Weird 'Engine Of The Reef' Revealed

Source:

http://www.sciencedaily.com/releases/2007/08/070830165013.htm

Science Daily — A team of coral researchers has taken a major stride towards revealing the workings of the mysterious ‘engine’ that drives Australia’s Great Barrier Reef, and corals the world over.

The science has critical importance in understanding why coral reefs bleach and die, how they respond to climate change – and how that might affect humanity, they say.
Scientists at the ARC Centre of Excellence for Coral Reef Studies, James Cook University and the University of Queensland have compiled the world’s first detailed gene expression library for Symbiodinium, the microscopic algae that feed the corals – and so provide the primary energy source for the entire Reef.
“Symbiodinium uses sunlight to convert CO2 into carbohydrates for the corals to feed on. At the same time there’s evidence the corals control its output, suggesting that they are farming their captive plants” Professor David Yellowlees explains.
“But these microscopic algae are quite weird and unlike any other lifeform. They have different photosynthetic machinery from all other light harvesting organisms. They have 100 times more DNA than we do and we have no idea why such a small organism needs so much. They really are like no other living creature we know.
This is echoed by team member Prof Ove Hoegh-Guldberg who comments it is ‘like no other organism on planet’, jokingly labeling it “like an alien”.
This strange beast not only rules the fate of the world’s coral reefs – it also plays a significant role in soaking up carbon dioxide from the atmosphere, turning it into nourishment for the corals and powering calcification. Its decline would not only kill the reefs but accelerate CO2 buildup.
Dr Bill Leggat says the team has focused particularly on understanding the biochemical relationship between Symbiodinium and corals when they are stressed by heat, light, increased CO2 levels and pollutants from land run-off.
These stressful conditions cause corals to ‘bleach’ by expelling the Symbiodinium and – if they do not recover them within a few days – the corals die. Large-scale bleaching struck half of the Great Barrier Reef in 2002, and eight major bleaching episodes have been reported worldwide in the last 30 years due to warming sea water.
“Our aim is to identify the genes that make the symbiotic plants susceptible to these stresses, and lead to the coral expelling them,” Dr Leggat says.
In experiments at Heron Island Research Station they exposed corals to various stresses associated with climate change and then analysed the gene composition in the symbiotic algae. Another team analysed the effects in corals.
Working together and using the powerful micro-array technology, they hope to assemble a picture of the ‘chemical conversation’ that goes on between the corals and its symbiotic plants that leads to a breakdown in the relationship, a divorce - and the corals starving themselves to death.
“An example of the challenge we face is the gene which is expressed the most when Symbiodinium is stressed. It’s obviously important - but at this stage we have no idea what it does. It is even stranger when you consider that this gene was originally acquired from a bacterium” Prof Yellowlees says.
So far the team has identified about 4500 genes in Symbiodinium, compiling them into the world’s first gene expression library for this symbiotic organism. It is hoped this will have value for understanding other symbiotic relationships in nature.
Symbiodinium is part of a larger group of organisms called dinoflagellates, responsible for events like red tides and ciguatera poisoning. Together, the dinoflagellates process about one third of all CO2 entering the oceans – and are thus vital players in helping to remove CO2 from the atmosphere. Understanding how they function will help fill in one of the critical gaps in our understanding of climate change – how much CO2 the oceans can trap and how this will affect ultimate climate change.
Details of the team’s research findings will be published in the Journal of Phycology later this year.
Note: This story has been adapted from a news release issued by ARC Centre of Excellence in Coral Reef Studies.

Fausto Intilla

www.oloscience.com

Monkeys Use 'Baby Talk' To Interact With Infants

Source:

http://www.sciencedaily.com/releases/2007/08/070824095804.htm

Science Daily — Female rhesus monkeys use special vocalizations while interacting with infants, the way human adults use motherese, or "baby talk," to engage babies' attention, new research at the University of Chicago shows.

