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Early springs surprise many species

April 7, 2014 in Adaptation, Arctic, Climate, Polar ice, Species loss, Warming, Wildlife

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Roe deer numbers have been particularly hard hit by seasonal disruption.  Image: Marek Szczepanek via Wikimedia Commons

Roe deer numbers have been particularly hard hit by seasonal disruption.
Image: Marek Szczepanek via Wikimedia Commons

By Tim Radford

As seasonal change suffers ever more disruption, many species are struggling to adapt quickly enough.

LONDON, 7 April – Spring is arriving earlier. This is not necessarily welcome news for Arctic creatures or the roe deer of France. It could be awkward for flower festival organisers as well.

Julienne Stroeve of the US National Snow and Ice Data Centre and colleagues will report in Geophysical Research Letters that the length of the Arctic melt season is growing by several days each decade. When the melt starts earlier, the Arctic Ocean absorbs more radiation: enough in some places to melt four feet in thickness from the Arctic ice cap.

“The lengthening of the melt season is allowing for more of the sun’s energy to get stored in the oceans and increase ice melt during the summer, overall weakening the sea ice cover,” says Stroeve. The Arctic sea ice has now been in decline for four decades.

The seven lowest September sea ice extents in the satellite record have all occurred in the last seven years. A new examination of satellite imagery and data from 1979 to the present shows that the Beaufort and Chukchi Seas are freezing up between six and 11 days later per decade. But the earlier melt is more ominous than the later freeze: the sun is higher and brighter, and delivers more warmth to the seas.

Festival disruption

The earlier spring presents no problems for many plants but it may not be much fun for the organisers of flower festivals who like to announce their events well in advance. Tim Sparks of Coventry University reports in the journal Climate Research that over its 46-year history, the Thriplow Daffodil Weekend in Cambridgeshire in eastern England has been forced to bring its dates forward by 26 days.

The event can attract up to 10,000 visitors, and has raised £300,000 (US $500,000) for charity, so it clearly helps the organisers to set up some advance publicity. Since 1969, mean temperatures in March and April in the UK have risen by 1.8°C.

“The study represents one of the first solid pieces of evidence of flower tourism having to adapt to climate change,” said Professor Sparks. “The issues faced by Thriplow are a microcosm of the wider picture.”

Flower festivals may be able to adapt. Sadly, the roe deer of Champagne have yet to get the message about climate change. To flourish, both nectar seekers and herbivores have to time their breeding patterns to the surge in plant growth.

Three French scientists looked at records of a population of roe deer in the Champagne region of France, and found that although spring has been arriving increasingly earlier, the fawns are being born at around the same dates as they were 27 years ago, and their survival rate is falling, they report in the Public Library of Science journal PLOS Biology. Overall, the roe deer population in the region is also in decline.

Great tits have kept up with climate change, because reproduction is cued by temperature, so they are around at the same time as the explosion in food sources. What sets the biological pace for roe deer is day length, the authors think, and this is not affected by climate change. - Climate News Network

Climate change ‘raises extinction risk’

February 28, 2014 in Endangered Species, Extinction, USA, Warming, Wildlife

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A weather eye for possible risks: Climate change will make extinction likelier for many species Image: By Ren West via Wikimedia Commons

A weather eye for possible risks: Climate change will make extinction likelier for many species
Image: By Ren West via Wikimedia Commons

By Tim Radford

Climate change doesn’t pose a unique threat of extinction to a species, scientists say. It just makes the risk more likely to become a reality.

LONDON, 28 February – Environmental scientists believe they have a blueprint for extinction. They report in Nature Climate Change that they have identified those factors that might make a species more likely to slip away into eternal oblivion as the planet warms and climate conditions change.

It turns out that they knew them all along. There is, the researchers conclude, nothing specifically different about climate change as a threat: it could however make extinction much more likely.

Richard Pearson of University College London (and formerly of the American Museum of Natural History) and colleagues decided to take a small subset of species at risk, and look closely at the factors that determine species extinction.

They chose 36 amphibians and reptiles endemic to the United States. Reptiles and amphibians almost everywhere seem to be vulnerable for a mix of reasons: among them habitat destruction, environmental pollution and the introduction of new predators and new diseases. The more exquisite the ecological niche occupied by the species, the smaller its overall population and the more precarious its chances of survival.

