American Association for the Advancement of Science - Virginia Morell
Scientists have long worried whether animals can respond to the
planet’s changing climate.
Now, a new study reports that at least one
species of songbird—and likely many more—already knows how to prep its
chicks for a warming world.
They do so by emitting special calls to the
embryos inside their eggs, which can hear and learn external sounds.
This is the first time scientists have found animals using sound to
affect the growth, development, behavior, and reproductive success of
their offspring, and adds to a growing body of research revealing that birds can “doctor” their eggs.
“The study is novel, surprising, and fascinating, and is sure to lead
to much more work on parent-embryo communication,” says Robert Magrath,
a behavioral ecologist at the Australian National University in
Canberra who was not involved in the study.
The idea that the zebra finch (Taeniopygia guttata) parents
were “talking to their eggs” occurred to Mylene Mariette, a behavioral
ecologist at Deakin University in Waurn Ponds, Australia, while
recording the birds’ sounds at an outdoor aviary.
She noticed that
sometimes when a parent was alone, it would make a rapid, high-pitched
series of calls while sitting on the eggs.
Mariette and her co-author,
Katherine Buchanan, recorded the incubation calls of 61 female and 61
male finches inside the aviary.
They found that parents of both sexes
uttered these calls only during the end of the incubation period and
when the maximum daily temperature rose above 26°C (78.8°F).
To find out whether the calls somehow prepared the chicks for higher
temperatures, the scientists artificially incubated 166 eggs at a
standard temperature of 37.7°C (99.9°F).
During the last 5 days of
incubation, they exposed the eggs to either recorded incubation calls or
the parents’ normal contact calls.
When the chicks hatched, those that had listened to the incubation
calls were more vocal than the control nestlings.
What’s more, the
chicks that had been exposed to the incubation calls weighed less than the controls, they report online today in Science.
That could be an advantageous adaptation in a hot environment, the
scientists argue. “With a smaller body size, they’re better at losing
heat,” Mariette says.
She and Buchanan suggest that their lower body
mass might also reduce oxidative damage, the harmful buildup of unstable
molecules in proteins, fats, and DNA that can adversely affect
reproduction.
They clinched their results with data on the success of the chicks:
When kept in hot conditions, the lower weight chicks did indeed go on to
produce more fledglings in their first breeding season than did the
control birds.
But the control birds were more successful in cooler
conditions. And the incubation calls may have other lasting effects.
For
two breeding seasons, the males that heard these sounds preferred
nesting boxes that were hot, whereas the control males chose cooler
homes.
“It’s interesting and surprising that vocal communication at such an
early stage of development could have such persistent effects,” says
Renee Duckworth, an evolutionary ecologist at the University of Arizona
in Tucson.
Incubation calls were first found in superb fairy wrens (Malurus cyaneus),
another Australian songbird in a different family.
Unlike the finches,
the fairy wrens’ calls teach their embryos a special “password” to
elicit food from their parents after hatching.
Mariette and others now
suspect that the calls may be widespread and used in various ways to
program chicks for future challenges.
“This remarkable paper helps us understand how animals could adapt to
changing climate by showing that parental care alters nestling growth,”
says Sonia Kleindorfer, a behavioral ecologist at Flinders University
in Adelaide, Australia, who was not involved in the study. “It also
shows that … embryos can learn much more than we ever imagined.”
But
Kleindorfer, who studies fairy wrens, wonders whether the calls are
really sending a specific signal about the temperature, and are not just
a natural response to the heat.
She also wonders how often finches use
the incubation calls in the wild, because fairy wrens suffer increased
predation when they make these sounds.
Mariette thinks the finches’ ability to prepare their offspring for
their future environment makes sense because they live in arid habitats
and they breed whenever conditions are good—irrespective of the season.
She adds that these finches show that some animals, at least, aren’t
just sitting ducks when it comes to climate change—they may be much
better able to adapt to a warming world than we thought.
Links
Study Identifies Key Species Which Act As Warning Signs Of Ecosystem Collapse
The Guardian - James Dyke*
The success or failure of certain species can be used to predict the future health of an entire ecosystem, research says
The Earth's biodiversity is under attack. We would need to travel
back over 65 million years to find rates of species loss as high as we
are witnessing today.
Conservation often focuses on the big, enigmatic animals - tigers, polar bears, whales. There are many reasons to want to save these species from extinction. But what about the vast majority of life that we barely notice? The bugs and grubs that can appear or vanish from ecosystems without any apparent impact?
