Category: Environment

{Global changes in temperature due to human-induced climate change have already impacted every aspect of life on Earth from genes to entire ecosystems, with increasingly unpredictable consequences for humans — according to a new study published in the journal Science.}

The study found a staggering 80 percent of 94 ecological processes that form the foundation for healthy marine, freshwater and terrestrial ecosystems already show signs of distress and response to climate change.

Impacts to humans include increased pests and disease outbreaks, reduced productivity in fisheries, and decreasing agriculture yields.

“There is now clear evidence that, with only a ~1 degree C of warming globally, very major impacts are already being felt,” said study lead author Dr Brett Scheffers of the University of Florida. “Genes are changing, species’ physiology and physical features such as body size are changing, species are rapidly moving to keep track of suitable climate space, and there are now signs of entire ecosystems under stress.”

Said the study’s senior author, Dr. James Watson from the Wildlife Conservation Society and University of Queensland: “The level of change we have observed is quite astonishing considering we have only experienced a relatively small amount of climate change to date. It is no longer sensible to consider this a concern for the future. Policy makers and politicians must accept that if we don’t curb greenhouse gas emissions, an environmental catastrophe is likely.”

But the study also points to hope as many of the responses observed in nature could be applied by people to address the mounting issues faced under changing climate conditions. For example, improved understanding of the adaptive capacity in wildlife can be applied to our crops, livestock and fisheries. This can be seen in crops such as wheat and barley, where domesticated crops are crossed with wild varieties to maintain the evolutionary potential of varieties under climate change.

{No matter what we do, it is inevitable that the record hot year of 2015 will soon become an average year.}

The hottest year on record globally in 2015 could be just another average year by 2025 if carbon emissions continue to rise at their current rate, according to new research published in the Bulletin of American Meteorological Society.

And no matter what action we take, human activities had already locked in a “new normal” for global average temperatures that would occur no later than 2040, according to lead author Dr Sophie Lewis, from the Australian National University (ANU) hub of the ARC Centre of Excellence for Climate System Science (ARCCSS).

However, while annual global average temperatures were locked in, it was still possible with immediate and strong action on carbon emissions to prevent record breaking seasons from becoming average — at least at regional levels.

“If we continue with business-as-usual emissions, extreme seasons will inevitably become the norm within decades and Australia will be the canary in the coal mine that will experience this change first,” said Dr Lewis.

“That means the record hot summer of 2013 in Australia — when we saw temperatures approaching 50°C in parts of Australia, bushfires striking the Blue Mountains in October, major impacts to our health and infrastructure and a summer that was so hot it became known as the “angry summer” — could be just another average summer season by 2035.

“But if we reduce emissions drastically to the lowest pathway recommended by the Intergovernmental Panel on Climate Change (RCP2.8), then we will never enter a new normal state for extreme seasons at a regional level in the 21st Century .”

The idea of what the term “new normal” actually means was the cornerstone of this new research. It has often been used when talking about climate change but it had seldom been clearly defined. Dr Lewis and colleagues have now developed a scientific definition for the term.

“Based on a specific starting point, we determined a new normal occurred when at least half of the years following a record year were cooler and half warmer. Only then can a new normal state be declared,” she said.

After this process was used by the researchers to determine new normal conditions for global average temperatures, it was used again to examine record hot seasonal temperatures at a regional level.

Using the National Computational Infrastructure supercomputer at ANU to run climate models, the researchers explored when new normal states would appear under the Intergovernmental Panel for Climate Change’s four emissions pathways.

The research team then examined seasonal temperatures from December to February across Australia, Europe, Asia and North America.

The results revealed that while global average temperatures would inevitably enter a new normal under all emissions scenarios, this wasn’t the case at seasonal and regional levels.

“It gives us hope to know that if we act quickly to reduce greenhouse gases, seasonal extremes might never enter a new normal state in the 21st Century at regional levels for the Southern Hemisphere summer and Northern Hemisphere winter,” Dr Lewis said.

“But if If we don’t act quickly Australia’s “angry summer” of 2013 may soon be regarded as mild. Imagine for a moment, if a summer season like 2013 became average. The likely impacts of an extremely hot year in 2035 would beyond anything our society has experienced.”

