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Bird brains more precise than humans’

Enviro talk

(Phys.org) —Birds have been found to display superior judgement of their body width compared to humans, in research to help design autonomous aircraft navigation systems.

A University of Queensland (UQ) study has found that budgerigars can fly between gaps almost as narrow as their outstretched wingspan rather than taking evasive measures such as tucking in their wings.

UQ Queensland Brain Institute researcher Dr Ingo Schiffner said previous research showed humans unnecessarily turned their shoulders to pass through doorways narrower than 130 per cent of their body width, whereas birds are far more precise.

“We were quite surprised by the birds’ accuracy – they can judge their wingspan within 106 per cent of their width when it comes to flying through gaps,” Dr Schiffner said.

“When you think about the cluttered environments they fly through, such as forests, they need to develop this level of accuracy.

“When they encounter a narrow…

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September 22, 2014 at 6:18 am Leave a comment

My conservation education experience with children

Enviro talk

In 2013, I took up something I never did before. Though journalism is and always be my first love, there was something that was going on in my mind when it comes to conservation. How can we tell the children the importance of forests and its links to the water we get everyday?

In South India, almost 69 rivers originate from the Western Ghats. The mountains absorbs the rains during monsoon and reserves it. Then it slowly releases the water-drops of water form small rivulets, then a stream flows, and finally the river gushes, giving us our daily supply of water.

The film that portrays this in its best is Save our Sholas by Shekar Dattatri

A bit about the film:

Titled ‘SOS – Save Our Sholas’, the 24-minute film, narrated by celebrated conservationist, Valmik Thapar, showcases the rich biodiversity of the southern Western Ghats forests and the problems…

View original post 800 more words

April 7, 2014 at 5:58 am Leave a comment

Banned pollutants are still found in sparrowhawks

High levels of polluting chemicals which are used as flame retardants have been detected in the livers of sparrowhawks in the UK.

So-called PBDEs (Polybrominated Diphenyl Ethers) are a group of 209 closely related chemicals – some of which are toxic.

They are used as flame retardants in electronics and a wide range of products, including furnishings and cars, but they are released into the air during the lifetime of the product and can also flake off and become airborne as dust. PBDEs can accumulate on the feathers of the birds, which end up eating them when they preen.

Previous studies have shown these pollutants can be detected in sparrowhawk eggs. But this new research has characterised contamination levels in the birds themselves and shows that adult birds have higher levels in their livers compared to juveniles. The higher level in adult birds suggests the toxins accumulate over time.

The work also shows that if the bird was malnourished, then concentrations of PBDEs in the liver can be up to fifteen times higher than in the level seen in chicks or well-fed birds.

Professor Richard Shore from the Centre for Ecology & Hydrology, co-author of the study, explained that birds with poor nutrition accumulate dramatically higher levels of these toxins in their liver. This is because PBDEs may be found in fat stores and other tissues which a bird remobilises as it goes through starvation and, in addition, the liver shrinks in size. 

‘These birds have the same amount of chemicals inside them as non-starved birds, but a smaller amount of tissue to store them in. So, even though the amounts are the same, the concentration is higher,’ he says. This has emphasised the need to look at an animal’s body condition if liver concentrations are used as a way of monitoring persistent organic pollutants, like these.

Scientists don’t currently know how high the concentration of these PBDEs needs to be to prove harmful to birds. But even at relatively low concentrations they can disrupt hormones and affect the reproductive success of the species.

Because of this, many PBDEs have already been banned. But levels of these banned toxins don’t appear to be lowering in sparrowhawk populations, unlike in other birds.

‘What we found happened with gannets was that levels of PBDEs rose sharply in the early 1990s when usage increased but they also fell very sharply when they were banned. We didn’t see this with sparrowhawks,’ says Shore.

‘It’s possible that since gannets are seabirds there is something in the marine system which metabolises these toxins, which we just don’t have in the terrestrial system,’ he explains. ‘We know some fish are capable of metabolising PBDEs, but perhaps there is no equivalent in the terrestrial system.’

Shore stresses that the ban has been effective, but as these compounds are phased out, a range of newer compounds are being introduced in their place. ‘A main focus on future work is to continue to monitor and analyse new compounds to see if they are entering the food chain, and if they are having any adverse effects,’ he says.

http://planetearth.nerc.ac.uk/news/story.aspx?id=1442

April 29, 2013 at 10:35 am 3 comments

Urban noise leads to less songbird diversity: Study

 

A team of Canadian researchers has found that anthropogenic noise (noise created by people that impacts other species) in urban areas leads to less songbird diversity. In their paper published in the journal Global Change Biology, the researchers describe how in studying songbird diversity in and around the city of Edmonton, they noted that songbirds that sang in low frequencies tended to have difficulty in communicating when having to compete with urban noise, leading to less mating and offspring production.

