New Species of Bat, Hipposideros griffini Discovered in Vietnam

ScienceDaily (Feb. 20, 2012) — A distinctive echolocation frequency led to the discovery of a new species of bat within the genus Hipposideros. Although this bat is similar to the speciesHipposideros armiger, differences in acoustics, size, and DNA between these bats led to the identification of the new species. This new member of the bat community, which has been found in two locations in Vietnam, has been given the scientific name Hipposideros griffini.

The current article of the Journal of Mammalogy reports on findings from a survey of bats in Vietnam over a span of three years. Eleven of 308 bats of the Hipposideros genus that were captured and handled for study displayed differing characteristics from all known taxa of Hipposideros and represent a new species.

Captured bats were measured for features such as forearm length, ear height, nose-leaf width, tooth row length, and body mass. Tissue samples were taken for genetic analysis. Recordings were made inside a flight tent, in front of caves, and under forest canopies, identifying calls of bats when they left their roosts and when they were foraging. Researchers used software for bat call analysis that can display color sonograms and measure frequencies.

Read on:  http://www.sciencedaily.com/releases/2012/02/120220142451.htm

A Battle of the Vampires, 20 Million Years Ago?

ScienceDaily (Feb. 3, 2012) — They are tiny, ugly, disease-carrying little blood-suckers that most people have never seen or heard of, but a new discovery in a one-of-a-kind fossil shows that "bat flies" have been doing their noxious business with bats for at least 20 million years.

For bats, that's a long time to deal with a parasite doing its best vampire impression. Maybe it is nature's revenge on the vampire bat, an aggressive blood consumer in its own right that will feed on anything from sheep to dogs and humans.

The find was made by researchers from Oregon State University in amber from the Dominican Republic that was formed 20-30 million years ago. The bat fly was entombed and perfectly preserved for all that time in what was then oozing tree sap and later became a semi-precious stone.

This is the only fossil ever found of a bat fly, and scientists say it's an extraordinary discovery. It was also carrying malaria, further evidence of the long time that malaria has been prevalent in the New World. The genus of bat fly discovered in this research is now extinct.

The findings have been published in two professional journals, Systematic Parasitology and Parasites and Vectors.

"Bat flies are a remarkable case of specific evolution, animals that have co-evolved with bats and are found nowhere else," said George Poinar, Jr., an OSU professor of zoology and one of the world's leading experts on the study of ancient ecosystems through plants and animals preserved in amber.

"Bats are mammals that go back about 50 million years, the only true flying mammal, and the earliest species had claws and climbed trees," Poinar said. "We now know that bat flies have been parasitizing them for at least half that time, and they are found exclusively in their fur. They are somewhat flat-sided like a flea, allowing them to move more easily through bat fur."

Not every bat is infested with bat flies, and some of the contemporary flies are specific to certain species of bats. But they are still pretty common and found around the world.

Bat flies only leave their bat in order to mate, Poinar said, and that's probably what this specimen was doing when it got stuck in some sticky, oozing sap.

http://www.sciencedaily.com/releases/2012/02/120203102414.htm

Bats occupy Israeli army ghost bunkers

(Reuters) - Abandoned Israeli army bunkers along the Jordan River are providing a lifeline for bats on the endangered species list, researchers say.

Soldiers left Israel's underground forts along the frontier with Jordan after a 1994 peace treaty between the two countries. With much of the former front line, some of it dotted by mine fields, still designated by the military as off-limits to civilians, bats swooped into the secluded and dark steel caverns.

Several years ago, researchers from Tel Aviv University were granted access to the ghost bunkers. Now, they say, they have identified 12 indigenous bat species in the 100-kilometre- (60 mile)-long tract between the Sea of Galilee in Israel and the Dead Sea's northern edge in the occupied West Bank.

Two of the species commonly known as the Mediterranean horseshoe bat and Geoffroy's bat are on the critical list and three others are designated as endangered.

"There is no doubt that by being in a closed military zone that has prevented human interference, the bat habitat will allow these delicate creatures to thrive," said one of the researchers, Eran Levin.

But he said it was too early to quantify the growth of the local bat population, estimated to be in the thousands, because the research project was not yet complete.

One former bunker -- overlooking the spot along the Jordan River where some Christian faithful believe Jesus was baptized by John -- has been turned into a more accommodating home for the webbed-wing mammals.

