When you look outside and see how many birds are in your yard or at your feeders, you know there are hundreds of nests hidden just out of sight. Their success determines in many ways whether we will have just as many birds next year in our yards and at our feeders. Wind storms, house cats, cold and wet weather, non-native birds, and raccoons are just some of the threats the nest and their occupants face, yet through the centuries birds have managed to keep replenishing their numbers and providing us with year after year of pleasure.
A male House Wren working on the nest building challenge.
Maybe you have put up actual birdhouses to attract bluebirds, tree swallows, or house wrens. If you have some nest boxes set up, but aren’t sure which species of bird is using them; it’s pretty easy to distinguish the tree swallows from the bluebirds. The former will always have feathers added to the top of the nest, often longish ones with tips that curl back over the eggs. The bluebirds just use dried grasses and weeds in their nest, forgoing any additional ornamentation. The swallow’s eggs are a pure, smooth white, while the bluebirds are pale blue, typical of all the members of the thrush family.
A female Rose-breasted Grosbeak on her nest.
These nests are easy ones to locate and observe, but I’m always on the lookout for other bird nests, not built in cavities. One Eastern phoebe has built her nest on top of a light fixture in our barn. Another has done the same thing at the Audubon Center where I work occasionally
Most birds build an open nest, but almost always well concealed from us humans. Birds have learned the art of camouflage and secrecy in order to preserve the vulnerable eggs and fledglings from predators, both two legged or four legged. The variety of shape, material and size of bird’s nests is just about as numerous as there are bird species, but looking at the two extremes we have the hummingbird nest measuring a mere 1 ¾ inches across, big enough to hold two miniscule eggs. The bald eagle on the other hand builds a nest five feet across, made from branches and sticks. These nests are reused year after year and can weigh hundreds of pounds. They also hold just one to two eggs/chicks.
A male Eastern Bluebird feeding chicks at the nest box.
The key to finding bird’s nests is watching in the spring as the birds gather material in their bills. Follow on foot or with your eyes as they carry the material back to their nest site, but while they’re constructing the nest always stay back far enough that they are not spooked away from the nest.
The Cornell Lab of Ornithology has a program designed to give people an opportunity to share their observations with scientists. Like FeederWatch, which is done in the cold months by “citizen scientists”, NestWatch can contribute valuable information about the species and the number of eggs and young that successfully fledge. The combined information coming from thousands of volunteers can show if there is change in the numbers nests, compared with records from the past. Other data that is gathered can show whether declines or growth is related to habitat change or possibly climate change.
Pay extra attention this summer and see how may nests you can find and if you have access to a computer and the internet sign up for Nestwatch and share your observations with the rest of the country. This would be an especially good project for a child or grandchild who would like to spend some time during the summer on an easy and interesting research project that could be turned in as a report sometime during the next school year.