Many cities around the world have begun to implement plans to host songbirds—they are seen as an attractive feature in parks and other semi-natural settings. Unfortunately, such efforts have not lived up to expectations in many areas as diversity has been much lower than anticipated. Seeking to discover why, this new research effort focused on the idea that many songbirds may have trouble competing with urban noise, and as a result, fail to thrive.

The researchers surveyed 113 natural sites in and around the city of Edmonton Canada, noting the richness of songbird diversity, as well as elements commonly associated with their habitat, such as vegetation, food source etc. In analyzing their data, the team found a correlation between high urban noise level and songbird diversity—the more noise, the fewer the number of species. More specifically, they found that those songbirds that sang in low frequencies were more adversely impacted by urban noise, which they note generally comes from traffic, which also creates a lot of low frequency noise. 

The researchers suggest that interference from low frequency traffic noise could cause interruptions in mating songs in addition to general communication problems between the birds, leading to less mating, and fewer offspring. The result is urban environments that favor songbirds that sing in high frequencies, at the expense of those that are more heavily impacted by noise in their environment, i.e. less diversity. 

The team also studied seven particular species of songbirds to see if their numbers decreased as the level of noise around them increased, and found that the three species that sang in low frequencies did indeed show smaller and smaller population levels as the level of urban noise in the area increased. 

More humans reside in urban areas than at any other time in history. Protected urban green spaces and transportation greenbelts support many species, but diversity in these areas is generally lower than in undeveloped landscapes. Habitat degradation and fragmentation contribute to lowered diversity and urban homogenization, but less is known about the role of anthropogenic noise. Songbirds are especially vulnerable to anthropogenic noise because they rely on acoustic signals for communication. Recent studies suggest that anthropogenic noise reduces the density and reproductive success of some bird species, but that species which vocalize at frequencies above those of anthropogenic noise are more likely to inhabit noisy areas. We hypothesize that anthropogenic noise is contributing to declines in urban diversity by reducing the abundance of select species in noisy areas, and that species with low-frequency songs are those most likely to be affected. To examine this relationship, we calculated the noise-associated change in overall species richness and in abundance for seven common songbird species. After accounting for variance due to vegetative differences, species richness and the abundance of three of seven species were reduced in noisier locations. Acoustic analysis revealed that minimum song frequency was highly predictive of a species’ response to noise, with lower minimum song frequencies incurring greater noise-associated reduction in abundance. These results suggest that anthropogenic noise affects some species independently of vegetative conditions, exacerbating the exclusion of some songbird species in otherwise suitable habitat. Minimum song frequency may provide a useful metric to predict how particular species will be affected by noise. In sum, mitigation of noise may enhance habitat suitability for many songbird species, especially for species with songs that include low-frequency elements.

 

Journal reference: Global Change Biology

March 15, 2013 at 6:17 am 1 comment

How human language evolved from bird songs?

 

“The sounds uttered by birds offer in several respects the nearest analogy to language,” Charles Darwin wrote in “The Descent of Man” (1871), while contemplating how humans learned to speak. Language, he speculated, might have had its origins in singing, which “might have given rise to words expressive of various complex emotions.”

Now researchers from MIT, along with a scholar from the University of Tokyo, say that Darwin was on the right path. The balance of evidence, they believe, suggests that human language is a grafting of two communication forms found elsewhere in the animal kingdom: first, the elaborate songs of birds, and second, the more utilitarian, information-bearing types of expression seen in a diversity of other animals.

“It’s this adventitious combination that triggered human language,” says Shigeru Miyagawa, a professor of linguistics in MIT’s Department of Linguistics and Philosophy, and co-author of a new paper published in the journal Frontiers in Psychology.

The idea builds upon Miyagawa’s conclusion, detailed in his previous work, that there are two “layers” in all human languages: an “expression” layer, which involves the changeable organization of sentences, and a “lexical” layer, which relates to the core content of a sentence. His conclusion is based on earlier work by linguists including Noam Chomsky, Kenneth Hale and Samuel Jay Keyser.

Based on an analysis of animal communication, and using Miyagawa’s framework, the authors say that birdsong closely resembles the expression layer of human sentences — whereas the communicative waggles of bees, or the short, audible messages of primates, are more like the lexical layer. At some point, between 50,000 and 80,000 years ago, humans may have merged these two types of expression into a uniquely sophisticated form of language.

