Este site dedica-se às aves e a relação com o Homem. O canto do Canário Timbrado, Canário Harz Roller, do canário Malinois e outros canários.. O objectivo de site é contar as aventuras e os arcos de descobertas relacionados com Homem e as aves. This site is dedicated to birds.singing canaries song,canaries,canaries de chant. carmelita=carmelo=jardim
Mostrar mensagens com a etiqueta . Man and birds .O homem e as aves.Lo Hombre y los pajaros.. Mostrar todas as mensagens
Mostrar mensagens com a etiqueta . Man and birds .O homem e as aves.Lo Hombre y los pajaros.. Mostrar todas as mensagens
30 de novembro de 2011
6 de abril de 2009
26 de fevereiro de 2009
Naturlink
Os versáteis olhos dos animais
"A evolução da recepção e interpretação de estímulos luminosos, traduziu-se numa imensidade de alternativas de visão no reino animal.
Cada uma delas traduz diferentes formas de vida, constituindo um vasto e fascinante campo de estudo.
Todas as formas de vida animal, desde a amiba ao homem, reagem de algum modo à luz. Os animais mais simples, como os unicelulares, são sensíveis apenas a mudanças de intensidade luminosa.
A minhoca, ser já com elevado grau de complexidade, continua a não ter olhos, mas toda a sua pele é coberta por células sensíveis à luz. Animais mais evoluídos, como as aves e os mamíferos, desenvolveram estruturas oculares complexas, que registam imagens detalhadas do mundo que os cerca.
O modo de cada animal perceber a luz é ditado pelas suas necessidades específicas - a forma pela qual obtém alimento, como fogem de inimigos, se voa, nada ou rasteja, e se o seu dia começa ao amanhecer ou ao anoitecer. "
Naturlink -Maria Carlos Reis
18 de fevereiro de 2009
The netlabel Birdsong
The netlabel Birdsong was founded in 2004 as a way of distributing the music we love and believe deserves a better fate than that of independent CDs lost and forgotten on the shelves of neighborhood stores. Much like any other netlabel, Birdsong operates nearly exclusively within the web, surpassing all geographical boundaries and outdated means of distribution. All the music we've chosen to distribute on our website is available for free downloading with the artists' consent under the creative commons license.
It's not that we believe the artists don't deserve money; we feel this is the lesser of two evils since the unfortunate choice is between free distribution and the local music store graveyard.
17 de fevereiro de 2009
Bird Song Discoveries May Lead To Refinement Of Darwinian Theory
One of her projects is to record and map out the songs of Savannah sparrows that spend the warmer months on a small Canadian island, Kent Island, in the Bay of Fundy. With the help of microphones, binoculars, and a well-documented set of individual birds, her research is beginning to create a richer view of how birdsong moves from neighbor to neighbor and generation to generation in the wild. And it could lead to a refined way of looking at how communication fits into evolutionary theory.
Using sound to communicate is common to many animal species, but learning different ways to use the tools physiology gave them to create more complex means of communication is rare. Human language is the most obvious example, but we alone among primates are capable of vocal learning (though other kinds of mammals including dolphins, whales, and a few species of bats and seals do learn their vocalizations). On the other hand, over 5,000 species of birds learn their songs.
Previous generations of birdsong researchers have shown that birds learn their songs in ways very similar to the ways human infants learn language. They start with a period of close listening, followed by a "subsong" phase akin to human "babbling," as they work out the phonemes they can physically make and map the sounds to the motor skills it takes to make them, "to calibrate the vocal instrument," as Prof. Williams puts it. After that comes the "plastic song" phase, when they begin to put the parts together in imitation of models they've heard, and a "crystallization" period when they settle on a tune that works.
Since 2004, Prof. Williams has made several trips to Kent Island, about an eight-hour drive, followed by a two-hour ferry ride to Grand Manan Island. From there it takes another hour on a lobster boat to reach the island. The island is managed as a scientific research station by Bowdoin College, and has been a protected area for more than 70 years. Many researchers use it as an open-air laboratory to study the island's flora and fauna.
One ongoing research effort begun by Nathaniel Wheelwright of Bowdoin College is to catalog the life stories of a broad sample of the Savannah sparrows that summer on the island. Since 1987, thousands of the little birds have been caught, tagged with bands on their legs, and had their blood sampled. The result is a rich census of the island's sparrow population, with detailed information about the birds' life-span, mating habits, and territorial awareness.
