Virginia Tech University ornithologist Curt Adkisson notes, however, that pine grosbeak
irruptions into the Northeast occurred more frequently in the past.
They feed on tree seeds: Crossbills eat the brown seeds of conifer cones; redpolls eat the small seeds within the caterpillarlike catkins of birch and alder trees; pine grosbeaks
eat buds and the seeds of ashes, along with berries from many shrubs.
The common redpoll, like white-winged and red crossbills and the pine grosbeak
, breeds to the edge of the tundra in North America, Europe and Asia.
From the diminutive nuthatch to the peaceful pine grosbeaks
to the more aggressive cedar waxwings and redwing blackbirds, the three crows just seem to bop about getting along with everybody.
Hulled sunflower seeds will appeal to the greatest variety: They will attract jays, red-bellied woodpeckers, finches, goldfinches, Northern cardinals, evening grosbeaks, pine grosbeaks
, chickadees, titmice, nuthatches and grackles.
But some species of native feeder birds, including American goldfinches, purple finches, evening and pine grosbeaks
-- all members of the same family -- have been infected by conjunctivitis, though to a far less catastrophic degree.
CBCs can illustrate the presence of irruptive species such as certain "winter finches"--redpolls, pine siskins, crossbills and pine grosbeaks
that occasionally travel south in large numbers.
flock in occasionally, stay a few days, and then leave again.