Tag Archives: Climate change

Climate change risk for animals living in prime conditions


(Physorg, University of Exeter 13 June 2017)

Animals living in areas where conditions are ideal for their species have less chance of evolving to cope with climate change, new research suggests.

The study examined whether birds might be able to evolve to adapt to changes to the natural environment within their range – the geographical area where the birds nest, feed, migrate and hibernate over the course of their lifetimes.

It found that populations that experienced both the most favourable conditions, usually at the centre of their species’ range, and toughest conditions found at the very edges of the range had the lowest evolutionary potential. The populations that displayed the greatest potential to evolve with changing conditions were found living between the two extremes, the study showed.

The research team, including scientists from the University of Oviedo, University of Málaga, Doñana Biological Station, the University of Exeter and the University of Western Australia, studied data on 12 European bird species.

“We were surprised to find reduced evolutionary potential among birds living in the centre of a species’ range,” said co-author Dr Regan Early, of the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.

“The reasons for this are not clear, but high levels of competition in prime areas might lead birds with certain traits to survive – meaning little genetic variety in the population and consequently little scope for evolution.

“We found that populations of birds on the edge of a species’ range – like those in the centre – had a reduced ability to evolve,” said lead author Dr Jesus Martinez-Padilla, of the University of Oviedo.

“This is probably because they already live in tough conditions for their species. As climate warms, these populations will probably have to move or die out. This is what might happen to populations of the Pied Flycatcher in southern Europe. These populations have little genetic variation compared to northern populations, so they won’t be able to adapt to a changing climate. The birds living in places neither the best nor the most hostile environmental conditions – appear to have the best evolutionary potential.”

“Evolution could prolong the period in which these populations are able to survive in situ as conditions worsen, or allow these populations to evade local extinction altogether”, Dr Regan Early pointed out.

Understanding the likelihood that evolution may occur could improve our understanding of how species will respond to climate change, the scientists say.

The paper, published in the journal Proceedings of the Royal Society B, is entitled: “Evolvability meets biogeography: evolutionary potential decreases at high and low environmental favourability.”

Finding new homes won’t help emperor penguins cope with climate change

(ScienceDaily, Woods Hole Oceanographic Institution 7 June 2017; Photo: Stephanie Jenouvrier)

Unlike other species that migrate successfully to escape the wrath of climate change, a new study shows that dispersal may help sustain global Emperor penguin populations for a limited time, but, as sea ice conditions continue to deteriorate, the 54 colonies that exist today will face devastating declines by the end of this century.

If projections for melting Antarctic sea ice through 2100 are correct, the vanishing landscape will strip Emperor penguins of their breeding and feeding grounds and put populations at risk. But like other species that migrate to escape the wrath of climate change, can these iconic animals be spared simply by moving to new locations?

According to new research led by the Woods Hole Oceanographic Institution (WHOI), they cannot. Scientists report that dispersal may help sustain global Emperor penguin populations for a limited time, but, as sea ice conditions continue to deteriorate, the 54 colonies that exist today will face devastating declines by the end of this century. They say the Emperor penguin should be listed as an endangered species. The study was published in the June 6, 2017 edition of the journal Biological Conservation.

“We know from previous studies that sea ice is a key environmental driver of the life history of Emperor penguins, and that the fifty-percent declines we’ve seen in Pointe Géologie populations along the Antarctic coast since the 1950s coincide with warmer climate and sea ice decline,” said Stephanie Jenouvrier, WHOI biologist and lead author of the study. “But what we haven’t known is whether or not dispersal could prevent or even reverse future global populations. Based on this study, we conclude that the prospects look grim at the end of 2100, with a projected global population decline as low as 40 percent and up to 99 percent over three generations. Given this outlook, we argue that the Emperor penguin is deserving of protection under the Endangered Species Act.”

The relationship between Emperor penguins and sea ice is a fragile one: Too little sea ice reduces the availability of breeding sites and prey; too much sea ice means longer hunting trips for adults, which in turn means lower feeding rates for chicks. Only in the past few years have scientists become aware of the penguins’ ability to migrate to locations with potentially more optimal sea ice conditions.