Biodiversity increases resilience: more species means each individual species is better able to withstand impacts. Think of decreasing biodiversity as popping out rivets from an aircraft. A few missing rivets here or there will not cause too much harm. But continuing to remove them threatens a collapse in ecosystem functioning. Forests give way to desert. Coral reefs bleach and then die.
New research that I have been involved in suggests that there biodiversity has a value that has been overlooked, but could be vitally important if we are to manage our impacts on ecosystems. Our study, published in the journal Ecology, shows that crucial information about the overall health or resilience of an ecosystem may be lurking in data about supposedly inconsequential species. In fact, the presence or absence of some of the rarest species may be giving us important clues as to how near an ecosystem is to a potential collapse.
Such rare species we call ecosystem canaries. Like canaries that coal miners used to check for poisonous gasses deep underground, ecosystem canaries are often the first species to disappear from a stressed ecosystem. Their vanishing can be linked to changes in the functioning of ecosystems, which can serve as a warning that a collapse is approaching.
Our study used data collected from lakes in China that showed changes in the abundance of species from algae (diatom) and aquatic midges (chironomid) communities as they compete for resources under environmental pressures. From this data it was possible to identify three types of organism: slowly-replicating but strongly competitive 'keystone' species; weakly-competitive but fast-replicating 'weedy' species; and slowly-replicating and weakly-competitive 'canary' species.
Runoff
of fertiliser from surrounding fields has a major environmental impact
on these lake ecosystems. As the situation worsens the canary species is
the first to suffer.
With continuing degradation affecting all species, this leads to the eventual collapse of the keystone species as they are replaced by the weedy species. The loss of keystones tips the ecosystem into a critical transition – the point at which a system shifts into an alternate state which in lakes is dominated by smothering algae and absence of many plant and animal species. Moving a lake back to a clear water, high biodiversity state can be extremely difficult.Better to avoid the collapse in the first place.
Waiting to observe changes in the keystone species would not allow any intervention because the system would already be spiralling towards collapse. By searching for changes in the structure of populations that includes the ratio of keystone, weedy and canary species, we were able to detect a clear signal of an impending collapse many years, sometimes decades before the actual event. Time enough to put in place changes to farming and other practices.
The ecological theory underpinning this approach should apply to many other aquatic and terrestrial ecosystems. Given the extent and rapidity of human impacts there should not be any shortage of ecosystems to apply our findings to.
*James Dyke is a lecturer in sustainability science at the University of Southampton.
Links
The success or failure of certain species can be used to predict the future health of an entire ecosystem, research says
 |
| The coal miner's canary provided a warning of dangerous levels of toxic gases. Photograph: Don McPhee for the Guardian |
Conservation often focuses on the big, enigmatic animals - tigers, polar bears, whales. There are many reasons to want to save these species from extinction. But what about the vast majority of life that we barely notice? The bugs and grubs that can appear or vanish from ecosystems without any apparent impact?
Biodiversity increases resilience: more species means each individual species is better able to withstand impacts. Think of decreasing biodiversity as popping out rivets from an aircraft. A few missing rivets here or there will not cause too much harm. But continuing to remove them threatens a collapse in ecosystem functioning. Forests give way to desert. Coral reefs bleach and then die.
New research that I have been involved in suggests that there biodiversity has a value that has been overlooked, but could be vitally important if we are to manage our impacts on ecosystems. Our study, published in the journal Ecology, shows that crucial information about the overall health or resilience of an ecosystem may be lurking in data about supposedly inconsequential species. In fact, the presence or absence of some of the rarest species may be giving us important clues as to how near an ecosystem is to a potential collapse.
Such rare species we call ecosystem canaries. Like canaries that coal miners used to check for poisonous gasses deep underground, ecosystem canaries are often the first species to disappear from a stressed ecosystem. Their vanishing can be linked to changes in the functioning of ecosystems, which can serve as a warning that a collapse is approaching.
Our study used data collected from lakes in China that showed changes in the abundance of species from algae (diatom) and aquatic midges (chironomid) communities as they compete for resources under environmental pressures. From this data it was possible to identify three types of organism: slowly-replicating but strongly competitive 'keystone' species; weakly-competitive but fast-replicating 'weedy' species; and slowly-replicating and weakly-competitive 'canary' species.
 |
| One of the lakes mentioned in study. Photo taken in July 2015 shows Erhai Lake in Dali, in southwest China's Yunnan Province. Yunnan plans to spend 26.4bn yuan (US$4.1bn) to tackle pollution in the Erhai Lake, which saw blooms of blue green algae in 1996 and 2003. Photograph: Lin Yiguang/Xinhua/Alamy |
With continuing degradation affecting all species, this leads to the eventual collapse of the keystone species as they are replaced by the weedy species. The loss of keystones tips the ecosystem into a critical transition – the point at which a system shifts into an alternate state which in lakes is dominated by smothering algae and absence of many plant and animal species. Moving a lake back to a clear water, high biodiversity state can be extremely difficult.Better to avoid the collapse in the first place.
