Archive for August, 2007
Canada.com, Canada - Aug 28, 2007
Elizabeth Le Geyt, The Ottawa Citizen
Published: Monday, August 27, 2007
Although the summer seems to be slipping into an early fall, there is still plenty of interesting birding around Ottawa and in Grand Manan, N.B., and Machias Island.
Wilson Hum spent some time on Machias Island, in the Gulf of Maine, where the puffins, common murres and razorbills nest.
He was able to get close-up pictures of adult puffins returning from a fishing trip with their bills full of sand eels. Breeding puffins have large triangular orange, yellow and grey bills, black and white plumage and orange legs. The nickname “sea parrot” comes from the spectacular bill. This bill has grooves in it that enable the bird to carry six or seven sand eels at the same time.
The chicks can eat their weight in eels a day and may consume as many as 2,000 during their time in the sandy burrow.
There used to be Arctic terns nesting on the island but they have moved away. Mr. Hum saw two of them but not on the island. All the shearwaters, a northern gannet, black-legged kittiwakes and black guillemots were seen.
At Mud Lake, Mr. Hum saw a merlin catch a tree swallow in flight, one great blue and three black-crowned night herons in the same tree. As many as 10 migrating nighthawks flew over.
Kathy Bissett has been in the Canadian High Arctic in a Russian research ship. She saw the three jaegers, including the long-tailed like the one that was recently seen in Ottawa. Fulmars, glaucous gulls, black guillemots and black-legged kittiwakes were on Bylot Island.
Large numbers of dovekies that nest in Greenland were flying over Baffin Bay. There were families of common eiders and red-throated loons on the Arctic ponds. The dovekie is an 18-centimetre, chunky black and white bird, the smallest of the alcids (auks, puffins and skuas). They travel in flocks of many thousands.
The reports of chimney swifts in Winnipeg prompted a call from Julia Capriani. She reported a sizable colony of these birds in a chimney in Chinatown belonging to the Dominican Fathers that has been there for many years. She said that she has seen as many as 200 of these cigar-shaped brown birds in the spring.
Saul Bocian saw the gray jays in Algonquin Park. The park naturalist told him that global warming is having a harmful effect on these birds. They store food for the winter and it needs to be kept frozen. The warmer temperatures are causing it to thaw and become inedible or even poisonous.
A correction: Peter Campbell saw a white-tailed eagle take a fulmar from the cliff face, not a gyrfalcon.
Ted Busby found at least 100 least sandpipers, semi-palmated plovers, greater and lesser yellowlegs at Shirleys Bay and Ottawa Beach. He watched a peregrine falcon attack a wood duck and saw a merlin perched in a tree. A juvenile cormorant was sunning itself in
Andrew Haydon Park. Juvenile birds have a light streak down the front of the neck.
Bryan Shane reported two kestrels in Ottawa. Terry Kojtila in Almonte says the evening grosbeaks are back at her feeder. Gary Fairhead watched a northern harrier hunting low over the cattails on Petrie Island. Gerard Cleary saw two ospreys fishing off Bate Island, and Don Wigle reported the redstart is still in the Britannia Woods with yellow and black-and-white warblers.
Tony Beck has an interesting program of bird expeditions planned for the fall. He is offering a package deal for any interested birders who would like to go on all the day outings and the occasional overnight trip.
Call him at 613-828-5936 or e-mail him at beck.tony@sympatico.ca for information. His website has all the details of the planned expeditions (www3.sympatico.ca/beck.tony).
Enjoy all the activity around the movement of the birds with their grown-up families, preparing for
migration.
Please send birding reports and specify
location to 613-821-9880 or e-mail elegeyt@rogers.com. The Wild Bird Care Centre for orphaned and injured birds is at 613-828-2849.
© The Ottawa Citizen 2007
August 30th, 2007
earthlife.net
Birds, far more than any other animal besides man, are notable for their tendency to build a home in which to raise their young, and in some cases to use all year round.
Birds are not the only animals to make a nest; fishes, mammals, insects and spiders also build nests, sometimes quite complex ones, for rearing young and for their own general protection. For the extent of this page we will define a nest as anything constructed by a bird or where a bird lays its eggs. This is the broadest possible definition and allows us to discuss the full extent of bird nesting habits.
Bird nests range from non-existent to extensive, multi-chambered apartments which can be fully weatherproof and may last for years or even decades. Nests come in a wide range of categories, the following groups cover most nests you will find. Some of these 12 categories are quite small, others are large containing a huge diversity:
Introduction
Before building a nest the pair have to decide on where to build. This is called ‘nest site selection’ behaviour. Different species go about this in various ways, in many species both partners work together to decide on the site. Birds in this category include many gulls. In some species, though the pair work together the female takes a definite lead on the proceedings, i.e. Blackbirds, Turdus merula, and surprisingly the Red-necked Phalarope Phaleropus lobatus. This is surprising because once the site has been chosen the female lays her eggs and departs, leaving the male to do all the incubation. In other species such as the Dunnock, Prunella modularis, the female chooses the site and builds the nest. In contrast, with Blue tits, Parus caerulea, European Sparrows, Passer domesticus, and Wrens, Troglodytes troglodytes, it is the male who chooses the site and then tries to attract the female to it. The male Wren is a bit of a workaholic and builds several nets, normally 4 or 5, but up to 12. The female chooses one of these and the male uses another to roost in. Just to prove that variety is the spice of life, Scottish Crossbills, Loxia pinicola, show no definite patterns. In some couples the male leads, in others the female.
The second behavioural activity is material collection and building. These range from ’sideways throwing’ - a simple single movement to get nesting material to the nest, this is limited to ground nesters only. ‘Sideways building’ is similar but involves more care in the placing of the material and results in a better constructed nest. Sideways throwing and sideways building are exhibited by many ducks, geese, gulls, petrels, pheasants swans and waders.
Physically carrying material to the nest site is the next step up and is carried out by all the remaining nest building birds. At the simplest it is shown by penguins carrying a stone in their bills few metres to the nest site. At its most complex it involves birds searching out for particular substances such as cobwebs and feathers to bring to the nest.
