Archive for November, 2006
pubmedcentral.nih.gov
P L Lee, D H Clayton, R Griffiths, and R D Page
Department of Zoology, University of Oxford, United Kingdom.
Abstract
Swiftlets are small insectivorous birds, many of which nest in caves and are known to echolocate. Due to a lack of distinguishing morphological characters, the taxonomy of swiftlets is primarily based on the presence or absence of echolocating ability, together with nest characters. To test the reliability of these behavioral characters, we constructed an independent phylogeny using cytochrome b mitochondrial DNA sequences from swiftlets and their relatives. This phylogeny is broadly consistent with the higher classification of swifts but does not support the monophyly of swiftlets. Echolocating swiftlets (Aerodramus) and the nonecholocating “giant swiftlet” (Hydrochous gigas) group together, but the remaining nonecholocating swiftlets belonging to Collocalia are not sister taxa to these swiftlets. While echolocation may be a synapomorphy of Aerodramus (perhaps secondarily lost in Hydrochous), no character of Aerodramus nests showed a statistically significant fit to the molecular phylogeny, indicating that nest characters are not phylogenetically reliable in this group.
November 30th, 2006
lifeofguangzhou.com
Besides sharing an exorbitant price tag (not surprising considering that the first is made from the hardened saliva of the swiftlet bird, while the second requires days of preparation before arriving at the pharmacy) both of these exotic foodstuffs are reputed to be good for complexion and help skin grow. Fortunately so is the less expensive Fish Maw.
Made from the air bladder of certain types of fish, it works well in soups and stews, absorbing the flavors of the foods it is cooked with.Â
November 29th, 2006
blinkbits.com
Many; see text.
The swifts are birds superficially similar to swallows but are completely unrelated to those passerine species; swifts are in the separate order Apodiformes, which they formerly shared with the hummingbirds.
The resemblances between the swifts and swallows are due to convergent evolution reflecting similar life styles based on catching insects in flight.
The family scientific name comes from the Greek απους, apous, meaning “without feet”, since swifts have very short legs and never settle voluntarily on the ground, perching instead on vertical surfaces. The tradition of depicting swifts without feet continued into the Middle Ages, as see in the heraldic martlet.
Swifts are the most aerial of birds and some, like the Common Swift, even sleep and mate on the wing. One group, the Swiftlets or Cave Swiftlets have developed a form of echolocation for navigating through dark cave systems where they roost.
Like swallows and martins, the swifts of temperate regions are strongly migratory and winter in the tropics.
Many swifts have a characteristic shape, with a short forked tail and very long swept-back wings that resemble a crescent or a boomerang. The flight of some species is characterised by a distinctive “flicking” action quite different from swallows.
The nest of many species is glued to a vertical surface with saliva, and the genus Aerodramus use only that substance, which is the basis for bird’s nest soup.
Taxonomy
In the Sibley-Ahlquist taxonomy, the old order Apodiformes is split. Swifts remain in that order, but hummingbirds are put into a new order, Trochiliformes.
The taxonomy of this group is in general complicated, with genus and species boundaries widely disputed, especially amongst the swiftlets.
The treeswifts are closely related to the true swifts, but form a separate family.
