Asteroid tracked from space to Earth for 1st time
Last Updated: Wednesday, March 25, 2009 | 2:59 PM ET
CBC News
Scientists for the first time have recovered meteorite pieces from an asteroid first observed in space — a stroke of luck that could prove valuable when tracking space rocks heading on a collision course toward Earth.
The asteroid, called 2008 TC3, was first observed on Oct. 6 by astronomers in Arizona and was subsequently tracked as it entered the atmosphere and became a shooting star, the first time astronomers have managed that feat.
The space rock broke up in the atmosphere about 35 to 40 km above Sudan, giving astronomers little hope that they might recover fragments.
But SETI Institute astronomer Peter Jenniskens worked with colleagues at the University of Khartoum in the Sudan and, in December, they made an expedition to the Nubian Desert in northern Sudan.
Desert treasure trove
A flat, open and dry region with little vegetation, the desert turned up a treasure trove of pieces: 47 fragments with a total mass of 3.95 kg.
The findings were reported in this week's issue of the journal Nature.
For astronomers who have long clamoured for funding to send a robot probe to an asteroid to analyze the material, the finding was like a gift from the heavens, said University of Western Ontario astronomer Peter Brown, one of the authors of the report.
Being able to match lab analysis of meteorite composition to the data from asteroids — mostly in the form of light reflected from the space rocks — represents the "Holy Grail" for asteroid researchers, said Brown.
"This is really the first end-to-end sample recovery," he said. "This allows us to extend the concept of large-scale interplanetary prospecting."
The recovered meteorites were part of a group called ureilites, known for their dark colouring and porous structure and for containing microscopic nano-diamonds, while the asteroid seen in space was an F-class asteroid, defined for its dark and reflectionless surface.
Brown said the combined data from the asteroid observation and recovery of fragments means scientists can for the first time describe the material of F-class asteroids.
Astronomers believe asteroids are the remnants of material from the early days of the solar system, fragments that were never able to collide and merge to form into planets because of the disruptive influence of gravity from giant planets like Jupiter.
As a result, they are like a time capsule from the early days of the solar system, making them of intense interest to astronomers.
Tracking asteroids is also a priority for astronomers because of the potential threat of collision with Earth, although because of their fragility, F-class asteroids are more likely to break up in the atmosphere than hit the Earth.
The Canadian Space Agency is planning to launch a satellite in 2010 called the Near Earth Object Surveillance Satellite, or NEOSSat, capable of spotting asteroids whose path lies within Earth's orbit of the sun, which Brown says will aid in the tracking of future asteroids.
But even with more sophisticated methods, he says the odds of being able to track an asteroid, see it enter the atmosphere and recover the fragments is likely to be a rare trifecta.
"I think it will take another decade before we get another chance like this," he said. "This was an unusual event."
Showing posts with label Natural Sciences. Show all posts
Showing posts with label Natural Sciences. Show all posts
Thursday, March 26, 2009
Whale and dolphin strandings and beachings
Last Updated: Tuesday, February 24, 2009 | 6:36 PM ET
By Emily Chung, CBC News
Whales and dolphins are creatures of the water, but as mammals, they also rely on air to breathe, and they face death if they become stranded away from either element.
The plight of three dolphins trapped in the ice off the northeast coast of Newfoundland last week captured the hearts of local residents.
After listening to their cries during the night, a group of fisherman from Seal Cove cut a path through the ice in the bay for the dolphins and even towed one of the animals to safety with a rope. Their rescue efforts drew criticism from at least one whale-rescue expert who said they might have done the dolphins more harm than good.
Is it rare for whales and dolphins to get trapped in the ice along Canada's coasts?
Most whales and dolphins do move farther south or away from the coast during the winter, but there have been a few cases of whales getting trapped in the ice along coasts in the northern part of the country in the past few years.
Earlier this winter, hundreds of narwhals became trapped in the ice near Pond Inlet, Nunavut. The whales were killed on the advice of local elders, who said it would spare them from further suffering and death by drowning as the ice thickened.
A number of other examples have made the news in recent years. In May 2008, 15 to 20 beluga whales were trapped in the sea near Grise Fiord, Nunavut.
In November 2006, 100 to 200 beluga whales became trapped in the Husky Lakes, a string of saltwater lakes and inlets east of Tuktoyaktuk, N.W.T., after a channel connecting the lakes to the Beaufort Sea froze. They, too, could not be freed and were instead culled.
What causes the animals to become trapped in the ice?
Most often, whales and dolphins are stranded in the ice when winds or currents shift suddenly, says Laurie Murison, executive director of the Grand Manan Whale and Seabird Research Station in New Brunswick.
However, human activity that causes a lot of underwater noise might also play a role when the animals are near the edge of the ice, Murison said.
"They may panic and end up in an area where the ice can close in on them," she said.
In the case of the whales trapped in the Husky Lakes in 2006, the animals often liked to feed in the lakes during the summer. The local mayor reported that the Department of Fisheries and Oceans used to help chase away the whales but had stopped doing that four or five years earlier.
What types of whales and dolphins are susceptible?
Species that aren't used to a lot of ice, such as grey whales and many dolphins, might have more difficulty getting out, Murison said.
"They just don't have the ability to find those ice leads [channels of open water] as easily as animals that normally are in ice conditions, like bowheads or narwhals or belugas."
Some species can't swim that far underwater before they need to come up for air, she added.
However, even species that are accustomed to the ice can sometimes become trapped.
What should people do if they find a whale or dolphin stranded in the ice?
It might be possible to rescue the animals depending on the circumstances, but it's important to find experts familiar with the best rescue methods, says Andrew Reid, a co-ordinator the Marine Animal Response Society (MARS) in Nova Scotia.
"Dragging the animal by their tail is something you definitely wouldn't want to do," he said. That method could dislocate the animal's spine or pull them underwater.
Reid said involving boats is always risky.
"Anytime you bring boats near animals, there's always the possibility of hitting them," he said.
He added that frozen seas are also a dangerous place for people.
Tonya Wimmer, president of MARS, said rescuers face risks such as dehydration, hypothermia or even being hurt by the animal itself, depending on the conditions.
"People will do some crazy things to save an animal," she said, adding that they sometimes think of the animal before themselves. "Which is lovely, but we have to make sure people's lives aren't in danger while we do these things."
Where do whales become beached or stranded on land?
Canada's southeastern coasts and waters aren't free of traps for whales and dolphins either, as the animals can also become stranded or beached on land. Occasionally, dozens of animals become beached at once.
Including both live and dead animals, about 30 to 40 beachings are reported along Nova Scotia's coast alone each year, Reid estimated.
However, that is likely an underestimate, he said, as some people who have seen beached animals aren't sure whom to call, and some coastal waters are remote areas where a beached animal will never be found.
Similar incidents take place all over Canada's coastline.
Wimmer said there are no readily available Canada-wide statistics, but her group is currently trying to compile information for her region and make sure people know whom to call when they spot a stranded whale or dolphin.
What types of whales and dolphins become beached?
Species that navigate by sonar and travel in groups, such as pilot whales, are more likely to end up beached in large numbers. Such whales are mostly smaller species, and most have teeth.
However, single baleen whales, which are massive filter feeders, can also become beached occasionally.
What can cause them to beach themselves?
Whales and dolphins that are old, sick or injured often come toward the shore. They might be too tired to swim any longer, said Reid.
Healthy whales can become beached because of a navigational error.
Sometimes, the whales are fooled by a natural geographic trap, such as the one that exists at Welfleet, Mass., in Cape Cod, says Murison.
"They think they're going out to sea, and they actually end up in an ever [increasingly] shallow area," Wimmer said.
Sometimes, the animals just get caught up in feeding.
"A lot of the time, we get animals in Bay of Fundy who end up in rivers," Wimmer said. "A lot of that is, literally, they've followed their stomach and get caught on the really fast drop in tide."
Could humans be sometimes responsible?
Toothed whales also use a form of sonar for navigation, listening for the echo of their own, high-pitched voices to determine how far away they are from shore.
Their hearing and their navigational abilities can be damaged by explosions or other loud underwater noises. In fact, some beached whales show signs of damage in their ears, Murison said.
"Hearing is the most critical sense for whales," she added.
Dolphins and whales, including baleen whales, also rely on their voices and their hearing to communicate with one another.
Environmental groups have expressed concerns that noise pollution from commercial shipping, seismic surveys and sonar technology might be causing an increase in beachings.
A paper published in Nature in October 2003 noted mass strandings have taken place near naval exercises that included the use of military sonar.
The beached whales and dolphins showed symptoms of decompression sickness, or the bends, which affects divers who surface too quickly, the paper said. Researchers have suggested that human-generated underwater noise is causing the animals to dive and surface beyond healthy physical limits.
Some environmental groups, led by the Natural Resources Defense Council, have filed lawsuits against the U.S. navy in recent years in an effort to curb the use of mid-frequency sonar, alleging it disturbs and sometimes kills whales and dolphins.
In November 2008, the U.S. Supreme Court ruled in favour of the navy in one suit. A month later, the navy announced it had reached a deal with the council and other groups to continue research on how sonar affects whales and other marine mammals. However, the navy has not agreed to adopt any additional measures to protect animals when it uses sonar.
What should be done about beached whales and dolphins?
Groups such as MARS have protocols to deal with beached animals but only attempt a rescue if they appear to be healthy.
Wimmer said rescuers check the whale over and look for injuries before attempting a rescue.
"Do they look like they're a nice, fat healthy whale? Do they look like they're skin and bones?" she said.
