Identification - This bird is the size of a small sparrow. It is the only small all-yellow warbler with a noticeable round black cap on top of its head. It is olive green above and bright yellow below. Its wings and tail are unmarked.
Morsels - The Wilson's Warbler builds a larger than usual nest for its size. The bulky structure is constructed of dead leaves, mosses, grasses, and is lined with fine grasses and occasionally animal hair. Such a nest must be well insulated, holding in the heat of the incubating parent for night temperatures which in spring can drop near freezing in some subalpine areas.