{Study has important implications for global .}

A new study by University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science researchers found that the Indian Ocean’s Agulhas Current is getting wider rather than strengthening. The findings, which have important implications for global climate change, suggest that intensifying winds in the region may be increasing the turbulence of the current, rather than increasing its flow rate.

Using measurements collected during three scientific cruises to the Agulhas Current, the Indian Ocean’s version of the Gulf Stream, researchers estimated the long-term transport of the current leveraging 22 years of satellite data. They found the Agulhas Current has broadened, not strengthened, since the early 1990s, due to more turbulence from increased eddying and meandering.

One of the strongest currents in the world, the Agulhas Current flows along the east coast of South Africa, transporting warm, salty water away from the tropics toward the poles. The Agulhas, which is hundreds of kilometers long and over 2,000-meters deep, transports large amounts of ocean heat and is considered to have an influence not only on the regional climate of Africa, but on global climate as part of the ocean’s global overturning circulation.

“Changes in western boundary currents could exacerbate or mitigate future climate change,” said Lisa Beal, a UM Rosenstiel School professor of ocean sciences and lead author of the study. “Currently, western boundary current regions are warming at three times the rate of the rest of the world ocean and our research suggests this may be related to a broadening of these current systems.”

Previous studies have suggested that accelerated warming rates observed over western boundary current regions, together with ongoing strengthening and expansion of the global wind systems predicted by climate models relate to an intensification and pole-ward shift of western boundary currents as a result of human-made climate change.

“To find decades of broadening, rather than intensification, profoundly impacts our understanding of the Agulhas Current and its future role in climate change,” said study co-author Shane Elipot, a UM Rosenstiel School associate scientist. “Increased eddying and meandering could act to decrease poleward heat transport, while increasing coastal upwelling and the exchange of pollutants and larvae across the current from the coast to the open ocean.”

{Extreme weather increasingly linked to global warming.}

The World Meteorological Organization has published a detailed analysis of the global climate 2011-2015 — the hottest five-year period on record — and the increasingly visible human footprint on extreme weather and climate events with dangerous and costly impacts.

The record temperatures were accompanied by rising sea levels and declines in Arctic sea-ice extent, continental glaciers and northern hemisphere snow cover.

All these climate change indicators confirmed the long-term warming trend caused by greenhouse gases. Carbon dioxide reached the significant milestone of 400 parts per million in the atmosphere for the first time in 2015, according to the WMO report which was submitted to U.N. climate change conference.

The Global Climate 2011-2015 also examines whether human-induced climate change was directly linked to individual extreme events. Of 79 studies published by the Bulletin of the American Meteorological Society between 2011 and 2014, more than half found that human-induced climate change contributed to the extreme event in question. Some studies found that the probability of extreme heat increased by 10 times or more.

“The Paris Agreement aims at limiting the global temperature increase to well below 2 ° Celsius and pursuing efforts towards 1.5 ° Celsius above pre-industrial levels. This report confirms that the average temperature in 2015 had already reached the 1°C mark. We just had the hottest five-year period on record, with 2015 claiming the title of hottest individual year. Even that record is likely to be beaten in 2016,” said WMO Secretary-General Petteri Taalas.

“The effects of climate change have been consistently visible on the global scale since the 1980s: rising global temperature, both over land and in the ocean; sea-level rise; and the widespread melting of ice. It has increased the risks of extreme events such as heatwaves, drought, record rainfall and damaging floods,” said Mr Taalas.

The report highlighted some of the high-impact events. These included the East African drought in 2010-2012 which caused an estimated 258,000 excess deaths and the 2013-2015 southern African drought; flooding in South-East Asia in 2011 which killed 800 people and caused more than US$40 billion in economic losses, 2015 heatwaves in India and Pakistan in 2015, which claimed more than 4,100 lives; Hurricane Sandy in 2012 which caused US$67 billion in economic losses in the United States of America, and Typhoon Haiyan which killed 7,800 people in the Philippines in 2013.

The report was submitted to the Conference of the Parties of the United Nations Framework Convention on Climate Change. The five-year timescale allows a better understanding of multi-year warming trends and extreme events such as prolonged droughts and recurrent heatwaves than an annual report.

WMO will release its provisional assessment of the state of the climate in 2016 on 14 November to inform the climate change negotiations in Marrakech, Morrocco.