Continued:  http://uk.reuters.com/article/2012/01/27/us-israel-bats-idUKTRE80Q0NI20120127

Miami Roofers Discover Massive Bat Colony In One Roof

Think about how many houses in South Florida have roofs with barrel tiles. Now imagine that each one contains thousands of squealing bats.

In the video above, Miami roofers discover a particularly dense roosting area for bats. As noted by Buzzfeed, it conjures up visions of Temple of Doom.

Bats are quite common in Florida. Local pest removal companies cite the most common types are the Brazilian, or Mexican Free-Tail Bat, and the Evening Bat.

According to Florida Fish and Wildlife Conservation Commission says, as bats' natural habitats disappear, they're more likely to settle in places like roof titles. And when this video was taken in July, bats nestle in crevices to give birth and nurture their young.

As cringe worthy as these flying mammals are, it's illegal to kill bats in Florida because they are a very necessary part of our local ecosystem. The FWC reports that a single bat can eat up to 3,000 insects a night. Come mosquito season in July, you'll be wishing for your very own bat infestation.

See below for a close-up shot of one of the little bats at minute 1:05. (The FWC says that bats are very fragile and remind Floridians to avoid handling them.)

See videos here:  http://www.huffingtonpost.com/2012/01/22/miami-roofers-bats_n_1221915.html

New Clue in Battle Against Australian Hendra Virus: African Bats Have Antibodies That Neutralize Deadly Virus

ScienceDaily (Jan. 12, 2012) — A new study on African bats provides a vital clue for unravelling the mysteries in Australia's battle with the deadly Hendra virus.

The study focused on an isolated colony of straw-coloured fruit bats on islands off the west coast of central Africa. By capturing the bats and collecting blood samples, scientists discovered these animals have antibodies that can neutralise deadly viruses known in Australia and Asia.

The paper was published 12 January, in the journal PLoS ONE, and is a collaboration of the Department of Veterinary Medicine at the University of Cambridge, the Zoological Society of London and the CSIRO Australian Animal Health Laboratory.

Hendra virus in Australia and Nipah virus in Asia are carried by fruit bats and sporadically "spill over" into people with tragic consequences. The findings of the new study are significant as they yield valuable insights for our understanding of how these viruses persist in bat populations.

Cambridge PhD student Alison Peel explains, "Hendra and Nipah viruses cause fatal infections in humans, but we currently understand very little about how the viruses are transmitted from bats to other animals or people. To understand what the risk factors for these 'spill-overs' are, it is crucial to understand how viruses are maintained in bat populations. The ability to study these viruses within an isolated bat colony has given us new insight into these processes."

Continued at: http://www.sciencedaily.com/releases/2012/01/120112193438.htm

Bat Brains Parse Sounds for Multitasking

ScienceDaily (Jan. 3, 2012) — Imagine listening to music while carrying on a conversation with friends. This type of multi-tasking is fairly easy to do, right? That's because our brains efficiently and effectively separate the auditory signals -- music to the right side; conversation to the left. But what researchers have not been able to do in humans or animals is to see a parsing of duties at the single neuron level -- until now.

Publishing in the European Journal of Neuroscience, bat researcher Jagmeet Kanwal, PhD, associate professor in the department of neurology at Georgetown University Medical Center, reports on how and in which hemisphere of the brain, bats process incoming signals that allow them to orient and navigate while at the same time, make sense of what other bats are trying to tell them.

To understand auditory brain function, bats are especially interesting animals to study because they process sound through echolocation, which is a kind of biological sonar. Bats emit loud pulses and then listen to their own echoes produced when those pulses bounce off nearby objects. And while bats aren't blind, as is the common myth, they exclusively use echoes to navigate and to hunt while flying.

Read more at:  http://www.sciencedaily.com/releases/2012/01/120103135504.htm

New bat species found in Cambodia

Tube-nosed bat named after Wildlife Conservation Society scientist October 2011. Scientists discovered the small brown-and-white bat during surveys in the Van Sai Protected Forests in north-eastern Cambodia. Little is known about Southeast Asia's tube-nosed bats, so named for their extraordinary nostrils. Several new species have been described in recent years.


To honour of Joe Walston, The Wildlife Conservation Society's Executive Director for Asia Programs and to highlight Walston's work to save bats and other wildlife in Southeast Asia, a group of scientists have dubbed the newly discovered bat species Murina walstoni, or Walston's tube-nosed bat.