The researchers examined all the information available on salamanders, turtles, tortoises, snakes and lizards and concluded that, overall, there was a 28% chance of extinction by 2100. But without climate change, this risk dwindled to 1%.

“Surprisingly, we found that the most important factors – such as having a small range or low population size – are already used in conservation assessments,” said Dr Pearson. “The new results indicate that current systems may be able to better identify species vulnerability to climate change than previously thought.”

Carry on conserving

And his co-author Resit Akçakaya of Stony Brook University in the US said: “The bad news is that climate change will cause many extinctions unless species-specific conservation actions are taken; but the good news is that the methods conservation organisations have been using to identify which species need the most urgent help also work when climate change is the main threat.”

So to preserve biodiversity conservationists have to do what many are doing already: focus on species that occupy a small or dwindling space, or are few in number.

Other predictions of future extinction under climate change have usually been based on the rate at which habitat with the right climate will shift or contract, and researchers have been more concerned with how easily species can adapt or migrate and why some species do better than others at shifting to new ground.

In the latest research, the scientists selected a class of animals but did not try to make individual predictions for each species: what they were looking for were general principles.

“Our analysis will hopefully be able to help create better guidelines that account for the effects of climate change in assessing extinction risk,” said Dr Pearson. – Climate News Network

Half of plants may move in warmer world

February 16, 2014 in Adaptation, Agriculture, Arctic, China, forest fires, Vegetation changes, Warming, Wildlife

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Vegetation changes on a warmer planet may mean that giant pandas go hungry Image: Jeff Kubina via Wikimedia Commons

Vegetation changes on a warmer planet may mean that giant pandas go hungry
Image: Jeff Kubina via Wikimedia Commons

By Tim Radford

An international team of scientists says that by the end of the century one probable consequence of climate change will be a change in patterns of vegetation over much of the planet’s land surface.

LONDON, 16 February – By 2100, vegetation patterns will be shifting in almost half the land area of the planet, according to new research in the journal Global and Planetary Change.

Song Feng of the University of Arkansas in the US and colleagues in Nebraska, China and South Korea have taken a long cool look at what the projected patterns of warming are likely to do to the planet’s mosaic of climate types. And they predict dramatic changes.

Climate type is a century-old idea useful for making sense of geographical zones: regions are grouped according to the type of vegetation they support. Since a global map of native vegetation types can also deliver useful information about altitude, rainfall, soil type, prevailing weather and latitude, geographers regard the Köppen-Geiger classification – and an updated version known as Köppen-Trewartha – as a helpful way of describing the world.

Feng and his colleagues decided to see what projected changes in temperature would do to climate types. He wasn’t the first to do so; scientists from the US National Oceanic and Atmospheric Administration reported in 2013 in Nature Climate Change on the probable speed of change in such zones.

But science advances by challenge and replication, and the Arkansas team began looking for themselves at the details of simulated change under the notorious “business as usual scenario”  – the one in which global fossil fuel use continues to increase and higher levels of carbon dioxide and other greenhouse gases concentrate in the atmosphere.

The Intergovernmental Panel on Climate Change has made a series of predictions of rising global average temperatures, but plants, of course, don’t care about global average temperatures: they are however distinctly vulnerable to local extremes of frost and heat.

The Feng scenario projected an increase of between 3°C and 10°C; the team analysed observations made between 1900 and 2010, and then ran computer simulations from 1900 to 2100.

Drastic changes ahead

In the last three decades of the 21st century, for instance, northern winter temperatures are likely to rise by between 3° and 12°C; Arctic coastal temperatures are likely to rise by 8°C; warming in mid-latitudes is likely to be between 5°C and 7°C, the tropics and the southern hemisphere around 5°C.

The Arctic will shrink. Sub-polar vegetation is expected to advance by 5° of latitude and the temperate zones will push northwards too. Arid and semi-arid climate zones are expected to expand by somewhere between 3.3 and 6.6 million square kilometers in the last three decades of this century.

What this does to native vegetation types is hard to predict in detail but some projections have been made. In the Qinling mountain region of China, for instance, somewhere between 80% and 100% of the bamboo forests on which the giant pandas depend could disappear, because the rising temperature would be “no longer feasible for bamboo growth.”

In the south-western US higher temperatures and drier conditions could lead to more forest fires, and pest outbreaks could lead to changes in forest structure and composition.

