Brown-headed Cowbird
Molothrus ater
Notes:

A part of me wants to protect the phoebes from cowbird eggs each year. But cowbirds are native and protected by law. The Nestwatch link below provides options for deterring them.

Links:
Photos:
We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.
Aldo Leopold
A Sand County Almanac