Once material is brought to the site it needs to be incorporated into the nest. For ground nesting species this can be as simple as just picking it up. For tree nesting species, it usually involves some degree of interweaving the individual items until they form some sort of matrix. This can be fairly straight forward in the platform nests of pigeons, but reaches great sophistication in the weavers where material is actually sown together, where a considerable degree of manipulatory skill is needed. Whatever the type of nest, watching a bird build one is a fascinating and rewarding experience.
Architecture but not Nests
Finally there are structures built by birds which do not really fit into any of the above categories, because they are not nests, these are the bowers of the various species of Bowerbird.
Male Bowerbirds build structures which though often involving great effort are not actually nests. These bowers, built by 14 of the 18 known species of Bowerbird are stages or advertisements. They are built to attract females which presumably are attracted to larger more ornate structures and which judge a male on his collection of treasures. The real nest is built by the female after she has been mated by her chosen male and she incubates the eggs and raises the young on her own while the male stays with his bower to try and attract more females. Bowerbirds build different sorts of bowers even within one species. Different populations build different designs and collect different ‘treasures’. Some simple bowers consist of an avenue of twigs which the male bird walks up and down to display himself to the female. Some of these may have the sticks painted with yellow, brown or purple plant juices.
More complicated bowers involve towers of sticks and display arenas on which the male arranges his collection of treasures and around which he displays himself. Treasures include feathers, particularly blue ones, snail shells, beetle wings and heads, bones, flowers and anything else which takes the bird’s fancy which may include man-made objects such as silver spoons, car keys, gun cartridges, tin mugs, buttons and other colourful scraps of material.
The most impressive bower is built by the Vogelkop Gardener Bowerbird (Amblyornis inornatus) from New Guinea which in some areas builds a huge open-fronted roofed hut up to 2.2 m tall and 2 or more metres across. This structure is built by a bird the size of a Song Thrush.
Australasian Bowerbirds are not the only birds to build structures that are not ever destined to be nests. Others include the Tooth-billed Cat Bird (Scenopoeetes dentirostris), also from Australia, and Jackson’s Whydah (Euplectes jacksoni) from Kenya and Tanzania. Both of these make structures which are quite simple in comparison with some of the bowers described above. Cat birds line a 1-2 m arena with upside down fresh leaves which they cut from vegetation with their toothed bill. Jackson’s Whydah is a leking species in which each male has a personal arena about 1 m across with a pseudo-nest. Mating normally takes place during inspection of the pseudo-nest by the female. Like all leking species the female builds the true nest later, incubates the eggs and raises the young on her own.
Recommended Reading
If you have found this page at all interesting you will want to read “Birds as Builders” by Peter Goodfellow ISBN 0 7153 7410 (Out of Print). Not only does it contain far more fascinating information than I was able to include here, being 160 pages long, but it is much better illustrated.The simplest nest of course is no nest at all. Quite a few birds do not build any nest at all, though they do make a choice of where to lay. Beyond this is a simple scrape in the ground. Nightjars (Caprimulgidae) do not make even a scrape. They lay their two eggs directly onto the ground. While Short-eared Owls, Asio flammeus, lay simply on some trampled vegetation. Many waders, such as Plovers, lay in a simple scrape on bare ground, relying on the cryptic colouration of their eggs to protect them from predation.
Some of the more unusual examples of no nest laying include the Potoos, Nyctibius spp., which lay their single egg on top of a broken off tree stump. The bird then sits on top of the stump with its head pointing to the sky. In this position it looks like an extension of the dead timber. It generally chooses stumps of similar diameter to itself. Even trickier are the ‘nests’ of Fairy Terns, Sterna nereis, another species which lays only one egg. The egg is laid on a branch on a rock face, generally on an area too small to support 2 eggs. Laying the egg in a position where it won’t roll off is tricky and young birds often lose their first attempts before they get the hang of choosing a safe spot. Fairy Terns have two adaptations to help them survive this seemingly precarious nesting habit - The adults have evolved to be very careful when settling on and getting off the egg - both sexes incubate the egg. The second adaptation is that young Fairy Terns have disproportionally large feet and very sharp claws which help them hang on. The master of no nest nesting, however, has to be the Emperor Penguin (Aptenodytes forsteri). These birds nest in the Antarctic during winter when the temperature can fall to less than -30 degrees C. They nest well inland and when the female has laid the single egg she leaves for the coast to feed. Meanwhile the male has immediately taken over care for the egg by moving it up onto the top of his feet. He has special folds of skin on his belly which enfold the egg keeping it safe against all the severity of the elements. Here he stays, a living nest with an egg on his feed for the next 60 days without a meal or much movement until his mate returns and the egg hatches. During this time he has maintained the internal temperature of the egg at 40 degrees C, as much as 80 degrees C higher than the surrounding ambient temperature.
Simple Nests
Simple nests are constructed of either plant material, normally sticks or stones. They are quite common and like no nest nesters all the birds that use them are non-passerines.
The best example of a simple stone nest is that of Adelie Penguins. The nest is basically a mound of stones which serves as protection against flooding.
Most simple nests, however, are made of sticks and twigs built into a simple platform, which though it may have a depression in the middle and be quite extensive does not really have an inside and outside.
A common example of a simple platform nest are those constructed by many doves and pigeons. Those, like that of the Ruddy Quail Dove, Geotrygon montana, are often a simple lattice with just enough twigs to support the egg. In these cases the egg can often be seen through the nest from beneath. Sometimes a flimsy lining of grass and rootlets may be added and in some cases the lining may be more complete. Another bird which builds a simple platform is the Hoatzin from S. America. Another well known example of a platform nest and one which is more substantial than a pigeon’s is that of the European White Stork, Ciconia ciconia, which has for centuries nested on chimneys and specially erected platforms across Europe. More complicated than the previous nests, it consists of sticks interwoven then plastered to some extent with mud. A depression in the middle is often lined with grass or paper.