"There are other multi-year studies of birds," Williams said. "But not many have accumulated this kind of longevity and this breadth of approaches."
In some ways, it can seem like a very complicated episode of "Melrose Place." One particular long-lived male is known as "S.RN," so-called because his left leg has a striped band, and his right leg a red band over a navy blue one. In 2004, he mated with five different females, and raised 20 nestlings.
Using sound to communicate is common to many animal species, but learning different ways to use the tools physiology gave them to create more complex means of communication is rare. Human language is the most obvious example, but we alone among primates are capable of vocal learning (though other kinds of mammals including dolphins, whales, and a few species of bats and seals do learn their vocalizations). On the other hand, over 5,000 species of birds learn their songs.
Previous generations of birdsong researchers have shown that birds learn their songs in ways very similar to the ways human infants learn language. They start with a period of close listening, followed by a "subsong" phase akin to human "babbling," as they work out the phonemes they can physically make and map the sounds to the motor skills it takes to make them, "to calibrate the vocal instrument," as Prof. Williams puts it. After that comes the "plastic song" phase, when they begin to put the parts together in imitation of models they've heard, and a "crystallization" period when they settle on a tune that works.
Since 2004, Prof. Williams has made several trips to Kent Island, about an eight-hour drive, followed by a two-hour ferry ride to Grand Manan Island. From there it takes another hour on a lobster boat to reach the island. The island is managed as a scientific research station by Bowdoin College, and has been a protected area for more than 70 years. Many researchers use it as an open-air laboratory to study the island's flora and fauna.
One ongoing research effort begun by Nathaniel Wheelwright of Bowdoin College is to catalog the life stories of a broad sample of the Savannah sparrows that summer on the island. Since 1987, thousands of the little birds have been caught, tagged with bands on their legs, and had their blood sampled. The result is a rich census of the island's sparrow population, with detailed information about the birds' life-span, mating habits, and territorial awareness.
"There are other multi-year studies of birds," Williams said. "But not many have accumulated this kind of longevity and this breadth of approaches."
In some ways, it can seem like a very complicated episode of "Melrose Place." One particular long-lived male is known as "S.RN," so-called because his left leg has a striped band, and his right leg a red band over a navy blue one. In 2004, he mated with five different females, and raised 20 nestlings.
Subsequent blood work revealed that only 16 of them were actually his offspring (he didn’t lose much overall, because he fathered at least five that hatched in other males’ nests). More importantly, four of his offspring returned to breed the next year -- a good result as usually only one in ten return.
Matching singers and song samples
Starting from such a broad and ever-growing inventory, Prof. Williams has set about trying to match specific songs to specific individuals. With binoculars, a good microphone, and a little patience, she has been able to match hundreds of song samples to their singers, despite challenges like stiff ocean winds that often make recording impossible, and birds that sometimes stubbornly refuse to present their leg bands in plain view.
Male Savannah sparrows sing a single, individually distinct song their entire lives, which they appear to learn from other males. It is a high-pitched song that lasts two to four seconds and is in four basic parts: an introduction of three to eight high-pitched notes, a portion made up of sharp staccato notes and whistles, then a long broad-frequency buzz, and finally a quick series of notes called the terminal trill.
Prof. Williams takes the recordings of the songs and views them as a spectrogram, which plots pitch against time. With hundreds of samples gathered from hundreds of individual birds, she is patching together an amazingly detailed schematic representation of how their songs vary according to calendar year, age, and location (males stake out specific territories for themselves). It maps out the subtle variations in the songs between older and younger birds, as well as differences between nearby locations.
From what she has gathered so far, she says that "singing doesn't seem to be the basis of mate choice by females." There doesn't seem to be a particular kind of song that appeals particularly well to females, nor does seem to matter how well or how cleanly a male sings his song.
The way singing functions in bird society "doesn't seem to be simple," Prof. Williams said. It raises the question: What is the point of singing in the first place? If further research confirms these early observations, she believes it may lead to a refinement of Charles Darwin's theory of sexual selection. Darwin wrote that that the differences between the sexes in a species evolved either to compete for or to attract mates. But that idea has had to be expanded more recently to account for research on cooperative behavior. Prof. Williams notes that in some bird species, males share a common territory where they make elaborate displays to impress females, even though only a few get mates.
"Several lines of research are leading towards another extension that focuses on coalitions of subordinate males," Williams said. For the Savannah sparrows, the song may serve yet another purpose. "I'm looking for evidence that song is used in forming what I might call 'cultural coalitions' that allow a group of males that would not normally be prominent - perhaps because of age or status - to gain prominence by banding together under a learned 'cultural' trait," she said.