Species list: Family Apodidae
Tribe Cypseloidini
* Chestnut-collared Swift, Cypseloides rutilus
* Tepui Swift, Cypseloides phelpsi
* Black Swift, Cypseloides niger
* White-chested Swift, Cypseloides lemosi
* Rothschild’s Swift, Cypseloides rothschildi
* Sooty Swift, Cypseloides fumigatus
* Spot-fronted Swift, Cypseloides cherriei
* White-chinned Swift, Cypseloides cryptus
* White-fronted Swift, Cypseloides storeri
* Great Dusky Swift, Cypseloides senex
* White-collared Swift, Streptoprocne zonaris
* Biscutate Swift, Streptoprocne biscutata
* White-naped Swift, Streptoprocne semicollaris
Tribe Collocaliini - swiftlets
* Waterfall Swift, Hydrochous gigas
* Glossy Swiftlet, Collocalia esculenta
* Cave Swiftlet, Collocalia linchi
* Pygmy Swiftlet, Collocalia troglodytes
* Seychelles Swiftlet, Aerodramus elaphrus
* Mascarene Swiftlet, Aerodramus francicus
* Indian Swiftlet, Aerodramus unicolor
* Philippine Swiftlet, Aerodramus mearnsi
* Moluccan Swiftlet, Aerodramus infuscatus
* Mountain Swiftlet, Aerodramus hirundinaceus
* White-rumped Swiftlet, Aerodramus spodiopygius
* Australian Swiftlet, Aerodramus terraereginae
* Himalayan Swiftlet, Aerodramus brevirostris
* Indochinese Swiftlet, Aerodramus rogersi
* Volcano Swiftlet, Aerodramus vulcanorum
* Whitehead’s Swiftlet, Aerodramus whiteheadi
* Bare-legged Swiftlet, Aerodramus nuditarsus
* Mayr’s Swiftlet, Aerodramus orientalis
* Palawan Swiftlet, Aerodramus palawanensis
* Mossy-nest Swiftlet, Aerodramus salangana
* Uniform Swiftlet, Aerodramus vanikorensis
* Palau Swiftlet, Aerodramus pelewensis
* Guam Swiftlet, Aerodramus bartschi
* Caroline Islands Swiftlet, Aerodramus inquietus
* Atiu Swiftlet, Aerodramus sawtelli
* Polynesian Swiftlet, Aerodramus leucophaeus
* Marquesan Swiftlet, Aerodramus ocistus
* Black-nest Swiftlet, Aerodramus maximus
* Edible-nest Swiftlet, Aerodramus fuciphagus
* German’s Swiftlet, Aerodramus germani
* Papuan Swiftlet, Aerodramus papuensis
* Scarce Swift, Schoutedenapus myoptilus
* Schouteden’s Swift, Schoutedenapus schoutedeni
Tribe Chaeturini - needletails
* Philippine Spinetail, Mearnsia picina
* Papuan Spinetail, Mearnsia novaeguineae
* Malagasy Spinetail, Zoonavena grandidieri
* Sao Tome Spinetail, Zoonavena thomensis
* White-rumped Needletail, Zoonavena sylvatica
* Mottled Spinetail, Telacanthura ussheri
* Black Spinetail, Telacanthura melanopygia
* Silver-rumped Needletail, Rhaphidura leucopygialis
* Sabine’s Spinetail, Rhaphidura sabini
* Cassin’s Spinetail, Neafrapus cassini
* Bat-like Spinetail, Neafrapus boehmi
* White-throated Needletail, Hirundapus caudacutus
* Silver-backed Needletail, Hirundapus cochinchinensis
* Brown-backed Needletail, Hirundapus giganteus
* Purple Needletail, Hirundapus celebensis
* Band-rumped Swift, Chaetura spinicauda
* Lesser Antillean Swift, Chaetura martinica
* Gray-rumped Swift, Chaetura cinereiventris
* Pale-rumped Swift, Chaetura egregia
* Chimney Swift, Chaetura pelagica
* Vaux’s Swift, Chaetura vauxi
* Chapman’s Swift, Chaetura chapmani
* Short-tailed Swift, Chaetura brachyura
* Ashy-tailed Swift, Chaetura andrei
Tribe Apodini - typical swifts
* White-throated Swift, Aeronautes saxatalis
* White-tipped Swift, Aeronautes montivagus
* Andean Swift, Aeronautes andecolus
* Antillean Palm Swift, Tachornis phoenicobia
* Pygmy Swift, Tachornis furcata
* Fork-tailed Palm Swift, Tachornis squamata
* Lesser Swallow-tailed Swift, Panyptila cayennensis
* Great Swallow-tailed Swift, Panyptila sanctihieronymi
* Asian Palm Swift, Cypsiurus balasiensis
* African Palm Swift, Cypsiurus parvus
* Alpine Swift, Apus melba
* Mottled Swift, Apus aequatorialis
* Alexander’s Swift, Apus alexandri
* Common Swift, Apus apus
* Plain Swift, Apus unicolor
* Nyanza Swift, Apus niansae
* Pallid Swift, Apus pallidus
* African Swift, Apus barbatus
* Forbes-Watson’s Swift, Apus berliozi
* Bradfield’s Swift, Apus bradfieldi
* Madagascar Swift, Apus balstoni
* Pacific Swift, Apus pacificus
* Dark-rumped Swift, Apus acuticauda
* Little Swift, Apus affinis
* House Swift, Apus nipalensis