Baby whales without their mothers aren't usually rescued, as they wouldn't survive on their own, Wimmer said.
If a rescue is attempted, smaller animals, such as dolphins, are placed on a stretcher and carried out to sea. For larger animals such as pilot whales, a tarp is put under the animal and attached to inflatable pontoons used to move the animals away from the shore.
How can whale beachings be prevented?
Reid said efforts have been made to prevent whale and dolphin injuries, which can be caused by getting entangled in fishing gear or collisions with ships. For example, shipping lanes in the Bay of Fundy between Nova Scotia and New Brunswick have been moved to minimize collisions with whales, and different fishing methods are being used to reduce the chance that whales and dolphins will be hurt.
Murison said Canada's Department of Fisheries and Oceans has some guidelines in place for activities that produce a lot of underwater noise, such as blasting, seismic surveys and naval activity. In particular, the department recommends conducting those activities when the tide is low, to reduce the propagation of the noise. If they must be done at high tide, those involved in the activity are asked to look out for whales in the area.
Last Updated: Tuesday, February 24, 2009 | 6:36 PM ET
By Emily Chung, CBC News
Whales and dolphins are creatures of the water, but as mammals, they also rely on air to breathe, and they face death if they become stranded away from either element.
The plight of three dolphins trapped in the ice off the northeast coast of Newfoundland last week captured the hearts of local residents.
After listening to their cries during the night, a group of fisherman from Seal Cove cut a path through the ice in the bay for the dolphins and even towed one of the animals to safety with a rope. Their rescue efforts drew criticism from at least one whale-rescue expert who said they might have done the dolphins more harm than good.
Is it rare for whales and dolphins to get trapped in the ice along Canada's coasts?
Most whales and dolphins do move farther south or away from the coast during the winter, but there have been a few cases of whales getting trapped in the ice along coasts in the northern part of the country in the past few years.
Earlier this winter, hundreds of narwhals became trapped in the ice near Pond Inlet, Nunavut. The whales were killed on the advice of local elders, who said it would spare them from further suffering and death by drowning as the ice thickened.
A number of other examples have made the news in recent years. In May 2008, 15 to 20 beluga whales were trapped in the sea near Grise Fiord, Nunavut.
In November 2006, 100 to 200 beluga whales became trapped in the Husky Lakes, a string of saltwater lakes and inlets east of Tuktoyaktuk, N.W.T., after a channel connecting the lakes to the Beaufort Sea froze. They, too, could not be freed and were instead culled.
What causes the animals to become trapped in the ice?
Most often, whales and dolphins are stranded in the ice when winds or currents shift suddenly, says Laurie Murison, executive director of the Grand Manan Whale and Seabird Research Station in New Brunswick.
However, human activity that causes a lot of underwater noise might also play a role when the animals are near the edge of the ice, Murison said.
"They may panic and end up in an area where the ice can close in on them," she said.
In the case of the whales trapped in the Husky Lakes in 2006, the animals often liked to feed in the lakes during the summer. The local mayor reported that the Department of Fisheries and Oceans used to help chase away the whales but had stopped doing that four or five years earlier.
What types of whales and dolphins are susceptible?
Species that aren't used to a lot of ice, such as grey whales and many dolphins, might have more difficulty getting out, Murison said.
"They just don't have the ability to find those ice leads [channels of open water] as easily as animals that normally are in ice conditions, like bowheads or narwhals or belugas."
Some species can't swim that far underwater before they need to come up for air, she added.
However, even species that are accustomed to the ice can sometimes become trapped.
What should people do if they find a whale or dolphin stranded in the ice?
It might be possible to rescue the animals depending on the circumstances, but it's important to find experts familiar with the best rescue methods, says Andrew Reid, a co-ordinator the Marine Animal Response Society (MARS) in Nova Scotia.
"Dragging the animal by their tail is something you definitely wouldn't want to do," he said. That method could dislocate the animal's spine or pull them underwater.
Reid said involving boats is always risky.
"Anytime you bring boats near animals, there's always the possibility of hitting them," he said.
He added that frozen seas are also a dangerous place for people.
Tonya Wimmer, president of MARS, said rescuers face risks such as dehydration, hypothermia or even being hurt by the animal itself, depending on the conditions.
"People will do some crazy things to save an animal," she said, adding that they sometimes think of the animal before themselves. "Which is lovely, but we have to make sure people's lives aren't in danger while we do these things."
Where do whales become beached or stranded on land?
Canada's southeastern coasts and waters aren't free of traps for whales and dolphins either, as the animals can also become stranded or beached on land. Occasionally, dozens of animals become beached at once.
Including both live and dead animals, about 30 to 40 beachings are reported along Nova Scotia's coast alone each year, Reid estimated.
However, that is likely an underestimate, he said, as some people who have seen beached animals aren't sure whom to call, and some coastal waters are remote areas where a beached animal will never be found.
Similar incidents take place all over Canada's coastline.
Wimmer said there are no readily available Canada-wide statistics, but her group is currently trying to compile information for her region and make sure people know whom to call when they spot a stranded whale or dolphin.
What types of whales and dolphins become beached?
Species that navigate by sonar and travel in groups, such as pilot whales, are more likely to end up beached in large numbers. Such whales are mostly smaller species, and most have teeth.
However, single baleen whales, which are massive filter feeders, can also become beached occasionally.
What can cause them to beach themselves?
Whales and dolphins that are old, sick or injured often come toward the shore. They might be too tired to swim any longer, said Reid.
Healthy whales can become beached because of a navigational error.
Sometimes, the whales are fooled by a natural geographic trap, such as the one that exists at Welfleet, Mass., in Cape Cod, says Murison.
"They think they're going out to sea, and they actually end up in an ever [increasingly] shallow area," Wimmer said.
Sometimes, the animals just get caught up in feeding.
"A lot of the time, we get animals in Bay of Fundy who end up in rivers," Wimmer said. "A lot of that is, literally, they've followed their stomach and get caught on the really fast drop in tide."
Could humans be sometimes responsible?
Toothed whales also use a form of sonar for navigation, listening for the echo of their own, high-pitched voices to determine how far away they are from shore.
Their hearing and their navigational abilities can be damaged by explosions or other loud underwater noises. In fact, some beached whales show signs of damage in their ears, Murison said.
"Hearing is the most critical sense for whales," she added.
Dolphins and whales, including baleen whales, also rely on their voices and their hearing to communicate with one another.
Environmental groups have expressed concerns that noise pollution from commercial shipping, seismic surveys and sonar technology might be causing an increase in beachings.
A paper published in Nature in October 2003 noted mass strandings have taken place near naval exercises that included the use of military sonar.
The beached whales and dolphins showed symptoms of decompression sickness, or the bends, which affects divers who surface too quickly, the paper said. Researchers have suggested that human-generated underwater noise is causing the animals to dive and surface beyond healthy physical limits.
Some environmental groups, led by the Natural Resources Defense Council, have filed lawsuits against the U.S. navy in recent years in an effort to curb the use of mid-frequency sonar, alleging it disturbs and sometimes kills whales and dolphins.
In November 2008, the U.S. Supreme Court ruled in favour of the navy in one suit. A month later, the navy announced it had reached a deal with the council and other groups to continue research on how sonar affects whales and other marine mammals. However, the navy has not agreed to adopt any additional measures to protect animals when it uses sonar.
What should be done about beached whales and dolphins?
Groups such as MARS have protocols to deal with beached animals but only attempt a rescue if they appear to be healthy.
Wimmer said rescuers check the whale over and look for injuries before attempting a rescue.
"Do they look like they're a nice, fat healthy whale? Do they look like they're skin and bones?" she said.
Baby whales without their mothers aren't usually rescued, as they wouldn't survive on their own, Wimmer said.
If a rescue is attempted, smaller animals, such as dolphins, are placed on a stretcher and carried out to sea. For larger animals such as pilot whales, a tarp is put under the animal and attached to inflatable pontoons used to move the animals away from the shore.
How can whale beachings be prevented?
Reid said efforts have been made to prevent whale and dolphin injuries, which can be caused by getting entangled in fishing gear or collisions with ships. For example, shipping lanes in the Bay of Fundy between Nova Scotia and New Brunswick have been moved to minimize collisions with whales, and different fishing methods are being used to reduce the chance that whales and dolphins will be hurt.
Murison said Canada's Department of Fisheries and Oceans has some guidelines in place for activities that produce a lot of underwater noise, such as blasting, seismic surveys and naval activity. In particular, the department recommends conducting those activities when the tide is low, to reduce the propagation of the noise. If they must be done at high tide, those involved in the activity are asked to look out for whales in the area.
'Armed' chimps go wild for honey
By Rebecca Morelle
Science reporter, BBC News
Cameras have revealed how "armed" chimpanzees raid beehives to gorge on sweet honey.
Scientists in the Republic of Congo found that the wild primates crafted large clubs from branches to pound the nests until they broke open.
The team said some chimps would also use a "toolkit" of different wooden implements in a bid to access the honey and satisfy their sweet tooth.
The study is published in the International Journal of Primatology.
Crickette Sanz, from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, said: "The nutritional returns don't seem to be that great.
"But their excitement when they've succeeded is incredible, you can see how much they are enjoying tasting the honey."
Honey monsters
Chimps' love of honey and their ingenuity at accessing it are well known amongst primatologists - previous studies have revealed how the great apes can fashion sticks to dip into or prise open nests. The chimps will go up there and hang at all sorts of precarious angles to get to the honey
Crickette Sanz
But until now, nobody realised how prevalent the beehive-bashing behaviour was amongst chimpanzees in the Goualougo Triangle in the Congo Basin.