2011-2015 was the warmest five-year period on record globally and for all continents apart from Africa (second warmest). Temperatures for the period were 0.57 °C (1.03 °F) above the average for the standard 1961-1990 reference period. The warmest year on record to date was 2015, during which temperatures were 0.76 °C (1.37 °F) above the 1961-1990 average, followed by 2014. The year 2015 was also the first year in which global temperatures were more than 1 °C above the pre-industrial era.

Global ocean temperatures were also at unprecedented levels. Globally averaged sea-surface temperatures for 2015 were the highest on record, with 2014 in second place. Sea-surface temperatures for the period were above average in most of the world, although they were below average in parts of the Southern Ocean and the eastern South Pacific.

A strong La Niña event (2011) and powerful El Niño (2015/2016) influenced the temperatures of individual years without changing the underlying warming trend.

Ice and snow

Arctic sea ice continued its decline. Averaged over 2011-2015, the mean Arctic sea-ice extent in September was 4.70 million km2, 28% below the 1981-2010 average. The minimum summer sea-ice extent of 3.39 million km2 in 2012 was the lowest on record.

By contrast, for much of the period 2011- 2015, the Antarctic sea-ice extent was above the 1981-2010 mean value, particularly for the winter maximum.

Summer surface melting of the Greenland ice sheet continued at above-average levels, with the summer melt extent exceeding the 1981-2010 average in all five years from 2011 to 2015. Mountain glaciers also continued their decline.

Northern hemisphere snow cover extent was well below average in all five years and in all months from May to August, continuing a strong downward trend.

Sea level rise

As the oceans warm, they expand, resulting in both global and regional sea-level rise. Increased ocean heat content accounts for about 40% of the observed global sea-level increase over the past 60 years. A number of studies have concluded that the contribution of continental ice sheets, particularly Greenland and west Antarctica, to sea-level rise is accelerating.

During the satellite record from 1993 to present, sea levels have risen approximately 3 mm per year, compared to the average 1900-2010 trend (based on tide gauges) of 1.7 mm per year.

Climate change and extreme weather

Many individual extreme weather and climate events recorded during 2011-2015 were made more likely as a result of human-induced (anthropogenic) climate change. In the case of some extreme high temperatures, the probability increased by a factor of ten or more.

Examples include the record high seasonal and annual temperatures in the United States in 2012 and in Australia in 2013, hot summers in eastern Asia and western Europe in 2013, heatwaves in spring and autumn 2014 in Australia, record annual warmth in Europe in 2014, and a heatwave in Argentina in December 2013.

The direct signals were not as strong for precipitation extremes (both high and low). In numerous cases, including the 2011 flooding in South-East Asia, the 2013-2015 drought in southern Brazil, and the very wet winter of 2013-2014 in the United Kingdom, no clear evidence was found of an influence from anthropogenic climate change. However, in the case of the extreme rainfall in the United Kingdom in December 2015, it was found that climate change had made such an event about 40% more likely.

Some impacts were linked to increased vulnerability. A study of the 2014 drought in south-east Brazil found that similar rainfall deficits had occurred on three other occasions since 1940, but that the impacts were exacerbated by a substantial increase in the demand for water, due to population growth.

Some longer-term events, which have not yet been the subject of formal attribution studies, are consistent with projections of near- and long-term climate change. These include increased incidence of multi-year drought in the subtropics, as manifested in the 2011-2015 period in the southern United States, parts of southern Australia and, towards the end of the period, southern Africa.

There have also been events, such as the unusually prolonged, intense and hot dry seasons in the Amazon basin of Brazil in both 2014 and 2015, which are of concern as potential “tipping points” in the climate system.

{Ancient feeding marks from hungry insects in South American leaf fossils are shedding new light on the mass extinction that wiped out the dinosaurs.}

Scientists analyzed insect feeding damage to thousands of leaf fossils from Patagonia, Argentina, over the Cretaceous-Paleogene boundary, and found evidence that ecosystems there recovered twice as fast as in the United States.

The findings, published today (Nov. 7) in the new journal Nature Ecology & Evolution, offer important evidence of how terrestrial ecosystems outside the U.S. responded after an asteroid struck Chicxulub, Mexico, some 66 million years ago, marking the end of the Cretaceous period.