* Horus Swift, Apus horus
* White-rumped Swift, Apus caffer
* Bates’ Swift Apus batesi
Reference
* Swifts by Chantler and Driessens, ISBN 1-873403-83-6
*
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eo:Apusedoj
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de:Mauersegler
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November 28th, 2006
glycob.oxfordjournals.org
Hiroki Nakagawa 1, Yoichiro Hama 2, Toshihisa Sumi 2, Su-Chen Li 3, Karol Maskos 3, Kittiwan Kalayanamitra 4, Shuji Mizumoto 5, Kazuyuki Sugahara 5, and Yu-Teh Li 6 *
1 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112; Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
2 Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
3 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112
4 Department of Biochemistry, Kobe Pharmaceutical University, Higashinada-ku, Kobe 658-8558, Japan
5 Department of Biochemistry, Kobe Pharmaceutical University, Higashinada-ku, Kobe 658-8558, Japan; Lab. of Proteoglycan Signaling and Therapeutics, Faculty of Advanced Life Science, Hokkaido University, Frontier Research Center for Post-Genomic Science and Technology, Kita 21-jo, Nishi 11-choume, Kita-ku, Sapporo 001-0021, Japan
6 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA
* To whom correspondence should be addressed.
Yu-Teh Li, E-mail: yli1@tulane.edu
  Abstract
Despite their wide occurrence, proteoglycans (PGs) have never been isolated from the saliva of higher animals. We found that the collocalia glycoproteins isolated from edible bird’s nests (the dried forms of regurgitated saliva of male collocalia swiftlets) were rich in a PG containing non-sulfated chondroitin glycosaminoglycans (GAGs). We have devised a method to isolate a PG from the water extract of the white nest built by Aerodramus fuciphagus (white nest swiftlets) with a yield of 2 mg PG/g nest. This PG contained 83% of carbohydrates of which 79% was GalNAc and GlcUA in an equimolar ratio. By using chondroitin AC lyase the structure of GAGs in this PG was established to be chondroitin (4GlcUA1Â Â 3GalNAc1Â Â )n chains. The average molecular mass of the chondroitin chain was estimated to be 49 kDa by gel filtration. We have isolated a linkage region hexasaccharide, HexUA1Â Â 3GalNAc1Â Â 4GlcUA1Â Â 3Gal1Â Â 3Gal1Â Â 4Xyl, from this PG by chondroitinase ABC digestion to show that the GAGs in this PG are also linked to the core protein through the common tetrasaccharide linker, GlcUA1Â Â 3Gal1Â Â 3Gal1Â Â 4Xyl, found in various PGs. As water was not effective in extracting uronic acid-containing glycoconjugates from the black nest built by black nest swiftlets (A. maximus), we used 4 M guanidium chloride, and anion-exchange chromatography in the presence of urea to extract and isolate about 30 mg of a chondroitin PG preparation from 10 g of the desialylated black nest. As the biological significance of chondroitin is still not well understood, bird’s nest should become a convenient source for preparing this unique GAG to study its biological functions.
Keywords: chondroitin; proteoglycan; glycosaminoglycan; bird’s nest; saliva.
November 27th, 2006
The Mercury (subscription), South Africa - Oct 25, 2006
October 25, 2006 Edition 1
At last people are talking sense about the plight of the barn swallows at the Mount Moreland roosts (The Mercury October 19).
In the past even some ornithologists have been heard to say that the swallows don’t matter, but put in the context that the roost accommodates at least 13% of the known population makes the threat to the roost, if Dube Tradeport goes ahead, an international crisis.
I have been monitoring the swallows since 1992. There are two roost sites at Mount Moreland, one on each side of the village. The mitigation for phase one of the tradeport was that the majority of any storm water run-off would go through the smaller wetland, but nobody from the Institute of Natural Resources, who are meant to be doing the EIA, had checked whether any swallows roost there. They do.