As the plants change, the animal species that evolved with the vegetation types could be increasingly at risk. Altogether, up to 46.3% of the planet’s land area could shift to warmer or drier climate types

“Climates are associated with certain types of vegetation. If the surface continues to get warmer, certain native species may no longer grow well in their climate, especially in higher latitudes. They will give their territory to other species. That is the most likely scenario”, said Feng. – Climate News Network

Cat litter killer in the whales of the North

February 14, 2014 in Adaptation, Arctic, Atlantic, Disease, Ice Loss, Indigenous peoples, Marine ecology, Ocean Warming, Polar ice, Wildlife

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Blissful domesticity: But even domestic cats can spread Toxoplasma gondii

Blissful domesticity: But even domestic cats can spread Toxoplasma gondii

By Tim Radford

One consequence of a warming climate is new patterns of disease, and researchers have identified two parasites formerly unknown in the Arctic in marine mammals.

CHICAGO, 14 February – The great Arctic thaw – up to 50% of sea ice by area and 75% by volume in the summer season – could be offering new opportunities for one of the planet’s most successful parasites. Toxoplasma gondii, an infection spread by almost all cat species, has been identified for the first time in the western Arctic Beluga whale.

Toxoplasma is found almost everywhere that cats settle: domestic pets, ocelots, cougar, wild cats all carry and spread oocysts of the parasite (structures it uses to transfer to new hosts) in their faeces, to be spread further with discarded cat litter.

The parasite is notoriously hard to kill. Scientists store their samples in sulphuric acid, and the creature can survive unharmed in bleach. It is, however, routinely killed by freezing conditions, or boiling water.

The suspicion is that with the steady, sustained warming of the Arctic over the past 30 years, chiefly because of a buildup of carbon dioxide in the atmosphere, the retreat of the ice has begun to allow new traffic in parasite infections.

Another parasitic killer, a new strain called Sarcocystis pinnipedi, normally found only in the highest, iciest latitudes, has been linked with mass deaths too: 406 grey seals died in 2012 in the north Atlantic. It has also been observed to kill Steller’s sea lions, Hawaiian monk seals, walruses, grizzly bears and polar bears as far south as British Columbia.

In the case of Toxoplasma, warming polar summers could have created conditions in which the parasite could find new warm-blooded hosts further north. In the case of the second parasite, the loss of ice has meant a greater mixing of species, and allowed Sarcocystis to find new hosts in warmer waters.

Cause of blindness

“Ice is a major barrier for pathogens”, Michael Grigg, of the US National Institutes of Health told the American Association for the Advancement of Science annual meeting here. “What we are seeing with the big thaw is the liberation of pathogens gaining access to vulnerable new hosts and wreaking havoc.”

Toxoplasma can also infect people: it is the leading cause of infectious blindness in humans, and can be dangerous to unborn children and to people with compromised immunity.

It has been found in human communities in northern Quebec, perhaps spread by the consumption of dried seal meat. The discovery of Toxoplasma in Beluga whales has begun to worry health officials. Belugas are part of the traditional diet of the Inuit hunters of the far North.

Seals, walruses and polar bears are all what scientists like to call “ice obligate animals”: the ice sheet provides them with their preferred habitat. With the loss of the ice, new species are colonizing the Arctic, and those creatures that cannot now use the ice sheet have been forced to invade new habitats.

“Marine mammals can act as ecosystem sentinels because they respond to climate change through shifts in distribution, timing of their movements and feeding locations”, said Sue Moore of the US National Oceanic and Atmospheric Administration. “These long-lived mammals also reflect changes to the ecosystem in their shifts in diet, body condition and physical health.” – Climate News Network

Equatorial fish feel the heat

February 12, 2014 in Adaptation, Fish, Food security, Indonesia, Marine ecology, Ocean Warming, Warming, Wildlife

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Weaving through the coral: Small fish like these are important sources of food for larger reef species Image: D. Dixson

Weaving through the coral: Small fish like these are important sources of food for larger reef species
Image: D. Dixson

By Alex Kirby

Many species of fish living near the Equator are sensitive to variations in heat and will not thrive in the warmer oceans of the future, scientists in Australia have found.

LONDON, 12 February – Lying in a hot bath may be a pleasant experience, because you can always get out when you’ve had enough. For some of the fish that swim in equatorial seas, though, that is not an option: climate change threatens to make the water not just uncomfortable, but unendurable.

