Some environmentalists and scientists have begun calling our current epoch the “Anthropocene”—to acknowledge the massive changes humans have induced in global ecosystems. But biologist and author Edward O. Wilson has proposed an alternative name: “Eremocene,” or the “Age of Loneliness,” a name that alludes to the fact that we are in the midst of a sixth mass extinction, one for which humans are primarily responsible.

The impending loss of so many of our fellow creatures means that humanity faces what can best be described as a kind of “species loneliness.” Regardless of what we call this new epoch, there are witnesses emerging—writers attuned to their environment—who are keenly aware of the implications of species loss, and who vow to document past beings and savor the life that remains.

In Giant Sloths and Sabertooth Cats: Extinct Mammals and the Archaeology of the Ice Age Great Basin, zooarchaeologist Donald Grayson surveys North America’s last mass extinction. In all, the last ice age wiped out 37 genera, and Grayson pays particular attention to 20—mostly megafauna—that once populated what’s known today as the Great Basin, which covers most of Nevada and parts of five adjoining states. He compiles incisive obituaries for each bygone species, including mammoths, mastodons, sabertooth cats and the largest flying bird ever recorded, the giant teratorn, which “weighed about 150 pounds, and had a wingspan of about 23 feet,” analogous to “a Cessna 152 light aircraft.”

Grayson compresses and addresses centuries of ignorance surrounding extinction by offering a series of hard-boiled clarifications. His is a temperate voice, wary of global theories of extinction. He is more interested in advocating for a compendium of individual species’ histories. Because it is “difficult to extract definitive answers from the fossil record,” an extinction narrative must instead be singular and idiosyncratic to each unique species.

While the fossil record preserves the story of extinct species, one can turn to a field guide to apprehend extant species.

For more than a century, North American naturalists have been compiling field guides to aid citizen scientists in identifying the native flora and fauna of particular regions. In the case of The Sonoran Desert: A Literary Field Guide, editors Eric Magrane and Christopher Cokinos are both guides and anthologists; this is a Sonoran Desert tour led by a park ranger with an MFA. But The Sonoran Desertis not just a field guide, but also an anthology of prose and poetry about the Arizona Upland. As in earlier “literary field guides” such as Califauna and Califlora (Heyday 2007, 2012), each species’ passage is accompanied by an essay or poem, an illustration, and a spirited description of its morphology, habitat and life history.

These 63 literary stewards of the Sonoran Desert were mostly recruited during the National GeographicBioBlitz in Saguaro National Park in 2011, an event where citizen scientists teamed up with professionals to develop a 24-hour species inventory. The resulting anthology is varied—a blend of witness and imagination, intention and happy accident, anthropomorphism and zoomorphism. In a single-sentence piece about the broad-billed hummingbird, Arizona’s first poet laureate, Alberto Alvaro Ríos, writes: “Hummingbirds are quarter notes which have left the nest of the flute.” Elsewhere, Alison Hawthorne Deming observes, “The saguaros all hum together like Tibetan or Gregorian monks / one green chord that people hear when they drive.”

Giant Sloths and Sabertooth Cats and The Sonoran Desertare both significant literary offerings. For those who dread the prospect of an Age of Loneliness, these books provide excellent company, bringing to life the precious biota of the American West—both the species that have long since vanished, and those that still survive, at least for now.

This piece originally appeared in High Country News.

Giant Sloths and Sabertooth Cats: Extinct Mammals and the Archaeology of the Ice Age Great Basin

By Donald K. Grayson

University of Utah

320 pages, $24.95

The Sonoran Desert: A Literary Field Guide

Edited by Eric Magrane and Christopher Cokinos

University of Arizona

216 pages, $19.95