Bald Eagles Rebound, Other Birds of Prey in Trouble (1 Viewer)

Bald Eagles Rebound, Other Birds of Prey in Trouble

Wed Oct 6, 8:03 AM ET

By Ed Stoddard

BANGKOK (Reuters) - The bald eagle is out of the woods but other birds of prey are in trouble.

An icon of conservationists, the bald eagle was on the brink of extinction in America's lower 48 states four decades ago, when its numbers stood at just 417 nesting pairs.

Anti-poaching measures, a reduction in the use of lethal pesticides and the transfer of eagles from Canada have seen its numbers rise in the lower 48 to several thousand. Washington now says that some of the bird's safeguards can be loosened.

Classified as endangered in 1978 under the Endangered Species Act, it was downgraded to threatened in 1995 and the U.S. Fish and Wildlife Service has proposed that it be removed from the list.

At the Convention on International Trade in Endangered Species (CITES) conference which began in Bangkok on Saturday, Washington is proposing that the bird's global status be shifted from a list of critically endangered animals to one that would allow some commercial trade in the species.

The gesture is in some ways symbolic as global demand for the bird and its parts is modest and limited mostly to collectors of Native American artifacts.

"There appears to be little evidence suggesting a strong demand for eagles or eagle parts on an international scale," says the U.S. proposal to CITES.

Outside America's lower 48 states, bald eagles are flourishing. In Alaska and British Columbia there are believed to be close to 100,000 of the birds, which are a common sight soaring high above the region's thickly wooded coastline.

TROUBLE ELSEWHERE

Other winged predators are not so lucky and conservationists say that the bald eagle's success should not lead to a false sense of complacency regarding its feathered kin.

BirdLife International has classified about a quarter of the planet's roughly 305 known raptor species as threatened.

"Many birds of prey are in global decline," said BirdLife's Richard Thomas.

Birds under threat include the majestic saker falcon, which is being pushed toward extinction because of demand from wealthy Gulf Arabs who prize the animal for its hunting prowess.

The saker falcon is the traditional species used by Gulf falconers when hunting the houbara bustard.

BirdLife said recent surveys show its population has fallen to around 4,000 pairs in 2003 from about 10,000 pairs in 1990 -- a decline of 60 percent throughout its range, which stretches from eastern Europe to western China.

Even CITES -- a convention credited with saving a range of animals -- would have difficulty regulating this trade.

"I don't think that CITES can do all that much for the saker falcon. The sums involved are just too great and the trappers are just too poor," said Dr Nigel Collar of BirdLife.

Many of the worst-off populations are in developing countries, where the use of pesticides in agriculture is not always subject to strict or properly enforced regulations.

As top predators, birds of prey often suffer heavily from contamination as the poison works its way up the food chain.

"A lot of birds of prey are doing better in Europe now because of the elimination of pesticides such as DDT," said BirdLife's Thomas.

In much of Africa, this is not always the case.

Rampant deforestation and habitat loss is also reducing raptor numbers in parts of the developing world.

Ridgway's Hawk is down to only a few dozen in its only home, Haiti and the Dominican Republic.

URBAN SCENE MIXED

Urbanization has had a more mixed impact.

The elimination of habitat associated with urban sprawl may not be good for bigger species such as eagles but others take to cities like ducks to water.

In South Africa's bustling commercial center of Johannesburg, owls can sometimes be spotted atop telephone poles at dusk while various hawks and kites hunt the city's parks.

"Some of the smaller raptor species capitalize on human settlement and they are an indicator of an altered environment," said Andrew Jenkins of the Percy FitzPatrick Institute of African Ornithology in Cape Town.

"Suburban gardens ... support a high number of birds and bird-eating hawks can make hay out of the situation," he said.

High-rise buildings are also good nesting sites for some predatory birds while others thrive on the rat and mice populations that accompany dense human settlements.

The bald eagle's comeback in the continental United States may give hope for some birds of prey but its fall to near extinction was a sign that an even worse fate may await others.

When the bald eagle was adopted as the national symbol of the United States in 1782 it was estimated that there were 250,000 of the birds in the land that today forms the lower 48 states.

Hunting, poisoning and habitat loss as America expanded west all took their toll on the bird, driving down its numbers to the few hundred that were left in 1963 in the continental United States.