An international team of researchers based in Australia reports in Global Change Biology that the rapid pace of climate change is threatening the future of some of the fish which live near the Equator.

Over a 14-day period the team tested four species of damsel fish and two of cardinal fish. They say: “Our results indicate that low-latitude reef fish populations are living close to their thermal optima and may be more sensitive to ocean warming than higher-latitude populations.”

“Our studies found that one species of fish could not even survive in water just 3°C warmer than it lives in now”, says the lead author of the study, Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University in Queensland.

Dr Rummer and her colleagues studied six common species living on coral reefs near the Equator. She says many species in this region experience only a very narrow range of temperatures throughout their lives, and so are probably adapted to perform best at those temperatures.

The world’s oceans are projected to warm by 2-3°C by the end of this century. “Such an increase in warming leads to a loss of performance”, Dr Rummer said. “Already, we found four species of fish are living at or above the temperatures at which they function best.”

Breeding compromised

The team measured the rates at which fish use oxygen across different temperatures – at rest and during maximal performance. The results showed that in warmer water fish lose their ability to perform properly. In the wild this would limit activities crucial to survival, such as evading predators, finding food, and finding the energy to breed.

With many of the Earth’s equatorial wild populations now living close to their thermal limits, there will be serious consequences if some – like the fish the researchers studied – cannot adapt to the speed at which the oceans are warming.

The response of many species to increasing warmth is to migrate to somewhere that suits them better, which could help to drain the equatorial oceans of fish which play a key role there. Dr Rummer suggests there will be declines in fish populations as species move away from the Equator to find refuge in areas with more agreeable temperatures.

“This will have a substantial impact on the human societies that depend on these fish,” she says. Many developing countries are in the equatorial zone, and fish are central to the livelihoods and survival of millions of people, including many in Indonesia and south-east Asia.

With rapid climate change, the scientists say, understanding the link between an organism and its environment is crucial to developing management strategies to conserve biodiversity and to allow the sustainable use of marine fisheries. This is especially urgent for ensuring food security for people. – Climate News Network

Penguins feel climate change’s impacts

February 1, 2014 in Antarctic, Climate, Extreme weather, Marine ecology, Rainfall, South America, Weather, Wildlife

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Adélie penguin chicks chase an adult in the hope of finding food Image: Liam Quinn from Canada via Wikimedia Commons

Adélie penguin chicks chase an adult in the hope of finding food
Image: Liam Quinn from Canada via Wikimedia Commons

By Tim Radford

Scientists have identified climate change as the direct cause of rising mortality among penguin chicks hatched in Argentina.

LONDON, 1 February – Climate change is bad for penguin chicks. If rain doesn’t soak their feathers and kill them with cold, then extremes of heat could finish them off with hyperthermia.

Over a 27-year research project in the world’s largest colony of Magellanic penguins, on the arid Argentine coast, researchers have seen a greater number of deaths directly attributable to climate change.

“We’re going to see years where almost no chicks survive if climate change makes storms bigger and more frequent during vulnerable times of the breeding season”, says Ginger Rebstock, who, with Dee Boersma, reports on the state of penguin survival in the Public Library of Science journal PLOS One.

The two scientists, biologists from the University of Washington, Seattle in the US, believe starvation and weather are going to make life harder for the offspring of the 200,000 pairs of penguins that breed each year at Punta Tombo, on Argentina’s Atlantic coast.

The number of storms during the first two weeks of December – when all the chicks are less than 25 days old and their downy coats are not yet waterproof – has increased between 1983 and 2010.

Every new chick is at hazard: over the span of study, the researchers calculate that 65% of chicks do not survive, 40% of them die by starvation. But climate change has begun to offer new dangers.

A Magellanic chick, still too young to have an adult's waterproofing, in the rain Image: D Boersma/University of Washington

A Magellanic chick, still too young to have an adult’s waterproofing, in the rain
Image: D Boersma/University of Washington

Some years up to half of all chicks die because of the weather. Punta Tombo is historically an arid region. In the last 50 years, the scientists report, rainfall has increased. The number of wet days has increased, the number of consecutive wet days has increased and the level of rainfall during those days has continued to increase.

Air temperatures changed too. The minimum temperatures decreased by up to 3°C and the number of these colder days increased. Storms, too, make it more difficult for foraging parents to gather enough food to feed their chicks.