Adapted from materials provided by Williams College, via Newswise.
Matching singers and song samples
Starting from such a broad and ever-growing inventory, Prof. Williams has set about trying to match specific songs to specific individuals. With binoculars, a good microphone, and a little patience, she has been able to match hundreds of song samples to their singers, despite challenges like stiff ocean winds that often make recording impossible, and birds that sometimes stubbornly refuse to present their leg bands in plain view.
Male Savannah sparrows sing a single, individually distinct song their entire lives, which they appear to learn from other males. It is a high-pitched song that lasts two to four seconds and is in four basic parts: an introduction of three to eight high-pitched notes, a portion made up of sharp staccato notes and whistles, then a long broad-frequency buzz, and finally a quick series of notes called the terminal trill.
Prof. Williams takes the recordings of the songs and views them as a spectrogram, which plots pitch against time. With hundreds of samples gathered from hundreds of individual birds, she is patching together an amazingly detailed schematic representation of how their songs vary according to calendar year, age, and location (males stake out specific territories for themselves). It maps out the subtle variations in the songs between older and younger birds, as well as differences between nearby locations.
From what she has gathered so far, she says that "singing doesn't seem to be the basis of mate choice by females." There doesn't seem to be a particular kind of song that appeals particularly well to females, nor does seem to matter how well or how cleanly a male sings his song.
The way singing functions in bird society "doesn't seem to be simple," Prof. Williams said. It raises the question: What is the point of singing in the first place? If further research confirms these early observations, she believes it may lead to a refinement of Charles Darwin's theory of sexual selection. Darwin wrote that that the differences between the sexes in a species evolved either to compete for or to attract mates. But that idea has had to be expanded more recently to account for research on cooperative behavior. Prof. Williams notes that in some bird species, males share a common territory where they make elaborate displays to impress females, even though only a few get mates.
"Several lines of research are leading towards another extension that focuses on coalitions of subordinate males," Williams said. For the Savannah sparrows, the song may serve yet another purpose. "I'm looking for evidence that song is used in forming what I might call 'cultural coalitions' that allow a group of males that would not normally be prominent - perhaps because of age or status - to gain prominence by banding together under a learned 'cultural' trait," she said.
Adapted from materials provided by Williams College, via Newswise.
9 de fevereiro de 2009
Teoria questiona causas das alterações climáticas
Muitos dos que negam que as alterações climáticas sejam causadas por acções do ser humano baseiam a sua argumentação na teoria do cientista sérvio Milutin Milankovic, que assegura que as variações do clima na Terra dependem das radiações solares.
As descobertas de Milankovic (1879-1958), alvo de uma grande exposição que abriu esta semana em Belgrado, permitiram ajudar a entender um dos grandes mistérios da história terrestre: os períodos de sucessão das eras glaciais.
A teoria do cientista sérvio dá protagonismo às radiações solares e atribui a mudança do clima a uma combinação de três ciclos astronómicos, explicou Slavko Maksimovic, meteorologista e presidente da Associação Milutin Milankovic.
Estas mudanças estão relacionadas com movimentos da Terra em redor do Sol: a revolução do eixo de rotação do planeta; variações na inclinação do seu eixo; e a oscilação da excentricidade da órbita da Terra em torno do Sol«A sua grandeza está no facto de que tentou encontrar o vínculo entre os três fenómenos, algo que ninguém tinha feito. Ele introduziu na pesquisa a matemática, o que foi incomparável, e no final sobrepôs os três fenómenos. O resultado ou consequência desses fenómenos é o nosso clima», disse Maksimovic.
Aplicando os seus cálculos matemáticos, Milankovic chegou à conclusão de que o clima na Terra é formado por grandes ciclos que se sucedem, e que agora nos encontramos numa época que qualifica como «interglacial».
A quantidade da radiação solar influi de forma directa no sistema climático da Terra, no avanço e na retirada das massas de gelo no planeta.
O sérvio trabalhou na sua teoria durante 30 anos, desde 1910, e publicou as suas pesquisas primeiro em alemão, língua na qual estudou Engenharia Civil em Viena, no início do século XX.
Maksimovic explicou que o factor humano não pode influir no processo de alterações climáticas definido por Milankovic.O homem não pode mudar a posição do Sol, nem da Terra, nem a quantidade (de energia solar) que chega ao planeta», disse.
