The male's bright yellow color, along with the chestnut streaks on the breast, make it one of the easiest warbler to identify. Yellow warblers will inhabit any are as long as patches of trees or shrubs are present. Their diet consists mainly of caterpillars such as the cankerworms, many of which are destructive to foliage of trees. They also eat many other types of insects such as moths, beetles, weevils, and grasshoppers. The nest is constructed primarily by the female and is shaped into a well-formed cup made of fibers, fur, lichens, and spider's silk.
Eggs are green-white and spotted with brown and gray.
The black-headed grosbeak prefers open deciduous forests and is found throughout the western United states. Its diet consists mainly of large seeds but will often eat berries and insects. Grosbeaks are somewhat tame and readily visit bird feeders during the spring and summer. Nests are usually built in deciduous trees or shrubs bordering streams and rivers. Both the male and the female share the duty of incubation.