Dr Sanz said: "It seems these chimps in central Africa have developed more sophisticated techniques for getting at the honey than populations in eastern and western Africa - maybe it is some kind of regional feature."
Perhaps for obvious reasons, the chimps avoided bee species that sting, targeting the hives of stingless bees instead.
The chimps can spend hours trying to access the honey
Dr Sanz told the BBC: "But these nests are tough to get into - they can be at the top of the forest canopy, at the end of a branch - and the chimps will go up there and hang at all sorts of precarious angles to get to the honey, using these clubs in any way that they can to access it."
The video footage, which was filmed by the researchers over four years, revealed the chimps' sheer determination to get at the sweet stuff.
Dr Sanz explained: "Nobody knew they would pound over 1,000 times to get to the honey.
"Sometimes it could take several hours - they would start in the morning at around 1000, then take some rests, and then finish up at about 1400 or 1500 in the afternoon.
"It is quite physically challenging - in the videos you can see how large those pounding clubs are - some weigh over a kilogram."
Advertisement
Success at last - the researchers say the chimps have a real sweet tooth
The primatologists also found that the Congo chimps' tool use was more sophisticated than previously thought.
David Morgan, a co-author on the study from the Wildlife Conservation Society and Chicago's Lincoln Park Zoo, said: "One of the most exciting aspects is that they are using multiple tools to access the honey that is in these hives.
"They have a tool kit ready when they go for honey.
Chimps craft ultimate fishing rod
"They will have large pounding clubs and they'll use those to hammer the hives.
"And if that doesn't do, if the holes are too small, then they'll access them using smaller, thinner dipping wands. And they are also using smaller sticks for leverage to get better access to the hive."
The researchers also said that once the chimps had spotted and then crafted a suitable club from a branch, by pulling off unwanted twigs and leaves with their teeth or hands, they would set it aside for later use.
Dr Morgan said: "They cache them in the canopy."
Last week, the same team also reported how Goualougo Triangle chimps were crafting fishing rods with a brush-tipped end to fish for termites, and the scientists say there is still much to learn about tool use in these chimps.
However, they told the BBC that the chimps' future was uncertain, as the primates and their habitat were under threat.
Dr Morgan said: "These beehives are found in tree species that are exploited for logging, so this could be a direct affect we have on their behaviour, their feeding and their conservation."
By Rebecca Morelle
Science reporter, BBC News
Cameras have revealed how "armed" chimpanzees raid beehives to gorge on sweet honey.
Scientists in the Republic of Congo found that the wild primates crafted large clubs from branches to pound the nests until they broke open.
The team said some chimps would also use a "toolkit" of different wooden implements in a bid to access the honey and satisfy their sweet tooth.
The study is published in the International Journal of Primatology.
Crickette Sanz, from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, said: "The nutritional returns don't seem to be that great.
"But their excitement when they've succeeded is incredible, you can see how much they are enjoying tasting the honey."
Honey monsters
Chimps' love of honey and their ingenuity at accessing it are well known amongst primatologists - previous studies have revealed how the great apes can fashion sticks to dip into or prise open nests. The chimps will go up there and hang at all sorts of precarious angles to get to the honey
Crickette Sanz
But until now, nobody realised how prevalent the beehive-bashing behaviour was amongst chimpanzees in the Goualougo Triangle in the Congo Basin.
Dr Sanz said: "It seems these chimps in central Africa have developed more sophisticated techniques for getting at the honey than populations in eastern and western Africa - maybe it is some kind of regional feature."
Perhaps for obvious reasons, the chimps avoided bee species that sting, targeting the hives of stingless bees instead.
The chimps can spend hours trying to access the honey
Dr Sanz told the BBC: "But these nests are tough to get into - they can be at the top of the forest canopy, at the end of a branch - and the chimps will go up there and hang at all sorts of precarious angles to get to the honey, using these clubs in any way that they can to access it."
The video footage, which was filmed by the researchers over four years, revealed the chimps' sheer determination to get at the sweet stuff.
Dr Sanz explained: "Nobody knew they would pound over 1,000 times to get to the honey.
"Sometimes it could take several hours - they would start in the morning at around 1000, then take some rests, and then finish up at about 1400 or 1500 in the afternoon.
"It is quite physically challenging - in the videos you can see how large those pounding clubs are - some weigh over a kilogram."
Advertisement
Success at last - the researchers say the chimps have a real sweet tooth
The primatologists also found that the Congo chimps' tool use was more sophisticated than previously thought.
David Morgan, a co-author on the study from the Wildlife Conservation Society and Chicago's Lincoln Park Zoo, said: "One of the most exciting aspects is that they are using multiple tools to access the honey that is in these hives.
"They have a tool kit ready when they go for honey.
Chimps craft ultimate fishing rod
"They will have large pounding clubs and they'll use those to hammer the hives.
"And if that doesn't do, if the holes are too small, then they'll access them using smaller, thinner dipping wands. And they are also using smaller sticks for leverage to get better access to the hive."
The researchers also said that once the chimps had spotted and then crafted a suitable club from a branch, by pulling off unwanted twigs and leaves with their teeth or hands, they would set it aside for later use.
Dr Morgan said: "They cache them in the canopy."
Last week, the same team also reported how Goualougo Triangle chimps were crafting fishing rods with a brush-tipped end to fish for termites, and the scientists say there is still much to learn about tool use in these chimps.
However, they told the BBC that the chimps' future was uncertain, as the primates and their habitat were under threat.
Dr Morgan said: "These beehives are found in tree species that are exploited for logging, so this could be a direct affect we have on their behaviour, their feeding and their conservation."
Complex clues in a kiss
By James Morgan
Science reporter, BBC News, Chicago
When you share a kiss with your lover on Valentine's Day, you may be revealing a lot more than you realise.
Locking lips not only stimulates our senses, it also gives us subtle clues about our suitability as mates, US scientists have found.
A man's saliva has a "cocktail of chemicals" hinting at his fertility and evolutionary fitness, they said at a conference in Chicago.
That may be why the first kiss is often the last - "the kiss of death".
Primitive instinct
"Kissing is a powerful adaptive mechanism - otherwise we wouldn't see it all over the world. Over 90% of human societies practice kissing," said anthropologist Helen Fisher, of Rutgers University in New Jersey, at the annual conference of the American Association for the Advancement of Science (AAAS) in Chicago.
"Chimpanzees and bonobos kiss. Foxes lick each other's faces. Birds tap their bills together and elephants put their trunks in one another's mouths.
"So why do we do it? I think it is a tool for mate assessment. When you kiss, you can touch, see, feel, taste somebody. A huge part of our brain lights up.
"This is a real assessment tool - and can be highly positive or highly negative. In one study, 66% of women and 59% of men had experienced a first kiss which killed the relationship. It was the kiss of death."
Chemical bond
As well as acting as a "screening" mechanism for potential mates, Dr Fisher believes kissing evolved to stimulate what she has described as the three key brain systems for mating and reproduction.
The first of these is sex drive.
"Male saliva has testosterone in it. And men as a group seem to like wet kisses, with an open mouth and more tongue action.
"So it may be that, unconsciously, they are attempting to transfer testosterone - to trigger the sex drive in women and push them into being more sexually receptive."
Men also have a poor sense of smell, she said, so by open mouth kissing "they might be trying to pick up traces of a woman's oestrogen cycle, to figure out the degree of her fertility."
The second mechanism is romantic love.
"Kissing is novel, at least at the beginning of a relationship, and novelty stimulates dopamine - which is associated with romantic love," said Dr Fisher.
Finally, kissing promotes what she referred to as "attachment" or "pair bonding".
It helps us to stay together "at least long enough to have children," she said.
To study the chemistry which underlies kissing and pair bonding, neuroscientist Dr Wendy Hill, of Lafayette College, recruited a group of college students.
The young lovers - 15 couples in all - were then split into two groups. Some were asked to smooch for 15 minutes, to the soundtrack of relaxing music. The others sat holding hands and talking.
Romantic setting?
"Afterwards, we measured the changes in their levels of cortisol - a stress hormone - in their saliva.
"Levels had declined for everyone in the kissing group. And the longer the relationship, the lower the cortisol."
Dr Hill also took blood samples from the couples to measure levels of oxytocin - a messenger molecule associated with trust and sexual intimacy.
After 15 minutes of kissing, the males saw a significant increase in the "pair bonding" chemical.
But in the females, a decrease in oxytocin was observed.
"This was very surprising," Dr Hill admitted. "We are exploring the possibility that the setting - a college health centre - was just not very romantic.
"After all, this is a place where students go when they are ill. That may have had an effect on the females."
Dr Fisher is now running the study again "in a more romantic setting.
"We have a secluded room with a couch, flowers, candles, and a light jazz CD playing."
Interestingly, the females on birth control pills had significantly higher oxytocin levels, even before kissing began.
But with so few couples taking part in the study, which has yet to be published, it was not clear if there was any direct link between the two.
By James Morgan
Science reporter, BBC News, Chicago
When you share a kiss with your lover on Valentine's Day, you may be revealing a lot more than you realise.
Locking lips not only stimulates our senses, it also gives us subtle clues about our suitability as mates, US scientists have found.
A man's saliva has a "cocktail of chemicals" hinting at his fertility and evolutionary fitness, they said at a conference in Chicago.
That may be why the first kiss is often the last - "the kiss of death".