Mas as alterações climáticas pela acção humana, o uso cada vez maior de combustíveis fósseis e a poluição descontrolada «também têm a sua influência, dependendo da quantidade das matérias que causam o efeito de estufa», acrescentou.
«Cada vez mais se usa a teoria de Milankovic também para estabelecer em que medida tudo isso pode influir, o natural e o artificial. O que é seguro é que não podemos influir nas leis naturais e nas suas consequências. Quanto ao artificial, o homem causou-o e por conseguinte pode trocá-lo», declarou.
Pelos seus méritos na pesquisa sobre a Terra e a mecânica celeste, duas crateras em Marte e na Lua receberam o nome do cientista sérvio.
As descobertas de Milankovic (1879-1958), alvo de uma grande exposição que abriu esta semana em Belgrado, permitiram ajudar a entender um dos grandes mistérios da história terrestre: os períodos de sucessão das eras glaciais.
A teoria do cientista sérvio dá protagonismo às radiações solares e atribui a mudança do clima a uma combinação de três ciclos astronómicos, explicou Slavko Maksimovic, meteorologista e presidente da Associação Milutin Milankovic.
Estas mudanças estão relacionadas com movimentos da Terra em redor do Sol: a revolução do eixo de rotação do planeta; variações na inclinação do seu eixo; e a oscilação da excentricidade da órbita da Terra em torno do Sol«A sua grandeza está no facto de que tentou encontrar o vínculo entre os três fenómenos, algo que ninguém tinha feito. Ele introduziu na pesquisa a matemática, o que foi incomparável, e no final sobrepôs os três fenómenos. O resultado ou consequência desses fenómenos é o nosso clima», disse Maksimovic.
Aplicando os seus cálculos matemáticos, Milankovic chegou à conclusão de que o clima na Terra é formado por grandes ciclos que se sucedem, e que agora nos encontramos numa época que qualifica como «interglacial».
A quantidade da radiação solar influi de forma directa no sistema climático da Terra, no avanço e na retirada das massas de gelo no planeta.
O sérvio trabalhou na sua teoria durante 30 anos, desde 1910, e publicou as suas pesquisas primeiro em alemão, língua na qual estudou Engenharia Civil em Viena, no início do século XX.
Maksimovic explicou que o factor humano não pode influir no processo de alterações climáticas definido por Milankovic.O homem não pode mudar a posição do Sol, nem da Terra, nem a quantidade (de energia solar) que chega ao planeta», disse.
Mas as alterações climáticas pela acção humana, o uso cada vez maior de combustíveis fósseis e a poluição descontrolada «também têm a sua influência, dependendo da quantidade das matérias que causam o efeito de estufa», acrescentou.
«Cada vez mais se usa a teoria de Milankovic também para estabelecer em que medida tudo isso pode influir, o natural e o artificial. O que é seguro é que não podemos influir nas leis naturais e nas suas consequências. Quanto ao artificial, o homem causou-o e por conseguinte pode trocá-lo», declarou.
Pelos seus méritos na pesquisa sobre a Terra e a mecânica celeste, duas crateras em Marte e na Lua receberam o nome do cientista sérvio.
Além disso, foi um dos pioneiros da «paleoclimatologia», criador do primeiro modelo numérico do clima, fundador da climatologia cósmica e cientista responsável pela primeira interpretação matemática das mudanças da localização dos pólos da Terra.
Os testes empíricos geológicos e o grande projecto científico mundial CLIMAP (Climate: Long-range Investigation, Mapping, and Prediction) responderam nos anos 1970 a algumas dúvidas em torno da sua teoria, que, além disso, é aplicável a outros planetas.
Os testes empíricos geológicos e o grande projecto científico mundial CLIMAP (Climate: Long-range Investigation, Mapping, and Prediction) responderam nos anos 1970 a algumas dúvidas em torno da sua teoria, que, além disso, é aplicável a outros planetas.
1 de fevereiro de 2009
Rouxinol
L'usignolo Luscinia megarhynchos un uccello dell'ordine dei passeriformi, sottordine dei passeri. Secondo riconoscimenti biologico-molecolari sulla filogenesi degli uccelli canori deve essere annoverato fra i muscicapidi (Muscicapidae).
De nachtegaal (Luscinia megarhynchos) is een zangvogel uit de familie Lijsters (Turdidae). De naam is afgeleid van het Germaanse "galan" : zingen. Soms zijn ze in tuinen te horen, zien doe je de nachtegaal bijna niet, door zijn eenzaam karakter en onopvallend verenkleed.