"Motherese is a high pitched and musical form of speech, which may be biological in origin," said Dario Maestripieri, Associate Professor in Comparative Human Development at the University. "The acoustic structure of particular monkey vocalizations called girneys may be adaptively designed to attract young infants and engage their attention, similar to how the acoustic structure of human motherese, or baby talk, allows adults to visually or socially engage with infants."
In order to determine if other primates also use special vocalizations while interacting with infants, researchers studied a group of free-ranging rhesus macaques, which live on an island off the coast of Puerto Rico. They studied the vocalizations exchanged between adult females and found that grunts and girneys increased dramatically when a baby was present. They also found that when a baby wandered away from its mother, the other females looked at the baby and vocalized, suggesting that the call was intended for the baby.
"Adult females become highly aroused while observing the infants of other group members," explains lead author of the article, Jessica Whitham, a recent Ph.D. graduate of the University of Chicago, who investigated this topic as a doctoral student at the University and currently works at Brookfield Zoo near Chicago. "While intently watching infants, females excitedly wag their tails and emit long strings of grunts and girneys.
"The calls appear to be used to elicit infants' attention and encourage their behavior. They also have the effect of increasing social tolerance in the mother and facilitating the interactions between females with babies in general. Thus, the attraction to other females' infants results in a relatively relaxed context of interaction where the main focus of attention is the baby," Maestripieri and his colleagues write in the article, "Intended Receivers and Functional Significance of Grunt and Girney Vocalizations in Free-Ranging Rhesus Macaques" published in the current issue of the journal Ethology. In addition to Whitham and Maestripieri, Dr. Melissa Gerald, a researcher at the University of Puerto Rico, was also a co-author.
Researchers have long been interested in the noises that non-human primates make and how they are used for communication. Monkey vocalizations could be carrying information that the sender expects the recipient to understand, or they could be noises that the recipient can draw inferences from, but are not intended to carry information. A human sneeze, for instance, is a noise that people understand may be associated with a cold, but it did not develop evolutionarily to convey information.
The study by Maestripieri's team showed that the grunts and girneys emitted by the rhesus macaques fall into the category of vocalizations not intended to convey specific information, and appear to be used to attract other individuals' attention or change their emotional states. When females vocalize to young infants, however, the infants' mothers infer that the females simply want to play with the infants and are unlikely to harm them. Therefore, these vocalizations may facilitate adult females' interactions not only with infants, but with the infants' mothers as well. They found, for instance, that the grunts and girneys were sometimes followed by an approach and grooming of the mothers.
Additionally they discovered that, unlike human mothers, the rhesus macaque mothers did not direct grunts or girneys toward their own offspring. It could be that the monkey mothers are familiar with their own offspring and use the vocalizations with other babies because they are excited about the novelty of seeing a new infant, Maestripieri said.
Note: This story has been adapted from a news release issued by University of Chicago.

Fausto Intilla

www.oloscience.com

Sharks' 'Bite Force' Under The Spotlight

Source:

http://www.sciencedaily.com/releases/2007/08/070823122441.htm

Science Daily — While sharks instill fear in beachgoers worldwide, they instill a deep sense of curiosity in UT assistant professor and shark expert Dan Huber.

There are still many mysteries surrounding what makes sharks such perfect predators, so Huber’s research on sharks’ “bite force” – their hunting performance – may offer new insights on sharks’ habits, capabilities and evolution. The research may also lead to advances in protective swimwear, shark-proofing equipment and a better understanding of flexible cartilage – which forms the sharks’ whole skeletons, much like human ears and noses.
“There’s a ton of bad data on how hard sharks bite,” Huber said. “And the more we learn the more we can understand these animals, educate the public, and keep people safer.”
Huber traveled to Australia in July to study an 8-foot great white shark that had become entangled in netting, and is now helping create a 3-D digital recreation of the shark that should reveal the animal’s biological mechanics. A CAT scan was taken of the shark’s skull and data from the dissection will be used to create the digital model. The digital model will include millions of bits of information, which together will allow a simulation of a great white’s bite at full force.
A shark’s hunting performance, Huber said, is not just based on its teeth, but on its muscles, behavior and streamlined body.
Huber, who is working with biologists at the University of New South Wales in Sydney, Australia and the University of Newcastle in Newcastle, Australia, is also studying similar characteristics on feeding performance in tiger and bull sharks, which, along with the great white, are responsible for most attacks on humans. Huber believes the great white probably will not wind up at the top of the list of bite force.
“The white has the narrowest head of the three, so it has less space for jaw muscles,” Huber said. “Consequently, we’re expecting that it will have a lower bite force on a pound-for-pound basis.”
There are currently no accurate estimates of the maximum bite force of the great white, but according to Huber, the 3-D model will provide the world’s first accurate estimates.
But, Huber added that the great white – due to its excellent hunting abilities – doesn’t necessarily need to have the most powerful bite to take down prey.
“Much of the damage inflicted by white sharks is due to their teeth, and not necessarily to the force,” he said. Great white sharks have approximately 3,000 serrated teeth, and often shake whatever it bites into from side to side to initiate a sawing action.
View the 3-D model here: http://www.ut.edu/public_info/3D-white.gif
Note: This story has been adapted from a news release issued by University of Tampa.

Fausto Intilla

www.oloscience.com

Giant Panda Can Survive

Source:

http://www.sciencedaily.com/releases/2007/08/070824104831.htm

Science Daily — The giant panda is not at an "evolutionary dead end" and could have a long term viable future, according to new research involving scientists from Cardiff University.

Previous studies have found that the giant panda's isolation, unusual dietary requirements and slow reproductive rates have led to a lack of genetic diversity that will inevitably lead the species to extinction.
Now a study by Professor Michael Bruford and Dr Benoît Goossens from the School of Biosciences, in collaboration with Professor Fuwen Wei and colleagues from the Institute of Zoology along with the China West Normal University in Sichuan, has found that the decline of the species can be linked directly to human activities rather than a genetic inability to adapt and evolve.
"Our research challenges the hypothesis that giant panda's are at an 'evolutionary dead end'" said Professor Bruford. "It is however clear that the species has suffered demographically at the hands of human activities such as deforestation and poaching".
The study gives a new genetic perspective on the giant panda, as well as tracing its demographic history. The research also shows that in areas where habit conservation projects are in place, the giant panda is flourishing and population numbers are increasing.
"Our research suggests we have to revise our thinking about the evolutionary prospects for the giant panda" said Professor Bruford. "The species has a viable future and possesses the genetic capacity to adapt to new circumstances. Conservation efforts should therefore be directed towards habitat restoration and protection. In their natural environment, the giant panda is a species that can have a bright future."
The research is reported in the journal Molecular Biology and Evolution.
Note: This story has been adapted from a news release issued by Cardiff University.

