Archive for September, 2007
Auk, The, Â Oct 1999 Â by Sheldon, Frederick H, Â Winkler, David W
ANYONE WHO TRIES to identify a bird nest, without seeing the bird that constructed it, enters the realm of avian systematics. The attempt to determine the identity of the nest leads immediately to an effort to categorize the nest according to its overt features: Is it in a hole? Is it on a branch? If the nest lies in a hole: Where is the hole located? How big is it? How was the hole constructed? For the nest itself: What material is it made of? How is the material fitted together? How is the nest lined?
Such quests to identify nests depend ultimately upon evolution and the “nested” nature of nest architecture. Members of a group of closely related birds tend to build their nests based on a common architectural theme, and subgroups “nested” genealogically within larger groups tend to build nests that are variations on the larger theme. By examining a nest, we can quickly assess the general type of bird that constructed it (oriole, swallow) by the basic theme (pendant nest, mud nest). Then, by following a route of subthemes (e.g. shape, location, construction method, materials, etc.), we can whittle down the list of possible builders. The reason for the “nesting” of nest themes is that throughout evolutionary history, birds have met ecological challenges (e.g. changes in climate, predation, and competition) by adapting their nests to each new situation. These adaptations tended not to be revolutionary, because of genetic and selective constraints on the morphology and behaviors associated with nest building (Winkler and Sheldon 1994). Instead, they tended to be slight modifications on the main nesting theme. For bird systematists, who are scientists interested in understanding evolutionary patterns, this adaptive tinkering has provided invaluable clues to the history of avian life. It has created a hierarchy of nest types that, when deciphered, can shed light on the phylogenetic (genealogical) relationships of birds, and it has left an evidential trail of the interaction between genetics and ecology, the driving force of evolution. Thus, even a rudimentary consideration of the possible owners of an unidentified nest delves into the methods and logic of avian systematics and yields insights into bird evolution.
September 28th, 2007
pubmedcentral.nih.gov
Charles R Brown and Mary Bomberger Brown
Department of Biological Sciences, University of Tulsa, Tulsa, OK 74104, USA. charles-brown@utulsa.edu
Abstract
Comparisons across bird species have indicated that those more exposed to parasites and pathogens invest more in immunological defence, as measured by spleen size. We investigated how spleen volume varied with colony size, parasite load and an individual’s colony-size history in the cliff swallow, Petrochelidon pyrrhonota, a colonial passerine bird of North America. We used a sample of over 1700 birds that had all died during a period of inclement weather in 1996. We experimentally manipulated ectoparasitism by fumigating nests in some colonies prior to the bad weather. Birds from parasite-free colonies had significantly smaller spleens than those from naturally infested sites; spleen volume did not differ between the sexes and did not vary with age. Mean spleen volume increased significantly with the colony size at a site prior to the bad weather in 1996 and at the site in 1995, both measures of colony size being indices of ectoparasitism at a site. An individual’s history of breeding-colony size (defined as the average colony size it had occupied in years prior to 1996) had no association with its spleen size. The results are consistent with parasite-induced splenomegaly whenever birds are exposed to large numbers of ectoparasites. The results do not support spleen size as being a signal of differential life-history investment in immunological defence among individuals and thus run counter to interpretations from recent cross-species comparisons.
complete article please visit at www.pubmedcentral.nih.gov
September 27th, 2007
www.associatedcontent.com
The barn swallow, or Hirundo rustica, is an amazing bird to watch. These little birds travel a long distance in their six to eight years of life. These birds are found all over the world, except for Australia. The interesting thing about barn swallows is that they nest in large colonies. If you live near an open field or on the countryside, chances are you can easily attract these amazing birds. We have barn swallows that nest on our front porch every year. Watching these birds is a true delight.