Primitive instinct
"Kissing is a powerful adaptive mechanism - otherwise we wouldn't see it all over the world. Over 90% of human societies practice kissing," said anthropologist Helen Fisher, of Rutgers University in New Jersey, at the annual conference of the American Association for the Advancement of Science (AAAS) in Chicago.
"Chimpanzees and bonobos kiss. Foxes lick each other's faces. Birds tap their bills together and elephants put their trunks in one another's mouths.
"So why do we do it? I think it is a tool for mate assessment. When you kiss, you can touch, see, feel, taste somebody. A huge part of our brain lights up.
"This is a real assessment tool - and can be highly positive or highly negative. In one study, 66% of women and 59% of men had experienced a first kiss which killed the relationship. It was the kiss of death."
Chemical bond
As well as acting as a "screening" mechanism for potential mates, Dr Fisher believes kissing evolved to stimulate what she has described as the three key brain systems for mating and reproduction.
The first of these is sex drive.
"Male saliva has testosterone in it. And men as a group seem to like wet kisses, with an open mouth and more tongue action.
"So it may be that, unconsciously, they are attempting to transfer testosterone - to trigger the sex drive in women and push them into being more sexually receptive."
Men also have a poor sense of smell, she said, so by open mouth kissing "they might be trying to pick up traces of a woman's oestrogen cycle, to figure out the degree of her fertility."
The second mechanism is romantic love.
"Kissing is novel, at least at the beginning of a relationship, and novelty stimulates dopamine - which is associated with romantic love," said Dr Fisher.
Finally, kissing promotes what she referred to as "attachment" or "pair bonding".
It helps us to stay together "at least long enough to have children," she said.
To study the chemistry which underlies kissing and pair bonding, neuroscientist Dr Wendy Hill, of Lafayette College, recruited a group of college students.
The young lovers - 15 couples in all - were then split into two groups. Some were asked to smooch for 15 minutes, to the soundtrack of relaxing music. The others sat holding hands and talking.
Romantic setting?
"Afterwards, we measured the changes in their levels of cortisol - a stress hormone - in their saliva.
"Levels had declined for everyone in the kissing group. And the longer the relationship, the lower the cortisol."
Dr Hill also took blood samples from the couples to measure levels of oxytocin - a messenger molecule associated with trust and sexual intimacy.
After 15 minutes of kissing, the males saw a significant increase in the "pair bonding" chemical.
But in the females, a decrease in oxytocin was observed.
"This was very surprising," Dr Hill admitted. "We are exploring the possibility that the setting - a college health centre - was just not very romantic.
"After all, this is a place where students go when they are ill. That may have had an effect on the females."
Dr Fisher is now running the study again "in a more romantic setting.
"We have a secluded room with a couch, flowers, candles, and a light jazz CD playing."
Interestingly, the females on birth control pills had significantly higher oxytocin levels, even before kissing began.
But with so few couples taking part in the study, which has yet to be published, it was not clear if there was any direct link between the two.
Children's sweet tooth explained
By Victoria Gill
Science reporter, BBC News
A compulsion for sweets is a well-known part of childhood, and research could have now explained why children love sugar quite so much.
The study, carried out in the US, found a direct link between children's growth and their preference for sugary drinks.
It showed that youngsters who preferred the sweetest drinks were the ones that were growing the fastest.
Researchers from the University of Washington and Monell Chemical Senses Center collaborated on the work.
The team used what they described as a "sip and spit" method to test the children's preference for sugary drinks.
''Kids love sweets; they'll put sugar on frosted flakes. But that love seems to decline with age," said Susan Coldwell from the University of Washington, who led the study.
"We wanted to see what was going on as that shift happens - at around the age of 16."
More than 140 11-15 year-olds took part in the test. They were given six drinks to taste, each containing an increasing concentration of sugar.
The researchers asked the children to rate, on a scale of one to five, how much they liked the taste of each drink.
"Based on those taste tests, we divided the kids into a 'high preference' and a 'low preference' group," Professor Coldwell explained.
The scientists then tested urine samples from the children for a chemical associated with bone growth in children and adolescents.
"We tested for a [breakdown product] of bone," said professor Coldwell.
"It's found in the urine either when bones are growing or in older people with osteoporosis, when their bones are being destroyed."
Children with a high preference for sugar also had higher levels of this chemical.
"This gives us the first link between sweet preference and biological need," said Danielle Reed, a researcher from Monell, and one of the study's authors.
"When markers of bone growth decline as children age, so does their preference for highly sweet solutions."
By Victoria Gill
Science reporter, BBC News
A compulsion for sweets is a well-known part of childhood, and research could have now explained why children love sugar quite so much.
The study, carried out in the US, found a direct link between children's growth and their preference for sugary drinks.
It showed that youngsters who preferred the sweetest drinks were the ones that were growing the fastest.
Researchers from the University of Washington and Monell Chemical Senses Center collaborated on the work.
The team used what they described as a "sip and spit" method to test the children's preference for sugary drinks.
''Kids love sweets; they'll put sugar on frosted flakes. But that love seems to decline with age," said Susan Coldwell from the University of Washington, who led the study.
"We wanted to see what was going on as that shift happens - at around the age of 16."
More than 140 11-15 year-olds took part in the test. They were given six drinks to taste, each containing an increasing concentration of sugar.
The researchers asked the children to rate, on a scale of one to five, how much they liked the taste of each drink.
"Based on those taste tests, we divided the kids into a 'high preference' and a 'low preference' group," Professor Coldwell explained.
The scientists then tested urine samples from the children for a chemical associated with bone growth in children and adolescents.
"We tested for a [breakdown product] of bone," said professor Coldwell.
"It's found in the urine either when bones are growing or in older people with osteoporosis, when their bones are being destroyed."
Children with a high preference for sugar also had higher levels of this chemical.
"This gives us the first link between sweet preference and biological need," said Danielle Reed, a researcher from Monell, and one of the study's authors.
"When markers of bone growth decline as children age, so does their preference for highly sweet solutions."
Friday, March 20, 2009
Blobs in Photos of Mars Lander Stir a Debate: Are They Water?
By KENNETH CHANG
Published: March 16, 2009
Several photographs taken by NASA’s Phoenix Mars spacecraft show what look like water droplets clinging to one of its landing struts.
Some of the scientists working on the mission are asserting that that is exactly what they were. They contend that there are pockets of liquid water just under the Martian surface even though the temperatures in the northern plains never warmed above minus 15 degrees Fahrenheit during the six months of Phoenix’s operations last year.
The scientists believe that salts may have lowered the freezing temperature of the Martian water droplets to perhaps minus 90 degrees, or more than 120 degrees colder than the usual freezing temperature of 32 degrees for pure water.
Nilton O. Renno, a professor of atmospheric, oceanic and space sciences at the University of Michigan who proposed the hypothesis, was careful to say, “This is not a proof.”
But he added: “I think the evidence is overwhelming. It’s not circumstantial evidence.”
Dr. Renno will present his data and arguments this month in a talk at the Lunar and Planetary Science Conference in The Woodlands, Texas, and he is the lead author among 22 authors of a scientific paper submitted to The Journal of Geophysical Research.
Others are completely unconvinced. “There are simpler explanations,” said Michael H. Hecht, a scientist at NASA’s Jet Propulsion Laboratory and a co-investigator of the Phoenix’s wet chemistry instrument. Dr. Hecht, who described himself as the “designated curmudgeon,” said he believed that the process proposed by Dr. Renno to describe the formation and movement of water droplets was “flat-out wrong for these materials.”
Peter H. Smith, the mission’s principal investigator, is left to mediate the disagreement. He wonders whether the material, splashed up and possibly transformed by the heat and spray of chemicals from the thrusters when Phoenix landed, tells much or anything at all about the conditions on Mars.
Because of the lack of consensus, the Phoenix science team never brought up the liquid droplet hypothesis during any of the NASA news conferences.
The core facts are not in dispute. There were blobs on the strut. The blobs changed and moved over time before disappearing later in the mission.
The scientists also agree that the fundamental physics of Dr. Renno’s hypothesis is sound. And it dovetails with the major undisputed finding of the Phoenix mission: the unexpected discovery of chemicals known as perchlorates in the soil.
Perchlorates are salts, and if they were dissolved in high enough concentrations in water, the resulting brine would be a liquid at Martian surface temperatures.
Dr. Renno believes that Phoenix’s thrusters splashed a pocket of brine from just below the surface to the landing strut. He said the salts would have absorbed water vapor from the air, explaining how they appeared to grow in size during the first 44 Martian days before slowly evaporating as the temperatures dropped.
But Dr. Hecht believes that the droplet shape was in part a trick of low-resolution images and lighting. His simpler explanation is that these were just small clumps of frost.
The central scientific disagreement is whether the landing strut was warmer or colder than the ground. Exposed ice seen below the lander was clearly disappearing over time, vanishing into water vapor. Dr. Renno maintains that because of the heating systems on the spacecraft, the landing struts were warmer than the ground, and it is thermodynamically impossible for simple water frost to move from the cold ground to the warmer leg. But perchlorate salt could act as a sponge to absorb water vapor.
Dr. Hecht said that the strut was in the shadow of the lander and that the ground was in sunshine, so the leg was colder.
The Phoenix Mars lander, as expected, froze to death in November with the oncoming winter. But Dr. Renno and collaborators in Spain have been conducting experiments to see if they can replicate the behavior on Earth.
“The initial results,” Dr. Renno said, “are consistent with what we see as liquid water.”
By KENNETH CHANG
Published: March 16, 2009
Several photographs taken by NASA’s Phoenix Mars spacecraft show what look like water droplets clinging to one of its landing struts.