Sea ice changes

“Starving chicks are more likely to die in a storm”, says Prof Boersma. “There may not be much we can do to mitigate climate change, but steps could be taken to make sure the Earth’s largest colony of Magellanic penguins have enough to eat by creating a marine protected reserve, with regulations on fishing, where penguins forage while raising small chicks.”

Further south, extreme weather is beginning to make life difficult for the Adélie penguins of Ross Island in Antarctica. Amélie Lescroël from the CNRS in France and colleagues report in the same edition of PLOS One that abnormal sea ice conditions reduce access to food.

Antarctic penguins are of course adapted to sea ice: it is their preferred habitat. But they must respond to short and long term changes in ice levels. For 13 years, scientists have monitored the feeding success of the Ross Island colony and observed that the birds could cope in those seasons when there was less sea ice.

But climate change in Antarctica, too, creates new problems for the birds and limits their foraging efficiency.

“Our work shows that Adélie penguins could cope with less sea ice around their summer breeding grounds”, said Dr Lescroël. “However, we also showed that extreme environmental events, such as the calving of giant icebergs, can dramatically modify the relationship between Adélie penguins and sea ice.”

If the frequency of such extreme events increases, then it will become hard to predict how penguin populations will get by, she thinks. – Climate News Network

Be small, stay cool, forget the climate

January 25, 2014 in Adaptation, Temperature Increase, USA, Wildlife

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Moose are one of the large species likely to feel more stress in a warming world than smaller creatures Image: Hagerty Ryan, US Fish & Wildlife Service, via Wikimedia Commons

Moose are one of the large species likely to feel more stress in a warming world than smaller creatures
Image: Hagerty Ryan, US Fish & Wildlife Service, via Wikimedia Commons

By Tim Radford

Climate change is not affecting all species equally, US researchers say. The smaller the species, the less stress they are likely to feel than their bigger cousins.

LONDON, 25 January – When it comes to climate change, small could be beautiful. Christy McCain of the University of Colorado Boulder looked at more than 1,000 scientific studies of mammalian behaviour and responses to climate change in North America and came to one big conclusion: bigger animals are more likely to experience stress than the smaller ones. A tiny shrew in the American forests was 27 times less likely to respond to climate change than a moose not far away.

She settled on 140 scientific papers that contained population responses from 73 North American mammal species, and examined a number of observations that could be called a response. Was there some sort of local extinction? Did the creature’s range contract, did it shift, did the species numbers increase? Did seasonal behaviour betray any change? Was there any variation in body size? Or in genetic diversity?

She and her colleague Sarah King report in Global Change Biology that only about half of the mammals responded as expected to climate change; 7% did the opposite of what might be expected and the remaining 41% betrayed no response. Those characteristics that indicated a response to climate change were large body size and restricted times in the day when a mammal might be active.

Tailored conservation

Almost all the large mammals responded negatively to the gradual warming and seasonal shifts of recent decades. Mammals active only in the daylight, or only at night, were twice as likely to respond as mammals that had a more flexible approach to time-keeping.

Mammals in the high latitudes, or at high elevation ranges – polar bears in the first case, American pikas and shadow chipmunks in the second – were also more likely to be in some way affected than those further south or further downhill. Small mammals however seemed to be able to exploit a wider range of micro-climates – shady patches, burrows and so on – to shelter from the effects of climate change.

“Overall the study suggests our large charismatic fauna – animals like foxes, elk, reindeer and bighorn sheep – may be more at risk from climate change”, said Dr McCain. “If we can determine which mammals are responding to climate change and the ones that are at risk of disappearing, then we can tailor conservation efforts toward those individual species.” – Climate News Network

Swiss wildlife heads uphill fast

January 13, 2014 in Adaptation, Europe, Temperature Increase, Wildlife

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Plants are moving uphill because of rising temperatures - like this Leopard’s bane (Doronicum clusii) Image: Jörg Schmill

Plants are moving uphill because of rising temperatures – like this Leopard’s bane (Doronicum clusii)
Image: Jörg Schmill

By Tim Radford

Wildlife in Switzerland seeking relief from warming temperatures by moving further up the mountainsides is proving surprisingly mobile.

LONDON, 13 January – Alpine ecosystems are on the rise. Between 2003 and 2010, plants have managed to scramble up another eight metres of mountain slope. On the way up, they were overtaken by butterflies, which collectively gained another 38 metres of higher ground.  Alpine birds in turn fluttered an average of 42 metres higher.

