THE WOLF EFFECT

A history of wolves in Yellowstone that offers a salutary lesson in how ecosystem management is no walk in the park.

In both cumulative rhyme and a substantial prose afterword, Parry tracks what happened when the wolves of the Yellowstone National Park area were exterminated: “No slap of the beaver, no chirp of the sparrow; / The trees became scarce, and the streams became narrow.” When they were reintroduced in the 1990s, the wolves touched off a “trophic cascade” of habitat recovery and increased biodiversity. Thermes, too, goes for a multistranded approach. Maps and historical sidelights (“No Polling Places on Reservation,” observes a 1924 newspaper headline) are mixed with views of broad landscapes studded with wildlife. Inset graphic panels feature informative conversations between an anxious coyote and an omnivorous bear: “Mice are tasty.” “I love a good moth myself. Pine nuts? Fish? Don’t get me started. But wolves? They’re all elk, all the time.” That’s not strictly true, as the author admits, because wolves kill livestock, too (and so do coyotes and bears). Still, “conversations about how to best coexist” are ongoing, as she diplomatically puts it, and the overall benefits of the reintroduction are well documented. The artist appends a labeled gallery of the wild creatures that appear in the pictures, and a note explaining why she chose to portray railroad workers in one 19th-century scene as Chinese (though acknowledging she couldn’t confirm that Chinese immigrants built railways in Yellowstone).

An illuminating account of a spectacular eco-success story.