Some of the scientists working on the mission are asserting that that is exactly what they were. They contend that there are pockets of liquid water just under the Martian surface even though the temperatures in the northern plains never warmed above minus 15 degrees Fahrenheit during the six months of Phoenix’s operations last year.
The scientists believe that salts may have lowered the freezing temperature of the Martian water droplets to perhaps minus 90 degrees, or more than 120 degrees colder than the usual freezing temperature of 32 degrees for pure water.
Nilton O. Renno, a professor of atmospheric, oceanic and space sciences at the University of Michigan who proposed the hypothesis, was careful to say, “This is not a proof.”
But he added: “I think the evidence is overwhelming. It’s not circumstantial evidence.”
Dr. Renno will present his data and arguments this month in a talk at the Lunar and Planetary Science Conference in The Woodlands, Texas, and he is the lead author among 22 authors of a scientific paper submitted to The Journal of Geophysical Research.
Others are completely unconvinced. “There are simpler explanations,” said Michael H. Hecht, a scientist at NASA’s Jet Propulsion Laboratory and a co-investigator of the Phoenix’s wet chemistry instrument. Dr. Hecht, who described himself as the “designated curmudgeon,” said he believed that the process proposed by Dr. Renno to describe the formation and movement of water droplets was “flat-out wrong for these materials.”
Peter H. Smith, the mission’s principal investigator, is left to mediate the disagreement. He wonders whether the material, splashed up and possibly transformed by the heat and spray of chemicals from the thrusters when Phoenix landed, tells much or anything at all about the conditions on Mars.
Because of the lack of consensus, the Phoenix science team never brought up the liquid droplet hypothesis during any of the NASA news conferences.
The core facts are not in dispute. There were blobs on the strut. The blobs changed and moved over time before disappearing later in the mission.
The scientists also agree that the fundamental physics of Dr. Renno’s hypothesis is sound. And it dovetails with the major undisputed finding of the Phoenix mission: the unexpected discovery of chemicals known as perchlorates in the soil.
Perchlorates are salts, and if they were dissolved in high enough concentrations in water, the resulting brine would be a liquid at Martian surface temperatures.
Dr. Renno believes that Phoenix’s thrusters splashed a pocket of brine from just below the surface to the landing strut. He said the salts would have absorbed water vapor from the air, explaining how they appeared to grow in size during the first 44 Martian days before slowly evaporating as the temperatures dropped.
But Dr. Hecht believes that the droplet shape was in part a trick of low-resolution images and lighting. His simpler explanation is that these were just small clumps of frost.
The central scientific disagreement is whether the landing strut was warmer or colder than the ground. Exposed ice seen below the lander was clearly disappearing over time, vanishing into water vapor. Dr. Renno maintains that because of the heating systems on the spacecraft, the landing struts were warmer than the ground, and it is thermodynamically impossible for simple water frost to move from the cold ground to the warmer leg. But perchlorate salt could act as a sponge to absorb water vapor.
Dr. Hecht said that the strut was in the shadow of the lander and that the ground was in sunshine, so the leg was colder.
The Phoenix Mars lander, as expected, froze to death in November with the oncoming winter. But Dr. Renno and collaborators in Spain have been conducting experiments to see if they can replicate the behavior on Earth.
“The initial results,” Dr. Renno said, “are consistent with what we see as liquid water.”
Nations Near Arctic Declare Polar Bears Threatened by Climate Change
Paul J. Richards/Agence France-Presse — Getty Images
By ANDREW C. REVKIN
Published: March 19, 2009 NY Times
Five countries that created a treaty nearly four decades ago to protect polar bears through limits on hunting issued a joint statement on Thursday identifying climate change as “the most important long-term threat” to the bears.
The statement came at the end of a three-day meeting in Tromso, Norway, of scientists and officials from the United States, Norway, Canada, Russia and Denmark, all with territory abutting the Arctic Ocean that serves as habitat for the bears. (Denmark was represented through Greenland, which is moving toward becoming an independent country.)
Bear experts at the meeting said the treaty parties were committed to collaborating on programs aimed at limiting direct threats to bear populations from increasing tourism, shipping and oil and gas drilling in the warming region.
But they said the countries bound by the 1973 bear agreement would be unable, without worldwide cooperation, to address the looming risk to the species: the prospect that global warming from emissions of greenhouse gases would continue to erode the sheath of Arctic sea ice that the half-ton bears roam in pursuit of seals.
In a telephone interview from Tromso, Rosa Meehan, the division chief in Alaska for marine mammals management of the United States Fish and Wildlife Service, said that the agreement — among countries with a range of environmental views — signaled the strength of the science pointing to perils for the bears.
“Polar bears are facing a pretty rough road,” Dr. Meehan said. “The thing we need to do is look to the global community to seriously address and mitigate climate change.” The Norwegian government posted background on the meeting on the Internet at polarbearmeeting.org.
The species has probably existed across the Arctic for several hundred thousand years, researchers say. The animals are resilient, eating walrus, grasses and even snow goose eggs when they cannot hunt their preferred prey, bearded and ringed seals.
The bears were greatly depleted by unregulated hunting across much of the Arctic until the Soviet Union clamped down in 1956 and other countries followed, with the 1973 treaty one result. The current population across the Arctic has been estimated at 22,000 to 25,000 bears.
But last year the United States Interior Department granted the bears threatened status under the Endangered Species Act, citing the threat from retreating summertime sea ice. Other countries have been ratcheting up protections, although about 700 bears a year are still shot in Canada, Alaska and Greenland, according to Norway’s environment agency.
Not everyone from countries ringing the Arctic agrees that the bears need to be singled out for protection in the face of climate change. Fernando Ugarte, head of mammal and bird science at the Greenland Institute of Natural Resources, said the government was concerned that the rising pressure to protect bears, particularly in the face of global warming, might prompt other countries to press Greenland to clamp down on hunting.
“I am not sure there is a scientific reason to appoint polar bears as the main icon of climate change,” he said by telephone in Nuuk, Greenland’s capital. “There’s a long list of animals that will be affected. Why not the walrus, the narwhal, the ringed seal?” Mr. Ugarte said that scientists disagreed over why people around Baffin Bay and elsewhere had reported an increase in polar bear sightings in recent years. One explanation may be that the local bear population is robust. Another — more likely in Mr. Ugarte’s opinion — is that climate change is forcing the bears into new migration patterns.
The Tromso meeting was watched closely by environmental groups, which had warned that some countries might press to exclude strong language about global warming. The bears have been enduring icons in climate campaigns conducted by such groups, with at least three groups seeking contributions through “adopt a polar bear” programs.
But the animals have also become a focal point for some elected officials and scientists who reject the need for cuts in the heat-trapping greenhouse gases, despite broad scientific consensus linking the gases to warming since 1950. Their argument, pointing to studies by American government scientists and other groups, is that hunting restrictions have caused most of the populations of bears around the Arctic to grow in recent decades and that long-term forecasts of ice retreats are flawed.
Walter Gibbs contributed reporting from Oslo.
Paul J. Richards/Agence France-Presse — Getty Images
By ANDREW C. REVKIN
Published: March 19, 2009 NY Times
Five countries that created a treaty nearly four decades ago to protect polar bears through limits on hunting issued a joint statement on Thursday identifying climate change as “the most important long-term threat” to the bears.
The statement came at the end of a three-day meeting in Tromso, Norway, of scientists and officials from the United States, Norway, Canada, Russia and Denmark, all with territory abutting the Arctic Ocean that serves as habitat for the bears. (Denmark was represented through Greenland, which is moving toward becoming an independent country.)
Bear experts at the meeting said the treaty parties were committed to collaborating on programs aimed at limiting direct threats to bear populations from increasing tourism, shipping and oil and gas drilling in the warming region.
But they said the countries bound by the 1973 bear agreement would be unable, without worldwide cooperation, to address the looming risk to the species: the prospect that global warming from emissions of greenhouse gases would continue to erode the sheath of Arctic sea ice that the half-ton bears roam in pursuit of seals.
In a telephone interview from Tromso, Rosa Meehan, the division chief in Alaska for marine mammals management of the United States Fish and Wildlife Service, said that the agreement — among countries with a range of environmental views — signaled the strength of the science pointing to perils for the bears.
“Polar bears are facing a pretty rough road,” Dr. Meehan said. “The thing we need to do is look to the global community to seriously address and mitigate climate change.” The Norwegian government posted background on the meeting on the Internet at polarbearmeeting.org.
The species has probably existed across the Arctic for several hundred thousand years, researchers say. The animals are resilient, eating walrus, grasses and even snow goose eggs when they cannot hunt their preferred prey, bearded and ringed seals.
The bears were greatly depleted by unregulated hunting across much of the Arctic until the Soviet Union clamped down in 1956 and other countries followed, with the 1973 treaty one result. The current population across the Arctic has been estimated at 22,000 to 25,000 bears.
But last year the United States Interior Department granted the bears threatened status under the Endangered Species Act, citing the threat from retreating summertime sea ice. Other countries have been ratcheting up protections, although about 700 bears a year are still shot in Canada, Alaska and Greenland, according to Norway’s environment agency.
Not everyone from countries ringing the Arctic agrees that the bears need to be singled out for protection in the face of climate change. Fernando Ugarte, head of mammal and bird science at the Greenland Institute of Natural Resources, said the government was concerned that the rising pressure to protect bears, particularly in the face of global warming, might prompt other countries to press Greenland to clamp down on hunting.
