Man-made noise disrupts the growth of plants and trees

A US team found that industrial noise disrupted the behaviour of animals that pollinate plants and disperse seeds.

This, they suggest, could be slowly transforming our landscape, especially by changing the dispersal of slow-growing trees.

The study is published in the Royal Society Proceedings B.

The team, led by Clinton Francis from the National Evolutionary Synthesis Center (NESCent) in North Carolina, tested the effects of industrial noise on wildlife in Rattlesnake Canyon Habitat Management Area (RCHMA), New Mexico.

This large forested area has a high density of natural gas wells, providing scientists with a unique setting that allowed them to study the effects of noise without some of the “confounding factors” often associated with noisy areas, such as roadways and artificial light. Fewer pinon pine trees would mean less critical habitat for the hundreds of species that depend on them for survival”

In the first of two experiments, the team focused on birds, which, they explained, “are considered to be especially sensitive to noise pollution owing to their reliance on acoustic communication”.

They placed patches of artificial hummingbird-pollinated flowers in noisy and quiet areas.

These convincing flower copies contained tubes of nectar, enabling the researchers to track exactly how much sugary fluid was consumed by visiting hummingbirds.

Industrial din, the scientists discovered, actually increased the activity of the birds. One species in particular – the black-chinned hummingbird (Archilochus alexandri) – made five times more visits to noisy sites than quiet ones.

Dr Francis explained that these hummingbirds might prefer noisy sites because another bird species that prey on their nestlings, such as western scrub jays, tend to avoid them.

Natural gas wells in a forested area created the ideal setting to test the impact of noise on wildlife

In a second set of experiments, the team investigated the effect of noise on a species of tree that makes up much of the area’s forest habitat – the Pinon pine (Pinus edulis).

The team scattered pine cones beneath 120 trees in noisy and quiet sites, and used a motion-triggered camera to record the animals that took the seeds.

Over three days, several animals visited the sites to take seeds, including mice, chipmunks, squirrels, birds and rabbits. Most significantly though, mice much preferred noisy sites, whereas western scrub jays avoided them altogether.

This, the researchers explained, could be very bad news for the trees.

The seeds that are eaten by mice, Dr Francis explained, don’t survive the passage through the animal’s gut. So an increase in mouse populations near noisy sites could mean that fewer seeds germinate in those areas.

In contrast, one western scrub jay can take hundreds or even thousands of seeds and hide them in the soil to eat later in the year. Some of these will eventually germinate.

The team went on to count the number of pine seedlings and found that they were four times as abundant in quiet sites compared with noisy ones.

“Fewer seedlings in noisy areas might eventually mean fewer mature trees, but because pinon pines are so slow-growing the shift could have gone undetected for years,” Dr Francis explained.

The researchers concluded: “Noise pollution is growing [and] this study emphasises that investigators should evaluate the ecological consequences of noise alongside other human-induced environmental changes that are reshaping human-altered landscapes worldwide.”

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March 27, 2012 at 4:21 am Leave a 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

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

Birds sing louder amidst the noise and structures of the urban jungle

By Sharada Balasubramanian

Sparrows, blackbirds and the great tit are all birds known to sing at a higher pitch (frequency) in urban environments. It was previously believed that these birds sang at higher frequencies in order to escape the lower frequencies noises of the urban environment. Now, researchers at the University of Copenhagen and the University of Aberystwyth have discovered that besides noise, the physical structure of cities also plays a role in altering the birds’ songs.

Urban birds sing differently and at a higher frequency than woodland birds in an effort to penetrate the wall of constant noise produced by traffic, machines and human activity. However, architecture also has a profound affect on their songs. The study findings have recently been published in the esteemed scientific journal PLoS One.

A new explanation

“Urban architecture is a crucial determinant of how urban birds sing”. Noise amidst the urban landscape is typically composed of lower frequencies. Thus, one might jump to the conclusion that it would be smart for birds to distinguish their song by singing louder in order to drown out the competing noise. However, the recent study demonstrates that the noise explanation is incomplete, according to Professor Torben Dabelsteen of the Section for Ecology and Evolution at the University of Copenhagen’s Department of Biology, one of the authors of the study.

The city’s role in the song

Some researchers have never really bought into the idea that urban noise alone caused birds in the city to sing at higher frequencies. Either directly, because birds tried to sing at a higher tone and away from noise or indirectly, by the birds singing louder to drown out anthropogenic noise.

“Now, with the help of controlled sound recordings, we have shown that the higher frequencies in urban birds’ songs are also transmitted across cities when there isn’t any noise from traffic. This shows that the physical structure of cities must play a considerable role in the heightened frequencies,” explains Torben Dabelsteen.

