I checked a couple of our nest boxes this afternoon and discovered that the Eastern bluebirds have five eggs in one and the Tree swallows have five in another.  With the hordes of mosquitoes we have in our yard this year, there should be no shortage of food once the young hatch.

Tree Swallon in its nest box - note the long feathers lining the nest.

Tree Swallon in its nest box – note the long feathers lining the nest.

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 between the two.  Tree Swallows will always have feathers added to the top of the nest, often longish ones with tips that curl back over the eggs.  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

Male Eastern Bluebird sitting on a nest box especially designed for them.

Male Eastern Bluebird sitting on a nest box especially designed for them.

members of the Thrush Family.

These nests are easy ones to locate and observe, but birdwatching can include  looking for other bird nests, not built in cavities.  Usually the Eastern Phoebe builds her nest on top of a light fixture in the barn, but not this year, because Mike has been doing some wood working out there. I’m hoping they’ve found a new location.

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 birds nests is just about as numerous as there are bird species

The pale blue eggs of the Eastern Bluebird

The pale blue eggs of the Eastern Bluebird

Looking at the two extremes, we have the Ruby-throated Hummingbird nest measuring a mere 1 ¾ inches across, big enough to hold two miniscule  eggs, while the Bald Eagle 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.

The key to finding bird’s nests is watching as the birds gather nesting 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 Feeder Watch, which is done in the cold months by “citizen scientists”, nest watchers can contribute valuable information about the species they’re seeing and the number of eggs and young that successfully fledge.  It’s all very quick and easy to do on the website www.nestwatch.org.  The combined information coming from thousands of volunteers can show if there are changes in the numbers of 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 count and if you have access to a computer and the internet sign up (it’s free) 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.


By Kate Crowley