Saturday, August 13, 2005

Extinction Sometimes Is Not Forever

Above: Skeleton of a Dodo bird at American Museum of Natural History

Scientists beware: Don't count your extinct bird species because one of them may hatch.

Several supposedly extinct birds have recently been "rediscovered," raising hopes that others not seen for ages may still be taking to the skies.

"The real message of rediscoveries is that we didn't look hard enough in the first place," said Nigel Collar of UK-based conservation group BirdLife International.

"Rediscoveries" fall into two categories, the first being birds that were written off as extinct but subsequently found.

The second includes birds not seen for decades -- often because conflict made their home range inaccessible -- but that were not necessarily considered extinct.

One of the most startling avian "resurrections" was the New Zealand storm petrel, which was positively sighted in 2003. Believed by many to be extinct, it was previously only known from fossil material and three 19th century specimens. A group of bird watchers saw the black-and-white sea birds off New Zealand's North Island in January 2003.

Also in 2003, the long-legged warbler -- not seen by experts since 1894 -- was found alive in the mountains of Fiji.

Left: Two white-winged guans rest on perches in their cage in a protected area in northern Peru. A quarter of century ago, Perus white-winged guan, a species native only to this Andean bird paradise, was considered as dead as a dodo. Discovered in 1877 by a Polish ornithologist, the birds were believed extinct for 100 years until their rediscovery in 1977 by Gustavo del Solar, a hunter-turned-conservationist who founded a special breeding project to reintroduce it to the wild.

Last year, the rusty-throated wren-babbler -- not seen for almost 60 years -- was spotted in India's Himalayan mountains.

For some experts, the "Holy Grail" of lost birds has been hoisted with the rediscovery of the ivory-billed woodpecker, a large bird with striking looks that was believed to have fallen victim to the logging industry.

The southwestern African country of Angola, which is emerging from three decades of civil war is proving to be rich in "lost birds." South African ornithologist Ian Sinclair has been to Angola four times since war ended in 2002 and has found 18 endemic species not been seen and identified by experts for decades.

"We discovered that civil war, while obviously bad for people, was good for the habitat and the environment," Sinclair told Reuters. "All of these huge coffee plantations were abandoned ... A lot more habitat is available as a result."

A six-day expedition earlier this year yielded positive sightings of the orange-breasted bush-shrike and the white-headed robin-chat -- not seen by scientists since 1957.

The group also spotted a single pair of black-tailed or slender-tailed cisticolas. These are only found in Angola and neighboring Democratic Republic of Congo and had not been seen in the wild since 1972.

Swiestra's francolin -- similar to a grouse or partridge -- is the one Angolan endemic that Sinclair has yet to rediscover.

"It's only known from a single specimen collected in September 1964 in northwestern Zambia. So it's been off the map for 40 years," he said.

Also being sought is the pink-headed duck of India and Myanmar. There have been no reliable sightings since the late 1940s but there are reports of rural folk hunting it in Myanmar.

Still, there are clearly some no-hopers, such as the famed dodo of Mauritius, a large flightless bird that died out long ago.

Right: Watercolour of extinct Pink-headed Duck by Bhawani Das. Painted between 1777 and 1782 for Lady Impey in India, from living bird. National Museums Liverpool

Despite the new finds, BirdLife says the overall situation of the world's birds is worsening.

In a recent report, it said more than a fifth of the planet's bird species faced extinction as humans ventured further into their habitats and introduced alien predators.

* Reuters Story

In Massachusetts Gay Marriage Good For Swans Too

The not-so-aptly named Romeo and Juliet reside in the Public Garden in spring and summer. (Globe Staff Photo / John Tlumacki)
Boston's beloved pair of swans -- feted by city leaders, residents, and tourists alike as one of the Hub's most celebrated summer attractions -- are a same-sex couple. Yes, scientific tests have shown that the pair, named Romeo and Juliet, are really Juliet and Juliet.

The city's Parks and Recreation Department conducted the tests months ago, but didn't announce the results for fear of destroying the image of a Shakespearean love story unfolding each year in the Public Garden.

''Each year when the swans go in, the kids immediately come to us and say, 'Which one's Romeo, and which one's Juliet?' " parks spokeswoman Mary Hines said yesterday in response to a Globe inquiry. ''It's just like one of those fairy tales; why spoil it?"

This year and last, the swans have laid eggs in the spring and then stood guard at the nest as visitors and nearby residents made regular pilgrimages, hoping to see the eggs hatch. Neither batch did. Turns out, that's because they were never fertilized by a male swan.

The news ignited something of a debate among swan spectators in the Public Garden yesterday, with some insisting the city now should buy a true Romeo and others saying the city should embrace the two as a couple.

''If these two swans are happy together, they shouldn't have to have a guy," said Emma Stokien, a 15-year-old from New York. ''It's good to have the swans as a symbol of the acceptance in Massachusetts."

* Boston Globe Story

Wednesday, August 10, 2005

Mute Swan Song In Maryland?

The Maryland Department of Natural Resources has wrestled with the issue of invasive species for years. But, the story of the Mute Swan stands out among similar stories, mostly because many bird lovers have such affection for this beautiful, but environmentally destructive, species of swan. Here, an update on the agency’s efforts to resolve the fate of the Mute Swan in Maryland.

Despite their aesthetic appeal, mute swans can cause problems. The mute swan is native to Europe and Asia, but is an exotic species in the United States. In Maryland, a feral population of about 4,000 mute swans has become established from the original escape of five captive swans in 1962. The largest number of mute swans occurs in Talbot, Queen Annes, and Dorchester counties. Population growth and range expansion of this species has increased the number of swan-related problems for people and native wildlife.