I think the estimate of three million birds could be very low. We know that between 700 000 and two million birds come in to roost on any one night (and that does not include the birds on the other side of the village). What we don’t know is how many of these are resident or just passing through.
My hypothesis is that the roost is more a “motel” than a residential hotel. If my thoughts are correct, and I base them on the fact that the numbers each night vary greatly, then the actual number passing through the roosts each year could be 10 times higher than the three million suggested.
With regard to air strikes, I don’t think that 18gm of barn swallow, even if consumed in large numbers, is going to have much effect on a modern jet engine which is designed to withstand much larger birds.
November 24th, 2006
By Alan Hamilton
Times Online, UK - Nov 14, 2006
NATURE, red in tooth, claw and sometimes rump, is a cruel beast.
Birdwatchers who flocked with their high-powered binoculars, telescopes and long lenses to see a rare Mediterranean visitor to Lunan Bay, near Montrose, got more than they bargained for. They watched in horror as the red-rumped swallow was attacked and eaten by a Scottish sparrowhawk.
Local enthusiasts spotted the swallow, which had taken a wrong turning on its migration route from southern Europe to its wintering grounds in Africa. Word that it had arrived on the East Coast of Scotland spread quickly, and a large crowd had gathered to watch it flying over the beach.
The swallowâs fatal mistake was to take a rest high on the roof of a nearby farm building. The twitchers watched in disbelief as the large hawk appeared, swooped on the swallow, crushed it with its powerful talons and flew off with its tasty Mediterranean dinner.
Mike Sawyer, of the Dundee branch of the Royal Society for the Protection of Birds, said yesterday: âWe were horrified. We had just phoned local birdwatchers to tell them of this rare occurrence. Then we had to ring them back and tell them it had been eaten.â
According to the RSPB the red-rumped swallow, Hirundo daurica, is a rare visitor to the UK but occasionally turns up during the migrating season, probably having lost its way. A specimen was last sighted in the Tayside area in 1987, and there have been only about a dozen sightings in mainland Scotland.
The sparrowhawk, Accipiter nisus, is a large and common predatory native that preys on at least 120 species of small bird as well as on small mammals. The swallow, by contrast, lives on a diet of insects that it catches on the wing.
One red-rumped swallow may not make a summer, but it makes a red-letter day for twitchers. Its demise is the second death of a rare bird in Scotland in as many weeks.
Eileen Alexander, of Dundee, was delighted recently to find a rare Australian black-throated finch feeding in her back garden. But the creature, one of its home continentâs most vulnerable species, collapsed and died before her eyes.
âI was out in the garden feeding the birds when I noticed two sparrows watching this tiny bird that was hobbling around. Then the poor wee thing took a nosedive into the mud,â Ms Alexander said.
âI went to take a look at it but it was dead, so I called a friend to see if he could identify it. He said heâd never seen anything like it, so he took it away for investigation.â
As the finch does not migrate to Europe, Ms Alexander assumed that it had escaped from a local house or pet shop.
The body is now in the hands of Mike Nicoll, a Dundee taxidermist, who hopes to preserve it. âIt is not good in either welfare or ecological terms to release alien captive birds, and we hope this was not done intentionally,â he said.
The death of the red-rumped swallow at the claws of a skilled flyer, on the other hand, was very intentional indeed. And, even if it is now deceased, the twitchers can still tick it off their lists.
November 23rd, 2006
ingentaconnect.com
Author: Joseph J. Hobbs1
Source: Biodiversity and Conservation, Volume 13, Number 12, November 2004, pp. 2209-2226(18)
Publisher: Springer
Abstract:
Due to the value of their nests, there is great pressure on the populations of black-nest swiftlets (Collocalia maximus) and white-nest swiftlets (Collocalia fuciphagus) in the Malaysian provinces of Sarawak and Sabah. The problems are particularly acute at Gunung Mulu National Park, in spite of a complete ban on collection there, and at Niah National Park, where every participant in a complex collection and trading system has an incentive to take more nests than permitted. More successful harvest systems function in Sabah’s Gomantong and Madai Caves. Recommendations for improved management of the nest harvest include addressing corruption, ensuring that local people with traditional rights to collect nests do not lose income to illegal immigrant labor and to traders, improving research and education about the swiftlets’ behavior and ecology, and moving value-added processing of the nests closer to the caves where they originate and to the people who collect them.
