By Holly Grant, Project Assistant
Some birdwatchers and nature lovers like to celebrate the beginning of breeding season by providing nesting materials for use by the birds that will soon become their neighbors. Each spring we see a similar uptick in questions regarding which type of nesting materials are best to provide, ranging from pet hair, to dryer lint, to leftover yarn or fabric scraps. As a crafter myself, I too wish I could use my hobby to help birds, but these items are not usually the best options. With this in mind, I’ll share our best tips below, which will help you to ensure the good health and safety of your local birds.
When providing nest materials, it’s important to consider what your local species naturally use in their nests. Chickadee and phoebe nests, for example, are easily identifiable because they incorporate lots of bright green moss. Bluebirds and robins, on the other hand, make nests out of grasses and straw. So, when you’re deciding what to place outside for the birds, we recommend sticking to natural items such as moss, twigs, leaves, lichen, rootlets, or untreated grass clippings (i.e., those that have not had fertilizer, pesticides or other similar chemicals applied). If you have chickens or other poultry, their feathers may also be used by birds such as swallows, wrens, or flycatchers, though be sure that the feathers have not had chemical treatments applied. You can gather these items and place them in an empty, clean suet cage, or simply provide them in piles in your yard or on a deck railing. Be sure to refresh the offerings after rain, or if you notice any mold or mildew growing on them.
As I alluded to above, two of my favorite hobbies are birdwatching and knitting. While common advice used to say that yarn was safe to put out for birds, we now know that advice is outdated. Yarns are not always made of natural materials (e.g., acrylic or nylon), and even wool and cotton skeins may be treated with chemicals or dyes that can harm the delicate skin of nestlings. Stringy materials are also harmful because they can potentially wrap around the feet or neck of nestlings, either trapping the bird in the nest (preventing fledging) or restricting airflow. Hair from humans, pets, and/or livestock can be harmful to nestlings as well. Strands of hair are often infused with shampoos, dyes, flea and tick treatments, or other similar products, and if it’s longer than one inch, it poses the same risk as yarn and string. Hair, string, and yarn can also be choking hazards if mistaken for food. One other very popular idea is using dryer lint, but lint should never be provided for birds to use. The chemicals in detergents and the microplastics that may accumulate from synthetic fabric can be harmful. When considering these items, note that while you may have seen a bird using some in its nest before, it doesn’t always mean those items are safe. By making safer materials more readily available, you can contribute to the health and safety of your new “nest”-door neighbors.
Birds don’t need help from humans finding nesting materials, but if you do provide them, it’s best to go natural. The intent when providing nest materials is to try to mimic what these birds would use in nature, and keeping to that strategy will be one more step in the right direction for a successful fledge.
For more Do’s and Don’ts check out the Cornell Lab’s All About Birds website.
[Note: This article was originally published in the NestWatch Digest for the 2020 nesting season.]