“I am not sure there is a scientific reason to appoint polar bears as the main icon of climate change,” he said by telephone in Nuuk, Greenland’s capital. “There’s a long list of animals that will be affected. Why not the walrus, the narwhal, the ringed seal?” Mr. Ugarte said that scientists disagreed over why people around Baffin Bay and elsewhere had reported an increase in polar bear sightings in recent years. One explanation may be that the local bear population is robust. Another — more likely in Mr. Ugarte’s opinion — is that climate change is forcing the bears into new migration patterns.
The Tromso meeting was watched closely by environmental groups, which had warned that some countries might press to exclude strong language about global warming. The bears have been enduring icons in climate campaigns conducted by such groups, with at least three groups seeking contributions through “adopt a polar bear” programs.
But the animals have also become a focal point for some elected officials and scientists who reject the need for cuts in the heat-trapping greenhouse gases, despite broad scientific consensus linking the gases to warming since 1950. Their argument, pointing to studies by American government scientists and other groups, is that hunting restrictions have caused most of the populations of bears around the Arctic to grow in recent decades and that long-term forecasts of ice retreats are flawed.
Walter Gibbs contributed reporting from Oslo.
THE CANADIAN LANDSCAPE: MOUNT LOGAN
The Kluane National Park Reserve in the Yukon is home to the highest mountain in the country, Mount Logan. Part of the Mt. St. Elias range, Mount Logan, rising to 5959 metres, is also the second largest mountain in North America and is one of the largest massifs in the world.
In 1890, I.C. Russell of the U.S. Geographical Survey, while studying the Mt. St. Elias Mountains, named the mountain after Sir William Edmond Logan (1798-1875). Logan founded the Geological Survey of Canada in 1842. William Logan was born in Montreal and educated in Scotland, and over the course of his career, he was extremely interested in studying the geological nature of Canada. In 1992, the Geographical Survey of Canada organized an expedition to finally determine the height of Mount Logan. Using the Global Positioning System (GPS), a team of twelve members of the society, resolved the debate about Mount Logan's elevation.
Located west of Whitehorse and less than 100 kilometres from the coast, Mount Logan is subject to extreme weather conditions, meaning its climate is comparable to both the Antarctic and the Himalayas. The mountain is covered mainly by snow and ice, some of which may be thousands of years old, especially where it is in contact with the rock between 200-300 metres below the surface. The cover of ice and snow upon the mountain is permanent, and probably developed on the upper mountain several million years ago.
There are numerous rock outcrops that occur close to its many subsidiary peaks, and the mountain is composed largely of granodiorite, a course-grained plutonic rock containing quartz and plagioclase. The Mt. St. Elias range of mountains is still tectonically active, meaning the mountain is still growing!
Numerous teams from around the world travel to the Yukon to undertake the treacherous climb to Mount Logan's peak. To walk into or from the mountain, one would travel, by foot or skis, over one hundred kilometres of glaciers, taking upwards of two weeks. Therefore, most parties fly into the Icefields from Haines Junction and start their climb from there. The mountain was successfully conquered in 1925 by a team led by Albert A. MacCarthy. MacCarthy was an American mountaineer who spent sixty-five days traveling through the wilderness of both Alaska and the Yukon before reaching the top of the mountain on June 23.
In October 2000, Prime Minister Jean Chrétien announced his recommendation to change the name of Mount Logan to Mount Trudeau, after the late Pierre Elliott Trudeau.
Significant Events
Mount Logan was first surveyed as a result of a National Geographic Society Grant in 1890. In 1938, the Harvard University Alaskan expedition led by Bradford Washburn discovered one of the largest icefields and glacial groups outside of the polar regions by using aerial photography of Mount Logan and its surrounding areas.
The Kluane National Park Reserve in the Yukon is home to the highest mountain in the country, Mount Logan. Part of the Mt. St. Elias range, Mount Logan, rising to 5959 metres, is also the second largest mountain in North America and is one of the largest massifs in the world.
In 1890, I.C. Russell of the U.S. Geographical Survey, while studying the Mt. St. Elias Mountains, named the mountain after Sir William Edmond Logan (1798-1875). Logan founded the Geological Survey of Canada in 1842. William Logan was born in Montreal and educated in Scotland, and over the course of his career, he was extremely interested in studying the geological nature of Canada. In 1992, the Geographical Survey of Canada organized an expedition to finally determine the height of Mount Logan. Using the Global Positioning System (GPS), a team of twelve members of the society, resolved the debate about Mount Logan's elevation.
Located west of Whitehorse and less than 100 kilometres from the coast, Mount Logan is subject to extreme weather conditions, meaning its climate is comparable to both the Antarctic and the Himalayas. The mountain is covered mainly by snow and ice, some of which may be thousands of years old, especially where it is in contact with the rock between 200-300 metres below the surface. The cover of ice and snow upon the mountain is permanent, and probably developed on the upper mountain several million years ago.
There are numerous rock outcrops that occur close to its many subsidiary peaks, and the mountain is composed largely of granodiorite, a course-grained plutonic rock containing quartz and plagioclase. The Mt. St. Elias range of mountains is still tectonically active, meaning the mountain is still growing!
Numerous teams from around the world travel to the Yukon to undertake the treacherous climb to Mount Logan's peak. To walk into or from the mountain, one would travel, by foot or skis, over one hundred kilometres of glaciers, taking upwards of two weeks. Therefore, most parties fly into the Icefields from Haines Junction and start their climb from there. The mountain was successfully conquered in 1925 by a team led by Albert A. MacCarthy. MacCarthy was an American mountaineer who spent sixty-five days traveling through the wilderness of both Alaska and the Yukon before reaching the top of the mountain on June 23.
In October 2000, Prime Minister Jean Chrétien announced his recommendation to change the name of Mount Logan to Mount Trudeau, after the late Pierre Elliott Trudeau.
Significant Events
Mount Logan was first surveyed as a result of a National Geographic Society Grant in 1890. In 1938, the Harvard University Alaskan expedition led by Bradford Washburn discovered one of the largest icefields and glacial groups outside of the polar regions by using aerial photography of Mount Logan and its surrounding areas.
The Walrus
National Geographic Canada
The Arctic Ocean habitat of the Atlantic walrus ranges from the eastern Canadian Artic all the way to Greenland. This magnificent mammal, whose entire population is classified in one species, Odobenus rosmarus, was relentlessly hunted in previous centuries. European whaling ships slaughtered the walruses, sold their tusks for ivory and used their blubber for oil. As a result, the Atlantic population is still dangerously low. Today, the animals number between 10,000 and 50,000. While the levels are not low enough to warrant an IUCN (The World Conservation Union) listing, hunting the animals for sport or sale is prohibited except for Inuit families, who are allowed to legally kill four walruses per year for subsistence.
The walrus, awkward on land, is surprisingly fluid in the water. The average walrus swims at a rate of seven kilometres per hour but it can reach speeds upwards of 30 kilometres per hour. Preferring to inhabit shallow water regions (40 metres or less) near the coasts of the Artic Ocean, walruses live mainly on ice floes, but the males (bulls), in the summer season, may use inlets or isolated beaches. The females (cows) and the young stay on the ice floes all year round.
Their large tusks, called canines, can grow up to an average of 50 centimeters in length. Stiff beard bristles, or vibrissae, grow like moustaches over their tusks. A walrus uses its tusk for a variety of reasons: cutting through ice, hooking ice for stability while sleeping, helping to pull the body from the water, tearing apart prey for food, and, for males, battling for territories.
Walruses eat animals that live at the bottom of the ocean. On any one day, a walrus could eat mussels, snails, crabs, clams and shellfish. Their huge appetites are sometimes satisfied by eating fish, seals and young whales. A full-grown adult male can weigh up to 1700 kilograms; females are slightly smaller. They have tough, thick skin that becomes flushed when the animal lies in the sun, giving them the appearance of being sunburned.
Humans, polar bears and killer whales are the walrus' natural enemies. They tend to reside in herds on the ice floes, sitting in the company of thousands of other walruses, to protect themselves from their predators. These large congregations are organized according to tusk and body size and, in the non-breeding season, are segregated by the sexes where the young will obviously stay with the cows.
National Geographic Canada
The Arctic Ocean habitat of the Atlantic walrus ranges from the eastern Canadian Artic all the way to Greenland. This magnificent mammal, whose entire population is classified in one species, Odobenus rosmarus, was relentlessly hunted in previous centuries. European whaling ships slaughtered the walruses, sold their tusks for ivory and used their blubber for oil. As a result, the Atlantic population is still dangerously low. Today, the animals number between 10,000 and 50,000. While the levels are not low enough to warrant an IUCN (The World Conservation Union) listing, hunting the animals for sport or sale is prohibited except for Inuit families, who are allowed to legally kill four walruses per year for subsistence.
The walrus, awkward on land, is surprisingly fluid in the water. The average walrus swims at a rate of seven kilometres per hour but it can reach speeds upwards of 30 kilometres per hour. Preferring to inhabit shallow water regions (40 metres or less) near the coasts of the Artic Ocean, walruses live mainly on ice floes, but the males (bulls), in the summer season, may use inlets or isolated beaches. The females (cows) and the young stay on the ice floes all year round.
Their large tusks, called canines, can grow up to an average of 50 centimeters in length. Stiff beard bristles, or vibrissae, grow like moustaches over their tusks. A walrus uses its tusk for a variety of reasons: cutting through ice, hooking ice for stability while sleeping, helping to pull the body from the water, tearing apart prey for food, and, for males, battling for territories.