Fausto Intilla

www.oloscience.com

How Snakes Survive Starvation

Source:

http://www.sciencedaily.com/releases/2007/08/070824173005.htm

Science Daily — Starving snakes employ novel survival strategies not seen before in vertebrates, according to research conducted by a University of Arkansas biologist. These findings could be used in conservation strategies to determine the health of snake populations.

“These animals take energy reduction to a whole new level,” said Marshall McCue, a graduate student in biological sciences in the J. William Fulbright College of Arts and Sciences. He reported his findings in the journal Zoology.
While scientists knew that some snake species could survive for up to two years without a meal, no studies have examined the physiological changes that take place when a snake goes for prolonged periods without food. McCue examined three snake species – the ball python, the ratsnake and the western diamondback rattlesnake – to study their responses to prolonged periods without food.
The 62 snakes studied went about six months without eating – a time period that could well be duplicated in the wild, where food supplies can be scarce. McCue then looked at physiological, compositional and morphological changes in the snakes.
The results showed that the snakes could lower their standard metabolic rates, some by up to 72 percent.
“Snakes already had low energy demands. We didn’t know they could go lower,” McCue said.
Another surprising finding: The snakes continued to grow despite the lack of food – a counterintuitive finding, but a measurement that again does not appear in the research literature.
“To me, this suggests that there must be a strong selective advantage to growing longer,” McCue said. It also means the snakes have become extremely efficient in their ability to use available resources.
To illustrate the strategies employed by snakes to combat starvation, McCue uses an economic analogy of supply and demand.
“When you’re cut off from resources, you are an organism that still needs to expend energy,” he said. The “demand” end is met by decreasing their metabolic rate. The “supply” end must be met by frugal use of resources they have at hand for energy, which comes from within.
The body composition of snakes includes water, ash, protein, fats and carbohydrates. McCue found that the snakes used up selected fat stores first during starvation, but he also found crucial differences between the snake species. The ratsnakes, which typically have a more abundant rodent supply in their natural environment, began to break down proteins faster than the pythons or rattlesnakes.
“The protein use was higher in the snakes less well adapted to starvation,” McCue said.
Snakes are relatively new on the world scene, having been around for about 100 million years. Yet they currently comprise about half of all reptile species.
“Snakes are very evolutionarily successful,” McCue said. Understanding the physiology that allows them to succeed in low-energy environments will help scientists further their understanding of the snakes’ evolution and their adaptation to their current ecosystems.
Note: This story has been adapted from a news release issued by University of Arkansas, Fayetteville.

Fausto Intilla

www.oloscience.com

Elephantnose Fish 'See' With Their Chin

Source:

http://www.sciencedaily.com/releases/2007/08/070821114339.htm

Science Daily — Originating in Central Africa, Peters' elephantnose fish (Gnathonemus petersii), finds its bearings by means of weak electrical fields. Scientists from the University of Bonn have now been able to show how well this works. In complete darkness the animals can even distinguish the material of objects at a distance or dead organisms from living ones. The results have now been published in the Journal of Experimental Biology.

