One day in the 1970s, Al Larson read about the plight of bluebirds, and how their population was in decline. He also read that nestboxes were key to their survival. Larson put two and two together and built a little nestbox of his own. That first one fledged birds, so he kept at it. Decades later, he’s built hundreds of the boxes and fledged tens of thousands of birds from his Idaho property.