“There were these two pre-existing systems,” Miyagawa says, “like apples and oranges that just happened to be put together.”

These kinds of adaptations of existing structures are common in natural history, notes Robert Berwick, a co-author of the paper, who is a professor of computational linguistics in MIT’s Laboratory for Information and Decision Systems, in the Department of Electrical Engineering and Computer Science.

“When something new evolves, it is often built out of old parts,” Berwick says. “We see this over and over again in evolution. Old structures can change just a little bit, and acquire radically new functions.”

A new chapter in the songbook

The new paper, “The Emergence of Hierarchical Structure in Human Language,” was co-written by Miyagawa, Berwick and Kazuo Okanoya, a biopsychologist at the University of Tokyo who is an expert on animal communication.

To consider the difference between the expression layer and the lexical layer, take a simple sentence: “Todd saw a condor.” We can easily create variations of this, such as, “When did Todd see a condor?” This rearranging of elements takes place in the expression layer and allows us to add complexity and ask questions. But the lexical layer remains the same, since it involves the same core elements: the subject, “Todd,” the verb, “to see,” and the object, “condor.”

Birdsong lacks a lexical structure. Instead, birds sing learned melodies with what Berwick calls a “holistic” structure; the entire song has one meaning, whether about mating, territory or other things. The Bengalese finch, as the authors note, can loop back to parts of previous melodies, allowing for greater variation and communication of more things; a nightingale may be able to recite from 100 to 200 different melodies.

By contrast, other types of animals have bare-bones modes of expression without the same melodic capacity. Bees communicate visually, using precise waggles to indicate sources of foods to their peers; other primates can make a range of sounds, comprising warnings about predators and other messages.

Humans, according to Miyagawa, Berwick and Okanoya, fruitfully combined these systems. We can communicate essential information, like bees or primates — but like birds, we also have a melodic capacity and an ability to recombine parts of our uttered language. For this reason, our finite vocabularies can generate a seemingly infinite string of words. Indeed, the researchers suggest that humans first had the ability to sing, as Darwin conjectured, and then managed to integrate specific lexical elements into those songs.

“It’s not a very long step to say that what got joined together was the ability to construct these complex patterns, like a song, but with words,” Berwick says.

As they note in the paper, some of the “striking parallels” between language acquisition in birds and humans include the phase of life when each is best at picking up languages, and the part of the brain used for language. Another similarity, Berwick notes, relates to an insight of celebrated MIT professor emeritus of linguistics Morris Halle, who, as Berwick puts it, observed that “all human languages have a finite number of stress patterns, a certain number of beat patterns. Well, in birdsong, there is also this limited number of beat patterns.”

Birds and bees

The researchers acknowledge that further empirical studies on the subject would be desirable.

“It’s just a hypothesis,” Berwick says. “But it’s a way to make explicit what Darwin was talking about very vaguely, because we know more about language now.”

Miyagawa, for his part, asserts it is a viable idea in part because it could be subject to more scrutiny, as the communication patterns of other species are examined in further detail. “If this is right, then human language has a precursor in nature, in evolution, that we can actually test today,” he says, adding that bees, birds and other primates could all be sources of further research insight.

MIT-based research in linguistics has largely been characterized by the search for universal aspects of all human languages. With this paper, Miyagawa, Berwick and Okanoya hope to spur others to think of the universality of language in evolutionary terms. It is not just a random cultural construct, they say, but based in part on capacities humans share with other species. At the same time, Miyagawa notes, human language is unique, in that two independent systems in nature merged, in our species, to allow us to generate unbounded linguistic possibilities, albeit within a constrained system.

“Human language is not just freeform, but it is rule-based,” Miyagawa says. “If we are right, human language has a very heavy constraint on what it can and cannot do, based on its antecedents in nature.”

Source: http://web.mit.edu/press/2013/how-human-language-could-have-evolved-from-birdsong.html

February 22, 2013 at 1:56 pm Leave a comment

Have you cleaned your ear yet?

 

Often in the urban jungles, the voices of birds get muffled by the sounds of cranes (machine) and noise pollution. In such a scenario, how can we ‘listen’ to the voices of nature?

There are some scientists who are working on acoustic ecology to bring out these nature sounds for people. Apart from scientists, even musicians are making an attempt to revive nature sounds, like Troels Folmann, who is trying to raise awareness about music with bumblebees.