Barn swallows differ from the American swallow because the barn swallow has a tail that is deeply forked. A male barn swallow will have longer tails than the female, and both male and female have rust on the underside of their body, a tiny bill and dark, almost blue upperparts. An adult barn swallow will reach about six inches in length. Young barn swallows look very similar to the adult bird, but are often paler and have a short tail.Â
When barn swallows nest, they stay near their colony. If you have ever hosted barn swallows, you will know they are near. If you walk near the carefully constructed nest, the entire colony of birds, which are excellent at flying in sharp turns, will attempt to mob you. Often, these attractive and skilled birds will nest very near humans, often on the eves of porches or in barns, as their name suggests. This is because barn swallows prefer to eat bugs. They can eat a large amount of flies, beetles, bees, moths, mayflies, grasshoppers, and aphids. These birds are quite beneficial to humans. These birds often begin their hunt for insects late on warm summer afternoons. They fly close to the ground over fields and water. They carry the insects back to their young.Â
Barn swallows are also easy to identify because of their unique nest they build for their young. Both male and female will make several hundred trips to collect bits of mud pellets and plant fibers. Both the male and female barn swallow works to construct the nest. These nests are almost cylinder in shape and resemble a carefully woven basket of mud. After the nest is complete, the female bird lays between three and five eggs. The female bird has what is called a brood patch, which is a bare part of her underside to enable her to incubate her eggs. These feathers grow back. Barn swallow eggs will hatch in about 15 days and the young will leave the nest after about 18 to 24 days. In addition, the male and female barn swallow may choose to use the same nest to raise another brood within the same mating season.Â
Watching the barn swallows take care of their young is fascinating. The parent birds work tirelessly around the clock to hunt insects and carry them back to the waiting young. At night, the parent birds rest outside of the nest, often clutching to the eve of the porch so that the young has the entire nest.Â
September 26th, 2007
Belfast Telegraph, United Kingdom - Sep 14, 2007
Friday, September 14, 2007
Following this most accursed of summers, with the hay slain by the rain and lying in the muddy fields like lines of infantry on the Somme, the strangest things have been happening to our birdlife. Buzzards do not naturally live in this part of Leinster.
Indeed, most bird maps do not even record them much beyond the Antrim coast.
But this time last year, a pair appeared here, as if house-hunting, and after their apparent scrutiny of an avian estate agent’s properties, they paused to have a buzzard’s Big Mac - a luscious young rabbit in the neighbouring fields above us - before flying away.
Then, some weeks ago, five buzzards appeared in a spiralling, whistling gyre, above our home. They spent much of the day declaring their interest in the area, as swallows and martins - we have no swifts here, for yet another unaccountable reason - swooped in waves to dissuade them from staying. This is a curious hostility, for buzzards are no threat to swallow or martin, on either wing or nest, yet the hatred is implacable, incessant and intrepid; yet also in vain, for the buzzards have now moved in.
Are they sons and daughters of last year’s visitors? So have brother and sister decided to set up home together? It seems a rather unhealthy, not to say Pharaonic arrangement. Should I organise a party of vigilantes, and with the blessings of a brace of men of the cloth, put an end to their disgraceful conduct?
I might - except, I don’t speak buzzard, and I know of no way of determining whether a buzzard’s mate is her brother, her cousin, her father, or God help us, her grandmother. I’m all in favour of lynching the immoral - a regular pastime of mine - but what if I suspected an incestuous relationship between two nesting buzzards, and a gang of us, armed with stout sticks, broke up their home, only to discover that they were married, within the rites of the Church; were regular communicants, and sang in the church choir? Morality is all very well, you know, and I’m all in favour of it, but you can take it too far. And for all I know, raptors who prey together, stay together.
Anyway, whatever the mores concerned, a couple of buzzards are now nesting in a grove of trees in nearby Barretstown Castle demesne. And day after day, a cruising adult buzzard glides in wide, speculative arcs overhead, like a hunchbacked eagle, its wings dipping this way and that, its odd whistles filling the sky. So how does a raptor benefit from announcing its presence to its potential prey?
I’ve tried to indicate to my noisy buzzard friends the whereabouts of a particularly scrumptious colony of rats, at the bottom of our local boreen, but my frantic signals have been to no avail. Lord, I’ve tried everything - Morse code, flags, Braille, Esperanto, Riverdance, yodelling, even Basque, but the prowling buzzards of Barretstown, still haven’t raided the rat-larder below.
So what has happened to make this part of Kildare interesting to at least two breeding pairs of buteo buteo whose family almost certainly came from Antrim? Possibly they are former Paisleyites who dislike their party leader’s deal with the Shinners, and instead have sought out my more intransigent company: in other words, DUBs.
