It was late Saturday night, March 24, when my phone began to buzz. Setting down my drink, I stared at the screen in bewilderment. Spencer Pratt was FaceTiming me from the West Coast. I hesitated for a moment, ducked into a bedroom, and picked up. In the early 2000s, Pratt might have spent an evening like this in front of the camera, feuding with Lauren Conrad or his sister Stephanie for MTV’s hit show The Hills. But that life is no more. Today, Pratt simply has no time for drama; he’s too busy caring for a newborn son, four dogs, and the hundred-plus hummingbirds that visit his Los Angeles home. In case you missed it on social media, now you know: The 34-year-old reality star—or as some would say, reality villain—is obsessed with hummingbirds. And there’s a reason for it. He and his wife, Heidi Montag, were filming another reality show, Celebrity Big Brother, early last year, when they came across a hummingbird nest with two “tic-tac size” eggs in their...