Mute Swans’ (Cygnus olor)nests are an example of a different form of simple nest construction. No material is carried to the nest. Instead, once the site is chosen and the vegetation flattened, the eggs are laid and the female swan builds up the nest around her by dragging material within reach to her so that eventually it forms a rampart around her.Other birds which build simple nests include many gulls and herons. The most spectacular nests in this category are those built by various eagles. Most build in trees and the nests of the Bald Eagle (Haliaeetus leucocephalus)in N. America can be so heavy that they damage the tree supporting them. The largest nests on record, however, are those of the Golden Eagle, Aquila chrysaetos, which tend to build a new nest on top of the previous year’s nest, resulting in huge structures often containing more than a ton of material. Fortunately, Golden Eagles prefer rocky alpine crags as nest sites which can often support these massive structures more easily than a tree. Golden Eagles are known to adorn their nests with sprigs of green boughs throughout the nesting season, well after the young have hatched. Many of the foremost researchers believe that this is evidence of a rudimentary aesthetic sense.
Cup-shaped Nests
The next step up from a simple platform nest is a cup-shaped nest. These are the most numerous form of nest and one that most people consider a typical nest. They are distinguishable because they have a definite inside as well as an outside and the inside is normally lined. They require more effort to make but convey more protection to the eggs and young birds.
Cup-shaped nests can be built in a variety of places, but normally they are built in trees. Often the simplest form is wedged into a ‘Y’-shape division of a branch, but many birds bind or cement them directly to a bough.
The smallest cup-shaped nests belong to the Humming birds and Woodstars which build perfectly shaped thimble sized nests of moss and cobwebs. Often the female bird flies during the whole construction, hovering here and there while building up the shape. Different birds’ nests take different lengths of time to build. Some are completed in a day, others take 2-3 weeks to complete.
Cup-shaped nests are often built of a mixture of substances. Redwings, Turdus iliacus, build nests of leaves, grasses and fine twigs cemented together and then lined with moss and feathers. Not all cup-shaped nests have a soft lining though. The female Song Thrush, Turdus philomelos, lines her nest with mud, dung and rotten wood all of which is cemented together to form a very hard inner surface.
The other extreme to the delicate nest of the Humming birds are the large scraggly looking structures built by crows. The initial outside of the nest, built of twigs and grass cemented together with mud, is larger than the adult bird. Within this rough exterior a deep cup lined with moss and feathers is made. Crows’ Corvus corone nests often look rough and ready, but inside they are warm and comfortable. Crows build very well and their nests last for several years, but unlike the closely related but larger Raven Corvus corax, they never reuse a nest. Other birds, like Kestrels Falco tinnunculus, are happy to use them once the crow has finished with them.
Enclosed Nests
Enclosed nests are basically an extended cup nest where the basic cup has deeper walls and a roof, with an entrance hole. Domed or enclosed nests would seem to offer more protection for the eggs and young than a simple cup. In some cases they obviously do, and they also supply better protection from the elements, though there is not much scientific evidence to support the theory that they offer better protection from predators. As with all these categories of nests there is a gradient of complexity and quality among domed nests. The simplest have only a loose roof like those of the Chiffchaff, Phylloscopus collybita, or a separate roof constructed about the dome such as the nest of the Magpie, Pica pica. Wrens and Dipper build more solid domes.
Many domed nests are very intricate and solidly constructed. They may be small and beautiful such as the nests of the Long-tailed Tit, Aegithalos caudatus, which camouflages the outside with lichens and lines the inside with hundreds of thousands of feathers. The largest and most spectacular domed nests belong to the Hammerkop, Scopus umbretta. These birds build a huge dome of over 8000 sticks which can be 2 m high and nearly 2 m wide. This nest is easily strong enough to withstand a man walking across the top of it. They have a long entrance tunnel and are the avian equivalent of a fortress.
A more unusual example of a domed nest is the nest of the Rufous-breasted Castle Builder, Synallaxis crythrothorax, which creates a dumbbell-shaped nest with a tube connecting both chambers, only one of which is used
Hanging and Woven Nests
Hanging nests, particularly woven ones are perhaps the most admirable of bird architecture. They certainly look very beautiful and most require great skill on behalf of the bird to build.
The simplest hanging nests are cup-nests slung from an overhead bough by a few cobweb supports such as the nests of the Goldcrest, Regulus regulus, the Fire Crest, Regulus ignicapillus, and various White Eyes Zosteropidae.
An interesting variation is the hanging cup nest of the Hummingbird (Planalto Hermit), Phaethornis pretrei, which has only a single support cable for its nest. To help keep it stable it has a streamer of grass and cobwebs hanging down below the nest.
Other birds which build hanging nests include the Reed Warbler, Acrocephalus scirpaceus, the Fantailed Warbler, Cisticola juncidis, and the Rock Warbler, Origma rubricata, though this last species is not technically speaking a warbler.
Better known than these are the hanging, often on mass, nests of the Icteridae and Oriolidae. There are nearly 100 species of weaver birds renowned for their carefully woven hanging nests. These nests tend to be either hung from the tip of a branch or leaf, or suspended between two twigs. They are globular in shape with a single entrance hole. Apart form globular nests, weaver Birds also construct kidney-shaped nests and retort-shaped nests are basically globular nests with an entrance tunnel. Whatever their shape, nearly all weavers make their nests out of grass and the nests are truly woven with the bird moving from side to side, poking part of the strand of grass through the wall from the side and then pulling it completely through from the other.
Holes in the Ground
Many birds nest on the ground with nests of varying degrees of complexity but far fewer nest within holes in the ground. Nesting in holes would seem to be a better strategy than nesting in the open. One survey of over 180,000 eggs revealed that where non-hole nesters averaged 50% rearing success, hole nesters averaged 70%. Two main sorts of holes can be distinguished; those which open onto a cliff edge or a vertical edge of a river bank, and those holes in relatively flat ground. A second plane of division is between those birds which dig their own holes and those which make use of other people’s.
