Few photographic projects state their endpoint as plainly as Joel Sartore’s Photo Ark: to photograph, in studios, zoos, and sanctuaries, as many of the animal species living under human care as he can reach. National Geographic: The Photo Ark Vanishing, published by National Geographic Books in 2019, marks the project’s fifteenth year and narrows its lens. The species gathered here, in the book’s own framing, are either already gone from the wild or expected to disappear within decades.

Sartore’s method is consistent and severe: isolate the animal, light it cleanly, remove the habitat. What remains is a face — the armored bulk of a Sumatran rhinoceros, the small persistence of a Salt Creek tiger beetle — set against backgrounds that refuse to flatter. The comparison the book invites runs between shape, color, and temperament, and the knowledge that each may shortly survive only as a photograph. Alongside the plates, scientists and conservationists describe the work of protecting and, in some cases, restoring populations.

As an object, the book has weight: a hardcover of roughly 400 pages, close to square at about 26 by 26 centimeters and heavy in the hand. The format gives full-page portraits room to breathe and lets facing pages hold one animal against another. Page counts and dimensions vary slightly across catalog records, but the design intention is legible — the sequencing is the argument, placing species lost in the wild beside species still barely holding on.

For a collector, the case rests on the project rather than any promise of scarcity. Vanishing belongs to a multi-volume enterprise with a defined ambition and a long institutional record, and it documents a particular phase of that enterprise, when attention turned from abundance toward absence. The portraits function as working documents of animals that may not present themselves to a camera again. Elizabeth Kolbert is credited among the contributors, and the conservationist voices included supply a context the images alone withhold. It is a book worth keeping for what it records.