Waiting to observe changes in the keystone species would not allow any intervention because the system would already be spiralling towards collapse. By searching for changes in the structure of populations that includes the ratio of keystone, weedy and canary species, we were able to detect a clear signal of an impending collapse many years, sometimes decades before the actual event. Time enough to put in place changes to farming and other practices.
The ecological theory underpinning this approach should apply to many other aquatic and terrestrial ecosystems. Given the extent and rapidity of human impacts there should not be any shortage of ecosystems to apply our findings to.
*James Dyke is a lecturer in sustainability science at the University of Southampton.
Links
Towards A New Economic System For The 21st Century
Al Jazeera - C J Polychroniou*
The new economic system should be based on localised forms of industry, finance and participatory democracy.
In his Prison Notebooks, the Italian revolutionary Antonio Gramsci
wrote: "The crisis consists precisely in the fact that the old is dying
and the new cannot be born; in this interregnum a great variety of
morbid symptoms appear."
Today, it is the world economy, to be precise, that finds itself once again in the midst of an interregnum. The post-war model of economic growth that produced the golden age of capitalism is long gone, but a new economic system has yet to be born.
The morbid symptoms around abound: Intense and growing inequality, massive unemployment and extreme youth idleness in many parts of the world, rapidly declining standards of living, dangerously high levels of both public and corporate debt, a financial system that remains out of whack, and ecological collapse.
UpFront - Is capitalism driving climate change?
Moreover, the world economy not only continues to rely on fossil fuels to power growth, but is actually increasing the consumption of primary energy sources - such as coal, oil and natural gas - in spite of the phenomenon of global warming which threatens to destroy human civilisation as we know it.
Indeed, the existing economic model is defunct: consider also the fact that productivity growth in the advanced economies of the world since the eruption of the financial crisis of 2008 has been extremely slow in both absolute terms and relative to previous decades. But the model remains deadly dangerous.
Why a new deal is not enough
In light of the aforementioned reasons, many economists around the world, including Thomas Piketty, have been proposing the implementation of a new global deal on growth in the mould of Franklin D Roosevelt's "New Deal" programmes during the 1930s.
The call for a New Deal has also been adopted by several political movements in Europe, and the United States including Bernie Sanders and many of his supporters.
Roosevelt's New Deal, probably the greatest experiment of active state intervention under capitalism, saved many people's lives, but did not even end the Great Depression.
What really ended the Great Depression in the US was the mobilisation of all economic resources to support the war effort.
Roosevelt's New Deal did not advocate or promote economic democracy, nor did it seek to lay the basis for the emergence of a more rational socioeconomic order.
Indeed, when concerns about inflation and the federal deficit became widespread only a few years after the initiation of the New Deal programmes, the Roosevelt administration decided in 1937 to cut back on its economic stimulus, which caused the US economy to fall back into recession.
We need a new economic system
Unless we are willing to accept social disintegration, increased conflict and even wars as irreversible processes, and stand idly by while global warming caused by the logic of a fossil fuel-based economy destroys the planet, the existing system of neoliberal transnational corporate capitalism needs to be replaced by an economic order that is aligned with human interests and sustainable and balanced growth.
In actual practical terms, this means making a great shift away from the processes of constant capital accumulation, possessive individualism and economic globalisation.
It also means putting an end to the destructive practices of Western industrial extractive technologies and be respectful of the natural resources that sustain life.
Economic globalisation, which lies at the heart of the current economic system, is promoting a monoculture economy, and has devastating effects for the wellbeing of most communities in the global South and the environment alike.
Putting a halt to the current dynamics and contradiction of economic globalisation does not mean eliminating international trade.
But what it does require is doing away with the neoliberal trade treaties, which have given global corporations and banks such immense wealth and power that they can promote their own interests without concern for democracy, workers' rights and sustainability.
As such, we need to rethink terms such as development, growth and progress.
In this case, a revolution in consciousness is mandatory in order for a great shift to occur in the way the global economy works and the future we want.US tribes work with scientists against climate change Capitalism is a rather new, historical economic system that belongs to a certain era of humanity, which means that there is nothing to suggest that it will be around for ever.