Joe Walston began studying bats in Vietnam in 1994. In 2000, he found a critically endangered bat species in Cambodia that had only been caught once before - in 1912 from a cave in India nearly 2,000 miles away. He has been director for WCS's Asia programs since 2010.

The researchers, Csorba Gabor of the Hungarian Natural History Museum, Nguyen Truong Son of the Institute of Ecology and Biological Resources, Ith Saveng of the Royal University of Phnom Penh, and Neil Furey of Flora and Fauna International described the new species, along with two other new bats, in a recent issue of the Journal of Mammology.

http://www.wildlifeextra.com/go/news/cambodia-bats.html

How bat wings can heal themselves

Stitches and glue can be ineffective
October 2011: Certain bats will be spreading their previously-torn wings after a new way of treating them was discovered.

A bat carer, based at an RSPCA wildlife centre found that even the most dramatic of tears can heal themselves with some tender loving care.

Sarah Goodwin, from Stapeley Grange Wildlife Centre in Cheshire, said that the usual veterinary technique of stitching or glueing such tears could cause issues with the bats removing stitches or glue when grooming.

Good food and plenty of rest
She instead decided to care for bats that came into her care with wing injuries by keeping them warm, giving them antibiotics and feeding them vitamin and mineral-rich food. The veterinary nurse also restricted their flight and gave them time to rest and heal.

In nearly all cases she found that the wings had healed back together of their own accord.

'I couldn't believe how fast the wings grew back together
'Sarah said: ‘I just couldn't believe how fast the wings grew back together. It was amazing. All they needed was a bit of rest and care and their wing membranes healed all by themselves - ready for them to fly back safely into the wild.'

The bats in the ‘Heal to Fly' project had been injured in various ways, including attacks from cats. Out of the nine bats which have been admitted with severe wing tears over the past year, five have been returned to the wild, and two died from other injuries. The remaining two are still in care but Sarah is hopeful that they can be returned to the wild soon.

Read on ...

Bat killer cause confirmed as fungus (via Dawn Holloway)

White-nose syndrome (WNS), the disease rampaging its way through the bats of North America, is caused by a fungus, scientists have confirmed.

Researchers from a number of US institutions infected healthy bats with the fungus Geomyces destructans, and found they did develop the disease.

The team also showed that the fungus can pass from one bat to another.

Writing in the journal Nature, they say WNS "has the potential to decimate North American bat populations".

So far, the disease has killed more than a million bats in the eastern US and Canada since it was first identified in New York state in 2006.

G. destructans is usually found on the animals' snouts, where it causes a characteristic white colouration and, more significantly, lesions in the skin.

Although the fungus has been suspected as the disease's primary cause, researchers have not been able to prove it definitively.

Animals sometimes contract fungal diseases when their immune systems have been compromised, perhaps by a different infection, and this has been seen as a possibility for WNS as well.

The research group, led by David Blehert from the National Wildlife Health Center at the US Geological Survey, appears to have proven the primary role of the fungus.

No 'magic bullet'
By Richard Black Environment correspondent, BBC News
http://www.bbc.co.uk/news/science-environment-15460894

Read on ...

First Ebola-Like Virus Native to Europe Discovered

ScienceDaily (Oct. 20, 2011) — A team of international researchers has discovered a new Ebola-like virus -- Lloviu virus -- in bats from northern Spain. Lloviu virus is the first known filovirus native to Europe, they report in a study published in the journal PLOS Pathogens.

The study was a collaboration among scientists at the Center for Infection and Immunity (CII) at Columbia University's Mailman School of Public Health, the Instituto de Salud Carlos III (ISCIII) in Spain, Roche Life Sciences, Centro de Investigación Príncipe Felipe, Grupo Asturiano para el Estudio y Conservación de los Murciélagos, Consejo Suerior de Investigaciones Científicas and the Complutense University in Spain.

Filoviruses, which include well-known viruses like Ebola and Marburg, are among the deadliest pathogens in humans and non-human primates, and are generally found in East Africa and the Philippines. The findings thus expand the natural geographical distribution of filoviruses.

"The study is an opportunity to advance the knowledge of filoviruses' natural cycle," said Ana Negredo, one of the first authors of the study.

Scientists at ISCIII analyzed lung, liver, spleen, throat, brain and rectal samples from 34 bats found in caves in Asturias and Cantabria, Spain, following bat die-offs in France, Spain and Portugal in 2002 affecting mainly one bat species.

