Saturday, June 4, 2011

Phoebe and Freeloader

Janet was snooping around in central MA this morning, and discovered
this nest plastered to the wall of a cliff. This was well of the beaten
path, and the cliff wall faced a large wetland. As you can see, the
outer part of the nest is made of moss and other fibers, and lined with
fine grasses. I believe the nest and white eggs belong to an eastern
phoebe, and the speckled ones were left by a brown-headed cowbird.

Phoebes often build their nests on human made structures: under bridges,
on rafters, trestles, etc. Natural sites like you see here have become
fairly uncommon, according to what I read, so I was excited to find it.

I've also learned that, like this one has been, phoebe nests are heavily
parasitized by brown-headed cowbirds, and the phoebes often dessert the
nest and begin anew, when they discover those big speckled eggs.
However, these eggs were quite warm, so I think someone has been setting
on them. I must have frightened her away without realizing it.


  1. Nice find, Janet. It's always a treat to discover birds nesting in natural locations. I agree with your guess that this is the work of a phoebe. I found a very similar nest a couple of years ago, built on a window ledge of my shed, facing the woods. That nest contained a cowbird egg, too.

  2. Oh, yeah, I remember that now, I think you showed me that nest.

    I was a little surprised to see the cowbird eggs in this nest on the cliff, since it was well away from suburban edge habitat, which is where I envision cowbirds hanging out, but evidently they scout out nests in remote areas too.