The fish, which is as long as a cigar, hovers with its head inclined, close to the gravel-covered bed. While it swims forward slowly, its trunk-like elongated chin sweeps steadily from right to left, always at a distance of a few millimetres from the bottom. This way the fish behaves like treasure hunters searching for buried gold coins on the beach with their metal detector. Basically, this is precisely what the fish is doing. Hidden in the sediment there are large numbers of dead nematocera larvae waiting for it, its favourite food.
Zoologists from the University of Bonn have hidden the larvae there. 'We wanted to see whether it can find them and if the answer is yes, then down to what depth,' Professor Gerhard von der Emde explains. 'It', that is the African Peters' elephantnose fish. Yet its characteristically shaped chin does not work like a particularly sensitive nose. Instead, it contains more than 500 electric sensors with which it senses its surroundings. With this sense the animal has conquered the night. During the day it hides, only under cover of darkness does it goes searching for food.
The chin of Peters' elephantnose fish is basically its eye. In its tail is the corresponding torch. Via mutated muscle cells it produces regular electrical pulses of a few volts with it. 80 times per second the fish switches this little battery on and off for the blink of an eye. 'At the same time it measures the electrical field which builds up around it via sensors in the skin,' explains Professor von der Emde. Nearby objects distort the field, so that the fish obtains an image of its surroundings, which is a surprisingly complex one.
Professor von der Emde and his team have tested what the animals can perceive with their electric sense. For this they set up a small cube and a pyramid in an aquarium, for example. Whenever the fish swam to the pyramid, they were rewarded with a nematocera larva. Their eyes were no use to these agile fish, because the experiments took place with infrared lighting, so that only the researchers could see anything, using their special cameras. They were flabbergasted themselves by their results.
In nine out of ten cases the fish swam straight towards the pyramid through the pitch black darkness. Even when the researchers used wire models instead of solid objects, the fish could not be fooled. They were even able to handle discontinuous contours. 'For example, we removed the vertical edges of a cube, i.e. we embedded two wire squares on top of each other in a gel that was permeable for electrical fields,' Professor von der Emde says. 'The fish still perceived it as a cube, so they supplied the contours very much like humans would.' Furthermore, they seem to calculate the volume of objects in water. 'A cube has a larger volume than a pyramid of the same height,' Gerhard von der Emde explains. 'If we decreased the size of the cube so much that its volume became smaller than that of the pyramid, the fish often changed their minds and swam to the cube.' So, the Peters' elephantnose fish can also internalise abstract concepts: 'Always swim to the less voluminous of two objects, irrespective of their absolute size.'
As in Starship Enterprise
What Bones, the ship's doctor of the Enterprise does, the little fish from Africa has been doing for a long time, viz. distinguishing living from dying or dead organisms without touching them. 'With its electric sense, it measures their capacitative properties, i.e. their ability to store charges,' Prof. von der Emde explains. 'Dead plants or animals cannot do that.' The electrical field image even tells it what material the object in question is made of. The image of metal is very bright, by contrast non-conductors weaken the electrical field around the fish. And it can even measure distances to a precision of several millimetres. In order to do so, it uses the fact that the electrical image becomes increasingly 'blurred'. From the degree of fuzziness it thus calculates the distance.
There is a reason for this brain power. The cerebellum of Peters' elephantnose fish is hugely enlarged. In comparison with their body length the animals have a larger brain than humans. 'They are really intelligent,' the zoologist says fondly, 'that's why it is so much fun working with them.' At one point he tried to train electric fish from South America. 'That was a flop,' he reminisces, 'the fish are beautiful, but definitely too stupid for complex tasks.'
Note: This story has been adapted from a news release issued by University of Bonn.

Fausto Intilla

www.oloscience.com

How To Share A Bat

Source:

http://www.sciencedaily.com/releases/2007/08/070822143214.htm

Science Daily — New research shows how different species of plants evolve unique floral adaptations in order to transfer pollen on different regions of bats' bodies, thus allowing multiple plant species to share bats as pollinators.

A pattern of character displacement has only rarely been shown for plants, and this is the first study to examine the competitive mechanism and process driving this pattern.
When multiple plant species occur in the same habitat and share the same pollinator, large amounts of pollen may be transferred between different species. This form of plant-plant competition can reduce the fitness of all species by interfering with successful pollination. Dr. Nathan Muchhala, a post-doctorate researcher, and Dr. Matthew D. Potts, assistant professor in the University of Miami Department of Biology, studied such competition in remote cloud forests of the Ecuadorian Andes.
They found that co-occurring bat-pollinated species of the genus Burmeistera reduce competition by evolving differences in flower shape. This serves to place pollen in different regions of the bats bodies, and thus greatly reduces "incorrect" (between-species) pollen transfer. Experiments with bats and flowers showed that greater differences in flower shape between two species decreases "incorrect" pollen transfer and thus maximizes successful pollination.
"This research study clearly demonstrates that these plants are competing and the competition is strong enough for them to evolve unique characteristics in order to reduce competition for pollination," says Nathan Muchhala, Ph.D., researcher in the University of Miami Department of Biology.
Along with the experimental work, the research team also analyzed Burmeistera in 18 field sites, and found that differences in flower morphology between co-occurring species were much greater than what would be expected by chance.
The study, titled "Character displacement among bat-pollinated flowers of the genus Burmeistera: analysis of the mechanism, process and pattern", was recently published in the Proceedings of the Royal Society B.
This implies that Burmeistera evolve to use different portions of bats bodies than the co-occurring species in their habitat. This type of local divergence in some trait is termed character displacement.
Note: This story has been adapted from a news release issued by University of Miami Rosenstiel School of Marine & Atmospheric Science.

Fausto Intilla

www.oloscience.com

Where Have All The Dolphins Gone This Summer?

Source:

http://www.sciencedaily.com/releases/2007/08/070820095620.htm

Science Daily — Researchers from the wildlife conservation charity Marinelife are extremely concerned about what it is NOT seeing this summer in the Bay of Biscay.

