RED LIGHTS FLASHING ON MASSIVE LOSS OF NORTH AMERICAN BIRDS OVER LAST HALF-CENTURY

Migrant shorebirds such as sanderling are among those in decline

THE alarming worldwide collapse in bird populations has been underlined by a new report indicating that as many as three billion - almost 30 per cent - have been lost in North America since the 1970s.

The findings - which reflect those in Europe and other continents - raise fears that some species face the real prospect of extinction.

The report, which appears in Science, is based on research by Ken Rosenberg, of the Cornell University of Ornithology, and others.

They reached their conclusions after studying data collected by breeding bird surveys and counts across a range of almost 500 separate species including songbirds, waders and wildfowl.

Wetland birds have fared relatively well as have raptors (since a ban on the use of DDT), but, for other groups, it is a picture of decline.

Rosenberg and his colleagues report that grassland birds have declined by 53 per cent since 1970 - a loss of 700 million adults in  31 species such as including meadowlarks and northern bobwhites. 

Shorebirds such as sanderlings and plovers are down by about one-third.

Familiar birds that flock by the thousands in suburbs have not been exempt.

 "There's been an erosion of the numbers of common birds," Rosenberg says. 

Twelve groups, including sparrows, warblers, finches, and blackbirds, were particularly hard hit. 

Even introduced species that have thrived in North America, such as starlings and house sparrows, are losing ground.

The greatest decline has been in birds migrating up the eastern United States.

Habitat loss is thought mostly to be responsible for the collapse, but food depletion, agricultural pesticides, climate change, coastal development and other factors (even cats) have also contributed.

Says Rosenberg: "We want this to be the real wake-up call." 

Concurrent with the paper, a coalition of conservation groups has come up with policy recommendations and an action plan for citizens. 

Simple steps, such as keeping cats indoors or planting native plants, may help.

Ends Rosenberg: "I am not saying we can stop the decline of every bird species, but I am weirdly hopeful."