On the other hand, perhaps the explanation for their move south lies in the weather, which has certainly provided a boon for the corncrake, whose traditional survival strategy is to sit still on its nest, no matter the provocation.
Perhaps this works well in coping with predators - it is less successful in repelling a tractor-drawn hay-reaper. But no hay could be cut this year because of the rain, so an unusual number of corncrakes have made it to adulthood - hence the hen corncrake and a single fledgling my dogs put up the other day. Fortunately, I had my shotgun with me, and a left and a right accounted for them both.
That was a joke. Not a good one, but a joke. When I made a similar joke a couple of years ago about shooting a sitting corncrake on its nest (but then declared I had done nothing of the kind). Valerie Cox nonetheless announced on RTE’s It Says In The Papers that I had actually shot and eaten the birds. A bright girl, and clearly she’ll go far in RTE.
So no, my little cockscomb, I didn’t kill the corncrakes this time either, but if you want to proclaim yet again on air about my avicidal ways, you can certainly say that earlier this summer, I did kill a bird - a young adult magpie, not with a gun, but by trapping it and killing it with a broom. Two blows, very hard.
How difficult is it to beat a bird to death? Not difficult at all, once you’ve come across an entire colony of slaughtered fledgling swallows. I then hung the magpie corpse on the stable door.
Other magpies have since stayed well away, and the swallows are once again prospering within, thank God, just as the prowling, whistling buzzards are prospering without.
September 25th, 2007
birds.suite101.com
Manage Your Backyard Bird Habitat to Attract Nesting Birds
© Rosemary Drisdelle
Apr 27, 2007
The right features can increase your chances of attracting nesting birds to your property and having wild birds nest and raise young in your backyard bird habitat.
For avid birders, there are probably few things more delightful than having birds nesting on the property. Installing nesting boxes for birds is popular and is often very successful; however, with the right backyard bird habitat you can create natural nesting sites for birds.
The species of birds that you attract to your backyard bird habitat depends on what bird species breed in your area and what kind of real estate you have to offer. You won’t attract Chimney Swifts, for instance, unless you have a natural or abandoned chimney four metres tall or taller. Similarly, Cliff Swallows won’t nest if there’s no cliff. Of course, if you’re lucky enough to have an unusual feature like a cliff, cave, or wetland on your property, you may be able to attract nesting birds that the rest of us just can’t.
Leave good nesting sites alone
The secret to good backyard bird habitat for nesting birds is often simple non-interference. Removing old dead trees, clearing brush, knocking down old cacti, draining wetlands, demolishing outbuildings, and removing old nests all destroy possible nesting sites. Leave the rotting stump if you can do so safely. Tidy up the outbuilding, make sure it’s not a safety risk and leave it for the birds. You may notice owls, swallows, robins, and various other birds moving in. Leave tall grasses, low bushes, badger holes, and last year’s nests alone. Old nests may be reoccupied by the same birds or by a different species. Or they may be taken apart for building materials.
Attract birds that nest high in trees
Many birds nest in evergreen or deciduous trees eight metres above the ground or more. Crows nest high in evergreens, building a new nest each time—their abandoned nests are sometimes taken over by hawks or even Great Horned Owls, especially in rural areas. Mourning Doves nest high in trees as well, in the crotch of a deciduous tree or in the Y of a branch. Steller’s Jays usually nest in evergreens, at least four meters off the ground, while Blue Jays nest as high or higher in evergreens or deciduous trees.
Attract cavity nesting birds
Cavity nesting birds are the species attracted by nesting boxes—boxes are important to some species that have lost many natural nesting sites due to habitat destruction. Old dead or dying trees are important natural nesting sites for these birds or, if you are in the US Southwest or Mexico, saguaro cacti. Common cavity nesting birds in North America include chickadees, woodpeckers, bluebirds, nuthatches, and tree swallows. Woodpeckers and flickers will excavate a large saguaro cactus, and Elf Owls are frequently a subsequent tenant.
Attract birds that nest near or on the ground
Low bushes, ferns and grasses, and fallen trees attract nesting birds. Song Sparrows and American Goldfinches nest fairly near the ground in bushes. (Dense bushes provide good protection from predators.) Juncos nest right on the ground, hiding their nests in tall grasses or upturned tree roots so don’t be too hasty with the weed trimmer and the shovel. And if you live in badger and prairie dog country in the Canadian prairies or the American Midwest, those empty animal burrows might just attract a Burrowing Owl—leave them if you can.