Marinelife’s unique long-term monitoring project, the Biscay Dolphin Research Programme (BDRP) has been conducting scientific monthly whale, dolphin and seabird surveys through the English Channel and Bay of Biscay for the last 13 years, using the P&O Cruise Ferry, The Pride of Bilbao, as a research platform. In addition, a BDRP full-time Wildlife Officer collects daily data on dolphin abundance. The BDRP surveys have detected more than 20 species of whale and dolphin in the Bay of Biscay and counted over a hundred thousand animals.
Through the recent work of BDRP and other research groups, the Bay of Biscay has become known as a worldwide hotspot for whales, dolphins and seabirds with many passengers each year experiencing wonderful encounters with the marine wildlife, especially groups of dolphins that may number several thousand. However, this summer there has been a very obvious and worrying dearth of sightings, which is significant given that the Bay of Biscay is of European importance for dolphins and other cetaceans.
Early indications have shown that during June and July, the total number counted of the 3 main dolphin species, Common Dolphin, Striped Dolphin and Bottlenose Dolphin, are down by around 80% on the same time last year. Seabirds, such as auks, shearwaters, and gannets have also been in short supply and the situation has been ongoing since the early spring, with no signs of an improvement thus far during August.
Marinelife are worried that this very apparent decline in sightings of both dolphins and seabirds along the ferry route, could be more wide-ranging and could indicate a big reduction in fish stocks due to over fishing or a change in distribution of fish stocks due to temperature changes (in turn linked to climate change). This year has already been marked by a failure of the anchovy fishery, with bans being put in place for the Spanish and French fleets, but what else could be happening?
Marinelife’s Research Director, Dr Tom Brereton said: “Whatever the cause of the disappearance of dolphins this summer, it shows both how vulnerable they are and how alarmingly quickly local declines can occur when environmental conditions change. The changes highlight how we need to act quickly, to address major issues such as climate change and over-fishing.”
Marinelife are also well aware of the other pressures facing dolphins, especially those in Biscay and the Western Approaches to the English Channel and that too is related to commercial fishing – namely bycatch of dolphins in fishing nets. This activity is known to claim thousands of dolphins each year, many washing up dead on the beaches of the south west coastline and this situation has still not been adequately addressed by the fishing industry.
Marinelife continues to work in partnership with a number of other research groups, spearheading an international initiative, the Atlantic Research Coalition (ARC) that aims to describe changes in the status of whales and dolphins at European scale.
Note: This story has been adapted from a news release issued by MarineLife.

Fausto Intilla

www.oloscience.com

Last Hope For Cambodia's Parachuting Bird

Source:

http://www.sciencedaily.com/releases/2007/08/070816161012.htm

Science Daily — The Bengal florican – the rarest of the globe’s 27 bustards - is amongst 189 critically endangered birds being targeted by an initiative to find companies and individuals who will highlight each species’ plight and contribute funds towards helping them.

There are fewer than 1,000 Bengal florican’s left in Cambodia, India and Nepal, and conservationists have given the bird just five years if the destruction of its grassland habitat continues.
Three other birds - the Belding’s yellowthroat of Mexico, the Djibouti francolin and Brazil’s restinga antwren are also being championed at Birdfair, when the RSPB partner, BirdLife International, will launch its initiative, Preventing Extinctions: Saving the World's Critically Endangered Birds. Birdfair starts August 17 at Rutland Water and is co-organised by the RSPB and the Leicestershire and Rutland Wildlife Trust.
Ian Barber, the RSPB’s South Asia officer, said: “The Bengal florican is now hanging on in only three countries and is under huge pressure in all three.
“It is only eight years since the bird’s rediscovery in Cambodia and already it is facing oblivion. Even in protected sites in Nepal, land is being taken for agriculture leaving no room for the bird. This initiative may be its last hope.”
Fewer than 700 Bengal florican’s – which resemble small ostriches - remain on the floodplain of the Tonle Sap Lake, the largest freshwater lake in South East Asia. Numbers there have fallen from 3,000 in ten years.
The Nepalese population, which is legally protected, has dropped by more than 50 per cent in 25 years to fewer than 60 birds. In India, only about 250 are left.
The Birdfair is targeting the Cambodian population and money raised will boost a government-backed scheme encouraging farmers on designated sites to resume traditional grazing and scrub clearance on grasslands instead of switching to dry-season rice growing.
Government official, Seng Kim Hout, has seen how crucial the project is to the bird. “These grasslands are disappearing before our eye,” he said. “On revisiting many of our survey sites, we found the landscape unrecognisable from previous years, squeezing the floricans into a shrinking landscape in which they cannot survive. I even once saw a male florican displaying on a dam wall because all the grassland had been converted to irrigated rice.”
Bengal floricans were rediscovered in Cambodia in 1999 and are named after the region of Bengal where the species was first identified. They depend on traditionally managed grasslands for food and for males to perform their elaborate parachuting courtship display.
Martin Davies, the RSPB’s Birdfair Co-organiser, said: “It is still possible to save the florican and all of the other critically endangered birds. What we need is more of the right initiatives in the right places. We are not talking about ridiculous amounts of money to make this happen and coming to support and enjoy the Birdfair this weekend is the most straightforward thing anyone can do to help.”
Background information
The Bengal florican, Houbaropsis bengalensis, is 67cm tall, with a black head and neck and long, mostly white wings. It has a long neck and long yellow legs.
The Tonle Sap floodplain is the largest of any lake floodplain in the world. The Cambodian initiative involves establishing five sites, called Integrated Farming and Biodiversity Areas (IFBAs), totalling 100 square miles of land.
The Bengal florican project, called Conserving Bengal Floricans and Improving Rural Livelihoods around the Tonle Sap, the World’s Largest Floodplain Lake, Cambodia, is a joint initiative of BirdLife International Cambodia Programme, the Wildlife Conservation Society - Cambodia Program and the Forestry Administration of the Ministry of Agriculture, Forestry and Fisheries with financial support from Fondation Ensemble and the Wildlife Conservation Society.
Dry-season rice production involves the use of strip dams – deep ditches cut into the land that trap water as seasonal waters recede. This practice leads to wholesale conversion of grassland, destroying the florican’s habitat.
Floricans rely heavily on the traditional agricultural practices of grazing, burning and scrub-clearance. These methods expose areas for the birds to forage and for males to display to females.
Indian bustards are also known as floricans. Great bustards have been introduced to Salisbury Plain recently, from Russia.
The three main populations of Bengal floricans in Nepal are in Chitwan National Park, Royal Bardia National Park and Sukla Phanta Wildlife Reserve. About 100 hectares of grassland has been created at the Sukla Phanta and has been quickly colonised by floricans, proving that habitat availability is key. In India the birds are found in only three states, Uttar Pradesh, Assam and Arunachal Pradesh.
The restinga antwren is confined to a 10km square strip of beach scrub habitat in Rio de Janeiro state, Brazil. Its habitat is under intense pressure from clearance for beachfront housing and salt-industry developments.
Belding’s yellowthroat is found only on shrinking wetland fragments measuring less than 10 km square on Mexico’s Baja California peninsula.
The Djibouti francolin has declined by more than 80 per cent in the last 20 years because of overgrazing, firewood collection and other human disturbance in Djibouti’s small juniper forests.
Note: This story has been adapted from a news release issued by Royal Society for the Protection of Birds.