Structures and variations in the cityscape – houses, streets, open spaces and alleys – all serve to reflect and distort noise in differing ways, things that birds must take into account. Birds in the urban environment can easily spot one another, but must do what they can to reduce echoes from buildings and narrow streets in order to penetrate and communicate effectively.

High-pitched urban birds

Birds living beyond the urban landscape need not tweet away with full force. While the woodland’s trees and abundant foliage also distort sound through reflection, they also serve to obstruct clear lines of sight. Therefore, rural birds may utilize these distortions to help judge distances and locate one another.

“City-dwellers can look forward to the lively song of birds in the coming spring, and even though a side effect of the urban birds’ more powerful song is that they sing at a higher pitch, this is something that we are not typically able to hear,” explains Dabelsteen.

Provided by University of Copenhagen

http://www.physorg.com/news/2012-02-birds-louder-noise-urban-jungle.html

March 3, 2012 at 2:10 pm 3 comments

Top wolf expert Dave Mech talks about his interactions with wolves

Wild Arctic Wolf

“Don’t run!”    Sage advice from top wolf expert, Dave Mech, if you find yourself face to face with a wolf in the wild.  And he’s right.  

The reason he is right is that in most situations when encountering a wolf in the wild there is really no need to run.  They don’t view humans as prey, and Mech knows his stuff.  He has certainly had a lot of wolf encounters in his five and a half decades of working in the field which he discusses in this podcast interview.

In the interview Mech also talks about his devastation at the gross inaccuracies of the film The Grey which he believes will undoubtedly negatively influence the way the public feels about wolves.

I have had the privilege of spending time with Dave Mech and biologist colleagues in the Northwest Territories where we had numerous wolf encounters with a beautiful female wolf  (pictured) and her packmates, and this experience confirms what Mech says.   In this photo, the wolf was literally a few feet away from me, and during the encounters we had with her not once did I feel afraid.  She was simply curious, and as we discovered, hungry too, which is likely to be what motivated her to come so close to our camp.  For me it was a wonderful experience and like Mech I find it devastating that the public who see The Grey will come away with a totally inaccurate perception of wolves.

The Grey has made it all the more difficult for wolf conservationists, but it’s also made us all the more determined to carry on fighting for their protection.

Click here to listen to the podcast of interview with David L Mech

February 27, 2012 at 11:35 pm 2 comments

Will ‘The Grey’ set wolf conservation back?

A grey wolf

If you read the press at the moment, there is mounting pressure on wolves, particularly in America, where they have had a chequered history from the time Europeans settled on the continent.  It seems that the wolf is once again becoming fair game to be killed in their hundreds by whatever means necessary, whether this is aerial gunning, trapping, snaring or being shot.  Add to this the hysteria that is steadily building about wolves transmitting a tapeworm-like parasite to humans and you can begin to see that, once again, wolves are bearing the brunt of human hatred, fear, mistrust and ignorance towards a large predator that, actually, deserves none of this negative attention.

Amidst all this tension comes the release of The Grey, a blockbuster film that portrays the wolf as a manhunter.  And, in my opinion quite rightly, wolf advocates and conservationists all over the world have expressed their utter dismay at a portrayal of the wolf that will undoubtedly set back conservation efforts by decades.

As a long-time wolf advocate and conservationist, I have joined the protests about this film and in doing so provoked quite a response, not only from the director himself, Joe Carnahan, but also from others who have said: “Get over it, it’s just a film.”  But is it just a film?  Will audiences who have little or no real knowledge of wolf behaviour come away from this film with inaccurate opinions about the wolf?  Judging by the comments on the various websites talking about this film, there are a disturbing number of posts that suggest that some people are taking the film’s scenes at face value.  In other words, there are people out there who believe the scenes that depict wolves as blood-thirsty, man-hunters.  There are others who believe that wolves deserve everything they get and are cheering this film on, and seeing it as some kind of retribution against the wolf!  And then there are the macho, Rambo types who believe that this film is aimed at, and I quote, “manly types” who want their movies “real” and not portraying fantasy like werewolf and vampire films do.

Frankly, I’ve found reading all these posts very depressing.  Not because they show ignorance and a complete lack of regard for wolves themselves, but because with such an overwhelming lack of insight into the real problems in conservation, what chance do we have of saving species like the wolf that are predators, and as such are seen as dangerous?