Commonly recognised birds which nest in cliff edge holes include House Martins (Delichon urbica)and Sand Martins (Riparia riparia)and the widely distributed European Kingfisher (Alcedo atthis). Other Kingfishers such as the Malachite Kingfisher, Alcedo cristata, several parrots in the S. American genus Conure and the Ground Woodpecker, (Geocoloptes obroceus) of S. Africa also nest in cliff edges. More unusual are D’Arnoud’s Barbet, (Trachyphorus darnoudii), and the White-whiskered Soft-wing, (Malacoptila panamensis), which nest in holes dug into flat ground. These sorts of nests may all be lined to some extent and are generally dry well-protected homes.
Excavating your own holes, of course, is hard work and many birds are happy to take possession of someone else’s efforts. Thus the Shelduck, (Tadorna tadorna), among several ducks, and the Manx Shearwater, prefer to nest in abandoned rabbit holes. Not as pleasant as this, Cinclodes sp. and Sharp-tailed Stream Creeper’s (Lochmias nematura)nest in rodent burrows. In the latter case the burrows are often in the edges of open sewers giving the bird the nickname ‘President of Filth’ in Brazilian shanty towns.
Holes in Wood
Mud or earth, of course, is not the only place to make a hole and many birds nest in holes found or excavated in trees, cacti and even in termite nests.
Making a nest in a hole that already exists in a tree is not really an architectural feat as it involves little effort on the bird’s behalf. Still, holes in trees, alive or dead, make excellent nest sites and numerous bird use them. Some, like the Blue tit, Parus caerulea, and several of its relatives, Redstarts (Phoenicurus phoenicurus), the common Starling, Sturnus vulgaris, and many of its relatives, as well as various Flycatchers use existing holes to nest in, making very little modification to the hole except to supply some lining as nest material. Others, like the many hole nesting Parrots and Nuthatches, will modify existing holes to varying degrees. Fewer birds excavate their own holes in trees, but of those that do the woodpeckers, with their impressive hammer-drill impersonations are by far the best known.However, the prize for champion tree hole nester has to go to the various species of Hornbills, Bucerotiformes. These large birds, with the exception of the two species of African Ground Hornbill, all nest in hollows in trees. This is no simple matter. The Great Indian Hornbill is a large bird, nearly a metre from bill-tip to tail-end, which likes to nest between 20-45 metres up the tree trunk so can only nest in trees which have a diameter greater than 1-2 metres at this height. Trees this large are now rare in many forests putting serious pressure on the breeding capability of these birds.
Both males and females help excavate the hole which needs to be quite extensive to house the female and several chicks for some weeks. Once the hole is large enough to accommodate the female, she gets inside and helps the male wall up the entrance with a mixture of guano, woodchips and mud. The female will remain in the hole until the young are ready to fledge. Only a small slit will be left in the mud wall to allow the male to feed the female and her young. During this time she will not only raise the chicks in great security but also moult all her feathers in one go. Hornbills are long-lived birds and mate for life, so the male has a considerable vested interest in keeping the female well-fed.
Nesting in holes may be secure form many predators and much of the weather, but it has one drawback. The warm, humid conditions make ideal breeding conditions for various avian pests and nest parasites such as bird and feather lice, ticks an fleas. With a captive food supply in the young birds, parasite loads in nest holes build up rapidly. Hornbills never use the same hole twice and the need to escape these pests may have something to do with this.
Other favourite sites for nest holes are cacti, many of which grow as large as small trees, and termite nets. Each of these provides an interesting example of commensualism. Firstly, the Orange-fronted Parakeet (Cyanoramphus malherbi) of Central America nests almost exclusively in mounds built by Nasutitermes termites. Unlike other birds, mammals, etc, which nest in termite mounds, Orange-fronted Parakeets do not have the nest hole sealed off from the rest of the termite mound. Soldier termites can wander around the nest and workers remove the young birds’ faeces and any parasites they can find. Obviously, this is good for the Parakeet, but what the termites get out of it, no-on knows for sure.
The second relationship is quite amazing. The Gila Woodpecker (Melanerpes uropygialis) nests in holes which it excavates in the famous Giant Saguaro cactus of N. America. In the same hole with it, nests the Elf Owl (Micrathene whitneyi). The Elf Owl is tolerated because it has the amazing habit of catching Western Blind snakes and bringing them alive back to the nest. The snakes are insectivores so benefit by having a cosy home and free food in the form of avian parasites. The woodpecker benefits because it gets a reduced parasite loading, thus improving the health of its young. The Owl gets not only a reduced parasite loading and a free nest site but also protection for its young while it is hunting at night when the woodpecker is roosting in the hole.
Mound Nest
One of the strangest nesting habits is that followed by the Megapodes. On Saro in the Solomon Islands, come nesting time the already mated female Scrub Hens leave the forest where they have lived all year and come down to the beach to look for an area of sand known as a geu. In a geu the sand is heated form below by geothermal energy as well as from above by the sun. Into this sand the females dig a hole about 60 cm (2 ft) deep, and after testing the temperature of the sun with special heat sensors on their tongues (about 33 degrees C is best), they lay their eggs and fill the hole in. The females then return to the forest and expend no further effort on their offspring’s behalf.
This and similar systems by other Megapodes such as the use of hot springs on Celebes and rotting tree stumps on other Solomon Islands involve no building effort at all. However, these facilities are not always available and in Australia and Papua New Guinea various Megapodes use the heat generated by composting organic matter to hatch their eggs. These incubator composts can be huge and require a large input of effort on the bird’s behalf.
Malleefowl have the most complex nesting habits of all the Megapodes. A male will commence constructing an incubation mound months before the breeding season. He first scrapes a hole in the ground (Megapodes = big feed) about 0.5 m (1.5 ft) deep. On top of this he piles all the vegetation he can find, as well as nearby topsoil. The resulting mound will be about 5 m (16 ft) across and 1m (3 ft) high. Similar, but slightly less complex nesting rituals are shown by the Scrubfowl whose ancient nests may be 12 m (36 ft) across and 5 m (16 ft) high. Also similar are Brush Turkeys, Alectura lathami, whose nests are similar in size to a Malleefowl. Less evolved species such as the Moluccan Megapode, Eulipoa wallacei, simply dig a hole in the soil, lay the eggs and then cover them up. No further control is exercised.