Fausto intilla
www.oloscience.com

Researchers Track Declining Timber Rattlesnakes

Source:

http://www.sciencedaily.com/releases/2007/08/070817204701.htm

Science Daily — Western Carolina University researchers are using geographic information systems technology and radio transmitters to track timber rattlesnakes this fall to determine whether new mountain subdivisions and road-building are pushing an animal listed as a “species of special concern” toward the endangered list.

Ron Davis, WCU assistant professor of natural resources management, is spearheading the pilot project in which timber rattlers are implanted with special radio transmitter chips by a veterinarian. After their recovery, the snakes are released back into the wild and then monitored to study their habitat and their range.
“The timber rattler is probably the most misunderstood animal in Western North Carolina,” said Davis, who is working with the N.C. Wildlife Resources Commission. “Because people fear them, they want to kill them. Between the destruction of dens by development, wanton killing of the snakes, accidental road kills and illegal poaching, the population of these animals is declining dramatically.”
So what, some might argue about fewer venomous reptiles slithering through the WNC woodlands. Jenn Slagle, a senior from Shelby who is working with Davis on the project, said the timber rattlesnake is an important part of a larger ecosystem and helps control the rodent population. “This species was in the mountains long before we were living here,” said Slagle, who is majoring in natural resources management and political science.
As part of the project, Slagle developed a computer model using GIS software to determine probable locations of timber rattlesnake dens. WCU researchers are using radio telemetry throughout the summer and fall to find released snakes that were implanted with the radio transmitters, until the reptiles return to their dens for winter hibernation.
“When we track them, it’s like a giant game of hot or cold,” Slagle said. “When we point the antenna in the direction of the snake, the signal gets stronger – ‘you’re getting hotter.’ When we point it away from the snake, the signal gets weaker – ‘you’re getting colder.’”
Before beginning the project earlier this year, Davis obtained a permit from the N.C. Wildlife Resources Commission to work with a species of special concern, and he plans to seek grant funding to expand his studies. Among the properties where he is actively tracking timber rattlers is Balsam Mountain Preserve, a gated development between Sylva, N.C., and Waynesville, N.C.
“I don’t want to divulge other places we are working because of the threat of poachers trespassing onto this property and destroying the dens,” he said. “The goals of our project are conservation and education. When we build homes on the mountainsides, we are encroaching upon their territory. When people and rattlesnakes share the same space, the snakes usually lose.”
A major problem in snake-human interactions is that the snakes cannot simply be relocated, Davis said. “Moving a snake out of its home range is basically a death sentence for the snake,” he said. “Our work at places like Balsam will allow us to examine the effects of development and hopefully develop some ways in which people and snakes can co-exist.”
The ultimate goal of the project is to help preserve the snakes, in part by educating people that they are not vicious, aggressive animals, Davis said. Although serious, rattlesnake bites are very rare, and usually occur when someone is trying to handle or kill a snake.
“The snakes are defensive. The rattle is a defense mechanism, not an attack signal, and their survival depends upon not being seen. Given the chance, they will head for cover,” he said. “It can be frightening for some people when they see a rattlesnake, but this remarkable animal really deserves our respect rather than our fear. The best thing to do is to simply leave them alone.”
Note: This story has been adapted from a news release issued by Western Carolina University.

Fausto Intilla

www.oloscience.com

Uncertainties Of Savanna Habitat Drive Birds To Cooperative Breeding

Source:

http://www.sciencedaily.com/releases/2007/08/070816121108.htm

Science Daily — Delaying having kids to help raise the offspring of others seems like a bad choice if you want to reproduce, but many African starlings have adopted this strategy to deal with the unpredictable climate of their savanna habitats, according to a new study by University of California, Berkeley, and Cornell University biologists.