They screened these samples for a wide range of viruses using the polymerase chain reaction, a molecular technique that allows scientists to amplify genetic material, and. detected a filovirus. Filoviruses include ebolaviruses and marburgviruses, two viruses associated with severe disease in humans and other primates.

CII scientists used high-throughput sequencing to characterize the virus' genome. When they compared it to other well-known filovirus genomes, they found that Lloviu virus represents a class of viruses distantly related to all ebolaviruses and that it may have diverged from ebolaviruses about 68,000 years ago.

"The detection of this novel filovirus in Spain is intriguing because it is completely outside of its previously described range. We need to ascertain whether other filoviruses native to Europe exist, and more importantly, if and how it causes disease," said Gustavo Palacios, the other first author of the study.

Filoviruses typically do not make bats sick, but because the team of researchers only detected Lloviu virus in bats that had died and whose tissues showed signs of an immune response, they think Lloviu may be a cause for concern. They also did not detect Lloviu virus in samples of almost 1,300 healthy bats.

Bats have important roles in plant pollination, spreading plant seeds and controlling insect populations, and pathogens that attack bat populations could have dramatic ecological and health-related consequences.

"The Lloviu virus discovery highlights how much we still need to learn about the world of emerging infectious diseases and the importance of global collaboration and the One Health initiative in addressing the challenge," said CII Director Dr. Ian Lipkin.

This research was funded by the Defense Threat Reduction Agency, USAID PREDICT, the RICET Network on Tropical Diseases and the Ministerio de Educación y Ciencia in Spain.

http://www.sciencedaily.com/releases/2011/10/111020191850.htm

First superfast muscles in mammals help bats catch prey

Bats are able to locate their prey using echolocation produced by a special kind of "superfast" muscle, scientists have found.

These specially adapted muscles can contract 100 times quicker than most of the muscles in human bodies.

This is the first time such muscles have been seen in mammals, although they had previously been found in rattlesnakes, some fish and birds.

The Danish findings are published in the journal Science.
Bats use echolocation to navigate in total darkness, as well as to catch flying insects in mid air.

In order to pinpoint the insects with enough accuracy and speed to catch them before they fly away, the bats need to make a lot of calls in rapid succession.

As the bat approaches its prey target, the frequency of calls increases up to about 190 calls per second, creating what is known as the "terminal buzz".

Researchers at the University of Southern Denmark, led by Prof Coen Elemans, designed tests to investigate just how fast the terminal buzz could be.

They discovered that the maximum frequency of the buzz was not limited by the echo return time, but was controlled by the muscles in a bat's throat.

These muscles contracted once to produce each call, totalling nearly 200 contractions, or one every five milliseconds.

Such rapid contractions made these "superfast muscles", a type of muscle which has previously only been seen in the sound-making organs of rattlesnakes, the humming Oyster Toadfish, and many songbirds.

They had not been identified in mammals, but Prof Elemans said: "I had a hunch, that if they were in mammals, they would be in bats".

Fast but weak
The superfast muscles seen in these bats can contract 100 times faster than most muscles in the human body, and 20 times quicker than the fastest muscles we have - those that control the movement of our eyes.

Muscles that can contract so quickly need cells that have special adaptations.

The extra energy needed to power the cells comes from a much higher density of mitochondria - the energy producing machines within the cell. Compared with a "normal" cell, the superfast muscle cells have 30% more of these mitochondria.

By Leila Battison Science reporter
Read on...

Bats only roost with their closest buddies

Bats prefer to rest with their closest pals rather than with bats they don't know very well, researchers have discovered.

They found that although bats change where they sleep every few days, they nearly always roost with the same bunch of bats, forming tight-knit social groups with exclusive membership.

'Bats build long-term companionships with other individuals, and these companions are members of exclusive social groups that can last for many years,' explains Tom August from the Centre for Ecology & Hydrology (CEH), who's studying the bats as part of his PhD at the University of Exeter.
'I was interested in fitting together disease and ecology, and wanted to know if the ecology of bats influences the diseases they carry,' he says.

Despite being cute-looking creatures, a very small number of UK bats carry rabies-like viruses. They can also be the source of emerging diseases. 'The SARS virus is thought to have originated from bats in China,' says August.

By getting a better understanding of how individual bats interact with each other, researchers are hoping to predict how diseases might spread, 'which may point to ways in which the risks to humans can be reduced.'