(Floating) Aquatic Nests
Though a number of birds build their nests at the water’s edge, several groups build them out in the water. Coots build nests which though surrounded by water have a foundation of vegetation, which reaches the ground below. Interestingly the Horned Coot, Fulica cornuta, which breeds on mountain lakes in the Andes where water weed is scarce, build a foundation of stones nearly to water level before building the actual nest. More adventurous are various grebes. Grebes build the nests in shallow water, and though they are often anchored at one or two points they are basically floating on the water. This is necessary because grebes which are primarily water birds are very clumsy on land and find life works better if they can swim right onto the nesTwo other groups of birds build nests which are completely afloat. These are the Jacanas (Lily Trotters) which build extremely flimsy nests which often sink into the water while the bird is sitting. Fortunately, the eggs are waterproof so getting dunked regularly does them no harm. The others are the 3 species of Marsh Terns (eg, the Black Tern, Chilodonias niger) which build nests of broken reeds in water up to 120 cm (4 ft) deep. These nests are sometimes anchored to nearby vegetation.
Mud Nests
Mud is often a common resource and it makes sense that birds somewhere should have evolved to use it for nest building. Flamingos are well known and colourful birds which build very basic nests of mud. In the middle of the soda lakes of Africa, you can find both species building up piles of mud and faeces. These structures are basically a hollow mound with a depression in the centre. They are not built all at once, but some mud is built up above water level and as this dries more is put on top. They can be as much as 45 cm (1.5 ft) high. There is no lining in these nests except the mud.
Many birds build cup-shaped mud nests which rest on boughs of trees. These nests often have straw or grass mixed in with the mud making them stronger when dried, much like ancient bricks. Normally, these nets are lined with grasses, leaves, moss and feathers. Some examples of cup mud nests in trees are the Magpie Bird, Grallina cyanoleuca, and the Willie Wagtail, Rhipidura leucophrys, from Australia. Two other Australian birds, both communal breeders, the Apostle bird, Struthidae cinerea, and the White-winged Chough, Corcorax melanorhamphos, also build mud nests. In East Africa the Spotted Morning Warbler, Chichladusa guttata, also builds cup nests.
A number of birds build more unusual mud nests. In southern Europe the Rock Nuthatch, Sitta neumayer, builds a large mud nest on the sides of cliffs that looks like a rounded volcano on its side, i.e. if the cliff was level ground the volcano would be the right way up. In S. America the two species of Oven birds, Furnarius rufus and F. cristatus, build perhaps the most complicated mud nests of all. The nests are globular and often situated on tree stumps. They are about the size of a football. On one side is a domed entrance which leads to a passage which curves around the left hand side before going into the central chamber. The inner chamber is well lined and comfortable looking.
The best known mud nest builders are the Hirundines. Swallows and Martins all over the world labour during the Spring to build their hemispherical nests on the edges of cliffs and under the eaves of houses. The mud is collected in small pellets and moistened with saliva before being applied to the wall or existing nest. Swallow and Martins, in Europe at least, build only in the morning, spending the afternoon feeding, this means that each day’s work gets a chance to dry out and become strong before new mud is added. If this did not happen the whole thing would collapse under its own weight. Like other mud nesting birds, the nest is normally lined with dried grass and feathers.
Edible Nests
Perhaps the strangest nests of all are those built by the species of Swiftlet in the genus Collocalia. They nest in caves and build their nests of saliva. To do this they have enlarged salivary glands during the breeding season. To make them even more amazing, these Swiflets often nest in pitch dark caves. They are able to do this by using echolocation, similar to bats. Quite a few species use saliva in their nests to glue various materials together. Three species however, Collocalia fuciphaga, C. esculenta and C. maxima, produce nests made almost entirely, or entirely, out of saliva. These are the nests used by Chinese chefs to prepare bird nest soup, one of the more expensive and tasteless dishes in the world. The nests are collected from Niah caves and though collecting is controlled by law, it still results in a huge and unnecessary death of eggs and young birds.
August 29th, 2007
A General Reference to America’s Most Popular Little Bird
associatedcontent.com
By Lisa S
Published Aug 13, 2007
The Tree Swallow is one of North Americas most common birds. Tree Swallows are found in most parts of North America, however they will spend their winters in the most southern states and cross over into Central America as well.
The Tree Swallow is a small bird, averaging 5-6 inches long with a wingspan of 12-14 inches. They have forked tails and their beaks are extremely tiny. These small song birds prefer marshes and open fields, but can be found in suburban areas as well. The Tree Swallow is a migratory bird. They breed during warm weather in North America, and spend their winters in Mexico, Central America and the Caribbean. Both the male and female Tree Swallow have beautiful blue-green feathers on their backs, with a white belly, however young yearling females are brown.
Tree Swallows throughly enjoy making use of nesting boxes that many people have in their yards. They are cavity nesters, and will nest in natural or artificial cavities. Tree Swallows do prefer to be near a water source and often travel and live in large flocks. If you are looking to attract wild birds to your yard, you will probably have great success in attracting Tree Swallows. Do to deforestation, there are far fewer nesting sites for Tree Swallows, so they will readily seek out any artificial dwellings that you may put out. Tree Swallows will then build their nests of grasses and twigs within these dwellings. An interesting fact about the Tree Swallow nest is that they prefer using feathers from other birds in line their nest to help keep their young warm and also help keep the level of parasites and mites low as well.
Tree Swallows will generally only lay one brood of eggs per season, although some pay attempt to lay a second brood if their first nest fails. This will only occur however if the first brood fails early in the breeding season. The female Tree Swallow generally lays 4-7 eggs and incubates them soley by herself, with no help from the male. The eggs will take approximately 14 days to hatch. The young will then take between 16-24 days before they fledge.