Entice birds to come and look:
Install a Birdbath to Entice Birds
Garden Birds and Transition Zones
Spring Gardening for Birders
Build a Dust Bath for Birds
Sources:
Canadian Wildlife Service and Canadian Wildlife Federation. “Hinterland Who’s Who.”
Perrins, Christopher ed. Firefly Encyclopedia of Birds. Buffalo: Firefly Books, 2003
Willison, Marjorie. The Complete Gardener’s Almanac. Halifax: Nimbus; 1993.
September 24th, 2007
birds.suite101.com
How the Chimney Swift, Chaetura pelagica, roosts, nests, and eats
© Rosemary Drisdelle
JUli 5,2007
North American chimneys east of the Rockies are often occupied by roosting flocks of Chimney Swifts. These birds are also tireless fliers-masters of the air.
Bird or bat?
The sun is setting in a clear summer sky when your eye is drawn skyward by an odd twittering sound. Even stranger, you observe a gathering of some flying creatures wheeling above an old brick chimney. Around and around they circle, with a few individuals dipping suddenly toward the chimney top then returning to the rest. Their darting dipping movement and the twittering sound reminds you of bats, but something is wrong: bats emerge at dusk and fly away—these flyers seem to be congregating. Then, one or two drop abruptly into the chimney, and soon the whole wheeling darting flock spirals suddenly into the chimney like a small tornado being sucked down a manhole; like something out of Harry Potter. Now the air is empty and silent. What have you seen? They’re not bats, and they’re not chimney sweep birds, they’re Chimney Swifts, Chaetura pelagica.
Chimney Swifts
The Chimney Swift, sometimes called the American Swift (the similarity of chimney swift to chimney sweep no doubt accounts for another common name—chimney sweep birds), spends its days on the wing hunting insects, and nights clinging to vertical inner walls of hollow trees, chimneys, abandoned buildings and old stone wells. Before Europeans colonized North America and removed many of the old hollow trees, Chimney Swifts roosted almost exclusively in trees. They adapted readily to chimneys, however, and actually increased in numbers.
Chimney Swifts are migratory birds, spending their winters in Peru and the Amazon Basin. They appear in North America in early spring, and nest in May, with each pair raising three to five chicks. Young birds fledge by about the thirtieth day and join their parents in flight. In the fall, young and old congregate in large numbers and as soon as the weather turns cold and flying insects start to decrease, they are gone.
Interesting facts about Chimney Swifts
Chaetura pelagica is a fascinating bird. Here are some interesting facts about Chimney Swifts:
• A Chimney Swift can eat a third of its weight in insects every day. Many annoying and biting insect pests are removed from our environment by these voracious birds.
• Chimney Swifts do not perch or walk on the ground: their feet are designed for clinging to vertical surfaces. From the time they exit the chimney to the time they reenter it, they never land.
• The tail feathers of Chimney Swifts are tipped with stiff bristles, which help them stay in place while clinging to a vertical surface.
• Chimney Swifts have to do everything while in flight—catch flying insects, grab airborne nesting materials, and break twigs off trees for nest building.
• The nest is built mostly of twigs, glued to each other and to a vertical wall with saliva. While building, the bird’s salivary gland greatly enlarges to meet the demand.
• There is usually only one active nest in any one chimney or tree—thus, the funnel of birds you see entering the chimney are roosting, not nesting there.
• Some flocks of migrating birds contain both swifts and swallows.
The Chimney Swift is apparently declining once again, partly due to the disappearance of many old chimneys. To help conserve Chaetura pelagica, some people are preserving old brick chimneys, saving them from demolition, or building chimney-like structures where Chimney Swifts can roost and nest.
September 21st, 2007
birds.suite101.com
Bird Saliva Provides a Prized but Contentious Food
© Rosemary Drisdelle
Aug 23, 2007
What is bird’s nest soup, and why is it a source of conservation concern after centuries of East Asian tradition? Edible-nest swiftlets are in decline.
What is bird’s nest soup?