Bat numbers have dropped dramatically in recent years, because of loss of habitat. They like roosting in buildings and trees, and during the winter, tend to hibernate in caves. All bats in the UK are protected species.

Bat experts have long known that they often rest together: males roost on their own, or sometimes in small groups; while female bats establish so-called maternity colonies around June when many soon-to-be mothers come together to have their pups.

But this is the first time researchers have shown that bats form exclusive social groups – at least in the UK.

By revealing how bats stick together in distinct social groups, the research shows that conservation efforts should focus on whole areas used by groups, rather than just single roosts.

August and colleagues from CEH and the University of Exeter studied the hundreds of bats that live in Wytham Woods, just outside Oxford in the UK.

Around 200 Daubenton's and 200 Natterer's bats live in the woods, making use of some of the 1200 bird boxes which have been there for the last 40 or 50 years. Birds use them early in the season, but as soon as they leave, the bats move in.

Wytham Woods is owned by the University of Oxford and is probably the most heavily-studied woodland in the UK. Indeed all of the bats are fitted with tiny aluminium arm bands with unique numbers to make identifying them easier.

'The fact that bats change their roosts so frequently means this kind of study has been difficult up until now,' says August.

After taking meticulous notes of which bats associate with each other, August built up a 'spider-web' diagram to reveal the bats' social networks.

'Instead of a huge spider web, you get clusters, which clearly show how individual bats associate with each other,' August says. 'In this one wood, we found six or seven social groups.'

Groups appear to be made up of around 20 to 40 individuals. 'It could be that they're coming together to share information about where food is,' says August.

The study will be presented to delegates of the British Ecological Society's annual meeting in Sheffield today.

by Tamera Jones
http://planetearth.nerc.ac.uk/news/story.aspx?id=1062

New 'demon' bat discovered in Vietnam (via Chad Arment)

Scientists have discovered three previously unknown bat species in southern Indochina, reports Fauna & Flora International.
Researchers from Hungarian Natural History Museum (HNHM) and Fauna & Flora International (FFI) described the new species, which belong to a group known as tube-nosed bats.

One of the species, found in Vietnam and described as "diminutive but demonic-looking", is named the Beelzebub's tube-nosed bat.

"We chose the name Beelzebub to reflect the dark 'diabolic' coloration of the new species, and its fierce protective behavior", said Gabor Csorba of HNHM in a statement.

Little is known about the new species, although Neil Furey of FFI, warns that there dependence on forest habitats leaves them "especially vulnerable to ongoing deforestation in the region."

"Discovering these new species, while exciting, really represents the beginning," said Furey. "At this point, almost nothing is known about their ecology and what steps, if any, are needed to ensure their continued survival."

Paul Racey of the IUCN's Bat Specialist Group, added that because bat fauna is so poorly known, there are probably many more bat species to be discovered in the region.

"Though bats already represent nearly a third of SE Asian mammals, recent genetic research suggests that the true number of species in the region may be twice that presently known," Racey said.

Citation: Csorba, G., Nguyen Truong Son, Ith Saveng, Furey, N.M. 2011. Revealing cryptic bat diversity: three new Murina and redescription of M. tubinaris from Southeast Asia. Journal of Mammalogy 92(4):891-904. Doi: 10.1644/10-MAMM-A-269.1

http://news.mongabay.com/2011/0901-demon-bat.html

Bat traffic lights to be installed in train tunnel

Bat traffic lights are being put in a tunnel to stop trains killing the rodents.

Ecologists hope they will learn to get out of the way when the lights warn of an approaching train.

If the month-long trial, a first in the UK, is successful, it will speed up travel times for commuters and increase the number of trains using the tunnel.

It will be tested by researchers who will flash the lights on and off over four nights and monitor how the bats react.

Trial leader Geoff ­Billington said: “We hope they will learn to associate the two things.”

Chiltern Railways is backing the plan, set up under the A40 Wolvercote roundabout in Oxford.
A spokesman said: “This is a tried and tested ­technique on roads and we want to see if it is applicable to the railways.”