Popular culture and our attitudes towards large predators

Of course everyone knows about Little Red Riding Hood and the Three Little Pigs, and these fairy stories are often cited as encouraging our negative perceptions of wolves to prevail, instilling a sense of fear about deep dark forests and what ravenous beasts might be lurking there.  The wolf as a beast eager to eat innocent grandmothers and little girls is deeply embedded in the human psyche.  It’s hard to credit that such a simple story would have such an effect, but for centuries this image of the wolf has been fuelled by stories like this.  The story perpetuates because it speaks to us on different levels.  To a mother wanting to safeguard her young, it is the bogeyman to be avoided, so she tells her little ones not to go off into the woods alone.  To the farmer, the wolf is a threat to his livestock, and so the wolf as a predator surely must be the ravening beast described in the stories.  To the hunter, the wolf is competition for his own quarry, an adversary that must be beaten (and even if this means the destruction of the adversary).  The point is, many of the stories we tell ourselves are used to justify our actions and behaviours.  So the wolf, rather than being just a wolf that is a large predator, it becomes something “other”, and the more evil and rapacious we make it, the easier we can salve our consciences at its destruction.

Losing decades of conservation effort

For the past two decades, the tide has been slowly turning for wolf conservation.  We now have more knowledge about the wolf than we’ve ever had, and populations have once again started to flourish in much of the wolf’s former habitats and ranges.  Research carried out in Yellowstone following the reintroduction of the wolf after an absence of seven decades shows conclusively the integral and important role it has in the ecosystem, and the effect it has on the whole trophic cascade of the park.   What has happened since the return of the wolf is that it has changed the behaviour of the elk which had overgrazed the park after it had been left to its own devices with no threat from predators.  With the browsing behaviour of the elk drastically changed, it has allowed aspen and willow groves to flourish once more, which in turn has returned available habitat for smaller species and which has also had a beneficial effect on soil ecology.  Moreover, a wolf kill feeds lots of other species, which impacts on the richness of the biodiversity in Yellowstone.

Many of us working in conservation have been encouraged in recent years by what we have seen as a real and tangible move away from the Red Riding Hood syndrome and more towards a degree of tolerance.  Of course, it would be very naive to think that all in the wolf conservation garden was rosy.  It isn’t.  But there have been some very dramatic strides in progress, and especially across Europe.  I can cite many cases of changes in attitudes towards wolves in countries like Croatia, Russia, Poland, Bulgaria, Germany, France, Italy, Sweden, and Norway.  The changes aren’t wholesale, but enough to show that there is hope for the future of the wolf once more in what is left of wild (relatively) landscapes.

So, yes, in my view, this film and others like it, do push conservation efforts back by decades.  And unlike the fairy stories in print, the imagery being brought to us in graphic, high definition on huge screens, give us visual (and dare I say visceral) imprints that many will find hard to shake off the next time they walk through a wolf inhabited forest or tundra.

Restoring the balance

Having worked in wolf conservation for over 20 years, I am well aware that portraying wolves in too positive a light can also be damaging to its conservation.  There are many wolf advocates who want wolves to be portrayed as large, cuddly dogs with friendly dispositions and loving and generous natures.  Somewhere between this depiction of the wolf and that of a blood-thirsty, ravening beast lies the truth.

The wolf is a wolf.  It is a predator, it is a large carnivore, it eats meat to survive, a wolf kill is not a pleasant sight.  Equally, wolves can be friendly, playful, loyal, and to many of us, very beautiful animals to observe in their natural habitats.   What we humans are very bad at doing is accepting other species for what they are and adopting a “live-and-let-live” approach.  Instead, we are myth-makers, and the types of myths we make depend on our deeply entrenched attitudes and beliefs in that particular era.

It will be a sad day if we end up sliding back to the times when eradication of the wolf was the only thing that mattered.  And films like The Grey do help to form public opinion, and they continue to fuel the ignorance, fear and hatred that for centuries has led to the destruction of the wolf across the whole of the northern hemisphere.

Joe Carnahan accused me of being ignorant because I have not seen the film.  The trailer tells me everything I need to know and I can read the reviews to form an opinion.  I have no desire to see a film that perpetuates the myths nor to put money in his pocket which will further support the damage he has done, and will continue to do as long as unenlightened people go and see this film.   His knee-jerk reaction to my Twitter activity has only served to confirm my opinion of him, and it isn’t a good one.

Some of the recent blogs and reviews about ‘The Grey’

Marc Silver in National Geographic – Would Wolves Act Like the Wolves of The Grey

Professor Marc Bekoff in Psychology Today – The Grey Has it All Wrong

Dr Paul Paquet in the Calgary Herald – Pack of Lies

Sonia Horon, Global Animal blog – The Grey: A Bad Fairy Tale About Wolves

And in an attempt to end a piece of film footage that is positive about the wolf, here is the much acclaimed advert by Olgivy and Mather:

Please also check some of our short videos from Russia on our YouTube Channel.  The people who filmed these wolves work and live alongside them in the deepest taiga forests of Russia.  If anyone understands the true nature of wolves, it’s these guys, and they will tell you a completely different story to that portrayed by Joe Carnahan and his colleagues:

February 6, 2012 at 10:02 pm 9 comments

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