Bird’s nest soup has been an Asian culinary tradition for centuries. Made from the nests of edible-nest swiftlets—usually Aerodramus fuciphagus (formerly Collocalia fuciphaga) or Aerodramus maximus (formerly Collocalia maxima)—it can be either savory or sweet. Savory soup is made with chicken broth and contains pieces of nest, bits of chicken breast, mushrooms, quail eggs, and sometimes ham. Sweet bird’s nest soup is a simple recipe using nest, rock sugar, and water.
Edible birds’ nests have a rubbery texture and don’t appeal to many palates; however, they are thought to be very nutritious and to have aphrodisiac properties. Nutritional analysis reveals a high protein content and variable amounts of minerals.
Edible nests
Edible-nest swiftlets nest communally in caves, building nests high above the ground. During nest building, the birds’ salivary glands become enlarged and produce thick ropey sticky saliva that hardens quickly when exposed to air. Over a period of weeks, swiftlets gradually construct a cup-shaped nest about the size of a human ear. Nests may be white, golden, black, or red: white nests are very clean and contain nothing but saliva; black nests contain plant parts and feathers; red are believed to contain blood from the birds’ salivary glands, but the colour may actually come from insects that they have eaten, or minerals leaching from the cave wall.
Harvesting edible nests
Harvesting edible birds’ nests is dangerous work that requires climbing to great heights in dark caves and prying the nests off the cave wall. Deaths and injuries are not uncommon.
If the first nest is destroyed or harvested before the birds lay eggs, the birds will rebuild—traditionally, the people of Southeast Asia have harvested the nests of edible-nest swiftlets after the birds have built the first nest but before there are eggs or hatchlings. A second harvest is carried out after fledglings have left the second nest.
Today, some swiftlets are farmed, using wooden structures that mimic cave conditions. So-called “house nests” are cheaper but have the same nutritional value as cave nests.
Threats to edible-nest swiftlets
Today, edible birds’ nests are one of the most expensive foods on Earth—packaged bird’s nest costs more than $150 US for just a hundred grams, and a bowl of bird’s nest soup in a restaurant will cost $60 or more. High prices result from the difficulty of obtaining nests and the high demand for the product. Because the nests command such a high price, there is increasing incentive for harvesters to take too many nests and even to take nests with young birds in them. In some places, edible-nest swiftlet populations have declined precipitously, although they are not threatened globally.
Dangers of bird’s nest soup
Bird’s nest soup is very nutritious and it certainly is a novelty to westerner’s who enjoy trying new things, but is it worth it? Those who eat it should be aware of a few caveats:
• Edible birds’ nests are one of the most common causes of anaphylactic food-related allergic reactions in East Asian children.
• Commercial birds’ nests, especially the highly prized varieties, are often adulterated with karaya gum (a tree extract), red seaweed, or a variety of fungus.
• Birds’ nests may absorb toxic metals from the walls of caves.
• The increasing value of edible birds’ nests is resulting not only in overexploitation of the swiftlets, but also corruption and violence in the industry. Those who control the caves guard them carefully and unwary trespassers are sometimes seriously injured or killed.
September 20th, 2007
thisisgloucestershire.co.uk, UK - Sep 11, 2007
GARDENERS are being warned to be on the lookout after confirming reports a potentially deadly disease has struck the Forest bird population.
A repeat outbreak of Trichomoniasis has struck colonies of chaffinches, greenfinches and bullfinches, following reports of dead and dying birds spotted in gardens throughout the area.
The parasite in infected birds lives in the upper digestive tract, eventually causing its throat to tighten up and unable to swallow food, causing them to starve.
Steven Hodgkinson, an RSPB Community Project Officer based in the Forest, said finches are particularly susceptible because they are highly sociable birds that flock and feed together.
Mr Hodgkinson said: “This is not the first time we have seen Trichomoniasis in the Forest so it is essential that good hygiene practice including the regular cleaning of feeders, bird baths and feeding surfaces is carried out.
“This will help to lower the risk to the birds of this and many other bird diseases.”
The disease is found across Britain in relatively low numbers but with hot spots breaking out in other locations such as Somerset, Wiltshire, Cambridge and Lincolnshire.
Mr Hodgkinson said in the early stages of the disease, the birds will often be found around feeders as they attempt to eat with limited success.
He said bird owners could limit the spread of the disease by temporarily stopping putting out food, except in tit feeders and leaving birdbaths dry until sick or dead birds are no longer found in the garden.
