Widespread decline in US bird populations ????

From the Audubon Society website:

Audubon’s unprecedented analysis of forty years of citizen-science bird population data from our own Christmas Bird Count plus the Breeding Bird Survey reveals the alarming decline of many of our most common and beloved birds.

Since 1967 the average population of the common birds in steepest decline has fallen by 68 percent; some individual species nose-dived as much as 80 percent. [more]