Public opinion about mute swans is mixed. They are very large birds, measuring 56-62 inches in length. With little or no fear of humans, they are easily observed and provide opportunities for people to come in close contact with wildlife. Their vibrant orange bills with black knobs, white plumage and long, gracefully-held necks make them conspicuous. Their young, which have a dusky tinge and grayish bill, usually remain with their parents for about four months. Mute swans reside primarily in estuarine river habitats with smaller numbers on inland lakes and ponds.

Citizens frequently complain that mute swans reduce the availability of submerged aquatic vegetation, or SAV, to native wildlife, reducing recreational crabbing and fishing opportunities. Presently, we estimate that Maryland's mute swan population consumes about nine million pounds of SAV annually. Concentrations of mute swans have over-grazed bay grasses, eliminating habitats for crabs, fish, and other wetland dependent species.

In the early 1990s, a large molting flock of mute swans caused a colony of least terns and black skimmers, both state-threatened species, to abandon their nesting site on Barren Island in Dorchester County by trampling nests containing eggs and chicks. This was the only skimmer nesting colony in the Maryland portion of Chesapeake Bay. These swans also displaced nesting Forster's and common terns, declining species in Maryland. In other areas of the state, mute swans have also been documented killing mallard ducklings and Canada goose goslings.

* Maryland Department Of Natural Resources Page

Saturday, August 06, 2005

When Wings Sing

Richard Prum, a Yale ornithologist, was hiking through an Ecuadorean forest 18 years ago when he had one of the strangest experiences an ornithologist can have. He watched a bird sing with its wings.

Dr. Prum was observing a male club-winged manakin. The tiny red-headed bird was hopping acrobatically from branch to branch in order to attract female manakins. And from time to time, the male would wave its wings over its back. Each time the manakin produced a loud, clear tone that sounded as if it came from a violin.

"I was just utterly stunned," Dr. Prum said. "There's literally no bird in the world that does anything that prepares you for it. It's totally unique."

Ever since, Dr. Prum has wondered how the club-winged manakin managed this feat. Now he and a former student, Kimberly Bostwick of Cornell University, believe they have solved the mystery.

Club-winged manakins rake their feathers back and forth over one another, using an acoustic trick that allows crickets to sing. While the technique is common among insects, it has never been documented before in vertebrates.

The noise-making skill of manakins first came to the attention of naturalists in the 1800's. The club-winged manakin belongs to the manakin family (Pipridae), which includes about 40 species, many of which have peculiarly shaped feathers that allowed them to make sounds.

In many species the males use the noises during their courtship displays. "Some of them pop like a firecracker, and there a couple that make whooshing noises in flight," Dr. Prum said.

How Do They Do It?

Dr. Bostwick traveled to New York to study the manakin collection at the American Museum of Natural History. "I spent a lot of time playing with the feathers," she said. She noticed that next to the strangely ridged feather was another feather with a stiff, curved tip. She realized that each time a manakin shook its wings, its tip rakes across the ridges of the neighboring feather like a spoon moving across a washboard. Each time it hit a ridge, the tip produced a sound. The tip would strike each ridge twice - once as the feathers collided and once as they moved apart again.

Dr. Bostwick realized that this raking movement allowed a wing to produce 14 sounds during each shake. As a result, a bird could shaking its wings 100 times a second could produce a sound with a frequency of 1,400 cycles a second. "All the questions that hadn't made any sense just clicked into place," Dr. Bostwick said. (More from the NY TIMES)

Source: Science
* Video Manakin Mating Call (from Science Magazine)
* Cornell Press Release

Behind The Binoculars...Terrorist Or Birder?


Popular birding sites across the country, are facing stricter regulations -- in some cases being required to hire a police escort -- as authorities beef up national security.

Since the terrorist attacks of Sept. 11, 2001, Americans have been subject to increased government restrictions and scrutiny at airports and elsewhere. That bird-watchers have become a target is somewhat surprising, since all they do is ''walk quietly through the woods," as Brinkley put it.

But those woods are often around military bases, wastewater management plants, and dams -- places where government authorities fear that terrorists disguised as birders could lurk or strike.

And the equipment they carry -- binoculars, telescopes, and cameras -- can make birders look suspicious at first glance.

Birding at the Chesapeake Bay Bridge-Tunnel used to require only an annual permit that was easily available via mail, telephone, or fax; about 800 were distributed annually. To enter any of the three northern islands, which are not open to the public, a birder would only have to show the permit, a photo ID, and vehicle registration. The southernmost island, which has a restaurant and a fishing pier, is open to the public.

''Anyone could stop [on the islands]. We had no idea who was on the islands and who was not," said Clement Pruitt, director of operations and chief of police for the Chesapeake Bay Bridge-Tunnel.

But earlier this year, after Virginia's Department of Transportation determined that the ventilation buildings on each of the four islands were poorly secured, fences were erected around the buildings, and the three northern islands were closed to all but employees.

Under the rules, which took effect Friday, individuals or groups of no more than 15 people will have to arrange their visits in advance and pay $50 an hour to be escorted by an off-duty police officer. Upon arrival, all birders must provide photo identification and vehicle registration. Their belongings and vehicles may be examined at check-in and at any time during the visit.

''These sorts of national security issues seem to be intruding in ways one would never have expected. You expect airline security. You don't expect it when you go birding. Who knew you'd have a police escort?" said Perry Plumart, director of conservation advocacy for the American Bird Conservancy. (LA TIMES article via Boston Globe)

* The Chesapeake Bay Bridge-Tunnel Website