Tobias Roth and colleagues from the University of Basel and the Petite Camargue Alsacienne research station at St Louis in France report in PLOS One, the journal of the Public Library of Science, that, at least in the short term, alpine landscapes offer safe habitats in a warming world.

“An average of eight metres difference in eight years and across all plant species is quite impressive for the often not very mobile plant communities”, said Valentin Amrhein, one of the authors.

“The results show that the biological impacts of climate change will not only become apparent in the long term. Animals and plants are already today adapting to the rising temperatures at a surprising pace.”

Parallel from the UK

British researchers have just confirmed that British butterflies have been moving north as average temperatures increase. But, as always with surveys of biodiversity, the picture is complicated by other factors.

Natural cycles of explosive growth and dramatic failure are regular features of bird and animal populations, driven by the numbers of predators and the availability of prey.

Habitats change, and so do farming practices, and these changes too affect species numbers. But average temperatures also affect farming practices and natural habitats. So the Swiss research was another attempt to try to disentangle some of the influences on local fauna and flora.

The researchers worked their way through data collected from 214 sample plots between 2003 and 2010, between altitudes of 500 and 3,000 metres, covering all the major ecosystems of the region.

Puzzles remain

Between 1995 and 2010, summer temperatures rose in Switzerland by about 0.07% each year at all altitudes. The researchers found no decrease in the variation of ecological communities in their temperature niches, which, they say, suggests that global warming has not led to more homogenous ecosystems.

At low altitudes, there was a shift towards warm-dwelling species for all three groups. The high altitude birds continued to move uphill, but plants and butterflies showed no significant changes above the tree line, for reasons that remain puzzling.

“It is possible that land-use related changes in habitats near the tree line outweigh the effects of climate warming. For example, many alpine pastures have been abandoned in recent years”, said Tobias Roth.

“It is also possible that alpine plants are better protected against changing climatic conditions, due to the highly varied surface of alpine landscapes.” – Climate News Network

Species’ numbers alter climate migration

January 8, 2014 in Adaptation, United Kingdom, Warming, Wildlife

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The marbled white is one species which is expanding its range because of climate warming Image: Tim Melling/Butterfly Conservation

The marbled white is one species which is expanding its range because of climate warming
Image: Tim Melling/Butterfly Conservation

By Tim Radford

Wild species will not always migrate to colonise warmer habitats, scientists have found. They may stay put if their numbers are not robust in the first place.

LONDON, 8 January – Species can adapt to and take advantage of climate change – but only if populations are strong and stable in the first place, according to new research.

Louise Mair and colleagues from the University of York in the UK used data collected over decades by “citizen scientists” to confirm that many British butterflies have moved north as the world warmed – but not all. What seemed to make the difference were the levels of abundance in any one species.

The scientists report in Nature Climate Change that they worked their way through more than 1.2 million distribution records of 25 species of British butterfly at intervals over the past 40 years.

Britain has a long history of systematic bird and butterfly observation and much information had been recorded by enthusiastic amateur natural historians, and the partners in the study were agencies such as Butterfly Conservation and the Natural Environment Research Council.

In theory, any insects should be able to migrate to take advantage of warming temperatures: in fact, creatures that depend on the presence of specific plant species may not be able to travel so easily if the right habitats are not available.

Farming methods change, and with them the landscape and food sources available to the natural world. So conservationists anxious to protect biodiversity in a world of climate change must first consider all the other conditions for population stability in wild creatures.

Background of decline

The new research confirms that species once restricted to southern England were colonising northern England and Scotland in line with increases in average temperatures.

But although the temperatures might have become more hospitable, most British butterfly species have shown declines in population. In the first 20 years under study, nine species expanded their range and 16 retreated, and what seemed to dictate change was habitat availability.

In the most recent 20 years, 11 species expanded their range and 14 species went into retreat, and this time what seemed to matter most were levels of population abundance.

The argument is this: if a species is doing well, then it can deliver enough migrants to colonise new territory as conditions permit. If, on the other hand, numbers are in decline, there won’t be enough in the next generation to take advantage of milder climates and move to new sites.

The study doesn’t reveal a lot about climate change, but it could help conservationists understand why some creatures respond to change, while others see a decline in numbers.