This behavior, called cooperative breeding, is typical of many animals, from insects and shrimp to birds and even humans, but the reasons underlying its evolution and distribution among such a wide array of species have been unclear.
In the new study, behavioral ecologist and evolutionary biologist Dustin Rubenstein, a Miller Fellow in the Department of Integrative Biology and the Museum of Vertebrate Zoology at UC Berkeley, looked at the complete group of African starlings and found that all of the cooperative breeders among these birds live in savannas - highly seasonal habitats with great variation in rainfall, and thus food, from one year to the next. The species that do not engage in cooperative breeding are found mostly in forests, which have more reliable annual food resources.
"Faced with an uncertain and unpredictable environment, it pays evolutionarily to live and breed in social groups that will help you weather the bad times and make the most of the good times," he said. "Living in cooperative family groups may be like a form of insurance against the unpredictable nature of the environment, because it allows individuals to maximize their reproductive success over the course of their lifetimes."
Cooperative breeding is defined as one member of a group delaying breeding to assist another breeding couple. Because cooperative groups in most birds consist of extended families with grandparents, parents, offspring and other close relatives, helpers are typically related to the group members. Among most birds, females leave the group to try to breed elsewhere, so it is the males who often hang around for a year or two as helpers, primarily bringing food to the nestlings. Although they may occasionally breed with females in the group, the helpers often don't reproduce until later in life.
Helping relatives feed their kids increases the chances of passing on some of your genes, since siblings share a large proportion of their DNA. Yet, despite decades of research, it is still not clear why some animal species, including nearly 10 percent of bird species worldwide, show this apparently altruistic behavior, while other closely related ones do not.
In an attempt to answer this question, Rubenstein looked at the 45 species of starlings endemic to Africa to see if there was any relationship between cooperative breeding and the environment in which the birds live.
"Starlings are a model system in which to test this question because they are one of the most socially diverse groups in the world, exhibiting a wide range of social systems and living in a variety of different habitats across Africa," said Rubenstein.
Of the 117 known starling species worldwide, those in Africa, where savannas are extremely common, are the only ones known to engage in cooperative breeding. Those in the more temperate or jungle environments of Europe, Africa and Asia, including the European starling Sturnus vulgaris introduced to America, do not.
For much of the past decade, Rubenstein has intensively studied the social behavior of a variety of starling species in Kenya, home to 26 species - the most of any country in the world. Noting an apparent correlation between cooperative breeding and habitat in this family, he decided to use this socially diverse group to test several hypotheses about how environmental factors may have influenced the evolution of cooperative breeding.
Rubenstein and colleague Irby J. Lovette, director of the Fuller Evolutionary Biology Program at the Cornell Laboratory of Ornithology in Ithaca, New York, constructed a family tree of the African starlings using DNA from samples they captured on expeditions to Africa, from birds housed in zoos and from museum specimens. They used this evolutionary tree to determine whether specific lineages were associated with savanna or non-savanna habitats.
"What's important here is how many times behavior changed," said Lovette. "If you find the same pattern consistently repeated, you can be confident of cause and effect. In this case, we found cooperative breeding evolved when different starling species moved from forests to savannas."
The researchers found that more than one-third of the African starlings are cooperative breeders, and all live in savanna environments - semi-arid grasslands characterized by unpredictable rainfall patterns. In contrast, they found that most of the non-cooperative species live in forests, which are much more predictable and stable environments.
"If we saw just a single evolutionary origin of the behavior and a single switch in habitat, it would be very weak evidence of a relationship between these factors. But we found that cooperative breeding and habitat changed repeatedly in the same direction at the same points in the tree, so we can make a much more powerful statistical argument that the factors are related," Rubenstein said.
Using long-term rainfall data from the National Oceanic and Atmospheric Administration collected from over 2,000 sites across Africa and going back nearly 150 years at some locations, the researchers showed that African savannas are not only highly seasonal environments, but that rainfall is unpredictable and varies greatly from year-to-year. Statistical analyses and the researchers' evolutionary tree helped them isolate the specific environmental characteristic of savannas that might be responsible for this pattern: temporal, or year-to-year, variability in rainfall."Since rain equals food to the birds because it drives patterns of insect availability," said Rubenstein, "we think that by living in family groups with helpers that aid in feeding babies, these birds can cope better in these unpredictable savannas."
Rubenstein noted that this social strategy also helps in good years with lots of rain. Helpers bring enough extra food back to the nest to allow the cooperatively breeding species to breed longer and raise more broods of young than the non-cooperative ones.
"In some cases, the more social species tend to breed longer in benign years and thus produce more offspring," he said. "Often, parents don't have to spend so much time and energy going out and getting food because helpers compensate and do a lot of the parenting."
The origin of cooperative breeding in a savanna habitat may extend beyond starlings, Rubenstein said, noting that the first humans also lived in the savannas of East Africa.
"We think this relationship between sociality and temporal variability in rainfall and, hence, food availability, might help explain the distribution of cooperative breeding in other groups of birds, and even some mammals, living in semi-arid environments around the world," he said.
He added that with global warming, weather patterns are expected to become more variable worldwide and could possibly drive social behavior more toward cooperative breeding among temperate species that don't normally live in family groups.
Reference: Rubenstein et al.: "Temporal Environmental Variability Drives the Evolution of Cooperative Breeding in Birds." Publishing in Current Biology 17, 1--6, August 21, 2007 DOI 10.1016/j.cub.2007.07.032.
The research was supported by grants from the National Science Foundation, the Chapman Fund of the American Museum of Natural History, a Howard Hughes Medical Institute pre-doctoral fellowship and UC Berkeley's Miller Institute for Basic Research.
Note: This story has been adapted from a news release issued by University of California - Berkeley.