O rouxinol-bravo (Cettia cetti) é um pássaro da família Sylviidae.
A sua plumagem é castanha com tons arruivados. É uma espécie de hábitos furtivos, que geralmente se esconde por entre a vegetação, sendo por isso difícil de observar. Detecta-se mais facilmente pelo seu canto.
Apesar do nome, não é relacionada com o rouxinol, partilhando este nome devido a possuir algumas semelhanças com este, nomeadamente cantar durante a noite.
Esta espécie distribui-se principalmente pelo sul da Europa.
Apesar do nome, não é relacionada com o rouxinol, partilhando este nome devido a possuir algumas semelhanças com este, nomeadamente cantar durante a noite.
Esta espécie distribui-se principalmente pelo sul da Europa.
Em Portugal está presente durante todo o ano e frequenta sobretudo caniçais e zonas ribeirinhas com vegetação densa, sendo bastante comum no centro e no sul do país.
30 de janeiro de 2009
Sófocles se suma a los autores del festival de teatro juvenil grecolatino
El festival de teatro grecolatino, que organiza el instituto Santa Eulalia y que este año llega a su décimotercera edición, pondrá en escena obras de Plauto, Aristófanes y Sófocles, autor este último que se suma a este evento este año, en detrimento de Eurípides y Terencio, autores que sí estuvieron representados en el 2008.
Este año, el evento se desarrollará los días 21, 22, 23 y 24 de abril en el teatro romano, justo tres días después de que termine el festival de rock Extremúsika, con lo que Mérida protagonizará los eventos culturales en la región en abril.
Los participantes en la edición de este año del festival juvenil de teatro grecolatino serán el grupo Balbo, del instituto Santo Domingo del Puerto de Santa María (que repiten participación); el grupo Parodos, del instituto Siberia Extremeña de Talarrubias (este centro también participó el pasado año); el grupo Phersu, de la Facultad de Filosofía y Letras de la Universidad de Cádiz (también estuvo en el 2008), al igual que la Escuela Superior de Arte Dramático de la Universidad de Málaga; así como el grupo In Albis, del instituto Fuentenueva de Morón de la Frontera; y el grupo de teatro universitario clásico de la Universidad de Alicante.
La previsión de la organización es que se den cita en la ciudad durante esos días más de 15.000 alumnos de Secundaria.
PROGRAMACION Para abrir esta edición, repite el autor más representado en este evento, Plauto. El grupo Balbo, del instituto Santo Domingo del Puerto de Santa María, representará la obra Aulularia , el martes 21 de abril a las 11.30 horas. Ese mismo día, a las 17.30 horas, este mismo grupo pondrá en escena Antígona , de Sófocles.
Las funciones del 22 de abril comenzarán a las 11.30 horas con el grupo Parodos, del instituto Siberia Extremeña de Talarrubias, que representará la obra Gemelos , de Plauto. Las Avispas , de Aristófanes cerrará desde las 17.30 horas la programación de este día representada por el grupo gaditano Phersu.
Para la edición de este año vuelve un clásico de este tipo de eventos, Edipo Rey , de Sófocles. Será el 23 de abril a las 11.30 horas, a cargo de la Escuela Superior de Arte Dramático de la Universidad de Málaga. En la sesión de tarde, el grupo In Albis, de Morón de la Frontera, representará la obra Las Nubes .
Plauto cerrará esta edición, el 24 de abril a las 11.30 horas, con la obra Pseudolus , a cargo del grupo de teatro universitario clásico de la Universidad de Alicante.
Periodico Extremadura
Los participantes en la edición de este año del festival juvenil de teatro grecolatino serán el grupo Balbo, del instituto Santo Domingo del Puerto de Santa María (que repiten participación); el grupo Parodos, del instituto Siberia Extremeña de Talarrubias (este centro también participó el pasado año); el grupo Phersu, de la Facultad de Filosofía y Letras de la Universidad de Cádiz (también estuvo en el 2008), al igual que la Escuela Superior de Arte Dramático de la Universidad de Málaga; así como el grupo In Albis, del instituto Fuentenueva de Morón de la Frontera; y el grupo de teatro universitario clásico de la Universidad de Alicante.
La previsión de la organización es que se den cita en la ciudad durante esos días más de 15.000 alumnos de Secundaria.