He added: “Please only stop feeding the birds when you suspect that there are sick birds in the area and not as a preventative measure as birds rely on feeding stations.
For further advice on how to help prevent the spread of the disease, please contact the RSPB on 01767 693690.
September 19th, 2007
links.jstor.org
Nicola Saino, Stefano Calza, Anders pape Moller
The Journal of Animal Ecology, Vol. 66, No. 6 (Nov., 1997), pp. 827-836
doi:10.2307/5998
Abstract
1. Intra-brood competition and parental feeding effort are considered important determinants of survival of offspring in altricial bird species because they affect accumulation of fat reserves by nestlings. However, the causal relationship between rearing conditions and post-fledging survival might also be mediated by other mechanisms; for example, the amount and quality of food provided by parents to each nestling might affect development of immune system organs and functions and, hence, the ability of offspring to cope with parasites and pathogens. 2. The hypothesis that parental feeding effort, food quality and brood size affect immunocompetence of nestlings was tested for the first time in the barn swallow, Hirundo rustica, Linnaeus. 3. The intensity of T-lymphocyte cell-mediated immune responsiveness was evaluated after intradermal inoculation of a lectin (phytohaemagglutinin) in a large sample of nestlings from unmanipulated broods and broods whose size had been manipulated immediately after hatching. 4. In unmanipulated broods, immune response, body mass and body condition were correlated negatively with brood size and positively with the rate of parental feeding to each offspring. Nestlings in enlarged broods had smaller immune response and body mass, and received less food per capita than those in reduced broods. 5. Broods artificially provisioned with a food rich in proteins showed larger immune response, but not larger body mass, as compared to unprovisioned controls. 6. We conclude that T-lymphocyte cell-mediated immune response as well as body mass is influenced by the level of parental investment and brood size, perhaps via its effect on competition for food. Since T-lymphocytes are fundamental components of avian immunity, and parasites are known to affect survival of their avian hosts, our results suggest a new pathway through which rearing conditions might influence offspring survival.
September 18th, 2007
By Michael Fumento
Published 9/14/2007 12:08:00 AM
American Spectator - Sep 13, 2007
New scientific discoveries keep eating away at the prophecy that “bird flu,” avian influenza type H5N1, will become readily transmissible from human to human and unleash a disastrous pandemic. This leaves little but rhetoric and those big, terrifying, huge, terrifying (Did I already say that?) numbers that panic purveyors throw around based on nothing more than extrapolations from baselines of their own choosing.
Among them:
* “Flu Pandemic Could Kill 150 Million, U.N. Warns.” (Actually, a single UN”5 million to 150 million,” but the media aren’t too keen on ranges.)
* Laurie Garrett, former Newsday reporter, now a senior fellow at the Council on Foreign Relations, and the Paul Ehrlich of pandemics (always wrong; always rewarded for it), speaks of H5N1 as a “tidal wave over humanity.”
* University of Minnesota School of Public Health professor Michael Osterholm estimated180-360 million deaths worldwide simply by extrapolating the estimated death toll from the Spanish flu of 1918-19 to today’s world population.
* But the winner is Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at Columbia University, who claimed on ABC News’s Primetime, “We could have a billion people dying worldwide.” When I asked him about this, he rather sheepishly admitted he meant to say “one billion ill.” Personally, I’d rather be ill than dead.
Taking all this to heart, if not to head, novelist and essayist Mark Helprin has proposed spending 2.5 percent of the national budget, or about 1 percent of GDP, to stave off the alleged threat. When defense spending has only gone up 0.8 percent of GDP since 9/11 and we don’t even have money to repair our bridges, such calls are downright distressing. In any event Congress has already allocated $5.6 billion to prevent a U.S. epidemic, though President Bush had requested considerably more.
Since I began writing on avian flu back in early 1998 and then during the more recent panic in 2005, I’ve driven the scare-mongers, most of them left-wing like the mega-blog Daily Kos, absolutely nuts by pointing out there’s no evidence for a pending pandemic.