A similar system has been used in North Wales to encourage bats to stay away from traffic.

by Steve Myall, Daily Mirror
Read more: http://www.mirror.co.uk/news/animal-magic/2011/08/16/bat-traffic-lights-to-be-installed-in-train-tunnel-115875-23347676/#ixzz1WhU04iFc

Rare moth spotted during Lambeth wildlife count

Bat populations also thriving August 2011: A rare species of moth that until recently had hardly ever been seen in London has been spotted by volunteer conservationists in Brockwell Park in Lambeth.

The group discovered the rare Jersey tiger moth - which used to be found only in the Channel Islands and the far south of England - while recording local moth and bat populations in Brockwell and Ruskin Parks at night.

Experts believe that brightly coloured tiger moths are gradually moving northwards as the summers become more reliably warm, and they are becoming more common in London.

More than 40 local people volunteered to stay in Brockwell Park on two consecutive nights with local experts and the Friends of Brockwell Park to record the number of bats and moths found there.

BatsIn Brockwell Park at least 14 bats were spotted during the course of the first night, and included common pipistrelle in healthy numbers, as well as soprano pipistrelles and, even more excitingly, Daubenton's bat, which prefers hunting for insects over water.

Most bat activity centred on the park's middle pond which has good habitat structure for these flying mammals being sheltered on either side by trees. Bats are a superb indicator of the ‘ecological quality' of an open space, with each species tending to specialise - a range of species indicates a healthy balance of places to feed and travel, and the success of the park's meadow areas and ponds with 'wild' edges.

This success is also demonstrated by the variety and quantity of moths found next night in Brockwell Park, with 24 different species recorded, including the flame shoulder moth, marbled minor moth and notable sightings of the rare Jersey tiger and small clover case-bearer moths.

Ruskin Park, which contains a similar mixture of ponds and natural wildlife habitats, was also well used by common and soprano pipistrelle bats. A new wildlife-friendly community garden in the centre of the park is also helping to increase the number of feeding opportunities for bats as well as insects like moths on which they feed.

All of the sightings, both common and scarcer species, will be submitted to Greenspace Information for Greater London which collates and makes available information on London's wildlife, parks, nature reserves, gardens and other open spaces.

Donald Campbell from Veolia Environmental Services, which manages both Brockwell and Ruskin Park, said: ‘We're really pleased with the number of moths and bats recorded over each evening. It's great that the residents of Lambeth have this much biodiversity on their doorstep, and we will continue to ensure that all of our parks are a place for both residents and wildlife.'

Iain Boulton from Lambeth Council's Parks and Greenspaces department said: ‘To see a Jersey tiger moth was fantastic. This is an important sighting, which will be recorded and used to monitor the spread of Jersey moths as they apparently move further northwards through the UK. It's also interesting evidence of how our changing climate seems to be having an impact on wildlife.'
http://www.wildlifeextra.com/go/news/lambeth-moth.html

Bat on a plane sparks panic

A bat on a plane caused panic among passengers on board a flight in the US.


The animal was filmed flying through the cabin during a Delta Airways flight from Madison, Wisconsin, to Atlanta' Georgia.

It caused so much distress that the pilot was forced to return to the departure airport, reports the Daily Telegraph.

Passenger Mike Schmidt filmed the bat flying over passengers' heads as they ducked and screamed.

The animal was finally contained when it flew into the onboard toilet and a passenger shut the door.

Mr Schmidt said: "I woke up to a small scream and then I saw the bat fly over my head.

"I grabbed my phone to get some video as my friends would never believe this.

"It went up and down the aisle about four to five times before being trapped in the back lavatory

http://web.orange.co.uk/article/quirkies/Bat_on_a_plane_sparks_panic

How Bats Stay On Target Despite the Clutter

ScienceDaily (July 30, 2011) — In a paper published this week in Science, researchers at Brown University and from the Republic of Georgia have learned how bats can home in on a target, while nearly instantaneously taking account of and dismissing other objects in their midst. The trick lies in their neurons: Bats can separate the cavalcade of echoes returning from their sonar pulses by distinguishing changes in amplitude -- the intensity of the sound -- between different parts of each echo within 1.5 decibels, to decide whether the object is a target or just background clutter.


The minute change in amplitude is enough to cause a delay in the bats' neural response to an echo, letting the bat know what is clutter and what is the target. It is as if the bat is using two screens -- a main screen that keeps it locked in on its target by virtue of its neural response to the echo and another, secondary screen that keeps note of surrounding objects but doesn't fixate on them.


"Everything the bat sees using sonar is based on the timing of the neural responses and nothing else," said James Simmons, professor of neuroscience at Brown and an author on the paper.

