By Wendy Feltham

Have you noticed how birds become so round on cold days? During our latest snowstorm, I saw spherical birds sitting in the vine maple tree outside our window, taking turns at the sunflower seed and suet feeders. I posted a photo of a Varied Thrush on iNaturalist and noted that she was puffed up to keep warm. Someone commented, “What a borb!” I asked if he meant completely round, like an orb? He replied, “Exactly!” and sent a link to a long piece in Audubon magazine: www.audubon.org/news/whats-difference-between-borb-and-floof

If you’re like me, you aren’t following memes on social media and don’t have an account on Twitter or Reddit. That means I never knew that “birb” has been “affectionate internet speak for birds,” especially round ones, for years. It turns out that “borb” refers to the roundest birds. 

If you use a down jacket on winter days, you experience first hand the superb insulation feathers provide. On the Smithsonian website, Peter Marra, head of the Smithsonian Migratory Bird Center at the National Zoo, explains, “Feathers are incredibly specialized structures that serve many purposes including, for many species, keeping them warm.” He says birds fluff up to trap air in their feathers, since the more air they trap, the better insulated they are. You may have seen birds standing on one leg in winter while tucking the other leg into their feathers to keep it warm. What I’ve never seen is something else Marra mentions— small birds, like our Black-capped Chickadees, “gather in large groups at night and crowd together in a small, tight space to share body heat.”