The Brown-headed Cowbird is a North American brood parasite, meaning that it lays its eggs in the nests of other species, making no nest of its own. Reporting cowbird activity is important for understanding nesting success among a wide variety of “host” species (species that accept cowbird eggs). How can you recognize cowbird parasitism in nests you’re monitoring?
In our detailed post, you can learn about the basics of Brown-headed Cowbird natural history, then read about the six signs that a cowbird may have parasitized a nest. You’ll also find photos to help you identify eggs and nestlings of cowbirds. Common species that NestWatchers report as parasitized include Eastern Phoebe, Northern Cardinal, House Finch, American Robin, and, occasionally, box-nesting species.
Cowbirds are a native species and incapable of reproducing without a host. We have tips for discouraging cowbirds, but the single best thing you can do as a NestWatcher is to not visit a nest if you see or hear cowbirds in the area. Wait until another time to check the nest to avoid alerting the cowbird to its presence. If you do find cowbirds in a nest you’re monitoring, we ask that you leave them be and report their presence to NestWatch.
Sometimes it seems like birds have a sense of humor when they choose their nesting locations. Like this American Robin that nested on top of a toy backhoe, as if to get those really deep earthworms. If you find a cheeky nest, snap a picture, take a video, or capture it in artwork and send it in to the Celebrate Urban Birds Funky Nests in Funky Places challenge. You could win bird feeders, binoculars, or an iPad Mini! It’s not about being the best photographer; it’s about appreciating nature and having fun with it. So get outside, get creative, and capture those humorous nests that you see! Submissions are being accepted until June 15.
In this month’s Citizen Science Blog post, take a tour of the Cornell Lab’s 50-year history of nest monitoring in about 5 minutes. Click through an interactive timeline to see some of the highlights. Although the timeline only covers a fraction of the NestWatch publications, it is a good introduction to the breadth of topics to which citizen scientists have contributed. Think of it as speed science. Ready? Go!
PBS NATURE recently aired a three-part documentary called Animal Homes, and part one, The Nest, offers an informative look at our favorite subject. The documentary is a great introduction to some pretty outstanding bird nests, both close to home and far afield. NestWatchers in the United States (and territories) can enjoy this program online for a limited time. You can also pre-order the DVD here, for your classroom, or for enjoying at home after a day of checking nests outside.