Black-throated green warbler, Dendroica virens.
Image appears here with the kind permission of the photographer, Pamela Wells.
Click image for larger view in its own window.
Birds in Science
Wendy Reed and her research team’s study found that male dark-eyed juncos, Junco hyemalis, with extra testosterone were more attractive to females and produced more — but smaller — offspring. Smaller offspring had lower survival rates than larger offspring. The extra testosterone also made the male birds sing more sweetly and fly farther. The testosterone-laden birds proved irresistible to older, more experienced female juncos, but that attractiveness carried some risks. Elevated testosterone levels increased activity — possibly attracting more predators — and made the male dark-eyed juncos more susceptible to disease and shortened their lifespan. “They had lower immune function and paid a cost with lower survival rates,” said Reed. [AAAS mp3]. The podcast notes that such feathered Casanovas have a better sex life, but a shorter one than birds not receiving the extra testosterone in the study. Reed led the research as part of her postdoctoral work. [Reference: “Physiological Effects on Demography: A Long-Term Experimental Study of Testosterone’s Effects on Fitness.” The American Naturalist. May 2006, Vol. 167, No. 5, pgs 667-683. I can email this PDF to you.]
In a truly amazing technological advance, University of Florida scientists have delivered a gene through an eggshell to give sight to a type of chicken normally born blind. The finding, reported last Tuesday (May 23) in the online journal Public Library of Science-Medicine, proves, in principle, that a similar treatment can be developed for an incurable form of childhood blindness. “We were able to restore function to the photoreceptor cells in the retinas of an avian model of a disease that is one of the more common causes of inherited blindness in human infants,” said Sue Semple-Rowland, Ph.D., an associate professor of neuroscience with UF’s Evelyn F. and William L. McKnight Brain Institute. “The vision capabilities of the treated animals far exceeded our expectations.” GrrlScientist note: unfortunately, I was unable to link to the original article. Maybe I’ll have better luck later in the week.
This is not exactly a bird story, but it does focus on island biogeography by providing some insights into a long-standing biological mystery; Madagascar’s abundance of native species. In fact, explaining Madagascar’s extraordinary levels of plant and animal endemism has been called “one of the greatest unsolved mysteries of natural history.” The long separation of Madagascar from Africa and India explains only some aspects of the island’s endemism. Even more intriguing is that many of these plants and animals have very small distributions on the island, something that is called micro-endemism. For the first time, new research presents a comprehensive theory explaining how so many animals came to be limited to such small geographic areas across the island, which lies off the eastern coast of Africa. In some lowland areas of the island these animals tended to be isolated by the configuration of certain watersheds, and this isolation led to speciation, the evolution of new species.
People Helping Birds
In an impressive move, a 73-acre spit of sand, mud and rock considered one of the most significant shorebird migration stopovers in the world has been purchased by the nonprofit Conservation Fund for permanent habitat protection. The Mispillion Harbor purchase, announced last Wednesday, protects both an important spawning area for horseshoe crabs and a critical stopover point for migrating shorebirds, including the endangered red knot, Calidris canutus rufus. By some estimates, as many as 80 percent of the red knots that pass through the bay shore stop at Mispillion Harbor on the Delaware Bay to feed and rest. “It’s not an exaggeration to say that the few acres of beach in Mispillion are critical to the survival of the American red knot,” said said Nigel Clark, an ornithologist with the British Trust for Ornithology. “There is no other site of similar size anywhere in the world on which a whole bird population depends. When the weather is bad the protected beaches in the harbor allow the crabs to continue to spawn and provide a lifeline to the knot.”
Biologists monitoring the remote Northwestern Hawai’ian Islands were surprised last year when endangered Laysan ducks, Anas laysanensis (pictured), that had been translocated from Laysan Island to Midway Atoll National Wildlife Refuge began to breed six months later. They were again surprised when last year’s ducklings were already nesting this year. The first of Midway’s second generation ducklings hatched Sunday. “We did not expect the second generation of ducklings so soon,” said U.S. Geological Survey scientist Michelle Reynolds, the project leader for the Laysan duck reintroduction program. “It is a very encouraging sign that the Midway population is increasing naturally since the translocation of the wild birds from Laysan.” The Laysan duck was listed as endangered in 1966 because of its small population of less than 500 birds, small geographic range of less than four square miles, and dependence upon a fragile ecosystem.
Hawai’i Volcanoes National Park scientists are celebrating the most successful breeding year ever for the endangered nene goose, Branta sandvicensis (pictured), with 36 goslings surviving long enough to take their first flights. Normally, only about 15 newly hatched geese survive to become fledglings, or birds on their first flights, said Superintendent Cindy Orlando.