They desperately seem to want to see people keeling over in the streets. One avian flu blogger went so far last December as to predict a 50-50 chance of a pandemic within the next year. I offered the blogger and any other taker not 2 to 1 odds but rather 10 to 1 odds that it wouldn’t happen. Curiously, each entity I specifically challenged chickened out. They couldn’t get permission from their mothers, stuff like that. One of the chickens was a fellow named Crawford Killian who authors the — or shall we say the — H5N1 Blog. He pretends to be the ultimate resource on avian flu developments but refuses to link to my articles. On the other hand, he did see fit to recently link to an online novel in which pandemic flu kills the entire population of Sydney, Australia (4.3 million) save for 300 souls. After all, in tackling such an important issue you have to have priorities.
YET EVIDENCE CONTINUALLY MOUNTS that while there may well be another flu pandemic of some sort, there’s virtually no chance it will be H5N1. Recently reported research from David Finkelstein and his colleagues at St. Jude Hartwell Center in Memphis, Tennessee, is just the latest nail in the chicken coop.
The researchers analyzed almost 10,000 avian H5N1 sequences and almost 14,000 human sequences, including those of seven dead Indonesians who apparently caught the virus from another human. They looked for specific amino acids either more likely to appear in human flu virus proteins or in avian virus proteins. Reporting their results in the journal Virology, they found no sequence that even approached the mutations in the flu viruses that caused the three pandemics of the 20th century, including Spanish Flu.
In all, they identified 32 clear-cut changes in influenza viruses that differentiated a human H5N1 strain from that in birds, yet none of the viral samples from humans had more than two of those changes. “We think they need to get to 13 [mutations] to be truly dangerous,” Finkelstein told Reuters. He characterized his finding as “reassuring.”
Will this affect media perceptions? Yes, that’s a purely rhetorical question. “Doctors warn the H5N1 virus is dangerously close to mutating so that is would pass easily between humans — which could spark a global pandemic that could kill millions of people worldwide,” declared Voice of America News on September 12. Due to space limitations it was unable to tell us what doctors.
On the other hand, what’s called mutation through antigenic shift is only one of two ways in which the bird flu might become readily transmissible between humans. The second is through what’s called “recombination” or “reassortment,” in which avian flu and seasonal flu “mix” inside a human or another animal, creating a hybrid with the worst traits of both. But the pandemic purveyors have been disappointed on that front, too.
A study using one of few animal species that contracts human flu, ferrets, appeared last year in the Proceedings of the National Academy of Scientists. The ferrets were infected with several H5N1 strains in addition to a common human influenza virus that circulates almost every year. The infected animals were then either placed in the same cage with uninfected ferrets to test transmissibility by close contact or in adjacent cages with perforated walls to test spread of the virus from respiratory droplets.
None of the secondary ferrets contracted either a reassorted virus or even just H5N1, thereby mimicking what we’ve seen in humans.
Separately, the scientists used gene splicing to create a hybrid virus. They found these hybrids also did not pass easily between the animals. Moreover, ferrets injected with the reassorted virus were less ill than those who received pure H5N1. Reassortment appears to have weakened the germ.
H5N1 appears to be a virus that, if you could interview it, would tell you it very much does not want to cause a human pandemic.
ALL OF THIS ALSO helps explain one of the least-known facts about H5N1, even though it’s documented by the World Health Organization (WHO). The viral strain’s discovery in poultry dates back not to 1997, as we’re constantly told, but rather to 1959, when it was identified in Scottish chickens.
Okay, perhaps haggis had a protective effect on the farmers; perhaps the virus can’t penetrate kilts. But there was also a terrible outbreak of the related H5N2 among both chickens and turkeys in Pennsylvania in 1983-85 (17 million birds were destroyed) that appears to have originated as H5N1 in seagulls.
In other words humans have been exposed to this thing for half a century with no evidence it’s become the least bit more contagious to them. Small increases in the counted numbers of human cases over the last four years are probably nothing more than an artifact of better reporting. Better disease reporting, by the way, is generally regarded as good news.
Yet virologist Robert Webster, probably the most respected of the alarmists, last November in the New England Journal of Medicine, specifically cited the annual increases in bird-to-human H5N1 cases since 2002 as cause for alarm. So what does it mean that, according to the WHO, current to September 10, throughout this year such cases have significantly lagged behind those of last year? You already know: “It’s even worse than we thought!”
Michael Fumento is a Washington-based health, science, and military writer.
September 17th, 2007
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