Acoustic Ecology is a term coined in the early 1970s, emerging largely from the School of Communication at Simon Fraser University in Burnaby, British Columbia. The writings of R. Murray Schafer, most notably A Sound Education and The Tuning of the World (reissued asThe Soundscape), have provided a foundation from which several distinct yet related threads have grown.

Prominent themes in acoustic ecology today are:

  • The effect of soundscapes on humans, in cities, nature, and buildings, including urban planning and architectural design that takes sound into account.
  • Ways to become more aware of the sounds we are making, so we can make these choices more consciously.
  • Reflection on the soundscapes we encounter day to day.
  • The effects of human sounds on wildlife.
  • The “right to quiet,” which comes into play in wild lands recreation debates about motorized use, as well as in urban settings.
  • The idea of acoustic windows or acoustic niches, employed by various species in a given habitat to avoid masking each other’s vocalizations.

Source: http://www.acousticecology.org

Some researchers are attempting to find how people react to different sounds and how various sounds in daily lives impact them.

In the world that we live today, sounds of nature can actually heal us. Are you listening?

December 22, 2012 at 2:53 pm 1 comment

Bird Scientists Borrow Music Technology from Teenagers in Search for Rare Bird

Written by surfbirds on March 20, 2012 in RSPB, surfbirds archive

Britain’s teenagers have embraced portable MP3 technology to admire the latest releases from divas including Adele, Jessie J and Lady Gaga. But this year scientists are taking the lightweight players to our highest hills and mountains to help them appreciate singers of a completely different kind.

The ring ouzel, otherwise known as the mountain blackbird, is a bird which inhabits the highest and wildest countryside of Britain and Ireland. However, the song of this rugged bird has been fading away from some areas and scientists want to find out why the bird is disappearing from so many of its former haunts. The scientists will be using MP3 players – loaded with a track of the bird’s song – to establish where the birds are breeding during the second UK-wide ring ouzel survey, this year. In 1999, the scientists needed to take bulky cassette recorders and speakers to achieve the same result.

The survey partnership includes the RSPB, Natural England, Scottish Natural Heritage and the Countryside Council for Wales (CCW). The survey will begin as the birds return to their upland nesting sites – from the end of March – from their wintering grounds in the mountains and hills of North Africa and southern Spain.

The first national survey, which took place in 1999, revealed that the ring ouzel was disappearing from several upland areas where it was formerly widespread, including parts of Scotland, south Wales and large swathes of Ireland. The birds last nested in Shropshire in 2004 and on Exmoor a little earlier. In most areas it is believed to have declined alarmingly over the last century. In 1999, there were thought to be fewer than 7,500 pairs nesting in the UK. The declines were so marked that the ring ouzel was added to the red list of the Birds of Conservation Concern in 2002.

Innes Sim is an RSPB scientist who has been studying the bird for 14 years in Scotland. He said: “The ring ouzel has a beautiful song and it sings on some of our most wonderful stages, such as the highest mountains of Scotland, Wales and England. I have been studying these birds in Scotland since 1998 and I am deeply alarmed by its widespread and deepening disappearance: the hills would be lonelier without
them.”

CCW senior ornithologist Sian Whitehead said: “The status of ring ouzels in Wales continues to be a cause for concern, and so we welcome this year’s survey. This will provide a much-needed update on the status of this bird that is so iconic of the uplands of Wales.”

Allan Drewitt, a senior ornithologist with Natural England, said: “There is currently no accurate estimate of the ring ouzel’s population – this survey will tell us how many are left and where they are, and that gets us one step closer to understanding why they’re disappearing and how we can help bring them back.”

Andy Douse, an ornithologist with Scottish Natural Heritage (SNH) said: “This is a species in decline at the moment and the survey will give us a better understanding of this decline and should also give us more information about the pressure it may be facing. We are absolutely committed to this survey which will paint a clearer picture of the changes affecting this upland species.”

The scientists play a recording of the bird’s song at specific points. By observing the responses from male ring ouzels in the area, the scientists can establish the breeding status of any birds found.

Although scientists can’t fully explain the bird’s disappearance, recent research suggests a reduction in the survival of young and, possibly, adult birds may be to blame. Factors on the bird’s breeding and wintering grounds, or during migration, may include: climate change; changes in livestock grazing which can affect the bird’s nesting and feeding areas; hunting in Europe; and a reduction in the amount of juniper berries, which are the bird’s principal food source on the wintering grounds.

http://www.surfbirds.com/community-blogs/blog/2012/03/20/bird-scientists-borrow-music-technology-from-teenagers-in-search-for-rare-bird/

 

March 22, 2012 at 5:37 am Leave a comment

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