Walruses eat animals that live at the bottom of the ocean. On any one day, a walrus could eat mussels, snails, crabs, clams and shellfish. Their huge appetites are sometimes satisfied by eating fish, seals and young whales. A full-grown adult male can weigh up to 1700 kilograms; females are slightly smaller. They have tough, thick skin that becomes flushed when the animal lies in the sun, giving them the appearance of being sunburned.
Humans, polar bears and killer whales are the walrus' natural enemies. They tend to reside in herds on the ice floes, sitting in the company of thousands of other walruses, to protect themselves from their predators. These large congregations are organized according to tusk and body size and, in the non-breeding season, are segregated by the sexes where the young will obviously stay with the cows.
British-built robotic fish to detect pollution
From: http://www.montrealgazette.com/technology/personal-tech/British+built+robotic+fish+detect+pollution/1405840/story.html
LONDON - A shoal of robotic fish which can detect pollution in the water are set to released into the sea off Spain, British scientists said Thursday.
The fish, which are some 1.5 metres long and resemble carp, will be fitted with detectors which can identify the sources of pollution, such as ship fuel or chemicals in the water.
Five of the robots, worth some 20,000 pounds ($29,000 US) each, are being released into the Bay of Biscay at Gijon in northern Spain as part of a three-year joint project between engineering consultancy BMT Group and researchers at Essex University in southeast England.
The robots, which have an eight-hour battery and do not require remote control, are set to be released in around 18 months' time.
"The hope is that this will prevent potentially hazardous discharges at sea as the leak would undoubtedly get worse over time if not located," said Professor Huosheng Hu of Essex University, whose team is building the fish.
If successful, they hope the fish could be used around the world to prevent the spread of pollution.
© Copyright (c) Canwest News Service
From: http://www.montrealgazette.com/technology/personal-tech/British+built+robotic+fish+detect+pollution/1405840/story.html
LONDON - A shoal of robotic fish which can detect pollution in the water are set to released into the sea off Spain, British scientists said Thursday.
The fish, which are some 1.5 metres long and resemble carp, will be fitted with detectors which can identify the sources of pollution, such as ship fuel or chemicals in the water.
Five of the robots, worth some 20,000 pounds ($29,000 US) each, are being released into the Bay of Biscay at Gijon in northern Spain as part of a three-year joint project between engineering consultancy BMT Group and researchers at Essex University in southeast England.
The robots, which have an eight-hour battery and do not require remote control, are set to be released in around 18 months' time.
"The hope is that this will prevent potentially hazardous discharges at sea as the leak would undoubtedly get worse over time if not located," said Professor Huosheng Hu of Essex University, whose team is building the fish.
If successful, they hope the fish could be used around the world to prevent the spread of pollution.
© Copyright (c) Canwest News Service
Ecotourism
from http://www.learnenglish.org.uk/magazine/ecotourism.html
Imagine the scene. You're sitting in the hot sunshine beside the swimming pool of your international luxury hotel, drinking your imported gin and tonic. In front of you is the beach, reserved for hotel guests with motor boats for hire. Behind you is an 18-hole golf course, which was cleared from the native forest and is kept green by hundreds of water sprinklers. Around the hotel are familiar international restaurant chains and the same shops that you have at home. You've seen some local people - some of them sell local handicrafts outside the hotel. You bought a small wooden statue and after arguing for half an hour you only paid a quarter of what the man was asking. Really cheap!
Is this your idea of heaven or would you prefer something different?
Before you read on, try the vocabulary activity, which practises words and phrases that are important for you to understand the text.
Nowadays, many of us try to live in a way that will damage the environment as little as possible. We recycle our newspapers and bottles, we take public transport to get to work, we try to buy locally produced fruit and vegetables and we stopped using aerosol sprays years ago. And we want to take these attitudes on holiday with us. This is why alternative forms of tourism are becoming more popular all over the world.
But what is ecotourism?
There are lots of names for these new forms of tourism: responsible tourism, alternative tourism, sustainable tourism, nature tourism, adventure tourism, educational tourism and more. Ecotourism probably involves a little of all of them. Everyone has a different definition but most people agree that ecotourism must:
1 conserve the wildlife and culture of the area.
2 benefit the local people and involve the local community
3 be sustainable, that is make a profit without destroying natural resources
4 provide an experience that tourists want to pay for.
So for example, in a true ecotourism project, a nature reserve allows a small number of tourists to visit its rare animals and uses the money that is generated to continue with important conservation work. The local people have jobs in the nature reserve as guides and wardens, but also have a voice in how the project develops. Tourists stay in local houses with local people, not in specially built hotels. So they experience the local culture and do not take precious energy and water away from the local population. They travel on foot, by boat, bicycle or elephant so that there is no pollution. And they have a special experience that they will remember all of their lives.
This type of tourism can only involve small numbers of people so it can be expensive. But you can apply the principles of ecotourism wherever you go for your holiday. Just remember these basic rules.
Be prepared. Learn about the place that you're going to visit. Find out about its culture and history. Learn a little of the native language, at least basics like 'Please', 'Thank you', and 'Good Morning'. Think of your holiday as an opportunity to learn something.
Have respect for local culture. Wear clothes that will not offend people. Always ask permission before you take a photograph. Remember that you are a visitor.
Don't waste resources. If the area doesn't have much water, don't take two showers every day.
Remember the phrase "Leave nothing behind you except footprints and take nothing away except photographs." Take as much care of the places that you visit as you take of your own home. · Don't buy souvenirs made from endangered animals or plants.
Walk or use other non-polluting forms of transport whenever you can.
Be flexible and keep a sense of humour when things go wrong.
Stay in local hotels and eat in local restaurants. Buy local products whenever possible and pay a fair price for what you buy.
Choose your holiday carefully. Don't be afraid to ask the holiday company about what they do that is 'eco'. Remember that 'eco' is very fashionable today and a lot of holidays that are advertised as ecotourism are not much better than traditional tourism.
But before you get too enthusiastic, think about how you are going to get to your dream 'eco' paradise. Flying is one of the biggest man-made sources of carbon dioxide in the atmosphere. Friends of the Earth say that one return flight from London to Miami puts as much carbon dioxide into the atmosphere as the average British car driver produces in a year. So don't forget that you don't have to fly to exotic locations for your 'eco' holiday. There are probably places of natural beauty and interest in your own country that you've never visited.
These websites have lists of companies that offer 'eco' holidays:
Gonomad.com
Planeta.com
International Ecotourism Society
Read an article from The Guardian that gives the negative side of the ecotourism industry.
from http://www.learnenglish.org.uk/magazine/ecotourism.html
Imagine the scene. You're sitting in the hot sunshine beside the swimming pool of your international luxury hotel, drinking your imported gin and tonic. In front of you is the beach, reserved for hotel guests with motor boats for hire. Behind you is an 18-hole golf course, which was cleared from the native forest and is kept green by hundreds of water sprinklers. Around the hotel are familiar international restaurant chains and the same shops that you have at home. You've seen some local people - some of them sell local handicrafts outside the hotel. You bought a small wooden statue and after arguing for half an hour you only paid a quarter of what the man was asking. Really cheap!
Is this your idea of heaven or would you prefer something different?
Before you read on, try the vocabulary activity, which practises words and phrases that are important for you to understand the text.
Nowadays, many of us try to live in a way that will damage the environment as little as possible. We recycle our newspapers and bottles, we take public transport to get to work, we try to buy locally produced fruit and vegetables and we stopped using aerosol sprays years ago. And we want to take these attitudes on holiday with us. This is why alternative forms of tourism are becoming more popular all over the world.
But what is ecotourism?
There are lots of names for these new forms of tourism: responsible tourism, alternative tourism, sustainable tourism, nature tourism, adventure tourism, educational tourism and more. Ecotourism probably involves a little of all of them. Everyone has a different definition but most people agree that ecotourism must:
1 conserve the wildlife and culture of the area.
2 benefit the local people and involve the local community
3 be sustainable, that is make a profit without destroying natural resources
4 provide an experience that tourists want to pay for.
So for example, in a true ecotourism project, a nature reserve allows a small number of tourists to visit its rare animals and uses the money that is generated to continue with important conservation work. The local people have jobs in the nature reserve as guides and wardens, but also have a voice in how the project develops. Tourists stay in local houses with local people, not in specially built hotels. So they experience the local culture and do not take precious energy and water away from the local population. They travel on foot, by boat, bicycle or elephant so that there is no pollution. And they have a special experience that they will remember all of their lives.
This type of tourism can only involve small numbers of people so it can be expensive. But you can apply the principles of ecotourism wherever you go for your holiday. Just remember these basic rules.
Be prepared. Learn about the place that you're going to visit. Find out about its culture and history. Learn a little of the native language, at least basics like 'Please', 'Thank you', and 'Good Morning'. Think of your holiday as an opportunity to learn something.
Have respect for local culture. Wear clothes that will not offend people. Always ask permission before you take a photograph. Remember that you are a visitor.
Don't waste resources. If the area doesn't have much water, don't take two showers every day.
Remember the phrase "Leave nothing behind you except footprints and take nothing away except photographs." Take as much care of the places that you visit as you take of your own home. · Don't buy souvenirs made from endangered animals or plants.
Walk or use other non-polluting forms of transport whenever you can.
Be flexible and keep a sense of humour when things go wrong.
Stay in local hotels and eat in local restaurants. Buy local products whenever possible and pay a fair price for what you buy.
Choose your holiday carefully. Don't be afraid to ask the holiday company about what they do that is 'eco'. Remember that 'eco' is very fashionable today and a lot of holidays that are advertised as ecotourism are not much better than traditional tourism.
