What are some materials that I can place outside that birds can use in building their nests?

You can help birds in building nests for laying their eggs every spring by putting out short strips of yarn, natural fiber fabrics and cotton balls torn into small pieces. It doesn't matter what color the materials are; I've seen bright blue, yellow and red pieces that I've put out for them in their nests.

Just make sure they are free of chemicals and toxins, which can be very harmful for the birds and their babies. You can use the long cotton strips that come in some medications, such as the ones that are capsules or enteric coated. Otherwise, the residue of some of these medications can be toxic to the the birds. Just be sure to tear the cotton into small pieces so that it's easy for the birds to carry in their beaks and work with.

You can also put out dryer lint, torn into workable pieces, as well as clumps of dog hair. Also, leave small twigs and leaves on your lawn for them to use, since these are the 'foundation' of the nest.

You need to start putting these materials out in very early spring, or even sooner, since some birds begin building their nests early and lay at least two clutches of eggs each spring/summer.