Keywords: Birds nests; Borneo; Ethnicity and resource access; Malaysia; Poaching; Swiftlets
Document Type: Research article
DOI: 10.1023/B:BIOC.0000047905.79709.7f
Affiliations: 1: Department of Geography, University of Missouri-Columbia, 8, Stewart Hall, Columbia, MO 65211, USA ( HobbsJ@missouri.edu;, Fax: +1-573-884-4239) ), Email: HobbsJ@missouri.edu
November 22nd, 2006
Graham 2006
indonesianow.blogspot.com
When Achmad Basuni and his wife Siti Mariah were building their new house in 2000 great good fortune swiftly flew in the window.
Literally.
A pair of swallows darted into the half finished kitchen and cast knowing eyes around the walls and rafters. Like all astute real estate buyers they knew exactly what they wanted: Security, space, a cool atmosphere, friendly co-tenants and easy access.
Any Westerner who found feathered ferals moving into their kitchen would probably call a pest exterminator, but this couple rejoiced. âItâs a blessing from God,â said Achmad who runs a motorbike workshop. Commented Siti: âI felt pity on them. I didnât want them disturbed. So we just stopped building there.â
The kitchen was given over to the visitors and the home rapidly re-designed. When the swallows laid their first clutch Achmad substituted a pair of swiftletsâ eggs bought for Rp 60,000 (US $ 7)
Swiftlets have dark plumage. Theyâre closely related to swallows and slightly smaller. In flight they look sickle-shaped. Swallows are migratory and move between continents and hemispheres. Swiftlets live only in the tropics and usually nest in caves.
Unlike their bigger and better travelled cousins swiftlets build quite different homes; their nests are edible, keenly sought and highly prized: Theyâre the raw material for the Chinese dish Birdâs Nest Soup â also known as the Caviar of the East.
Depending on the quality and season a kilo of swiftletsâ nests (thatâs around 100) can fetch around Rp 10 million (US $1,150) at the barn door.
News about the swallowsâ selection flew rapidly round the coupleâs village of Jeru, about 20 kilometres west of Malang in East Java. Soon a stranger was knocking with a startling offer: Heâd buy their house for Rp 300 million (US $34,000), double its market value.
No sale. Achmad and Siti knew that if their unwanted bidder was prepared to pay that much cash it must be worth a lot more to them.
There are now more than 40 birds flashing in and out of their selected home through small holes set high in the four metre walls. After daybreak the birds zip across to Balekambang Beach on the south coast where the flying insects they catch on the wing are most prolific. The birds return at nightfall, a round trip of about 160 kilometres.
There are a few other lucky folk in Jeru. You can pick their bird barns by the flat grey windowless concrete walls. The giveaway features are small entrance and exit holes, about the size of two bricks.
Some families rejected by the birds find their neighboursâ good luck difficult to swallow. âThe big problem is thieves after nests and eggs,â said Achmad. âOne farm spends Rp 2.5 million a month on security, five times the normal rate for guards.
âOthers visit paranormals to persuade the birds to relocate. I know someone whose house has been abandoned three times by swiftlets after black magic has been applied. But the birds eventually came back.
âI donât know why we were chosen. Weâre just ordinary Muslims, certainly not fanatic about faith.â
Those more pragmatic than psychic are said to be using recorded sounds of swiftlets broadcast through speaker systems to entice passing birds to enter their barn. The birds emit clicks to guide them, a system known as echolocation.
Nests are harvested every three or four months after the chicks have flown. A pair of swiftlets can raise two or three broods a year. Buyers from Surabaya do the rounds of the roosts and take the nests for processing.
Environmentalists are concerned that nest harvesting isnât always well managed. Greedy gatherers who take nests before the chicks take wing are threatening the species.
(sidebar)
SWIFTSâ SPITTLE
Swiftlet nests are made from the birdsâ saliva produced by glands under the tongue. The nestsâ edible qualities have been known for at least 700 years. Whatâs not known is how the discovery was made and why anyone would think a dirty nest could make a tasty dish.
Our ancestors must have choked on a lot of sticks encrusted with dung and vomited feathers and broken eggs before they found an edible variety.
