Here’s a quick guide to identifying the nests of some of the most likely species you’ll find in your bluebird nest box:
Bluebirds: cup nest made of fine grasses and sometimes pine needles; eggs pale blue (rarely pure white.)
Tree swallow: cup nest of dried grass, always lined with feathers; eggs pure white.
House wren: nest made entirely of small twigs; eggs clear white, heavily speckled with reddish dots.
Titmouse: cup nest of roots, moss and dried leaves lined with hair, fur and scraps of string and cloth; eggs creamy white, speckled with small dots.
Chickadee: nest lined with moss, feathers, hair, rabbit fur and plant fiber; eggs white, evenly spotted.
Nuthatch: cup made with bark shreds, twigs, grasses, moss and feathers; eggs white, heavily speckled with pale-brown or purplish spots.
House sparrow: unkempt domed nest often with scraps of trash; eggs greenish white, splotched gray and brown.