The Tree Swallow not only eats insects such as grasshoppers, crickets and beetles, but also makes a substantial use of vegetable foods like berries and seeds. They are the only species of swallow that incorporates such a large amount of vegetable foods into their diet.
August 28th, 2007
Words on Birds , Steve Grinley
Daily News of Newburyport
The Daily News of Newburyport, MA - Aug 25, 2007
There are a couple of local spectacles happening in the bird world during these final weeks of summer. The egret and heron roost off Route 1 in Salisbury continues to attract crowds each evening as upward of 400 egrets, both great and snowy, descend upon the trees around a small pond just off the road.
Small numbers of great blue, little blue, green, black-crowned and yellow-crowned night herons have also used this roost in recent weeks. The egrets and herons start arriving in early evening, and their numbers continue to build past sundown. Wood ducks, mergansers, kingfishers and other birds are adding to the show.
If you go to see this event, DO NOT park on Route 1! Parking on a state highway is prohibited, and $75 tickets are being issued. Pull in off the road and walk the small path to the edge of the pond.
This is also the time of year when the swallows congregate on Plum Island. Their numbers will continue to build as they gather and feed in preparation for their journey south. Clouds of swallows will fill the sky, and every cattail in the marsh will have a swallow perched on it as they roost for the night. Doug Chickering of Groveland describes this spectacle well:
“Even as I sat on our deck in Groveland, looking up into the endless blue sky above me, I could see tree swallows. Usually when I sit out in the evening I might see one or two tree swallows. Many times I see none. They used to be more common here on summer evenings but no more. Yet tonight there were tree swallows. Several tree swallows. They glided and fluttered in the wind, sometimes right above me, and sometimes near the horizon of trees. Some no more than a hundred feet and above that through layers almost out of sight. There were not really many of them; maybe a dozen or perhaps a score with a few barn swallows mixed in. I saw them mostly to the east and could not help but conclude that my tree swallows in Groveland were the outer wash of the huge gathering of tree swallows at Plum Island.
“August dwindles away, the greenheads vanish, the peep sandpipers numbers crest, the first smatterings of passerines emerge, and the tree swallows gather at Plum Island. There are many events in the movement and lives of birds that are truly spectacular. This is one of them.
“Earlier today (Saturday, Aug. 18) Lois Cooper and I were on the island. The winds were blustery and because it was low tide, the shore birds were few. Not much to look at; except for the tree swallows. From the gate to Hellcat the tree swallows were riding the winds in various numbers, sometimes scattered above the dunes, sometimes filling the air right above your head and sometimes punishing a bayberry or honeysuckle bush by the side of the road in a massive frantic feeding frenzy, that was almost frightening in its intensity.
This Story Is Continued…
August 27th, 2007
taxonomy.zoology.gla.ac.u
Roderic D. M. Page, Patricia L. M. Lee, S. Anette Becher,
Richard Griffiths, and Dale H. Clayton
Related Web links
Tree of Life louse pages
TreeMap software
Dennyus Scanning electron micrographs
Host-Parasite Cospeciation
A key question in the study of coevolution is the tempo and mode of evolution of the interacting partners. Is the association an ancient one, reflecting a long and intimate interaction between the two organisms, or is it a recent event due perhaps to a parasite colonising a new host?
What is the relative rate of evolution between host and parasite? Answering these questions requires the comparison of evolutionary trees (phylogenies) for host and parasite (Figure 1). To the extent that the trees match, host and parasite have cospeciated, that is, parasite and host speciated at the same time. Mismatches between the host and parasite phylogenies signal processes other than cospeciation, such as host switching, speciation by parasites independently of their hosts, and parasite extinction (Page, Clayton et al. 1996). Because cospeciating taxa are, by definition, contemporaneous, we can compare amounts of evolutionary divergence in cospeciating pairs of hosts and parasites to measure relative rates of evolution in the two clades. Because host and parasite are often taxonomically distant (e.g., birds and insects), with differing generation times, population sizes, and metabolic rates, they are ideal systems to investigate the influence of these factors on rates of evolution Swiftlets and lice
The two dozen species of swiftlets and their lice show great promise as a model system for studying cospeciation. The lice are host specific, and transmission of Dennyus lice between individual hosts is known to be strictly vertical (between parent bird and its offspring) (Lee and Clayton 1995), suggesting that opportunities for colonizing new host taxa are quite limited. Swiftlets predominantly nest in caves (Figure 2), often in large colonies. This makes it feasible to undertake transfer experiments to test the survival of lice moved to foreign hosts.
Why use molecular data?
Swiftlet species are often difficult to distinguish morphologically (Figure 3), indeed the best guide to the identity of an individual is often its nest. Swiftlet nest structure is useful taxonomically, but is not phylogenetically informative
Dennyus lice show limited morphological variation, and some taxa were only discovered by using multivariate morphometrics. This morphological conservatism prevents cladistic analysis, so the only morphological estimate of relationships available is a cluster analysis of morphometric data While molecular data are useful in cases like this where morphological data is limited, there are two other compelling reasons to use DNA sequences in studies of host-parasite cospeciation:
• Homologous characters can be obtained for both hosts and parasites. In such taxonomically disparate taxa as birds and insects there are few homologous morphological characters which can be compared, whereas there are many genes that are homologous. Furthermore, molecular data permit the use of the same units (e.g., numbers of nucleotide substitutions per site) to measure evolutionary change, which is essential if we wish to compare rates of evolution.
• Molecular information can provide data on the relative ages of the host and parasite clades. Information on lineage age can help distinguish between host switching and the persistence of relict parasite lineages as alternative explanations of incongruence between host and parasite phylogenies.