The stratospheric price means birdâs nest soup is a food only for the mega rich. Few restaurants in Surabaya have it on their menu. Those who do can charge up to Rp 2 million a bowl (US $225).
For this sort of money diners want more than a lip-smacking experience. So itâs no surprise the nests are supposed to possess extraordinary characteristics from improving skin tone to warding off tuberculosis, curing consumption, dysentery, malaria ⊠the list has no full stop. And, of course, enhancing sexual performance.
These claims are unlikely to be denied by anyone whose credit card has just melted on the restaurant cashierâs swipe machine. The catch is that the real or imagined benefits donât come with just one big banquet to celebrate the commercial coup. Promoters say a regular diet of 10 grams a day is necessary.
The cooking process is critical. A microwaved or boiled nest will be nutrition-free. Best to steam slowly after soaking which expands the nest. The taste is said to be sweet, more like a dessert.
Surabaya distributor Dendy Van Hallen said the best nests came from bird barns in Java. These nests were usually clean and glossy, almost transparent. Cave nests from Papua and other outlying regions were often contaminated by feathers and dirt and worth only Rp 1 million a kilo (US $114).
âI send to restaurants on demand,â he said. âMost ask diners for a weekâs notice so they can prepare ahead â itâs not a dish you can order on the spot. The bulk of our nests go to Jakarta.
âWe do little preparatory work in Surabaya â cleaning up the nest is done in the restaurant where they soak and remove impurities.â
If youâd like to make your own soup at home a Malaysian company sells boxes of six tiny jars for Rp 200,000 (US $ 23). Each jar has an off-white jelly which the label says is made from birdsâ nests, ginseng, sugar and âwhite fungugâ.
Indonesia produces 80 per cent of the worldâs edible birdsâ nests. Most come from West Java and are exported to Hong Kong, Holland, Singapore and Taiwan. The last official published figures show Indonesiaâs annual production around 27 tonnes. Thatâs a lot of swiftlet spit.
##
(First published in Jakarta Kini, August 2006)
November 21st, 2006
glycob.oxfordjournals.org
Hiroki Nakagawa 1, Yoichiro Hama 2, Toshihisa Sumi 2, Su-Chen Li 3, Karol Maskos 3, Kittiwan Kalayanamitra 4, Shuji Mizumoto 5, Kazuyuki Sugahara 5, and Yu-Teh Li 6 *
1 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112; Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
2 Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
3 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112
4 Department of Biochemistry, Kobe Pharmaceutical University, Higashinada-ku, Kobe 658-8558, Japan
5 Department of Biochemistry, Kobe Pharmaceutical University, Higashinada-ku, Kobe 658-8558, Japan; Lab. of Proteoglycan Signaling and Therapeutics, Faculty of Advanced Life Science, Hokkaido University, Frontier Research Center for Post-Genomic Science and Technology, Kita 21-jo, Nishi 11-choume, Kita-ku, Sapporo 001-0021, Japan
6 Department of Biochemistry, Tulane University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA
* To whom correspondence should be addressed.
Yu-Teh Li, E-mail: yli1@tulane.edu
  Abstract
Despite their wide occurrence, proteoglycans (PGs) have never been isolated from the saliva of higher animals. We found that the collocalia glycoproteins isolated from edible bird’s nests (the dried forms of regurgitated saliva of male collocalia swiftlets) were rich in a PG containing non-sulfated chondroitin glycosaminoglycans (GAGs). We have devised a method to isolate a PG from the water extract of the white nest built by Aerodramus fuciphagus (white nest swiftlets) with a yield of 2 mg PG/g nest. This PG contained 83% of carbohydrates of which 79% was GalNAc and GlcUA in an equimolar ratio. By using chondroitin AC lyase the structure of GAGs in this PG was established to be chondroitin (4GlcUA1Â Â 3GalNAc1Â Â )n chains. The average molecular mass of the chondroitin chain was estimated to be 49 kDa by gel filtration. We have isolated a linkage region hexasaccharide, HexUA1Â Â 3GalNAc1Â Â 4GlcUA1Â Â 3Gal1Â Â 3Gal1Â Â 4Xyl, from this PG by chondroitinase ABC digestion to show that the GAGs in this PG are also linked to the core protein through the common tetrasaccharide linker, GlcUA1Â Â 3Gal1Â Â 3Gal1Â Â 4Xyl, found in various PGs. As water was not effective in extracting uronic acid-containing glycoconjugates from the black nest built by black nest swiftlets (A. maximus), we used 4 M guanidium chloride, and anion-exchange chromatography in the presence of urea to extract and isolate about 30 mg of a chondroitin PG preparation from 10 g of the desialylated black nest. As the biological significance of chondroitin is still not well understood, bird’s nest should become a convenient source for preparing this unique GAG to study its biological functions.
