Thursday, August 15, 2013

See them with your grandkids while you still can

When tomorrow's kids wonder what a wood thrush or a cerulean warbler looks and sounds like they might very well need to visit the “extinct” section of a natural history museum rather than a neighborhood woodlot.

The fear is – says avian scientists – that the thrush and the brightly beautiful cerulean warbler are each on the cusp of vanishing forever. Possibly even before today's parents become tomorrow's grandparents.

Such is the dire warning being heralded by the American Bird Conservancy, an avian advocacy group that has reported on the threat of household and feral cats on bird populations and the health risks on raptors and associated with using lead ammunition.

The Conservancy says a very real possibility exists for the extinction for the wood thrush (a for now common enough species in Ohio) along with the cerulean warbler in addition to the long-billed curlew, the upland sandpiper, and the Kirtland's warbler.

Charles Fenwick, the Conservancy's president, says all five species have seen tumultuous population declines within just the past few decades.

In the case of the cerulean warbler, the species' population has plummeted by 70 percent over a 30-year period spanning 1966 to 1996.

The destruction of the species' mountain-type habitat is widely thought to lead the list of reasons for the warbler's decline.

No different either is the case for the wood thrush, an often enough for now companion of mine around my Lake County, Ohio deer blind.

Scientists say that the wood thrush has undergone an unwanted population starvation diet. Whereas wood thrush numbers during the 1960s was pegged at around 13 million individual birds, that figure today is estimated at only about five million individuals.

The problem for the wood thrush is two-fold, biologists say. Not only is the species confronting habitat loss on its breeding grounds in the eastern United States but its winter home in Mexico and Central America likewise is under assault.

And the upland sandpiper shares something in common with the passenger pigeon. Back in the 19th Century flocks of each species would take hours to pass by.

Yet over-harvesting was a key (though not, only) reason for the passenger pigeon just as it was for the upland sandpiper.

Both species suffered greatly from the loss of habitat though the sandpiper has managed to hang on. At least for now.

Of course an argument can made how the Kirtland's warbler is hindered by having one of the smallest and restrictive breeding grounds of any North American bird species.
This nesting territory is framed in its entirety by an island of fire-controlled jack pine plantations in the very upper reaches of Michigan's Lower Peninsula and some pioneering breeding pairs in the state's Upper Peninsula.

Yet while the population of Kirtland's warbler has grown 15 times over the past few years it must be remembered as well as emphasized how the total actual number of birds remains low.
It was only 26 years ago that the entire known stock of breeding male Kirtland's warblers was a paltry 167 individuals.

Among the Kirtland's warbler's on-going threats is nest raiding by the parasitic brown-headed cowbird.

To help the survival of these five bird species and others, the Conservancy will meet later this month with other like-minded groups in the so-named “Partners in Flight” conference.
There bird scientists, avian experts and birders will discuss what is currently underway to preserve, protect and promote the survival of the Western Hemisphere's entire aery of bird species.

“The stakes are quite high,” Fenwick says. “Many migratory bird species are far less common today than they were even in the early 1990s when efforts to reverse these broad declines was launched.
"This is true in part because the details surrounding the migration of many bird species had been a mystery until recently; and that point made it more challenging to take corrective action.”
- Jeffrey L. Frischkorn

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