Animal Ark: Celebrating our Wild World in Poetry and Pictures appeared from National Geographic Books in 2017 as a hardcover, a near-square volume measuring roughly 26.5 by 26.4 centimetres. The photographs are by Joel Sartore, creator of the Photo Ark; the words are by Kwame Alexander, working with Mary Rand Hess and Deanna Nikaido. More than forty animal portraits are gathered here, and three gatefolds open within the sequence to carry additional species.

Sartore’s larger undertaking — to photograph every animal in the world, with particular attention to those that are disappearing — sets the terms for the pictures. Each is a portrait in the plain sense: one creature, given the page. Alexander’s poems do not caption what we see. They run alongside it, and the book’s meaning accumulates in the alternation between verse and image rather than in any single spread.

The result is a children’s book that keeps adult company. National Geographic’s editors built it for younger readers, and its heft — about 500 grammes, less than a centimetre thick — confirms the intention; yet the photographs belong to the same body of work that gives the larger archive its standing, and the poems are not written down to their audience. The collaboration is the point. A photographer’s long project, measured in decades and thousands of species, meets a poet’s short forms, and neither is asked to illustrate the other.

For collectors, the case for the book rests on what it records rather than on scarcity. It marks one of the earlier occasions on which Photo Ark material was shaped for a general readership, and it belongs on the shelf beside Sartore’s larger volumes precisely because it is a different kind of object: a designed encounter, with fold-outs and a square page, in which photograph and poem are held in equal weight. Bibliographies list it among the project’s related publications. That position, and the specific collaboration it preserves, are the reasons to keep it.