“Most of what we know about terrestrial recovery comes from the western interior United States, relatively close to the Chicxulub crater, which has limited our knowledge of recovery in the rest of the world,” said Michael Donovan, doctoral student in geosciences, Penn State and lead author on the paper. “We are giving another view of what was happening during that time, far away from the impact site.”

Donovan and his international team found leaf-mining insects completely disappeared in Patagonia during the extinction event, as previous studies show happened in the U.S. But unlike the U.S., where it took 9 million years to return to pre-impact insect diversity, recovery happened in just 4 million years in Patagonia.

“Insects and plants are the most diverse multicellular organisms in the world, and they are known to respond to major environmental changes,” Donovan said. “So they make a great resource to study our past.”

The team analyzed 3,646 fossils from Patagonia searching for signs of leaf miners — insect larvae named for the type of damage they cause tunneling though leaves for food. These feeding paths, and the insects’ droppings, both create distinctive patterns and can be compared among fossils at different sites.

“Michael developed this technique of very detailed examination of leaf miners, and new methods for looking at the critical differences among these feeding trails in fossil leaves,” said Peter Wilf, professor of geosciences, Penn State and paper co-author. “He’s teased apart this huge story from the tiny differences in how baby insects did their business in leaves that lived 66 million years ago.”

The scientists found no evidence that individual leaf miner species from the Cretaceous survived the extinction event in Patagonia, indicating the far south did not offer a refuge for the insects as Donovan’s team first hypothesized.

“There was no evidence of survival, which is similar to what I found when working on my master’s research at the Mexican Hat site in Montana,” Donovan said. “But what we do find in Patagonia is a pretty diverse group of novel leaf miners that appear much sooner than in the western U.S.”

The researchers suggested Patagonia’s further distance from the impact crater in Mexico and its ground zero effects could be responsible for insect diversity returning more rapidly to the southern location.

“The richness of plant-insect associations that we observed during the recovery may be a contributing factor to insect biodiversity in modern South America,” Donovan said. “We can look far into the past and see these patterns that influence life on Earth as it is today.”

Wilf said the study, the first of its kind outside the western U.S., can help scientists answer questions about modern global biodiversity.

“Our modern world is the legacy of this disaster,” Wilf said. “As we try to understand how today’s biodiversity evolved and why Earth’s millions of species live where they do, the global impact of this major catastrophe is a big sleeping elephant in a dark room — we can’t see much of it and just don’t know enough about it. As we turn on the lights, we see more of the elephant and understand our world better. This paper is a welcome step in that direction.”

{Life in the wild harbors the risk of predation, food shortages, harsh climates, and intense competition. Zoo animals, by contrast, are protected from these dangers. UZH researchers were part of an international team that studied over 50 mammalian species to determine whether the animals live longer in zoos than in the wild.}

How long do animals live? Although the question seems trivial, it is not easy to answer — especially in the case of free-ranging animals, as it is extremely difficult to determine accurate dates of birth and death of all members of a specific population. By comparison, zoos meticulously record the births and deaths of the animals in their care. Now, however, studies of known-aged individuals in the wild are available, making it possible to compare demographic parameters, including longevity.

{{Smaller species attain greater longevity}}

The research team led by the University of Lyon and the University of Zurich assessed the demographic parameters of more than 50 mammalian species. The scientists discovered that longevity was higher at the zoo for more than 80% of the mammals studied — species such as African buffalos, reindeer, zebras, beavers, or lions. “All 15 carnivore species in our dataset attained greater longevity at the zoo,” states Marcus Clauss, professor of nutrition and biology of zoo and wild animals at the University of Zurich. “It seems that even for predators, life in the wild is not necessarily without its perils.”

The greater longevity at the zoo was particularly prominent among smaller species having a generally shorter lifespan, for instance, tree shrews, weasles, white-tailed deer, or African wild dogs. The juveniles and adults of these species typically fall victim to predators or to intraspecific competition in the wild, thus reducing their average longevity. “With regard to long-lived species that generally have lower mortality rates in the wild, there is less that zoos can protect them from. As such, the effect is not as great and, indeed, in some cases is even reversed,” says Clauss.

