Monday, July 31, 2006
The Washington Post Features the The Washington Biologists' Field Club which is celebrating 100 years of self-professed geekdom (six years late) this year, with a 150-page volume summarizing a century of counting every living thing on Plummers Island, the club's buggy, overgrown paradise a few steps into the Potomac, just downriver from the American Legion Bridge.
Established in 1901 as a weekend retreat, Plummers Island, called by the field club "the most thoroughly studied island in North America," today represents one of the most comprehensive, longest-running biological inventories in the country.
Scrambling over Plummers Island's rock and scrub, club members have documented every living thing known to have existed there. To date, that includes 885 species of vascular plants, 70 mosses and 597 beetles -- not to be confused with the five different cockroaches they have found
The stories begin in 1899, when botanist Charles Pollard formed the Washington Biologists' Field Club, and began the search for a suitable field camp.
In 1901, the group leased Plummers Island, which it bought seven years later. For about $200, the members built at its rocky pinnacle a wooden cabin with few amenities beyond a big fieldstone fireplace and lean-to kitchen.
At the time, the island was a mix of untended farmland, forest, rock and shoreline. The blend drew plenty of creatures and plant life, and the members began collecting, each in his area of expertise.
For about three decades, Shetler has collected plants on the island. Opening a steel cabinet down the hall from his Smithsonian office, he flipped through yellowed folders. Inside rested mistflower specimens collected as early as 1917, the vivid blue blossoms on some still colorful.
*Washington Biologists' Field Club Website
Friday, July 28, 2006
The presence of mercury in lakes and streams is already well documented, and the New York Department of Health advises people to restrict the consumption of any freshwater fish caught in most of the state to no more than one meal a week.
But Dr. Evers is one of the first scientists to test for wildlife mercury contamination beyond fish. He began his work in this area in 1998 and found that common loons, which eat fish, had highly elevated levels of mercury that made them lethargic and caused their reproductive rates to drop.He then decided to study songbirds, which never eat fish. In particular, he wanted to study the wood thrush, a small bird with a distinctive song that was once common throughout the Northeast. The population of wood thrushes has declined 45 percent in recent decades.
It was once thought that destruction of the bird’s forest habitat was responsible for the decline. But Dr. Evers now suspects that mercury contamination might be a factor, along with the wide-ranging negative effects of acid rain on the forests....
Dr. Evers’s work suggests that when mercury falls on land, it is absorbed by soil and by fallen leaves that are consumed by worms and insects. Songbirds then feed on the bugs, absorbing the mercury.
While all the birds he tested last year had mercury in their blood, wood thrushes had the most, Dr. Evers said, an average of 0.1 parts per million. That is below the federal safe standard for fish (0.3 p.p.m.) but high enough to affect the birds’ reproductive cycle.
With fewer songbirds to eat potentially harmful insects, the state’s forests would be at greater risk for damage by gypsy moths and other pests, Dr. Evers said.
Beyond that, mercury leaching into soil could find its way into the food chain in ways that are still unknown, he said.
Friday, July 21, 2006
Ruddy Turnstone / Photo by Peter VankevichIf you missed DC Audubon's May field trip to Bombay Hook, you have another shot to watch shorebird migration with us. Watch our webpage for details on our upcoming field trip to the Delaware Marshes.
This photograph was taken by Peter Vankevich during a DC Audubon field trip to Bombay Hook. As you can see, it is a gull, but its identity is somewhat uncertain. Do you know what species this is? Leave a comment if you think you know. (The gull in question is the one in the center.)
Thursday, July 20, 2006
A federal judge today temporarily stopped construction on a $320 million irrigation project in Arkansas in order to protect the habitat of the ivory-billed woodpecker, whose existence has been hotly debated since a claimed sighting in 2004.
U.S. District Judge William R. Wilson halted the Army Corps of Engineers' Grand Prairie Irrigation Project because federal agencies might have violated the Endangered Species Act by not studying the habitat fully. The construction site is 14 miles from where researchers said they spotted the bird in the swamps of the Cache River National Wildlife Refuge in early 2004. The bird had been presumed extinct for 60 years.
Since then, scientists have published a number of articles claiming the bird was actually a more common pileated woodpecker. Cornell University ornithologists continued their search this summer but to no conclusive avail. Most recently, Arkansas wildlife officials last month offered a $10,000 reward to anyone who can prove the bird's existence (Greenwire, June 22).