Chris Mensing stood inside a chicken-wire cage, reached out and caught a Brown-headed cowbird, Molothrus ater (pictured), from the air. Mensing is a wildlife biologist with the U.S. Fish and Wildlife Service and spends much of this time of year checking more than 50 cowbird traps scattered across nine northern Michigan counties. The program is part of rehabilitation efforts in place for more than three decades to help the endangered Kirtland’s warbler, Dendroica kirtlandii. There were about 200 singing male Kirtland’s warblers counted in the year before cowbird trapping began in 1972, while last year more than 1,400 singing males were identified — an all-time record. [Photographer: Record-Eagle/Sheri McWhirter]
The Indian government has FINALLY taken the crucial first step towards reversing the dramatic plunge towards extinction for three vulture species, by ordering a halt to the production and sale of the veterinary drug diclofenac within three months. Slender-billed, Gyps tenuirostris (pictured), Indian, G. indicus, and white-rumped vultures, G. bengalensis, die from kidney failure after eating the flesh of cattle and water buffalo treated with diclofenac. “This ban is exceptionally good news and the crucial step we have all been looking for. The decline of these Asian vultures has been quicker than any other wild birds, including the dodo,” said Chris Bowden, Head of the RSPB’s Asian Vulture Program. But reversing the population declines will be a slow business: vultures do not breed until they are five years old, and they produce only one egg each year. “Making diclofenac illegal and removing it from shop shelves are the next steps – and we don’t yet know how big a job the latter will be,” Bowden added. “But this ban may well be the turning point in saving the vultures from outright extinction.” Vultures fulfill a vital ecological role, stripping down animal carcasses that would otherwise slowly rot and attract disease-spreading feral dogs and other vermin. [Photograph: Dave Dick/RSPB]
It is not every day a sub-Antarctic penguin standing almost a meter high takes a wrong turn and comes ashore near Hobart, Tasmania (Australia). But this gentoo penguin, Pygoscelis papua, waddled ashore at Conningham during the weekend — farther north than normal. Gentoo penguins breed on sub-Antarctic islands and on the Antarctic Peninsula. Their closest breeding ground to Tasmanian is 1500km away on Macquarie Island. The bird was captured and then later released in a safer location.
Nineteen African penguins (also known as the “jackass penguin” due to its loud braying voice), Spheniscus demersus (pictured), and two sea otters that were rescued from a New Orleans aquarium after Hurricane Katrina returned home last Monday on a cargo flight donated by FedEx Corp. These animals had been living at the Monterey Bay Aquarium since September after they were evacuated when Katrina forced the Audubon Aquarium of the Americas to shut down. The New Orleans aquarium reopened over Memorial Day weekend.
The first corncrake, Crex crex (pictured), of 2006 was heard calling near Clonown in Co. Roscommon (Ireland) on 19 April. The official corncrake census, carried out by BirdWatch Ireland fieldworkers, runs from 20th May to the 10th July. BirdWatch Ireland is appealing to anyone who hears a corncrake to phone the Corncrake Hotline and enable conservation action to be taken to help protect these birds at their vulnerable nesting sites. The call of the corncrake, whose Latin name ‘Crex crex’ is reminiscent of its harsh song, was once heard throughout Ireland. This rarely seen bird suffered a sharp decline in range and numbers during the last half century and is now confined to three core areas; the Shannon Callows, Mayo and Donegal.
Recently, BirdLife in Malaysia launched a campaign to save the Belum Temengor Forest Complex. Taman Negara is Malaysia’s prime National Park spanning Terengganu, Kelantan and Pahang, covering 4,343 square kilometres. The campaign aims to educate the public about the issues involved and to encourage the State and Federal governments to protect this critical area. Ideally, this would entail an end to all logging, as well as permanent protection of both forest reserves. It is hoped that with increased public awareness and proactive action from the government, Malaysian signature species, including majestic hornbills, elephants, tigers and tapirs, can remain alive in the wild rather than as stuffed museum specimens.
People Hurting Birds
The Northern Arapaho Tribe and a man accused of shooting a bald eagle, Haliaeetus leucocephalus, on Wyoming’s Wind River Indian Reservation, say the federal government makes it difficult for American Indians to apply to kill bald eagles for use in religious ceremonies. Federal law allows enrolled tribal members to get a permit to kill bald eagles in certain cases. But the accused, Winslow Friday, and the Northern Arapaho claim there is no clear way to apply for the permit.
