Some springtime advice from Deborah C Sharp
Please DO NOT offer yarn, string, or human hair for birds to build nests! Every year we see both young and adult birds being admitted to wildlife rehabilitators due to this. It can sometimes result in the bird losing their foot or entire leg from the yarn/string/hair slowly tightening and cutting off circulation.
DO NOT offer laundry dryer lint either. The lint collected in your dryer filter may seem like ideal nesting material, but it isn’t. It will soak up water and maybe steeped with chemicals unhealthy for birds, such as remnants of detergent and softener.
Also a warning about offering pet hair. Many of our pets are treated with special shampoos or tick/lice treatments which stay on the hair and can be harmful to birds collecting it for nesting material. DO NOT offer pet hair that has been exposed to any shampoo treatments or chemicals.
Some safer alternatives from the National Wildlife Federation’s Blog…
Twigs
For birds looking for small twigs, almost any tree or shrub you plant will do. When small branches or twigs fall from a shrub and gather at its base, leave them for birds to pick up, preferably in lengths under 4 inches.
Greenery
Some birds line nests with soft plant matter. You can provide this accouterment by growing catkin-bearing trees and shrubs such as cottonwood, maple, mulberry, willows, poplar, and beech.
Fluff
Many birds—hummingbirds spring to mind, but other songbirds as well—gravitate toward fluffy material, such as seeds with silky attachments designed to waft them on the wind or seed pods with a soft, hairlike covering. You can provide these items via cottonwood trees, lamb’s ear (ground cover), milkweed (also good for attracting monarch butterflies), honeysuckle, and clematis.
Mud
If you have a pesky spot in your garden that refuses to grow anything but dirt, try adding a little water and see if you can grow mud. Mud is a favored nesting material for swallows and swifts and even the common robin.
Dry grass
When you trim your yard, perhaps you can find a spot in your garden for laying out a selection of dried grass stems cut 2 to 4 inches long. Grass is a common ingredient in songbird nests, used by species from native sparrows to robins.
Moss
If you have a shady spot in your yard, trying growing moss; with its velvety green growth, moss is a beautiful highlight for any moist garden and is a favored building material of some hummingbird species.