{{Time lag in success measurement}}

The researchers emphasize that their results reflect historic animal husbandry conditions at zoos and not currently practiced conditions. “In order to evaluate longevity of a population, we only consider the ‘extinct cohort’ — that is, a group of individuals born in a certain period, all of which have died. Individuals that are still alive would skew the analysis,” says Dr. Jean-François Lemaître from the University of Lyon and researcher at the Centre National de le Recherche Scientifique (CNRS).This means that changes in the husbandry of long-lived animals introduced in the last decade have not yet influenced the results, as many members of the cohorts affected by these changes are still alive. Whether changes made today influence longevity can therefore only be determined thirty years from now.

{{Zoo ethics}}

The researchers emphasize that longevity as a single contributing factor cannot support complex ethical judgements on keeping animals. “A thorough assessment of the husbandry of a species demands consideration of many other aspects. The most important insight of our study is possibly that it demonstrates that life in the wild is not a life in paradise,” says Prof. Clauss.

{The birds have some clever adaptations to keep their noggins safe.}

During election season, everyone can relate to woodpeckers: We all feel like banging our heads against the wall.

The birds handle it better, though, so Weird Animal Question of the Week was pleased to look into Derek Halas’ question: “Why don’t woodpeckers get headaches?”

{{Little Drummer Bird}}

It’s a tough one to answer, says Walter Koenig, an ornithologist at Cornell University via email. But, he says, if pecking caused pain and injury, “presumably they wouldn’t be around for very long”—a hurt bird would likely succumb to predators.

There are more than 300 species of woodpeckers worldwide, and they peck wood for a variety of reasons: To excavate nest cavities, dig for insects or sap, or create holes to store food.

When selecting wood, the birds usually target trees weakened by fungal decay, which are easier to crack, Jerome Jackson, a behavioral ecologist at Florida Gulf Coast University, says via email.

The tapping is also “usually done with glancing blows—not a direct hit—thus not so hard on the woodpecker,” he says. (See “Weasel Rides Woodpecker in Viral Photo—But Is It Real?”)

Some woodpeckers practice drumming —a super-fast pecking that attracts mates and defends territory—on a resonant surface, like a hollow tree. That allows for a louder noise while avoiding punishing impacts.

Acorn woodpeckers of North and Central America have another strategy: They carve out individual holes into trees, each just big enough to jam “squeeze in a single acorn”—storage for leaner times, Jackson says.

In a recent incident in California, acorn woodpeckers stashed 300 pounds of acorns into a wireless antenna, disrupting communication in nearby towns. (Watch the incredible video.)

{{Bird Brains}}

Woodpeckers also have, well, a head for pecking.

For one, woodpeckers have tiny brains—just 0.07 ounce. The bigger the brain, the higher the mass, and thus the higher the risk of brain injury, says Lorna Gibson, a professor of materials science and engineering at MIT who has studied woodpecker brains.

“Size is the most important thing,” says Gibson, an avid birdwatcher who documented her results in a video series.

Another factor that protects woodpecker noggins is the limited time the tree and their bill are in contact, she says. It’s brief—just one-half to one millisecond. By comparison, a typical human head injury happens between about 3 and 15 milliseconds.

The woodpecker’s capacity to absorb blows has even inspired a system to reduce concussions in sports such as football.

{{Bone-Headed}}

The outside of woodpecker skulls made of dense bone, while the inside is porous bone, Gibson says.

The force applied during pecking are “distributed around the skull to the sturdy bone at the base and the back,” keeping the pressure off the brain, says Richard Prum, evolutionary ornithologist at Yale University via email. (Related: “Woodpeckers are Pros at Protecting Their Brains.”)

Woodpecker brains also fit snugly in those skulls, preventing the organ from banging around. The orientation of the brain is also important, MIT’s Gibson says: It sits at an angle toward the back of its head, like a half orange with the flat side facing the front. That creates more surface area to absorb those exacting blows.

A 2011 study suggested that the hyoid apparatus, a bone-and-muscle structure that wraps around the woodpecker skulls, also keeps the brain safe.

“The bottom line,” Prum says, “is good evolutionary design.”