PROGRAMACION Para abrir esta edición, repite el autor más representado en este evento, Plauto. El grupo Balbo, del instituto Santo Domingo del Puerto de Santa María, representará la obra Aulularia , el martes 21 de abril a las 11.30 horas. Ese mismo día, a las 17.30 horas, este mismo grupo pondrá en escena Antígona , de Sófocles.
Las funciones del 22 de abril comenzarán a las 11.30 horas con el grupo Parodos, del instituto Siberia Extremeña de Talarrubias, que representará la obra Gemelos , de Plauto. Las Avispas , de Aristófanes cerrará desde las 17.30 horas la programación de este día representada por el grupo gaditano Phersu.
Para la edición de este año vuelve un clásico de este tipo de eventos, Edipo Rey , de Sófocles. Será el 23 de abril a las 11.30 horas, a cargo de la Escuela Superior de Arte Dramático de la Universidad de Málaga. En la sesión de tarde, el grupo In Albis, de Morón de la Frontera, representará la obra Las Nubes .
Plauto cerrará esta edición, el 24 de abril a las 11.30 horas, con la obra Pseudolus , a cargo del grupo de teatro universitario clásico de la Universidad de Alicante.
Periodico Extremadura
29 de janeiro de 2009
20 de janeiro de 2009
19 de janeiro de 2009
Tags reveal birds' ocean odyssey
Electronic tags have offered an insight into the mysteries of the 20,000km migration of Manx shearwaters.
A team of UK scientists found that the birds made regular "stopovers" lasting up to two weeks, probably to feed and replenish their energy reserves.
The data was recovered from logging tags fitted to six breeding pairs of Puffinus puffinus from
A team of UK scientists found that the birds made regular "stopovers" lasting up to two weeks, probably to feed and replenish their energy reserves.
The data was recovered from logging tags fitted to six breeding pairs of Puffinus puffinus from
Skomer Island, off the coast of Wales.
"We have interpreted this as being stopover behaviour because this is common in terrestrial migrant birds; essentially, they stop to refuel," he told BBC News.
But, he added, sea birds that migrated over open seas did not normally display this behaviour because, unlike terrestrial species, they were not able to return to the same feeding spot each year.
However, in the case of the tagged Manx shearwaters, a small bird weighing about 400g, they appeared to have adopted the same behaviour as it offered the "optimal migration strategy".
Professor Guilford suggested that the birds were more likely to survive if they made a series of regular stops rather than flying directly to South America.
"If they flew directly, they would have to have a larger fat reserve in order to make the journey," he explained.
"They could do that, but on the other hand that would mean the bird would be flying the first part of the migration weighing more than it needed to.
"It is a complex trade-off between the aerodynamics of long distance flight and the risks and time constraints of having to stop and refuel.
Ringing true
Professor Guilford said the data did not throw up too many surprises as far as the birds' migratory route was concerned.
"The route that they took was very broadly consistent with what people using more traditional methods, such as ringing, thought they had taken.
"It is gratifying that these techniques, which have been the mainstay of our understanding of avian migration for so long, turn out to be broadly correct."
However, he added that the data from the tags did reveal a few differences.
"They go a little bit further south than we expected, but that was probably the result that human settlements were much more sparse, where there were fewer people to recover the rings."
The team used two different kinds of logging tags, both of which were designed and made by the British Antarctic Survey."They are very similar except that one is a slightly more recent version, which records contact with salt water," Professor Guilford explained.
"This allowed us to know whether the bird was sat on the water or diving, or whether it was flying." By combining the two data sets (location and flight/stationary), the researchers were able to work out the birds' migration pattern and behaviour en route.
Rather than using a satellite tag, which beams the data back almost straight away, the team opted for a "logging device" that stored the information until it was physically retrieved from the bird.
"This is the slightly nerve-wracking side of things," he admitted. "The primary benefit is that they are much smaller than devices that transmit."
All of the tagged birds returned to the UK breeding site, which suggested that the tags did not inhibit them during their seven-month migration.
"We have gone to great lengths to try and minimise the impact of our devices," said Professor Guilford.
Although the Manx shearwater, as a species, is not under threat, he added that the findings helped improve our understanding of what was happening in the world's seas and oceans.
"Although they are doing very well, they are still limited to big but compact populations on islands, which are very vulnerable to predators etc," he explained.
"So it is nice to say that we can now begin to understand what these birds depend upon in terms of resources on land, and now at sea.
"We won't be stopping with Manx shearwaters, we are beginning to put them on puffins as well." The findings appear in the journal Proceedings of the Royal Society B.