“My previous research revealed huge variations among butterflies in relation to their range expansion rates”, said Louise Mair. “It’s now clear from our new research that much of this variation can be accounted for once species population trends are known.” – Climate News Network

Some lose, some win in warming world

December 25, 2013 in Adaptation, Antarctic, Vegetation changes, Wildlife

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The Alpine ibex will be a clear winner, its horns growing in the warmer weather Image: User:Nino Barbieri via Wikimedia Commons

The Alpine ibex will be a clear winner, its horns growing in the warmer weather
Image: User:Nino Barbieri via Wikimedia Commons

By Tim Radford

Not all species will be damaged by climate change. Recent research has identified some of those who will benefit from a warmer world, as well as some of the losers.

LONDON, 25 December – And now for the good news: climate change could actually make life better for some creatures. The ibex in the Swiss Alps may find an extra spring in its step. The roly-poly pika of the American northwest might find it has gained an edge over its predators because it is adapted to a high fibre diet.

The news is not uniformly good: climate change is already taking its toll of Arctic peregrine falcons and chinstrap penguins on the Antarctic peninsula. But change is not always for the worse.

A team of scientists led by the Swiss Federal Institute of Forest, Snow and Landscape Research reports in Ecology Letters that they used dendrochronological techniques (the scientific method of dating based on the analysis of patterns of tree rings) to monitor the response of the mammal Capra ibex to patterns of climate change.

Climate scientists have been using these growth rings in tree trunks to read evidence of seasonal and annual change; the growth rings in the large, curved horns of the male Alpine ibex or wild goat would also tell a story.

They analysed more than 42,000 increments of horn growth from more than 8,000 male ibex, collected since 1964, in annual culls and hunting programmes regulated by the Swiss government. The ibex is a protected species, so careful records are kept of each kill.

Warmer weather, longer horns

To make sense of the data, the researchers had to allow for the age of the animal at death, and the year of its death. But a pattern began to emerge: horn growth is affected by changes in European springtime temperatures.

Warmer temperatures between March and May mean an earlier snowmelt and more and tastier alpine grasses and herbs for the ibex – and thus better vitality.

Such research was intended primarily to check on the health of the ibex population: the creature was once hunted almost to extinction.

The roly-poly pika of Oregon state is a little lagomorph – a member of the rabbit family – that tends to live in rockslides near sea level. In hot weather, most animals would be forced to leave the shade and shelter to go in search of food – and become easy prey for weasels or hawks or death from overheating.

The moss-eating, fibre-loving roly-poly pika has a bright future Image: Courtesy of Mallory Lambert, University of Utah

The moss-eating, fibre-loving roly-poly pika has a bright future
Image: Courtesy of Mallory Lambert, University of Utah

But the roly-poly pika has, according to a new study in the Journal of Mammalogy, one thing in its favour: it can flourish on a diet of moss. “Mosses are 80% fibre. It’s a bit like eating paper”, says the research author Jo Varner. “By consuming mosses that grow on the rockslides where they live, the pikas are released from foraging outside the safety and shady heat buffer of the rocks.

“Few herbivores consume moss because it’s so nutritionally deficient. The pikas in our study set a new record for moss in a mammal’s diet: 60%”.

Successful adjustment

The pika is sensitive to heat: the animal is almost spherical, with a thick fur coat and a high metabolic rate which should make it peculiarly at risk from global warming – either it moves higher up the mountain with each rise in temperature, or it dies. The Oregon state pikas seem to have adjusted to change by staying on the warmer, wetter slopes and adapting their diet.

Chinstrap penguins of the Antarctic peninsula, however, have been conspicuous victims of a warming world, according to US researchers who have been tracking population changes.

The Antarctic peninsula has warmed by 3°C in summer and 5°C in winter in the last 60 years. The researchers had started with the hypothesis that tourism – on the increase in the region – might be affecting penguin populations: however, they found that even at sites that experienced little or no tourism, there had been declines of as much as 50% in the population.

A study of Arctic peregrines in Canada, however, found an unequivocal connection between declines in falcon numbers and global warming. A team monitored nestboxes near Hudson Bay, and found that more than one third of peregrine chick deaths were caused by rain, linked to warmer summer temperatures.

“The nestlings died from hypothermia and in some cases from drowning in their flooded nests. Without constant parental care, they are most vulnerable to cold and wet conditions in the first three weeks of life”, said the research author, Alistair Franke of the University of Alberta. – Climate News Network