He and his colleagues learn through trial and error which capture methods work best, and where and in what types of tree nests are likely to be made. He was starting from scratch-he had never even heard the singular duet a mating pair exchanges on the winter air, “so synchronized that many people, hearing a fish owl pair vocalize, assume it is one bird,” until well after he had committed his career to the fate of the birds. Slaght began his study of them for his doctoral dissertation in 2006.

(The birds on Hokkaido, a few hundred miles across the Sea of Japan, are now protected.) Ten years later, Russia had only an estimated three to four hundred pairs. The first fish owl specimen was collected in 1883 in Japan, the first Russian nest discovered in 1971. (The owls hunt only rivers that don’t freeze over, and the region’s radon springs work perfectly for the purpose.) The dreadful enemy is usually the same in any tale recounting the quest to save a rare animal: humans in general, with our penchant for decapitating habitats. Slaght’s main mission is to formulate conservation guidelines that may save the uncommon species from loss: of the enormous, damaged but still standing trees it requires for nesting and of the highly particular waters that provide its food.

From the first paragraph of this propulsive narrative, Slaght chronicles his years-long campaign in Primorye, Russia, where he studies the endangered Blakiston’s fish owl, a sixto ten-pound magisterial behemoth of a raptor that feeds solely on fish.

JONATHAN SLAGHT, a modern-day knight-errant, adventures deep into the forests of the Russian Far East and returns with a magnetic account of conservation science wrapped in a literary thriller.

Owls of eastern ice