Mike

"allow some commercial trade" in Bald Eagles???

I am worried about ferruginous here in the west. I hope things turn around for this species.

also remember that mass die off down in south or central america, mis-use of pesticides and 1000's swainsons expired.


this is qouted info below................

The ferruginous hawk was previously listed as a Category 2 species for potential listing as threatened or endangered under the Endangered Species Act. The ferruginous hawk is a large western buteo with a range in mass from 977 to 1,194 grams (males), and from 1,501 to 1,866 g (females). The average length is 58 cm, with a wingspan of 135 cm. Nest sites include rock outcrops, hillsides, trees, or cliff-sides. Ferruginous hawks primarily prey on mammals, ranging from mice and voles to ground squirrels and full-grown jackrabbits.

Localized declines have made the Swainson’s hawk, a Neotropical migrant, a species of concern throughout its range. Extensive southward migration to the Pampas region of Argentina and colonial roosting has made it vulnerable to agricultural pesticides, particularly organophosphates. The Swainson's hawk nests in trees throughout the western United States. The average size is 53 cm in length and wingspan is 132 cm. Mass ranges from an average of 725g (males) to 1,150 g (females).



more on the swainson die off...

A total of three Swainson's hawks were tagged with 30 gram PTTs, the first on 6 September 1996, the second on 7 September 1996 and the third, on 8 September 1996. All were adult females and thought to be successfully nesting in the vicinity of Tooele and Grantsville, Utah. All three Swainson’s hawks followed a similar pathway southward to Argentina. Migration south began in the third week of September. They were detected in the southeastern corner of Utah by the end of September, continuing across New Mexico into Texas, following the Texas Mexico border, continuing along the coastal plains of Mexico, and passing Verracruz by mid-October (Fig. I-10). By the third week in October all three individuals had arrived in Panama. Then they entered Colombia, where they migrated along the eastern slope of the Andes mountains. These birds passed east of Iquitos, Peru and traveled through the Selvas region of Brazil, and through central Bolivia, with all individuals entering northern Argentina by the second week in November. They continued southward and east to arrive in the Pampas region of Argentina by mid-November (Fig. I-11). All three stayed within this heavily agriculturalized region, the major crops being sunflowers and alfalfa.

An international group of scientists studied Swainson’s hawks in this area during 1995 and 1996. Researchers documented colonial roosts, with hundreds (sometimes thousands) of Swainson’s hawks roosting in trees planted by resident farmers and ranchers. Swainson’s hawks foraged for grasshoppers, where they also became vulnerable to applications of organophosphates used by farmers to reduce insect pests. In some cases Swainson’s hawks came in direct contact with the pesticides as they were sprayed, or they ingested insects that were recently sprayed. Organophosphates act quickly in the body and in this case killed thousands of Swainson’s hawks in farm fields. Large numbers of dead hawks also were discovered at roost sites (B. Woodbridge and M. Fuller, pers. comm.).

Because Swainson’s hawks marked with PTTs helped this international team of researchers delineate the winter use area of Swainson’s hawks in the Pampas of Argentina, steps were taken to limit the use of organophosphates by local farmers through a voluntary program carried out by the chemical suppliers and local authorities. Area farmers were able to substitute another product that proved to be less harmful to hawks in place of the pesticide (i.e., monocrotophos) affecting Swainson’s hawks (M. Kochert, pers. comm.).

No mortalities of Swainson’s hawks were reported for the 1996/1997 winter period. All three of the Swainson’s hawks tagged at DPG began a northward migration by mid-March and followed the same pathway that they had used the previous autumn. All three birds were detected in Mexico during April and arrived in New Mexico by the first week of May. The tagged birds had returned to the breeding use areas by mid-May. An effort was made to recapture and remove the PTTs from these birds. All three radio-marked individuals attempted to breed. Two PTTs were recovered from birds that successfully fledged young. The third bird was on territory, but no young were observed, and trapping efforts failed.

Year-round information collected on Swainson’s hawks provides valuable insight for DPG base natural resource managers. It would be difficult to assess the management success for a species that spends most of the year on migration and in winter use areas. These types of movements expose this species to a wide array of threats that military installations cannot manage. This case in particular demonstrates the need to fully understand the natural history and potential problems a species is exposed to.