{As an international study conducted by the University of Zurich based on 3D reconstructions of animal skeletons reveals for the first time: Herbivorous mammals have bigger bellies than their usually slim carnivorous counterparts. In dinosaurs, however, there is no notable difference between carnivores and herbivores.}

What do enormous dinosaurs have in common with tiny shrews? They are both four-legged vertebrates, otherwise known as tetrapods. In the course of evolution, tetrapods developed various body shapes and sizes — from the mouse to the dinosaur — to adapt to different environments. Their feeding habits range from pure herbivory to fierce carnivory, and their body structure reflects this feeding diversity. As plants are usually more difficult to digest than meat, herbivores are thought to need larger guts and more voluminous bellies. Nevertheless, this hypothesis had never been tested scientifically.

{{No difference in dinosaurs}}

A European team of researchers headed by the University of Zurich and the Technical University Berlin has now studied the shape of the ribcage in more than 120 tetrapods — from prehistoric times up to the present day. With the aid of photogrammetry and computer imaging techniques, the scientists produced a 3D database for skeletons of dinosaurs, reptiles, birds, mammals and fossil synapsids (mammal-like reptiles). Using the computer-based visual evaluation of this data, they reconstructed the volume of the body cavity, which is delineated by the spinal column, the ribcage and the pelvis.

The result: On average, herbivorous mammals have a body cavity that is twice as big as carnivores of a similar body size. “This is clear evidence that plant-eating mammals actually have larger guts,” explains Marcus Clauss, a professor of comparative digestive physiology in wild animals at UZH. Far more surprising, however, is the fact that this pattern is not evident among the remaining tetrapods. “We were amazed that there wasn’t even the slightest indication of a difference between herbivores and carnivores in dinosaurs,” explains the first author. Numerous fossilized species were examined in the study — from the earliest amphibians to the largest herbivorous dinosaurs and mammoths.

{{Fundamental difference in morphology}}

On the one hand, the results can indicate that it is difficult to reconstruct dinosaur skeletons reliably. “On the other hand,” explains Clauss, “the discovery reveals that there’s a fundamental difference in morphological principles between mammals and other tetrapods.” For instance, the scientist suspects that a different respiratory system might be responsible for the divergent effect of the diet on the body structure in mammals and dinosaurs.

{The brains of wild cats don’t necessarily respond to the same evolutionary pressures as those of their fellow mammals, humans and primates, indicates a surprising new study led by a Michigan State University neuroscientist.}

Arguably, the fact that people and monkeys have particularly large frontal lobes is linked to their social nature. But cheetahs are also social creatures and their frontal lobes are relatively small. And leopards are solitary beasts, yet their frontal lobes are actually enlarged.

So what gives? Sharleen Sakai, lead investigator of the National Science Foundation-funded research, said the findings suggest that multiple factors beyond sociality may influence brain anatomy in carnivores.

“Studying feline brain evolution has been a bit like herding cats,” said Sakai, MSU professor of psychology and neuroscience. “Our findings suggest the factors that drive brain evolution in wild cats are likely to differ from selection pressures identified in primate brain evolution.”

Sakai and colleagues examined 75 wild feline skulls, representing 13 species, obtained from museum collections, including those at MSU. The researchers used computed tomography (CT) scans and sophisticated software to digitally “fill in” the areas where the brains would have been. From that process, they determined brain volume.

Sakai’s lab is interested in uncovering the factors that influence the evolution of the carnivore brain. One explanation for large brains in humans and primates is the effect of sociality. The idea is that dealing with social relationships is more demanding than living alone and results in bigger brains, especially a bigger frontal cortex.

“We wanted to know if this idea, called the ‘social brain’ hypothesis, applied to other social mammals, especially carnivores and, in particular, wild cats,” Sakai said.

Of the 13 wild feline species examined, 11 are solitary and two — lions and cheetahs — are social.

Here are some of the key findings of the research:

*Surprisingly, overall brain size did not differ, on average, between the social and solitary species of wild cats. But the part of the brain that includes the frontal cortex did differ between the two species.

*The female lion had the largest frontal cortex. Female lions are highly social, working together to protect and feed their young, hunt large prey and defend their territory. In contrast, males may live alone and may be dominant in a pride for only a few years. The larger frontal cortex in females compared to male lions and the other wild cats may reflect the lionesses’ demands of processing social information necessary for life in the pride.

