The 15 pairs of swallows that nest in my barn line their nest with feathers. I place curled, goose body feathers in an open space in front of my studio for them to swoop in and pick up off the ground. They especially like the large ones that are the width of the inside of their nests.
Besides the fun of watching swallows carry off these feathers which are sometimes longer than themselves, I feel like I am doing a good deed because these birds’ feathered nests are twice as successful at nests not lined with feathers.
That’s because the newborn birds have naked skin like us. Would you rather lie in a bed of grass or mud or a bed of feathers? It makes sense that feathering a nest helps eggs hatch by keeping the birds warm. The feathers also reduce parasites in the nest. I’m not sure exactly how.
I enjoyed reading through some of the studies but usually just skim and read the abstracts. Mostly people don’t find earth-shattering discoveries, but there are interesting little bits of knowledge that are gleaned from each study.