Data and Analysis
DNA sequences for an homologous region of the mitochondrial (mtDNA) cytochrome b gene were obtained from swiftlets and their lice using standard techniques (Lee, Clayton et al. 1996; Page, Lee et al. submitted). Dennyus lice feed on both feathers and blood, so to minimise the chances of mistaking host DNA for louse DNA the lice were starved for 24 hours prior to death. Sequences obtained from the insects were different from any bird sequence we obtained, and readily aligned with other insects (Figure 6). Different tree building methods yielded similar trees, differing only in resolving relationships among some distinctus species-group lice for which the phylogenetic signal is fairly weak. Conformity to molecular clocks was tested using maximum likelihood tests. Host and parasite trees were compared using TREEMAP (Page 1994). For contrasting views on the most appropriate of comparing host and parasite trees see Hoberg et al. (1997) and Paterson and Gray (1997).
Have swiftlets and lice cospeciated?
Detailed reconstruction of the history of a host-parasite association requires robust, fully resolved trees. Because of some areas of uncertainty in the louse phylogeny we can confidently compare only part of the trees
Louse mtDNA is rapidly evolving
Although Dennyus lice are very morphologically conservative, their mitochondrial DNA is highly divergent. The distinctus and thompsoni species groups differ only in minor details of head shape and setation (Figure 4), and yet show 25-30% DNA sequence divergence - greater than the divergence between swifts and and their sister taxon the Comparisons of cytochrome b amino acid sequences between lice and other insects (honeybee, fruitfly, mosquito and locust) show that Dennyus is among the most divergent insects known (Figure 
. This variation in rate of insect mtDNA evolution means that calibrations of absolute rate of evolution in other insects (for example, that based on the age of Hawiaiin island Drosophila) will not apply to lice, hence it is difficult to independently estimate the age of the lice relative to their hosts. However, we can directly compare amounts of sequence divergence in birds and lice.
Lice evolve more rapidly than their hostshummingbirds.
August 24th, 2007
DetNews.com, MI - Aug 20, 2007
What do you do when you’re the Michigan Department of Transportation and Mother Nature decides to set up a nursery in the middle of a construction project?
You tip-toe away quietly and let nature take its course. That is exactly what happened near Kalamazoo recently when a covey of bank swallows built nests in a work zone, as MDOT was widening Interstate 94.
“Bank swallows are pretty opportunistic; over the weekend they found the site and started excavating cavities on both sides of the road,” said MDOT wildlife expert Robert Wolinski. “The nests were noticed a few days later. I inspected the site and determined that the birds had laid eggs.”
Wolinski ordered the contractor to stop work in that immediate area.
“Once we have birds on incubating eggs we had to stop work in that vicinity because it might harm the birds, their nests or young,” Wolinski said.
“Vibrations from heavy equipment could cause the banks to collapse and cover the nests.”
The birds flew the coop Aug. 13, and the roadwork resumed.
According to Wolinski, bank swallows — which are not on the endangered species list — are pretty tough little cookies.
“They’re the smallest of all the member of the swallow family here in Michigan,” Wolinski said.
“They migrate to Central and South America and can even be found at the very southern tip of South America. They are small, but tough.”
MDOT had a similar situation with bank swallows on a project on M-59 in Howell, but workers were able to head the birds off before they started their nests.
August 23rd, 2007
portal.antara.co.id
Denpasar (ANTARA News) - Sarang burung walet yang dihasilkan dari goa bawah tanah di Bima, Pulau Sumbawa, Nusa Tenggara Barat, merupakan salah satu yang terbaik di dunia, sehingga harganya tergolong tinggi.
Goa bawah tanah yang menjadi sarang burung walet (Colocalia spp) sejak lama dan berada dalam kepemilikan Pemkab Bima itu kandungan proteinnya termasuk tertinggi, kata eksportir sarang walet asal Surabaya, Benny Koesno, kepada ANTARA News.
Ditemui di restoran sarang walet terpadu pertama di Indonesia, “Nest Village Restaurant & Store” di Mertasari, Sunset Road, Kuta, Bali, disebutkan bahwa harga sarang walet kini yang terendah sekitar Rp10 juta dan kualitas terbaik mencapai sekitar Rp20 juta per kilogram.
“Kami sejak lama menjalin kerjasama pengelolaan dan pemanenan sarang walet di goa bawah tanah tersebut dengan Pemkab Bima,” kata eksportir grup usaha King`s Nest tersebut.
Melalui grup usaha King`s Nest, Benny Koesno yang merintis usaha sarang walet sejak 1995, setahun kemudian hingga kini rutin mengekspor produknya ke China, Hongkong, Amerika Serikat dan Singapura.
Didampingi penanggungjawab restoran tersebut, Donald Manoch, disebutkan bahwa goa burung walet di Bima itu benar-benar berada di bawah tanah, sehingga burung walet keluar-masuk melewati lobang goa di permukaan tanah.
Sementara lingkungan sekitarnya berupa hutan yang masih tergolong lestari, sehingga ribuan burung tersebut mudah mendapatkan makanan dari alam yang mampu menghasilkan kandungan protein tinggi.
Sarang walet dari goa bawah tanah tersebut menjadi salah satu bahan ramuan makanan dan minuman yang disajikan di Nest Village, selain dijual di tokonya dalam bentuk olahan siap dimasak dengan label “King`s Nest”.
Ekspansi usaha restoran dan toko sarang walet tersebut dipadu dengan tempat wisata yang menyediakan miniatur “rumah walet” dan proses pengolahan sarang walet, di lokasi yang masih tergolong alami.
Bupati Bima, Ferry Zulkarnain ST, yang menjalin kerja sama dengan King`s Nest, sempat mengunjungi rumah makan sarang walet terpadu di Kuta tersebut.
Melalui rintisan usaha baru itu, Benny Koesno berharap kelak akan mampu membangun kesan atau “brand image” bahwa sarang walet merupakan produk Indonesia.
Hal itu mengingat selama ini produk sarang walet lebih dikenal sebagai milik masyarakat Hongkong, padahal sekitar 80 persen kebutuhan sarang walet dunia dipasok dari Indonesia.
Produksi sarang walet dari berbagai wilayah Indonesia, terutama kini dari rumah-rumah walet yang tersebar di perkotaan maupun pedesaan, diperkirakan mencapai 20 ton per bulan.
