to read in pieces, a chapter or two a day.

It is hard to peruse The Unfeathered Bird without wondering about the story behind the book. Van Grouw made every drawing life-size on oversized paper from a specimen—all borrowed from museums or found already dead; no birds were harmed in the making of this book. As the author has related in interviews and on the book’s website, freshly salvaged carcasses were boiled and cleaned in van Grouw’s house by her husband, Hein van Grouw, who also wired the skeletons into lifelike poses; the couple’s joint endeavors apparently gave their home a very distinctive look. In the acknowledgments, the author thanks people around the world for gifts of carcasses and alludes to what must have been a  memorable meal of bustard soup: I wish that she had recounted more such episodes in the book’s introduction, where they would have provided an engaging and illuminating context for the book’s drawings.

My other quibble with this book is the index, which covers only the illustrations, a matter that is not explained. Both English names and scientific names are indexed, with English names entered under their first word, for example, “Parakeet Auklet” rather than “Auklet, Parakeet.” This means you need to know exactly which bird you are trying to look up, and its precise, full, and correct name. There is no bibliography or list of recommended sources, a source of regret for the reader: I like seeing where people get their expertise and inspiration. I did enjoy the Mallard skeletons that frame the index, as well as the European Robin skeleton at the end of the book, flat on its back, legs in the air, clearly dead. After so many skeletons in action, this was a fun touch.

I saw an errant rooster this morning at my favorite birding patch. Instead of walking past, I watched it. I thought about its stationary eyes and flexible neck, its footpads and its four toes, three in the front, one in back, all reasons why it was walking so daintily over the graveled parking lot with its head bobbing. This is what I got from The Unfeathered Bird, a new way of looking at birds, even the most common ones. An anatomical point of view gives us a deeper understanding of the behavior we observe in the field; it adds to the information in our field guides and handbooks. The Unfeathered Bird is not a reference book, nor is it entirely an art book, despite its exquisite drawings. Its failure to fit completely into a genre niche is its strength, making this a unique volume that beautifully presents difficult information in a manner that is easy to understand. While not a necessary purchase, it is a book that I think will add value to the birder’s library.

What lies beneath? In the case of The Unfeathered Bird, a world of skeletal pleasure.

– Donna Schulman is an academic librarian and birder. The author of more than 120 book reviews, she is the Book Review writer at 10,000 Birds. Schulman birds in New Jersey and, across two rivers, in Queens, New York, where she is preparing for this November’s New York Birders Conference and annual meeting of the New York State Ornithological Association.

Recommended citation:

Schulman, D. 2013. What Lies Beneath? [a review of The Unfeathered Bird, by Katrina van Grouw]. Birding 45(3):65.