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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

Hummingbirds take no notice of flower color

 

Hummingbirds pay no attention to what colour a flower is when figuring out whether to raid it for nectar, the latest research suggests.

Instead, they seem to focus on flowers’ exact location.

The researchers who led the study say it’s not that the birds don’t see the colour of different flowers – just like us, they can see in colour throughout the visible spectrum. But location is a much more reliable source of information and overshadows any information provided by color.

“Although this goes against what you might expect – after all flowers must be coloured for a reason – our finding makes perfect sense,” says Dr. Sue Healy from the University of St Andrews, co-author of the study.

“If they’ve fed from nectar-rich flowers before, that’s a more useful guide to whether those flowers will contain nectar in the future than color is.”

Animals from dogs to butterflies and bees use color to help them work out if something is likely to be a tasty meal. So it’s not too far-fetched to expect that the color of flowers could be important to hummingbirds too.

Scientists have also noticed that the flowers that hummingbirds typically visit for food are often red. This led them to wonder whether this is just coincidence, or whether the birds prefer red flowers.

“Their color vision is better than ours, so you might expect them to focus on it,” says Healy.

Other researchers have found that hummingbirds tend to prefer to use the layout of a field of flowers rather than their color when searching for food. But Healy and colleagues from the universities of St Andrews and Lethbridge wanted to know if they rely on color if it provides useful information on top of their knowledge about where to look for food.

So, they presented hummingbirds with four different types of artificial flowers. Some flowers contained a 30 per cent sugar solution, while others contained just 20 per cent. They also varied how quickly the flowers refilled after the birds had taken their fill of sucrose. Some refilled after 10 minutes, others after 20 minutes.

They found that seven of the birds took just 30 hours – during which they averaged 189 visits – to work out the difference between the fast-filling and slower-filling flowers. One remarkable bird managed to learn the difference within 50 visits.

But they found that giving the birds clues about refill rates or concentrations using different colors made no difference at all to how quickly they learnt.

“Ultimately, this suggests they ignore colour and just focus on location,” explains Healy.

Healy’s own observations confirmed this when she had to move nectar-containing feeders to keep them away from bears in Canada in previous experiments.

“Even though we only moved the feeders by 20 to 50 centimetres, the birds just didn’t see them, because they weren’t in the same positions they expected to find them. So they just flew away, which was quite a surprise.”

“I guess it’s a bit like us in the supermarket. We know exactly where to look on the shelves and isles for our favourite products, which means that when the supermarkets move them, we have to really search to find them again,” explains Healy.

Different flowers vary in how much nectar they contain. This is true not just between species, but also on the same plant. “So relying on color to guide them isn’t necessarily going to be the most successful strategy to get food,” she adds.

The study is published in Animal Behavior.

March 21, 2012 at 6:23 am Leave a comment

Crows remember colours for a year: Japanese study

 

Birds that had identified which of two containers held food by the colour of its lid were still able to perform the task 12 months later, said Shoei Sugita, a professor of animal morphology at Utsunomiya University.

Sugita said 24 birds were given the choice between containers with a red and green lid, which held food, and containers with a yellow and blue lid, which did not.

After they had mastered the task, the crows were divided into groups and tested to see if they could recall the information they had learned.

Even those creatures that had not seen the different coloured lids for a year were able to correctly identify where they would be able to find food, Sugita said.

“Our study has shown that the crows thought and used their memories to take action,” Sugita said.

Crows are a major nuisance in many Japanese cities, particularly Tokyo, where they rummage through rubbish left out for collection.

The study was part-funded by Chubu Electric Power Company, in an effort to improve anti-nesting measures and protect the towers supporting power cables.

Sugita says his work proves crows are intelligent creatures and measures used to foil them need to be carefully thought out.

“This study shows that there is no good way (to counter crows). But we can use their memories against them to create new measures,” Sugita said.

(c) 2011 AFP

March 16, 2012 at 5:04 am Leave a comment

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