Fausto Intilla

www.oloscience.com

New Caledonian Crows Find Two Tools Better Than One

Source:

http://www.sciencedaily.com/releases/2007/08/070816121111.htm

Science Daily — Researchers have found that New Caledonian crows--which are known to make complex food-getting tools in the wild--can also spontaneously use one tool on another to get a snack.

The birds' tool-use skills rival those seen among great apes, according to the researchers. Moreover, it appears that the birds may have solved the problem that confronted them by using analogical reasoning rather than simple trial and error. Analogical reasoning requires the ability to see a novel situation as being essentially the same as a previous situation, the researchers explained.
"Evidence suggests that, from the earliest human stone tools, analogical reasoning has been at the core of human innovation," said Russell Gray of the University of Auckland. "This hallmark of human intelligence may also be at work in both the great apes and New Caledonian crows and may explain why--out of all the crow species in the world--only these crows routinely make and use tools."
In the study, the researchers presented crows with some meat in a hole and a stick that left the meat out of reach. The birds needed to get a long stick out of a "toolbox" in order to get the meat from the hole. However, the long stick was also out of reach. "The creative thing the crows did was to use the short stick to get the long tool out of the box so that they could then use the long stick to get the meat," said Alex Taylor, also of the University of Auckland.
In a second experiment, the researchers reversed the positions of the two sticks so that the small stick was inside the toolbox and the long stick was handy. The crows then briefly probed the box containing the short stick with the long stick before correcting their error by taking the stick directly to the hole.
"It was surprising to find that these 'bird-brained' creatures performed at the same levels as the best performances by great apes on such a difficult problem," Gray said. "Six out of seven birds tried to get the long stick with the short stick at their first attempt at solving the problem. To do this, they had to inhibit their normal response of trying to get the food directly with the short stick and realize that they could use the short stick to get the long stick."
The researchers report their findings online August 16 in Current Biology, a publication of Cell Press.
The researchers include Alex H. Taylor, Gavin R. Hunt, Jennifer C. Holzhaider, and Russell D. Gray of University of Auckland. This work was supported by a Commonwealth Doctoral Scholarship (to A.H.T.) and a grant from the New Zealand Marsden Fund (to G.R.H. and R.D.G.).
Taylor et al.: "Spontaneous Metatool Use by New Caledonian Crows." Publishing in Current Biology 17, 1--4, September 4, 2007. DOI 10.1016/j.cub.2007.07.057.
Note: This story has been adapted from a news release issued by Cell Press.

Fausto Intilla

www.oloscience.com

Birds Learn To Fly With A Little Help From Their Ancestors

Source:

http://www.sciencedaily.com/releases/2007/08/070814100515.htm

Science Daily — A researcher at the University of Sheffield has discovered that the reason birds learn to fly so easily is because latent memories may have been left behind by their ancestors.

It is widely known that birds learn to fly through practice, gradually refining their innate ability into a finely tuned skill. However, according to Dr Jim Stone from the University of Sheffield´s Department of Psychology, these skills may be easy to refine because of a genetically specified latent memory for flying.
Dr Stone used simple models of brains called artificial neural networks and computer simulations to test his theory. He discovered that learning in previous generations indirectly induces the formation of a latent memory in the current generation and therefore decreases the amount of learning required. These effects are especially pronounced if there is a large biological 'fitness cost' to learning, where biological fitness is measured in terms of the number of offspring each individual has.
The beneficial effects of learning also depend on the unusual form of information storage in neural networks. Unlike computers, which store each item of information in a specific location in the computer's memory chip, neural networks store each item distributed over many neuronal connections. If information is stored in this way then evolution is accelerated, explaining how complex motor skills, such as nest building and hunting skills, are acquired by a combination of innate ability and learning over many generations.
Dr Stone said: "This new theory has its roots in ideas proposed by James Baldwin in 1896, who made the counter-intuitive argument that learning within each generation could guide evolution of innate behaviour over future generations. Baldwin was right, but in ways more subtle than he could have imagined because concepts such as artificial neural networks and distributed representations were not known in his time."
Results are reported in: Stone JV, "Distributed Representations Accelerate Evolution of Adaptive Behaviours", PLoS Computational Biology, 2007 (in press).
Note: This story has been adapted from a news release issued by University of Sheffield.

Fausto Intilla

www.oloscience.com