Keywords: chondroitin; proteoglycan; glycosaminoglycan; bird’s nest; saliva.
November 20th, 2006
birdsofbritain.co.uk
Although declining in many localities the house martin remains a familiar bird. Its white rump, white feathered legs and shorter, less forked, tail distinguish it from the swallow.
The house martin feeding zone is higher than that of the swallow. It can often be seen ‘towering’ after insects in association with swifts high in the air. Gliding and stalling, diving and climbing it spirals overhead displaying great grace and mastery of flight.
On occasions house martins are attracted to hot-air balloons. The birds circle just above each balloon maybe gaining lift or free-ridings as in a thermal.
House martins breed over a vast area of the Palearctic region from the Atlantic towards the Pacific and as far north as arctic Scandinavia. Before man provided shelter in the shape of overhanging eaves, martins were cliff and cave dwellers. In remote mountain regions they occur at altitudes up to 14,000 feet. In southern Europe there are enormous colonies, the nests overlapping and forming huge tenements.
House martins do not often settle on the ground except when collecting pelts of almost liquid mud for nest construction. They are then very approachable. Both birds work at nest building, but before this begins there is much play.
A bird will fly up and dab a pellet of mud on the wall, then cling with head turned. Twittering an invitation to its partner who will settle alongside. Spreading wings they then drop performing a graceful arc before floating off for aerial courtship.
The birds soon took advantage of newly constructed motorway bridges colonising them within a season of their completion. This despite vehicles thundering a few feet away. Suffolk house martins discovered the advantages of building nests under circular lamp column shades. At its peak, the colony numbered almost 60 nests built under a dozen shades.
Even more resourceful are house martins nesting on ships. A pair once nested aboard a ferry travelling eight times a day between Copenhagen and Malmo in Sweden. The nest was situated on a ledge beneath a bulkhead close to the port rail.
The crossing was 15 miles in length. Following publication in British Birds magazine further occurrences came to light. Another Danish car ferry engaged on an internal route of some eight miles and a journey of 45 minutes (making a round trip of two hours) held up to nine house martin nests for a period of over a decade. In more than one year all the broods successfully fledged.
The adult birds visited the ferry only at the terminus, entering the vessel immediately the bowgate opened. The kindly ferry company deliberately did not use this ship at the beginning of each season because of the nesting martins.
In cold, wet weather early in the breeding season up to 14 house martins have been recorded sheltering in a single old nest. Many survive by this behaviour.
During nest building, disputes may arrive through the theft of both mud and lining materials. Parent house martins share brooding and feeding duties. Young from the first brood are known to feed later nestlings.
I have noted young still in the nest during the last week in October. After leaving their mud homes the young congregate in flocks, sun-bathing on southfacing roofs and roping the wires in company with swallows.
More than one mystery surrounds house martins. Where do they roost when not at their home colonies?
It seems likely the majority sleep in trees. Watch a flight of house martins during the hour before sunset. All fly high and at times binoculars are needed. Ten minutes or so after sunset all suddenly become excited and flight is accelerated for no apparent reason.
Then all come sweeping down the sky to treetop level before vanishing into high foliage at top speed. And the same trees may be occupied over several weeks.
As the time of autumn departure approaches, aerial exercises are intensified, the martin flocks wheeling restlessly. Then one morning the cables are deserted. The long journey through France and across the Sahara has begun. Another house martin mystery when in the African tropics is the scarcity of observations considering the great numbers which are still involved. Perhaps the answer is a high altitude lifestyle?
.By Michael J Seago
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November 17th, 2006
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