Male lions, for all their bluster and might, mostly depend on females to do the hunting. So when an eight-year-old male named Hildur picked up the scent of blood early one evening, he leapt to his feet. “He probably hadn’t eaten in two weeks,” recalls Michael Nichols, a former staff photographer and editor-at-large at National Geographic. “He took off running for five miles until he got to this pride that had killed something.”

As Hildur swiftly passed through the day’s fading light, his ribs sharply visible against his tawny torso, Nichols—hanging out the passenger window of a vehicle driven by his wife, Reba Peck—snapped photograph after photograph. One of those images made it into a 34-page feature in National Geographic. Published in 2013 with text by David Quammen, the story gave readers an intimate glimpse into the short, often brutal—but occasionally triumphant—lives of Serengeti lions.

Nichols and his editors selected photographs for the story that were not only aesthetically appealing and technically refined, but that also revealed something about the latest science on lions and their key roles in ecosystems. “This wasn’t an exercise in just photographing,” Nichols says. “We were fully intent on telling you what lions are all about, based on what had been learned from the research.”