There are many different types of warblers.
Warblers eat mostly insects and are important predators of insects.
The Cape May warbler helps control the spruce budworm caterpillar. The spruce budworm attacks forests by feeding on the leaves of the white spruce. This can cause a great deal of damage to the trees. The Cape May warbler is an extremely rare bird, but during an outbreak of the spruce budworm, its population increases dramatically. This increase in the Cape May warbler helps control and limit the damage done by the spruce budworm.