Watching eggs hatch and baby birds grow for science? Yup! This is BNRC’s first season participating in Cornell’s Lab of Ornithology NestWatch program, and what fun it has been!
NestWatch is a nationwide program designed to track the status and trends in the reproductive biology of birds, including the timing of nesting, number of eggs laid, how many eggs hatch, and how many hatchlings survive. The data participants help collect is used to study the condition of bird populations and how they may be changing over time due to environmental stressors such as climate change and habitat loss. Given that there has been a nearly 30% reduction in the North American bird population since 1970, research like this has never been so important (Rosenberg et al, 2019).
Among the volunteer participants was a family of homeschoolers who were quite literally doing this for science (class!). They braved the chilly spring and muddy trail, and it paid off, opening their box one day to find these beautiful eastern bluebird eggs and then a few days later, naked nestlings!
Another participant battled a pesky and persistent field mouse who kept returning to the nest box to make its home. Perhaps it confused itself for a bird? Thankfully, this dedicated volunteer was just as persistent and found a different nest box with a tree swallow nest. Tree swallow nests are easily distinguished from eastern bluebird nests by the feathers that characterize their nesting material. Additionally, tree swallow eggs are pinkish white, quite different from the eastern bluebird’s turquoise (see photos).
As we near the end of July, adult tree swallows and their fledglings are gearing up for their southern migration to overwintering sites in Florida and Central America, an early trip for songbirds. Meanwhile, eastern bluebirds are attempting a second and sometimes even a third brood, not migrating south until later in the season.
If you don’t have the time to participate in NestWatch you can make a difference by building your own nest box. Tree swallows and eastern bluebirds use the same nest box, so you can attract both species to your property and support their reproduction. See All About Birdhouses for more details and a free, downloadable construction plan.
By participating in NestWatch, BNRC was able to offer the public a new way of interacting with the natural world – an intimate window into the life of birds, and the chance to make a difference. For kids and adults alike, NestWatch offers a beginner-friendly introduction to the biology of birds and data collection and allows land trusts like BNRC to broaden our sphere of influence.
Rosenberg KV, Dokter AM, Blancher PJ, Sauer JR, Smith AC, Smith PA, Stanton JC, Panjabi A, Helft L, Parr M, Marra PP. Decline of the North American avifauna. Science. 2019 Oct 4;366(6461):120-124. doi: 10.1126/science.aaw1313. Epub 2019 Sep 19. PMID: 31604313.