Here we are, December 2015, days after the winter solstice, but in the midst of endless fall. My windows are flung open in steamy Brooklyn, though I know this means the still-lingering mosquitoes will probably get in. My mother texts from the foothills of the Blue Ridge Mountains in North Carolina to tell me that spring flowers are beginning to appear. This creeps us both out. I’ve just hung up the phone with Gary Frazer, assistant director of the Ecological Services Program at the U.S. Fish and Wildlife Service, and the news is good and not good.

I had gotten Frazer’s number because I’d been thinking about, to put it lightly, the end of things. The passing of another year inevitably brings on an enforced wave of nostalgia, whether it’s the drivel Facebook’s algorithms attempt to dredge back onto your timeline, the surfeit of Best of lists, or the inevitable Those We Lost. I had been thinking about those we lost and hoping I was wrong.

Earlier this year, reports had surfaced that the eastern puma, or the eastern cougar, a subspecies, an animal native to the Southeast and sacred to the Cherokee Indians, was, after 70 years, presumed extinct. I knew firsthand that its close relatives—the mountain lion and the Florida panther—were very much in existence. In recent years in Oregon, in California, and elsewhere, I had seen or heard them myself. When I contacted the International Union for the Conservation of Nature about this, the IUCN disputed the threat to the overall species—“There is nothing to raise concerns about the North American animals,” the IUCN’s Lynne Labanne wrote me—that is, the numbers are considered healthy. And because it was already believed extinct for some 70 years, the eastern puma had not been a candidate for protection under the Endangered Species Act, the historic measure passed by Congress in 1973 to identify, protect, and attempt to recover endangered species in an effort to preserve biodiversity.

“Some people refer to it as almost a religious statement,” said Frazer. Administering the act’s protection of land and freshwater species (the National Marine Fisheries Service is responsible for marine species in this country) consumes 90 percent of his job. This month, the Delmarva fox squirrel, one of the first animals to be protected under the act, had its protective status lifted. Its once dwindling numbers have been restored to a healthy population: a success story.