Blind, bald, and vulnerable, many baby birds can’t fend for themselves. They are altricial, meaning they need parental care—if not from adult birds, then from humans. Photographer Andrew Garn knows this firsthand. He volunteers as a wildlife rehabilitator at the Wild Bird Fund in New York City, where he has turned some of his avian patients into subjects. He is drawn to the young birds because their ungainly, alien look is so different from their adult form. “It’s amazing how they become so elegant,” Garn says. Growing Pains (above) Growing up is almost never a smooth transition. But what looks like a really bad hair day for this pigeon chick is just a step in the process of becoming an adult. Around 12 days old, it still sports yellow down but is also growing sheathed pin feathers, which pierce the skin and unfurl like a flag. These feathers won’t stick around for long, though. Just weeks after fledging, some pigeons start their first molt. Because shedding old...