Mystery surrounds the huge, inexplicable declines of birds that migrate thousands of miles from Africa to Europe each spring. Scientists fear that these birds’ dwindling numbers may be a warning of widespread environmental damage. Climate change, drought and desertification in Africa, and massive pesticide use on African farmland may all be to blame for the declines of once common UK birds such as the spotted flycatcher, Muscicapa striata, Northern wheatear, Oenanthe oenanthe, wood warbler, Phylloscopus sibilatrix, and European turtle-dove, Streptopelia turtur, a BirdLife Europe-wide study led by the RSPB (BirdLife in the UK) concludes. At the same time, birds such as the European roller, Coracias garrulous (pictured), pallid harrier, Circus macrourus and lesser kestrel, Falco naumanni, have also vanished from regular breeding sites on the continent. All three species are now classified as near- or globally threatened. [Photograph: Danielle Occhiato]
With 400 different species of birds living or breeding in Wisconsin, residents of that state brag that they are the state with most species of birds. But despite this, the birds seem to be disappearing. “A recent analysis of birds around the world suggested that almost 18 percent of birds around the world are declining in numbers. That’s one in six birds. And there was no obvious end to these declines unless we change our relationship with those birds,” said Stanley Temple, a UW Madison Wildlife Ecologist. He says there are four simple reasons why these birds are going extinct: over-killing, impact of exotic species, habitat loss, and ecosystem stress caused by pollution. Wisconsin has already lost around a dozen species of birds.
People Getting their Just Desserts
Everyone claimed that Colin Watson gave up raiding nests of rare and endangered birds to collect their eggs, but now that Britain’s most notorious egg-collector died after falling out of a tree that held the nest of a rare bird, well, I’ll just be polite and say that this convicted criminal died doing what he loved, which is far better than most of us can look forward to.
Avian Influenza News
The UN’s Food and Agriculture Organization (FAO) has finally come to their senses when it said it is unreasonable to blame wild birds as the source of H5N1, in the absence of rigorous research into their role in the ecology and dynamics of the virus. “It is indeed likely that (wild birds) can introduce the disease to unaffected areas from countries in which the disease has already been identified,” the FAO’s statement asserts. “But the disease is spread through the human activities of poultry production, improper hygiene and uncontrolled commercialization.” The ‘simple fact’, the FAO says, is that more research is needed to understand wild bird migration and the vulnerability of different species, in order to perform proper risk assessments, and recommend risk mitigation measures where required.
An extended family of eight have been infected with bird flu in Indonesia. The virus was likely passed among themselves, but world health officials said Wednesday there is no reason to raise its pandemic alert level. It is the fourth — and largest — family cluster of bird flu cases that were probably transmitted from person to person since the outbreak in Hong Kong in 2003, World Health Organization spokesman Gregory Hartl said. Six of the seven family members who caught bird flu have died, the most recent on Monday. An eighth family member who died was buried before tests could be done, but she was considered to be among those infected with bird flu.
This week on BirdNote, they present on Memorial Day, a tribute to the Passenger Pigeon, Ectopistes migratoria (pictured); Tuesday, the amazing song of the Canyon Wren, Catherpes mexicanus (one of my favorites); Wednesday, bird song ID; Thursday, BirdNote corrects an earlier error about avian flight; and Friday, Keep Your Cats Indoors 2006. BirdNotes transport the listener out of the daily grind with two-minute vignettes that incorporate the rich sounds of birds provided by Cornell University and by other sound recordists, with photographs and written stories that illustrate the interesting — and in some cases, truly amazing — abilities of birds. Some of the shows are Pacific Northwest-oriented, but many are of general interest. BirdNote can be heard live, Monday through Friday, 8:58-9:00AM in Western Washington state and Southern British Columbia, Canada, on KPLU radio and now also in North Central Washington state on KOHO radio. All episodes are available in the BirdNote archives, both in written transcript and mp3 formats, along with photographs. Listener ideas and comments are welcomed. [rss].
This week’s photoessay at This Week at Hilton Pond is devoted to telling you about the great times that the Hilton Pond naturalists had with birds during their recent visit to Mountain Lake Biological Station and the adjoining resort and hotel in Giles County, VA. Depicted this week are some great photographs of a Yellow-bellied Sapsucker and a female hummingbird, plus an active Ruby-throated Hummingbird nest. In addition, an account of birds banded during the period at Hilton Pond is included, along with a few miscellaneous nature notes. The server’s been a little sluggish lately, so if you can’t get the page to open right away, please refresh.
It’s a question that has baffled scientists, academics, philosophers and pub regulars throughout the ages: What came first, the chicken or the egg? Put simply, the reason is down to the fact that genetic material does not change during an animal’s life. Therefore the first bird that evolved into what we would call a chicken in prehistoric times must have first existed as an embryo inside an egg.
The Fine Print: Thanks to my bird pals; Scott, Biosparite, Sara, Bill, Dawn, Jeremy, Ellen and Ron for some of the news story links that you are enjoying here. Thanks in advance to Ian for catching my typos; as you might know by now, I put a few typographical errors in these documents just so Ian can find them! The featured image (top) appears here with the kind permission of the photographer. Please respect the photographer’s copyright and also support her generosity by purchasing a photograph from her.