"Every one of the 12 birds made at least one stop during its migration in one place for up to two weeks," observed co-author Tim Guilford of the Animal Behaviour Research Group at the University of Oxford.
But, he added, sea birds that migrated over open seas did not normally display this behaviour because, unlike terrestrial species, they were not able to return to the same feeding spot each year.
However, in the case of the tagged Manx shearwaters, a small bird weighing about 400g, they appeared to have adopted the same behaviour as it offered the "optimal migration strategy".
Professor Guilford suggested that the birds were more likely to survive if they made a series of regular stops rather than flying directly to South America.
"If they flew directly, they would have to have a larger fat reserve in order to make the journey," he explained.
"They could do that, but on the other hand that would mean the bird would be flying the first part of the migration weighing more than it needed to.
"It is a complex trade-off between the aerodynamics of long distance flight and the risks and time constraints of having to stop and refuel.
Ringing true
Professor Guilford said the data did not throw up too many surprises as far as the birds' migratory route was concerned.
"The route that they took was very broadly consistent with what people using more traditional methods, such as ringing, thought they had taken.
"It is gratifying that these techniques, which have been the mainstay of our understanding of avian migration for so long, turn out to be broadly correct."
However, he added that the data from the tags did reveal a few differences.
"They go a little bit further south than we expected, but that was probably the result that human settlements were much more sparse, where there were fewer people to recover the rings."
The team used two different kinds of logging tags, both of which were designed and made by the British Antarctic Survey."They are very similar except that one is a slightly more recent version, which records contact with salt water," Professor Guilford explained.
"This allowed us to know whether the bird was sat on the water or diving, or whether it was flying." By combining the two data sets (location and flight/stationary), the researchers were able to work out the birds' migration pattern and behaviour en route.
Rather than using a satellite tag, which beams the data back almost straight away, the team opted for a "logging device" that stored the information until it was physically retrieved from the bird.
"This is the slightly nerve-wracking side of things," he admitted. "The primary benefit is that they are much smaller than devices that transmit."
All of the tagged birds returned to the UK breeding site, which suggested that the tags did not inhibit them during their seven-month migration.
"We have gone to great lengths to try and minimise the impact of our devices," said Professor Guilford.
Although the Manx shearwater, as a species, is not under threat, he added that the findings helped improve our understanding of what was happening in the world's seas and oceans.
"Although they are doing very well, they are still limited to big but compact populations on islands, which are very vulnerable to predators etc," he explained.
"So it is nice to say that we can now begin to understand what these birds depend upon in terms of resources on land, and now at sea.
"We won't be stopping with Manx shearwaters, we are beginning to put them on puffins as well." The findings appear in the journal Proceedings of the Royal Society B.
"Every one of the 12 birds made at least one stop during its migration in one place for up to two weeks," observed co-author Tim Guilford of the Animal Behaviour Research Group at the University of Oxford.
VilaFalco.com
About us
We are a dedicated group of falconers with a common goal: to produce excellent birds of prey to be able to maintain our sport, falconry. The Breeding project is supervised by Eduardo Cabral, falconer and breeder of birds of prey with the Licence Number 1 from The Ministry of Environment of Portugal.
Our customers are experienced falconers from the entire world, that decided to obtain an hunting falcon with high hunting performances. Our peregrine and gyr females are mainly for our Middle East customers and the males for the European market. If you are a beginner in falconry, we don’t have the appropriated falcon for you.
Your collection
We breed birds of prey, mainly for pleasure and if you have an outstanding bird of prey, or a couple that would like to put in a serious breeding program, please contact with us....
We are a dedicated group of falconers with a common goal: to produce excellent birds of prey to be able to maintain our sport, falconry. The Breeding project is supervised by Eduardo Cabral, falconer and breeder of birds of prey with the Licence Number 1 from The Ministry of Environment of Portugal.
Our customers are experienced falconers from the entire world, that decided to obtain an hunting falcon with high hunting performances. Our peregrine and gyr females are mainly for our Middle East customers and the males for the European market. If you are a beginner in falconry, we don’t have the appropriated falcon for you.
Your collection
We breed birds of prey, mainly for pleasure and if you have an outstanding bird of prey, or a couple that would like to put in a serious breeding program, please contact with us....
We have formal agreements with private falconers and organizations on the base of a 50% share, which means that you deliver the couple to us; we manage all expenses and will send you, without any costs, 50% of our production. In the case you will only put a bird in our breeding program; you will get 25% of her production. For the moment we are open to agreements on the following species: Aquila chrysaetus homeyeri, Falco rusticolus, Falco peregrinus calidus and Falco pelegrinoides babylonicus. However, if you have other species, please don’t hesitate in contacting us.