Wilson said for legal purposes he had to assume the woodpecker exists in that area. "When an endangered species is allegedly jeopardized, the balance of hardships and public interest tips in favor of the protected species," he wrote. "Here there is evidence the IBW might be jeopardized" (Andrew DeMillo, AP/Washington Post online, July 20). -- DK
Tuesday, July 18, 2006
The hummingbird, known as the Marvelous Spatuletail, is among the strangest and most spectacular of all birds. Adult males have tails that are more than twice as long as their bodies and end in two great ungainly-looking spoon-shaped feathers. The birds are also cloaked in iridescent feathers, and like all hummingbirds, they are highly aggressive despite their small size. Local people once believed the birds conveyed aphrodisiac properties when consumed, likely compounding their problems which already include the conversion of their extremely limited habitat to cattle pasture and agriculture....The American Bird Conservancy has engaged in similar efforts in Colombia to save wintering habitat for the cerulean warbler.
Despite its remote location, the area where the hummingbird lives is already known to birdwatchers. In order to find the species it is often necessary to commission the services of one of the world’s youngest bird guides, ten-year-old Solomon Ortiz-Perez, who for a small fee will lead eager groups of bird tourists up steep slopes to search for the bird. The spatuletail is fast becoming a flagship species for tourism in the area, and has already appeared in travel advertisements in American magazines that aim to attract keen birdwatchers to the bird’s remote habitat. It has also been declared the “Regional Bird” for Peru’s Amazonas region.
Friday, July 14, 2006
Kenilworth Park and Aquatic Gardens
Blooming lilies and lotuses
DC Audubon will be there and lead a bird walk in the gardens. Come meet some of our board members and field trip leaders. Look for our table in the picnic area near the visitors center. There is no need to RSVP for this bird walk; just meet up at our table at about noon.
This is a wonderful time of year to visit the Aquatic Gardens, since most waterlilies and lotuses will be at their peak. In addition to the flowers, the gardens attract a diverse array of breeding and migrant birds. The marsh and river trail offer additional birding opportunities.
Tuesday, July 11, 2006
For North American birders, the results regarding chickadees are intriguing. Though the black-capped chickadee and carolina chickadee interbreed and are similar enough in appearance to make identification difficult, they are not as closely related as one might think. Instead, black-capped is more closely related to the mountain chickadee. Among carolina chickadees, there are significant genetic differences between the two subspecies, the eastern extimus and the carolinensis subspecies in Louisiana. Whether that would be enough to call for a species split is not addressed in the Birding summary.
Monday, July 10, 2006
Changes in this Supplement fall into the following categories: (1) three species are added because of splits from species already on the list (Calonectris edwardsii, Dendragapus fuliginosus, Loxigilla barbadensis); (2) one species is added because of new distributional information (Fregetta tropica); (3) two species replace others presently on the list because of splitting of extralimital forms (Cuculus optatus, Ficedula albicilla); (4) one species name (Streptopelia risoria) is changed because of recognition of its status as a feral form of S. roseogrisea; (5) one family is merged into another (Dendrocolaptidae into Furnariidae), with no resultant nomenclatural changes; (6) one subfamily is elevated to status of family (Stercorariidae), with no resultant nomenclatural changes; (7) one genus (Asturina) is merged with another (Buteo), resulting in a new name combination (B. nitidus); (8) one species (sissonii) is transferred from one genus (Thryomanes) to another (Troglodytes); and (9) two species (Myiozetetes similis, Catharus mexicanus), in addition to three of the four added to the entire list [see (1) and (2) above], are added to the list of species known to occur in the United States.Of these, the one likely to affect the most North American birders is the first. Blue Grouse (Dendrapagus obscurus) has been split into two species, Dusky Grouse (D. obscurus) and Sooty Grouse (D. fuliginosus). The two species were split based on mitochodrial DNA and behavioral evidence. Sooty Grouse inhabits the Pacific coast, while Dusky Grouse claims the interior mountain west. There is an intergrade zone in Washington state. The paper that led to the split is here.