The new economic system should be based on localised forms of industry, finance, participatory democracy, and the use of technologies which are congruent with community needs for the production and distribution of food in order to eradicate poverty and hunger and provide sustainable livelihoods.
This revolution in consciousness is already under way and it has been embraced by millions of people throughout the developed and developing world, particularly among urban youth, and could soon become the newest political and social movement to emerge as the old system is dying and a new one is struggling to be born.
*CJ Polychroniou is a political economist/political scientist who has taught and worked for many years in universities and research centres in Europe and the United States.
Links
The new economic system should be based on localised forms of industry, finance and participatory democracy.
 |
| A revolution in consciousness is mandatory in order for a great shift to occur in the way the global economy works and the future we want, writes Polychroniou [Reuters] |
Today, it is the world economy, to be precise, that finds itself once again in the midst of an interregnum. The post-war model of economic growth that produced the golden age of capitalism is long gone, but a new economic system has yet to be born.
The morbid symptoms around abound: Intense and growing inequality, massive unemployment and extreme youth idleness in many parts of the world, rapidly declining standards of living, dangerously high levels of both public and corporate debt, a financial system that remains out of whack, and ecological collapse.
UpFront - Is capitalism driving climate change?
Moreover, the world economy not only continues to rely on fossil fuels to power growth, but is actually increasing the consumption of primary energy sources - such as coal, oil and natural gas - in spite of the phenomenon of global warming which threatens to destroy human civilisation as we know it.
Indeed, the existing economic model is defunct: consider also the fact that productivity growth in the advanced economies of the world since the eruption of the financial crisis of 2008 has been extremely slow in both absolute terms and relative to previous decades. But the model remains deadly dangerous.
Why a new deal is not enough
In light of the aforementioned reasons, many economists around the world, including Thomas Piketty, have been proposing the implementation of a new global deal on growth in the mould of Franklin D Roosevelt's "New Deal" programmes during the 1930s.
The call for a New Deal has also been adopted by several political movements in Europe, and the United States including Bernie Sanders and many of his supporters.
Capitalism is a rather new, historical economic system that belongs to a certain era of humanity, which means that there is nothing to suggest that it will be around for ever.The problem with this approach is that a new global deal is inevitably structured towards the goal of saving the existing economic system, not overcoming its ultimate contradictions and replacing it with a new socioeconomic order, which is what today's world really needs. |
What really ended the Great Depression in the US was the mobilisation of all economic resources to support the war effort.
Roosevelt's New Deal did not advocate or promote economic democracy, nor did it seek to lay the basis for the emergence of a more rational socioeconomic order.
Indeed, when concerns about inflation and the federal deficit became widespread only a few years after the initiation of the New Deal programmes, the Roosevelt administration decided in 1937 to cut back on its economic stimulus, which caused the US economy to fall back into recession.
We need a new economic system
Unless we are willing to accept social disintegration, increased conflict and even wars as irreversible processes, and stand idly by while global warming caused by the logic of a fossil fuel-based economy destroys the planet, the existing system of neoliberal transnational corporate capitalism needs to be replaced by an economic order that is aligned with human interests and sustainable and balanced growth.
In actual practical terms, this means making a great shift away from the processes of constant capital accumulation, possessive individualism and economic globalisation.
It also means putting an end to the destructive practices of Western industrial extractive technologies and be respectful of the natural resources that sustain life.
Economic globalisation, which lies at the heart of the current economic system, is promoting a monoculture economy, and has devastating effects for the wellbeing of most communities in the global South and the environment alike.
Putting a halt to the current dynamics and contradiction of economic globalisation does not mean eliminating international trade.
But what it does require is doing away with the neoliberal trade treaties, which have given global corporations and banks such immense wealth and power that they can promote their own interests without concern for democracy, workers' rights and sustainability.
As such, we need to rethink terms such as development, growth and progress.
In this case, a revolution in consciousness is mandatory in order for a great shift to occur in the way the global economy works and the future we want.US tribes work with scientists against climate change Capitalism is a rather new, historical economic system that belongs to a certain era of humanity, which means that there is nothing to suggest that it will be around for ever.
The new economic system should be based on localised forms of industry, finance, participatory democracy, and the use of technologies which are congruent with community needs for the production and distribution of food in order to eradicate poverty and hunger and provide sustainable livelihoods.
This revolution in consciousness is already under way and it has been embraced by millions of people throughout the developed and developing world, particularly among urban youth, and could soon become the newest political and social movement to emerge as the old system is dying and a new one is struggling to be born.
*CJ Polychroniou is a political economist/political scientist who has taught and worked for many years in universities and research centres in Europe and the United States.
Links