15 de janeiro de 2009
Assobiar
The Black-bellied Whistling-duck (Dendrocygna autumnalis), formerly also called Black-bellied Tree Duck, is a whistling-duck
Assobio é a produção de som de altura definida a partir da expiração constante através da boca. O ar pode ser direccionado pela língua, lábios, dentes ou dedos para criar a turbulência necessária à geração do som. A boca serve como caixa de ressonância para reforçar o som resultante, actuando como um ressonador de Helmholtz. O assobio pode também ser produzido utilizando as mãos como caixa de ressonância.
Assobio é a produção de som de altura definida a partir da expiração constante através da boca. O ar pode ser direccionado pela língua, lábios, dentes ou dedos para criar a turbulência necessária à geração do som. A boca serve como caixa de ressonância para reforçar o som resultante, actuando como um ressonador de Helmholtz. O assobio pode também ser produzido utilizando as mãos como caixa de ressonância.
Un silbido es un sonido agudo, resultante de hacer pasar aire con fuerza a través de los labios fruncidos o colocando los dedos de cierta manera en la boca.
El sonido se varia con la posición de los labios, la lengua o los dientes. La boca actúa a modo de caja de resonancia.
El sonido se varia con la posición de los labios, la lengua o los dientes. La boca actúa a modo de caja de resonancia.
Human whistling is the production of sound by means of expelling, and sometimes inhaling, a stream of air through the mouth. The air is moderated by the tongue, lips, teeth, or fingers to create turbulence, and the mouth acts as a resonant chamber to enhance the resulting sound, thus acting as a type of Helmholtz resonator.
Whistling can also be produced by hands, or using an external instrument, such as a whistle or even a blade of grass or leaf. The ability to whistle is quite unpredictable, and is possibly enabled by a genetic trait.
Orlando di Lasso assobiador
Theo Schulz: Rülpsen wie ein Profi/The Belch-Prof - se for sensivel não veja este....
África: Cidades portuárias ameaçadas pelo nível das águas
As cidades portuárias africanas - Cabo, Lagos e Alexandria - estão ameaçadas pela subida do nível das águas, devido ao aquecimento global que pode obrigar ao deslocamento de milhões de pessoas, advertiram quarta-feira cientistas no Cabo (África do Sul).
«O risco de catástrofe é elevado quando a probabilidade de perigo é grande, quando a vulnerabilidade face a esse perigo é grande e quando a capacidade de gerir as consequências deste acontecimento é baixa», afirmou Geoff Brundrit, da Rede Global de Observação dos Oceanos em África.
Muitos países africanos não têm «resistência« face às tempestades cada vez mais devastadoras e ainda não recuperaram da passagem de uma e já estão a sofrer a seguinte, explicou aos jornalistas à margem de uma conferência internacional sobre o aquecimento global no Cabo, no sul da África do Sul.
Em Lagos, na Nigéria, a cidade mais densamente povoada de África, com mais de 15 milhões de habitantes, as tempestades inundaram já algumas favelas e existe o risco das terras ficarem submersas pela subida do nível do mar, estimou Geoff Brundrit.
«O risco de catástrofe é elevado quando a probabilidade de perigo é grande, quando a vulnerabilidade face a esse perigo é grande e quando a capacidade de gerir as consequências deste acontecimento é baixa», afirmou Geoff Brundrit, da Rede Global de Observação dos Oceanos em África.
Muitos países africanos não têm «resistência« face às tempestades cada vez mais devastadoras e ainda não recuperaram da passagem de uma e já estão a sofrer a seguinte, explicou aos jornalistas à margem de uma conferência internacional sobre o aquecimento global no Cabo, no sul da África do Sul.
Em Lagos, na Nigéria, a cidade mais densamente povoada de África, com mais de 15 milhões de habitantes, as tempestades inundaram já algumas favelas e existe o risco das terras ficarem submersas pela subida do nível do mar, estimou Geoff Brundrit.
Alexandria, no Egipto e uma das cidades mais antigas do mundo, também sofreu violentas tempestades e na Cidade do Cabo, na África do Sul, a subida de 2,5 metros do nível do mar pode colocar, nos próximos 25 anos, dois terços da população ao nível das águas, com o respectivo aumento dos riscos de inundações.
Diário Digital / Lusa
Diário Digital / Lusa
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