*The social cheetahs, in contrast, had the smallest overall brains and the smallest frontal cortex of the wild cats. Small brains weigh less and require less energy, factors that might contribute to the cheetah’s remarkable running speeds. “Cheetah brain anatomy is distinctive and differs from other wild cats,” Sakai said. “The size and shape of its brain may be a consequence of its unusual skull shape, an adaptation for high-speed pursuits.”

*Leopards’ frontal lobes were relatively large. Although the leopard is solitary, it is noted for its flexibility and adaptability — behaviors associated with enhanced brain processing and larger brain size in other species.

{Increasingly frequent extreme weather events could threaten butterfly populations in the UK and could be the cause of recently reported butterfly population crashes, according to research from the University of East Anglia (UEA).}

Researchers investigated the impact of Extreme Climatic Events (ECEs) on butterfly populations. The study shows that the impact can be significantly positive and negative, but questions remain as to whether the benefits outweigh the negative effects.

While it is well known that changes to the mean climate can affect ecosystems, little is known about the impact of short-term extreme climatic events (ECEs) such as heatwaves, heavy rainfall or droughts.

Osgur McDermott-Long, PhD student and lead author from the School of Environmental Sciences at UEA, said: “This is the first study to examine the effects of extreme climate events across all life stages of the UK butterflies from egg to adult butterfly. We wanted to identify sensitive life stages and unravel the role that life history traits play in species sensitivity to ECEs.”

The researchers used data from the UK Butterfly Monitoring Scheme (UKBMS), a high-quality long-term dataset of UK butterfly abundances collected from over 1,800 sites across the UK, spanning 37 years, to examine the effects of weather data and extreme events (drought, extremes of rain, heat and cold) on population change.

The team looked at resident species of butterflies, those which only breed once in a year, and those having more than one brood annually. Multi-brood species were found to be more vulnerable than single brood species and in general extremes of temperature rather than precipitation were found to influence changes in butterfly populations.

Dr Aldina Franco, co-author said: “A novel finding of this study was that precipitation during the pupal (cocoon) life-stage was detrimental to over one quarter of the species. This study also found that extreme heat during the ‘overwintering’ life stage was the most detrimental extreme weather event affecting over half of UK species. This may be due to increased incidents of disease or potentially extreme hot temperatures acting as a cue for butterflies or their larvae to come out from overwintering too early and subsequently killed off by temperatures returning to colder conditions.”

In addition to the negative impacts, the authors found that some life stages may benefit from climatic extreme weather, with extreme heat in the adult stage causing a positive population change in over one third of the UK species.

Dr Franco, added: “This is not an unexpected finding given that butterflies are warm loving creatures. Years with extreme warm summers and winters may have mixed effects. For example, this year was terrible for butterflies, although the summer was warm the number of butterflies counted during the Big Butterfly Count was particularly low. Our study indicates that this could have resulted from the detrimental effects of the warm winter, for example the recent low counts1 of Gatekeeper, Common Blue, Comma, Peacock and Small Tortoiseshell butterflies could be explained by our results due to their negative response to warm winters which was just experienced2.”

Mr McDermott Long said: “The study has demonstrated previously unknown sensitivities of our UK butterflies to extreme climatic events, which are becoming more frequent with climate change. Some of these effects are undoubtedly putting future populations at risk, such as extremely warm winters, however we’ve seen that warm and even climatically extreme hot summers may actually benefit butterflies.

Further research is needed regarding the balance of the importance that these variables could have, to see if the benefits of warmer summers will be outweighed by the detrimental winter effects.”

Dr Tom Brereton from Butterfly Conservation and a co-author of the study, said: “If we are to mitigate against extreme events as part of conservation efforts, in particular, we need a better understanding of the habitat conditions which can lead to successful survival of adult, pupal and overwintering life stages of UK butterflies in these situations.”

This work is part of Osgur McDermott-Long’s PhD project funded by the University of East Anglia and with Butterfly Conservation and the Biological Records Centre as project partners. Prof Rachel Warren, Dr Aldina Franco and Dr Jeff Price and are the PhD supervisors. External co-authors include Dr Tom Brereton from Butterfly Conservation and Dr Marc Botham from Centre for Ecology and Hydrology.

‘Sensitivity of UK butterflies to local climatic extremes: which life stages are most at risk?’ is published in The Journal of Animal Ecology.