The research is important because it could help refine the maneuverability of sonar-led vehicles and improve their ability to remain fixed on a target even in dense, distracting surroundings.

In a paper in the Proceedings of the National Academy of Sciences last year, Simmons and Mary Bates, who studied under Simmons and earned her doctorate last May, showed how bats avoid colliding with objects while flying in tight quarters. The key, they determined, is that bats tweak their sounds (chirps) and thus the echoes they receive to differentiate one broadcast/echo set from another. Building on that research, Bates and Simmons sought to determine how bats take note of objects in their sonar surroundings without being deterred by them -- how bats prioritize the waves of echoes they are receiving from their broadcasts.

"The problem the bat is facing is that it's flying around in this really complicated environment. It's getting all these echoes back [from the sonar broadcasts it emits], and the echoes are all arriving at almost the same time," said Bates, lead author on the Science paper. "And they have no trouble at all dealing with that. We're trying to figure out perceptually how these bats distinguish an echo from a nearby target from all the background echoes that are arriving within a similar time window."

In a series of experiments, the researchers studied those times when the bats would encounter a "blind spot," when the echoes were so close together that the bat could not distinguish its target from the surrounding clutter. The range in which the bats can detect when one echo interferes with another is a mere 50 milliseconds, the researchers report.

Harmonics plays a major role. Bat chirps -- sounds -- generally have two harmonics. When a bat chirps, it waits for the corresponding echo. It makes a mental fingerprint of the emitted sound and its echo; if the broadcast/echo fingerprints match up precisely, then the bat "will process it and produce an image," Simmons said. In many cases, that image is an object it is targeting. But when the second harmonic is weaker in the echo fingerprint, the neurons' response is delayed by as few as 3 microseconds. That delay, while undetectable to humans, is enough to tell the bat that the object is present, but it is not its primary interest.

"What the bat does is it takes clutter and defocuses it, like a camera would, so the target remains highly defined and in focus," Simmons said.

Tengiz Zorikov from the Institute of Cybernetics in the Republic of Georgia contributed to the research. The U.S. Office of Naval Research, National Institutes of Health, and the National Science Foundation funded the work.

http://www.sciencedaily.com/releases/2011/07/110728144747.htm

How to Invite Bats for Dinner

In advertising, it's all about finding the right medium for your audience, and the natural world is no different. A new study shows that one plant species uses acoustic tricks to reach its customers—in this case bats that use echolocation to navigate. The plant, a vine found in the Cuban jungle, displays a special, dish-shaped leaf above its flowers to make itself more conspicuous to the sonar of bats, which the plant needs to spread its pollen.


The paper will change the way researchers and botanists look at forests, predicts Brock Fenton, a bat researcher at the University of Western Ontario in London, Canada, who wasn't involved in the study. "It has certainly changed how I look at it," he says. "That leaf is like a big neon sign over a restaurant."

Whereas bees are the best known pollinators, many plants rely on birds, beetles, or bats to transfer their pollen. "There are approximately 40 species of highly specialized nectar-feeding bats in South and Central America and several hundred plant species that have adapted to them," says biologist Ralph Simon of the University of Ulm in Germany, who carried out the new study with colleagues at the universities of Erlangen-Nürnberg, also in Germany, and Bristol in the United Kingdom. Among these adaptations are big, wide-open blossoms and enough nectar to cater to small mammals.

The challenge for the bats, many of which have poor vision and rely on echolocation, is to find the plants amid thousands of others. "Acoustics in a forest are hell," says Jürgen Tautz, a biologist at University of Würzburg in Germany. The echoes of plants are mostly random, and for a bat flying through dense vegetation, the patterns are constantly changing.

In earlier research, Simon and colleagues had trained bats in the laboratory to recognize objects of various shapes. They had discovered that the animals were very good at finding hollow hemispheres and distinguishing them from other shapes. So when, high up in the canopy of the Cuban rain forest, they found a vine called Marcgravia evenia that is pollinated by bats and has a leaf resembling a dish reflector above each flower cluster, they wondered whether the leaves might serve as a beacon. Because the flowers are very rare and difficult to access, the researchers tested their hypothesis in the lab.