But before you get too enthusiastic, think about how you are going to get to your dream 'eco' paradise. Flying is one of the biggest man-made sources of carbon dioxide in the atmosphere. Friends of the Earth say that one return flight from London to Miami puts as much carbon dioxide into the atmosphere as the average British car driver produces in a year. So don't forget that you don't have to fly to exotic locations for your 'eco' holiday. There are probably places of natural beauty and interest in your own country that you've never visited.
These websites have lists of companies that offer 'eco' holidays:
Gonomad.com
Planeta.com
International Ecotourism Society
Read an article from The Guardian that gives the negative side of the ecotourism industry.
Pink elephant is caught on camera
By Rebecca Morelle
Science reporter, BBC News
A pink baby elephant has been caught on camera in Botswana.
A wildlife cameraman took pictures of the calf when he spotted it among a herd of about 80 elephants in the Okavango Delta.
Experts believe it is probably an albino, which is an extremely rare phenomenon in African elephants.
They are unsure of its chances of long-term survival - the blazing African sunlight may cause blindness and skin problems for the calf.
Mike Holding, who spotted the baby while filming for a BBC wildlife programme, said: "We only saw it for a couple of minutes as the herd crossed the river.
"This was a really exciting moment for everyone in camp. We knew it was a rare sighting - no-one could believe their eyes."
Documented evidence
Albino elephants are not usually white, but instead they have more of a reddish-brown or pink hue.
While albinism is thought to be fairly common in Asian elephants, it is much less common in the larger African species.
Ecologist Dr Mike Chase, who runs conservation charity Elephants Without Borders, said: "I have only come across three references to albino calves, which have occurred in Kruger National Park in South Africa.
"This is probably the first documented sighting of an albino elephant in northern Botswana.
"We have been studying elephants in the region for nearly 10 years now, and this is the first documented evidence of an albino calf that I have come across."
He said that the condition might make it difficult for the calf to survive into adulthood.
"What happens to these young albino calves remains a mystery," said Dr Chase.
"Surviving this very rare phenomenon is very difficult in the harsh African bush. The glaring sun may cause blindness and skin problems."
However, he told BBC News that there might be a ray of hope for the pink calf as it already seemed to be learning to adapt to its condition.
Dr Chase explained: "Because this elephant calf was sighted in the Okavango Delta, he may have a greater chance of survival. He can seek refuge under the large trees and cake himself in a thick mud, which will protect him from the Sun.
"Already the two-to-three-month-old calf seems to be walking in the shade of its mother.
"This behaviour suggests it is aware of its susceptibility to the harsh African sun, and adapted a unique behaviour to improve its chances of survival."
He added: "I have learned that elephants are highly adaptable, intelligent and masters of survival."
By Rebecca Morelle
Science reporter, BBC News
A pink baby elephant has been caught on camera in Botswana.
A wildlife cameraman took pictures of the calf when he spotted it among a herd of about 80 elephants in the Okavango Delta.
Experts believe it is probably an albino, which is an extremely rare phenomenon in African elephants.
They are unsure of its chances of long-term survival - the blazing African sunlight may cause blindness and skin problems for the calf.
Mike Holding, who spotted the baby while filming for a BBC wildlife programme, said: "We only saw it for a couple of minutes as the herd crossed the river.
"This was a really exciting moment for everyone in camp. We knew it was a rare sighting - no-one could believe their eyes."
Documented evidence
Albino elephants are not usually white, but instead they have more of a reddish-brown or pink hue.
While albinism is thought to be fairly common in Asian elephants, it is much less common in the larger African species.
Ecologist Dr Mike Chase, who runs conservation charity Elephants Without Borders, said: "I have only come across three references to albino calves, which have occurred in Kruger National Park in South Africa.
"This is probably the first documented sighting of an albino elephant in northern Botswana.
"We have been studying elephants in the region for nearly 10 years now, and this is the first documented evidence of an albino calf that I have come across."
He said that the condition might make it difficult for the calf to survive into adulthood.
"What happens to these young albino calves remains a mystery," said Dr Chase.
"Surviving this very rare phenomenon is very difficult in the harsh African bush. The glaring sun may cause blindness and skin problems."
However, he told BBC News that there might be a ray of hope for the pink calf as it already seemed to be learning to adapt to its condition.
Dr Chase explained: "Because this elephant calf was sighted in the Okavango Delta, he may have a greater chance of survival. He can seek refuge under the large trees and cake himself in a thick mud, which will protect him from the Sun.
"Already the two-to-three-month-old calf seems to be walking in the shade of its mother.
"This behaviour suggests it is aware of its susceptibility to the harsh African sun, and adapted a unique behaviour to improve its chances of survival."
He added: "I have learned that elephants are highly adaptable, intelligent and masters of survival."
Finches choose sex of offspring
By Victoria Gill
Science reporter, BBC News
Female Gouldian finches "decide" to have more male chicks if they are less compatible with their mate.
The birds, which have either red or black heads, prefer to mate with males with the same head colouring, as this signifies a better genetic match.
Chicks from a mismatched mating - particularly the females - are weaker and more likely to die very early.
A report in the journal Science says that the birds compensate for this by having more male chicks in their brood.
Colourful Gouldian finches can judge if a mate is genetically compatible just by looking at its head.
A female that mates with a male with the same colouring lays eggs that hatch much healthier chicks.
This new study has found that, when the female finches mate with a male that has a different head colour, they select the sex of their offspring - giving their chicks a better chance of survival.
Parental control
In birds, the sex of an egg is already determined before it is fertilised by the male.
Sarah Pryke, a biologist from Macquarie University in Sydney, led this study. She found that when female finches mate with mismatched males, 70% of their chicks are male.
This is beneficial for the birds, because male chicks from genetically mismatched parents are more likely to survive than females.
"It is pretty amazing to think that the female herself has so much control - subconsciously of course - over this basic physiology," said Dr Pryke.
The results were particularly striking because colour-matched matings, which result in much healthier broods, always produce roughly equal numbers of male and female chicks.
"Females really don't want to mate with a male with a different head colour.
"But there simply aren't enough compatible males, so later in the mating season they seem to use this control to make the best of a bad situation."
Birds of a feather
Dr Pryke's team disguised some of the male finches to show that this "sex bias" is entirely controlled by the females.
They blackened the head feathers of red males, using a non-toxic dye, and paired them to both red and black females to allow them to breed.
"It's actually quite hard to tell the experimentally blackened birds apart from natural black males," explained Dr Pryke.
The birds were fooled, and the team found that black females that mated with the "disguised" red males produced an equal ratio of male and female chicks.
"This is the clearest and perhaps most extreme example of sex biasing that has been found," said Dr Pryke. "It's really black and white - or in this case black and red."
She said that exactly how the birds select the sex of their eggs is still a "big mystery".
"We have an idea that hormones may play a role - but that's a working hypothesis we're looking to test."
Dr Ruedi Nager, a biologist from Glasgow University who specialises in avian reproduction described this as an "excellent experiment".
"It's now clear that the control is driven by the females," he told BBC News.
"Somehow the female recognises the sex of the follicle [or egg cell] and selects it based on how much she likes the male.
"Hopefully, this will reinvigorate the debate about how this works."
By Victoria Gill
Science reporter, BBC News
Female Gouldian finches "decide" to have more male chicks if they are less compatible with their mate.
The birds, which have either red or black heads, prefer to mate with males with the same head colouring, as this signifies a better genetic match.
Chicks from a mismatched mating - particularly the females - are weaker and more likely to die very early.
A report in the journal Science says that the birds compensate for this by having more male chicks in their brood.
Colourful Gouldian finches can judge if a mate is genetically compatible just by looking at its head.
A female that mates with a male with the same colouring lays eggs that hatch much healthier chicks.
This new study has found that, when the female finches mate with a male that has a different head colour, they select the sex of their offspring - giving their chicks a better chance of survival.
Parental control
In birds, the sex of an egg is already determined before it is fertilised by the male.
Sarah Pryke, a biologist from Macquarie University in Sydney, led this study. She found that when female finches mate with mismatched males, 70% of their chicks are male.
This is beneficial for the birds, because male chicks from genetically mismatched parents are more likely to survive than females.
"It is pretty amazing to think that the female herself has so much control - subconsciously of course - over this basic physiology," said Dr Pryke.
The results were particularly striking because colour-matched matings, which result in much healthier broods, always produce roughly equal numbers of male and female chicks.
"Females really don't want to mate with a male with a different head colour.
"But there simply aren't enough compatible males, so later in the mating season they seem to use this control to make the best of a bad situation."
Birds of a feather
Dr Pryke's team disguised some of the male finches to show that this "sex bias" is entirely controlled by the females.
They blackened the head feathers of red males, using a non-toxic dye, and paired them to both red and black females to allow them to breed.
"It's actually quite hard to tell the experimentally blackened birds apart from natural black males," explained Dr Pryke.
The birds were fooled, and the team found that black females that mated with the "disguised" red males produced an equal ratio of male and female chicks.
"This is the clearest and perhaps most extreme example of sex biasing that has been found," said Dr Pryke. "It's really black and white - or in this case black and red."
She said that exactly how the birds select the sex of their eggs is still a "big mystery".
"We have an idea that hormones may play a role - but that's a working hypothesis we're looking to test."
Dr Ruedi Nager, a biologist from Glasgow University who specialises in avian reproduction described this as an "excellent experiment".
"It's now clear that the control is driven by the females," he told BBC News.
"Somehow the female recognises the sex of the follicle [or egg cell] and selects it based on how much she likes the male.
"Hopefully, this will reinvigorate the debate about how this works."
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