Eksportir dan pedagang sarang burung walet pun bertebaran di berbagai daerah, bahkan di Surabaya dan daerah Jatim lainnya mencapai puluhan orang/pengusaha. (*)
August 22nd, 2007
pubs.acs.org
Motomu Oda, Shinji Ohta, Takayuki Suga, and Tadashi Aoki*
Nagasaki Prefectural Women’s Junior College, 1-4-1 Narutaki, Nagasaki 850, Japan, Instrument Center for Chemical Analysis, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739, Japan, Department of Chemistry, Faculty of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739, Japan, and Suzugamine Women’s College, 4-6-18 Inokuchi, Nishi-ku, Hiroshima 733, Japan
Received for review February 2, 1998. Revised manuscript received June 9, 1998. Accepted June 10, 1998. This work was supported in part by a Grant-in-Aid from the Ministry of Education, Science, Culture and Sports, Japan.
Abstract:
The N-linked asialo carbohydrate, released by digestion treatment of the glycoprotein of the edible bird’s nest of Collocalia fuciphaga, was identified as L-asparagine-linked fucose-containing triantennary oligosaccharide, composed of Gal14GlcNAc14(Gal14GlcNAc12)Man13(Gal14GlcNAc12Man16)Man14GlcNAc14(Fuc16)GlcNAc1, on the basis of chemical and spectroscopic methods, in addition to GLC and HPLC analyses on achiral columns.
August 20th, 2007
creativehomemaking.com
by Rachel Paxton
The Bird’s Nest Spruce is one of the most common dwarf evergreen shrubs. It is a member of the Norway Spruce (Picea abies) family; its Latin name is ‘Nidiformis’. This attractive, low-growing shrub gets its name from a depression in the center that makes it look like a bird’s nest.
A versatile shrub, it is perfect for mixed borders, group planting, rock gardens, and container gardening. It is well suited for transplanting because of its shallow root system.
The Bird’s Nest Spruce is very low maintenance because it grows so slowly. At 10 years of age you can expect the shrub to be 1′ tall and 2′ wide. You can, however, prune new growth to give the shrub a desired shape, even to resemble a bonsai plant.
This hearty shrub is dark green in color, but in the spring new growth will appear light yellow-green. By late spring the branches are a uniform green.
Grown in a variety of soil conditions, this shrub will thrive as long as there is adequate drainage. It prefers full sun with afternoon shade. You can apply low-nitrogen evergreen fertilizer in late fall or early spring for optimal growth, however, the shrub does not require regular fertilization.
The most common pests that may bother this shrub are spider mites. Low populations of spider mites can be controlled simply by regularly spraying your shrub with the garden hose. Heavier infestations will require a pesticide.
Best grown in zones three through eight, the Bird’s Nest Spruce will eventually achieve a height of 3′ and a width of 2-3′. Plants should be spaced 4-6′ apart. Water needs are minimal, this shrub can survive even in drought conditions.
Rachel Paxton is a freelance writer and mom who is the author of What’s for Dinner?, an e-cookbook containing more than 250 quick easy dinner ideas. For more recipes, organizing tips, home decorating, crafts, holiday hints, and more, visit Creative Homemaking at http://www.creativehomemaking.com.
August 16th, 2007
cat.inist.fr
uteur(s) / Author(s)
MARCONE Massimo F. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, Ont., N1 G 2 W1, CANADA
Résumé / Abstract
A few species of swiflets (genus Aerodramus) build edible nests that are consumed by humans worldwide, as a delicacy known as the Caviar of the East or as a medicinal food.
This study reports on the compositional properties of two types of nest, the white nest and the red blood nest. The order of composition (from lowest to highest) was found to be identical for both types of nests, i.e., lipid (0.14-1.28%), ash (2.1%), carbohydrate (25.62-27.26%) and protein (62-63%). It was also found that both nests share a common 77 KDa protein that has properties similar to those of the ovotransferrin protein in eggs. This protein may be partially responsible for the severe allergic reactions that sometimes occur among young children who consume edible bird’s nest products. It was found that SDS-PAGE electrophoretic fingerprinting might serve as a useful analytical technique for differentiating between white and red nests and for determining if the more expensive blood nest was adulterated with the less expensive white nest. Also evaluated were different analytical methodologies for detecting adulterants. Three of the most common adulterants found in retail bird’s nests are karaya gum, red seaweed, and tremella fungus, and they are routinely incorporated during commercial processing prior to final sale. Using crude protein determination, it was found that these adulterants (which typically accounted for 2-10% of the finished nest), reduce the overall crude protein content of the genuine white bird’s nest by as much as 1.1-6.2%. A modified xantho-proteic nitric acid test for proteins proved to be a rapid, and simple test to detect adulteration in both whole and finely ground nests, and would be suitable in the field where analytical facilities are not readily available. After simple nitric acid treatment, visual examination and comparison of whole nests adulterated with karaya gum, red seaweed, and Tremella fungus against the authentic white nest revealed that levels of adulteration as low as 1.7%, 1.8%, and 3.5%, respectively, could be identified visually. In the case of finely ground nests, the visual detection level was higher for all three adulterants: 1.1% for karaya gum, 1.2% for red seaweed, and 2.0% for Tremella fungus. The use of a reflectance colourmeter rendered this test even more sensitive, allowing detection at even lower levels.
Revue / Journal Title
Food research international (Food res. int.) ISSN 0963-9969
Source / Source
2005, vol. 38, no10, pp. 1125-1134 [10 page(s) (article)] (20 ref.)
Langue / Language
Anglais
Editeur / Publisher
Elsevier, Oxford, ROYAUME-UNI (1992) (Revue)
Mots-clés anglais / English Keywords
Vertebrata ; Caviar ; Aves ; Characterization ;
Mots-clés français / French Keywords
Vertebrata ; Caviar ; Aves ; Caractérisation ;
Mots-clés espagnols / Spanish Keywords
Vertebrata ; Caviar ; Aves ; Caracterización ;
Localisation / Location
INIST-CNRS, Cote INIST : 15518, 35400013181095.0030
August 15th, 2007
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