They hid a nectar feeder within an artificial foliage background and measured the time that it took flower-visiting bats (Glossophaga soricina) that had been trained for the task to find it. Mounting a replica of an ordinary foliage leaf on top of the feeder did not significantly reduce search times. But adding a replica of the dish-shaped leaf cut them in half, the team reports online today in Science. "This leaf reflects a loud and constant echo in many different directions, making it easier to locate for a bat than a normal leaf," Simon says.

Even though the scientists have not shown that Cuban bats actually use Marcgravia's special leaf to find it, the evidence strongly suggests they do, says Ulrich Kutschera, an evolutionary biologist at the University of Kassel in Germany.

"It is an interesting example of the ongoing coevolution of flowering plants and their animal pollinators," he says. "Darwin would have been thrilled."

Fenton, meanwhile, raises another question that the scientists have yet to answer: Are the special leaves only displayed when the flowers are ready? "After all, when a restaurant closes, it also switches off the neon sign," he says.


by Kai Kupferschmidt
http://news.sciencemag.org/sciencenow/2011/07/how-to-invite-bats-for-dinner.html?ref=hp

Large population of rare Bechstein’s bats found on proposed HS2 train route

Rare bats in the path of HS2 are nationally significant

July 2011. A significant population of rare Bechstein's bats has been discovered in Buckinghamshire - in ancient woodland either side of the proposed HS2 route and adjacent to the proposed site of a waste incinerator. Until 2010, only a single Bechstein's bat had been found in Bucks - in the far south of the county, at Cliveden.

65 Bechstein's bats in 1 tree
In one woodland alone, (Grendon & Doddershall Woods) an amazing count of 65 Bechstein's bats were observed emerging at dusk from their roost inside a tree. Several tree roosts have been found and Bechstein's bats are now known to occur in 10 woods within the Bernwood Forest area of Buckinghamshire.

Bechstein's bats are one of the rarest mammals in the UK and they, their roosts and their breeding sites are strictly protected under UK and European law.

The discoveries have been made by volunteers undertaking the Bernwood Forest Bechstein's Project. The Project was set up in 2011 to expand on work undertaken by the North Bucks Bat Group and the Bat Conservation Trust in 2010. Bechstein's bats were discovered in three North Bucks woodlands in 2010, with a further incidental discovery in 2011 at Finemere Wood, a Berks, Bucks and Oxon Wildlife Trust nature reserve.

Chris Damant, who has been co-ordinating the Bernwood study says "The discoveries in 2010 were very exciting, but we realised we knew very little about how the bats were using the woodlands and which other woods they might also be in. Three of us who had been involved in the 2010 surveys, decided to find out more and we designed and sought funding for an independent research project. Local landowners have been very supportive and allowed us access for the study."

Significant breeding population
Toby Thorne, another bat expert on the Project continues "We never expected to find Bechstein's bats in North Bucks last year; let alone the significant breeding population we've identified this year. It just goes to show you don't need to go abroad to discover rare wildlife - we've done it at home!"

Radio tracking bats
The team has also undertaken radio-tracking studies of individual bats. Tiny radio transmitters were attached to 4 female Bechstein's bats, which were then followed for up to 11 days and nights. Two bats stayed close to their tree roost in one woodland, whilst the other two were found to move up to 3km between woodlands in the area, including crossing the proposed route of HS2.

Jo Hodgkins, ecologist on the Project team says "The bats appear to be using a network of woodlands in the area and some are moving between woods. It's really important that we understand how they are using the landscape, before major infrastructure projects change it. If we don't, how can the impact of such developments be assessed? The radio-tracking work is in its early days and we plan to follow more bats in the coming months. We've still got more woods to survey as well - we're only a quarter of the way through our initial research - who knows what else we'll discover!"

10 species of bats
And it's not just Bechstein's bats being found; the Project team have so far recorded a total of 10 species of bat in these woodlands, with some species such as the protected Brown Long-eared bat being recorded in large numbers. The Bernwood Forest area appears to be an important ‘hotspot' for bats!


http://www.wildlifeextra.com/go/news/bechsteins-bats011.html#cr

Bats' hairs are 'airspeed sensor'

Tiny hairs that cover bats' wings seem to act as a complex airspeed sensor, researchers report in Proceedings of the National Academy of Science.

Experiments showed that bats' brains distinguished between airflow direction when air flowed over them at low speed.

However, with the hairs removed, the bats executed fewer tight turns and flew at higher speeds.
The researchers suggest the hairs allow fine control over aerodynamics as airflow changes during manoeuvres.

Read on...