In addition to the changes listed in the first blockquote, the AOU has rearranged species into new genera within the sandpiper and tern families. In the case of sandpipers, species in the
Heteroscelus and Catoptrophorus genera have been moved to the genus Tringa, so that the list is now as follows:
Xenus cinereus Terek SandpiperFive genera have been split from the Sterna genus in the tern family: Onychoprion, Sternula, Gelochelidon, Hydroprogne, and Thalasseus. The new order is as follows:
Actitis hypoleucos Common Sandpiper
Actitis macularius Spotted Sandpiper
Tringa ochropus Green Sandpiper
Tringa solitaria Solitary Sandpiper
Tringa brevipes Gray-tailed Tattler
Tringa incana Wandering Tattler
Tringa erythropus Spotted Redshank
Tringa melanoleuca Greater Yellowlegs
Tringa nebularia Common Greenshank
Tringa semipalmata Willet
Tringa flavipes Lesser Yellowlegs
Tringa stagnatilis Marsh Sandpiper
Tringa glareola Wood Sandpiper
Tringa totanus Common Redshank
Anous stolidus Brown Noddy
Anous minutus Black Noddy
Procelsterna cerulea Blue-gray Noddy
Gygis alba White Tern
Onychoprion fuscatus Sooty Tern
Onychoprion lunatus Gray-backed Tern
Onychoprion anaethetus Bridled Tern
Onychoprion aleuticus Aleutian Tern
Sternula albifrons Little Tern
Sternula antillarum Least Tern
Sternula superciliaris Yellow-billed Tern
Phaetusa simplex Large-billed Tern
Gelochelidon nilotica Gull-billed Tern
Hydroprogne caspia Caspian Tern
Larosterna inca Inca Tern
Chlidonias niger Black Tern
Chlidonias leucopterus White-winged Tern
Chlidonias hybrida Whiskered Tern
Sterna dougallii Roseate Tern
Sterna hirundo Common Tern
Sterna paradisaea Arctic Tern
Sterna forsteri Forster’s Tern
Thalasseus maximus Royal Tern
Thalasseus bergii Great Crested Tern
Thalasseus sandvicensis Sandwich Tern
Thalasseus elegans Elegant Tern
Thursday, July 06, 2006
The researchers calculated that since 1500 -- the beginning of the major period when Europeans began exploring and colonizing large areas of the globe -- birds have been going extinct at a rate of about one species per year, or 100 times faster than the natural rate.
And the rate has been faster in recent times. "Increasing human impacts accelerated the rate of extinction in the 20th century over that in the 19th," the report said. "The predominant cause of species loss is habitat destruction." ...
The new assessment considerably exceeds previous scientific estimates that 154 bird types disappeared during that past 500 years, according to the researchers.
One factor contributing to such large differences in estimates is that "more than half of the known species of birds were not discovered until after 1850, an important point that previous estimates of extinction rates have failed to take into account," Raven said. "One can't register a bird as extinct if it was not known to exist in the first place."
The authors of the piece advise better policies to prevent extinctions. The new report is not all bleak, Pimm said. "The good news in this report is that conservation efforts are reducing extinction rates to about one bird species every three or four years," he said, but he added that even this improved rate "is still unacceptable." Of the 9,775 known species of birds, "an estimated additional 25 would have gone extinct during the past 30 years if it were not for human intervention," Raven said. Despite conservation efforts, "some 1,200 more species are likely to disappear during the 21st century," he warned. "An equal number are so rare that they will need special protection or likely will go extinct, too."
Read the rest.
The new report is not all bleak, Pimm said. "The good news in this report is that conservation efforts are reducing extinction rates to about one bird species every three or four years," he said, but he added that even this improved rate "is still unacceptable."
Of the 9,775 known species of birds, "an estimated additional 25 would have gone extinct during the past 30 years if it were not for human intervention," Raven said.
Despite conservation efforts, "some 1,200 more species are likely to disappear during the 21st century," he warned. "An equal number are so rare that they will need special protection or likely will go extinct, too."
It appears that bird droppings managed to survive the launch of the shuttle Discovery.
NASA's rocket scientists have a new appreciation for the out-of-this-world power of bird droppings. The orbiting space shuttle Discovery sported some whitish splotches on its black right wing edge that NASA officials said appeared to be bird droppings.
Shuttle lead flight director Tony Ceccacci said he saw the same splotches on the identical part of the shuttle about three weeks ago when Discovery was on the launch pad and laughed when pictures beamed back from space Wednesday showed they were still there.
That means these bird droppings withstood regular Florida thunderstorms, a mighty Fourth of July launch during which 300,000 gallons of water is sprayed at the shuttle's main engines, and a burst upward through Earth's atmosphere. During that launch Discovery went from zero to 17,500 mph in just under 9 minutes.