“Before 2014, our studies of the impacts of climate change on these animals hadn’t factored in movement among populations,” said Jenouvrier. “But between then and now, a number of satellite imagery studies and genetic studies have confirmed their ability to disperse, so this was an important new variable to work into the equation.”

To determine whether migration will ultimately help Emperor penguins defend against population decline, Jenouvrier worked with mathematicians to develop a sophisticated demographic model of penguin colonies based on data collected at Pointe Géologie, one of the few places where long-term Emperor penguin studies have been conducted.

The model tracks the population connectivity between penguins as they take their chances moving to new habitats offering better sea ice conditions. “It’s like we’ve added roads between the cities the penguins live in and now get to see what happens when they travel between them,” she said.

A range of model inputs were used, including penguin dispersal distance, behavior and rate of migration. The model also factors in end-of-century sea ice forecasts from climate projection models to predict the fate of each colony.

According to Shaye Wolf, climate science director for the Center for Biological Diversity, the new modeling technique is key to informing policy around “much-needed protections” for the Emperor penguin.

“Dr. Jenouvrier’s research has been at the forefront of advancing our understanding of how climate change is impacting these animals now and into the future,” she said.

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More frequent extreme ocean warming could further endanger albatross

More frequent extreme ocean warming could further endanger albatross

(Physorg 31 May 2017; Photo: Henri Weimerskirch)

As Earth warms due to human-caused climate change, extreme climatic events like heat waves, droughts, and spikes in ocean temperatures have increased and are projected to become even more common by the end of this century.

As scientists grapple with the behavioral, ecological and evolutionary impacts of extreme climatic events, the journal Philosophical Transactions of the Royal Society B created a special June issue to explore what is known on the topic and pioneer new approaches to this challenging and rapidly expanding field of study. The issue, which was published online May 8, 2017, was co-edited by Wood Hole Oceanographic institution (WHOI) biologist Stephanie Jenouvrier.

“The ecological effects that these extreme climatic events will have on already stressed ecosystems are not known,” says Jenouvrier, a population biologist, “but understanding the impacts is crucial to future conservation efforts.”

In addition to her role as co-editor, Jenouvrier is also co-author of a study featured in the special issue, which examines how extreme ocean warming events further stress an already declining population of black-browed albatross in the French Southern and Antarctic Lands.

“Previous studies on the effects of climate change on ecosystems have mainly focused on changes in mean temperature—the average temperature during a given time period,” says Jenouvrier.

By looking at average temperatures from year-to-year, scientists can identify trends to determine if temperatures are warming, staying the same or getting colder and study how these trends affect ecosystems. However, because the trend reflects average temperatures, it “smoothes out” variability and extreme events and the dramatic effects those events can have on species and ecosystems. It is the effect of such variability and extreme events in ocean temperature on an albatross population that Jenouvrier and her team were determined to study.

“Changes in variability can have very different consequences on population dynamics for both animals and plants,” Jenouvrier says.

To assess impacts to albatrosses, Jenouvrier and her coauthors from the Centre d’Etudes Biologiques de Chizé in France, examined sea surface temperature data and records of extreme warming events since 1978 on albatrosses breeding at Kerguelen Island. To do so, they developed computer demographic models to compare the effects of changes in both the mean (average) sea surface temperature and the sea surface temperature variability on the population growth and proportion of age groups within the population.

A change in temperature variability leads to more frequent warmer and colder events while a change in the temperature mean increases the occurrence of warmer events but decreases the occurrence of colder events. The researchers found that changes in the variation of ocean temperatures had a threefold effect on the growth rate of the albatross population compared to changes in just mean ocean temperature. Increasing variation of ocean temperatures—temperatures that range well below or above the optimum for the species—leads to population decline, while increasing the mean (average) of ocean temperatures result in population increase.

Although, more frequent hotter extreme events will lead to population decline, a change in the mean leads to more frequent warmer events that favor this specific population because the optima value for albatross is actually warmer than the current historical temperature. In other words, the effect of extreme events can be buffered when species live in cooler than optimal environments, providing a kind of “climate safety margin” for those species.

“In this case, the historical mean (or average) of sea surface temperatures was lower than the optimal temperature for this species,” explains Jenouvrier. “If the mean temperature warms, these albatrosses will experience temperatures that will be more often at or near the optimum range for the species, so these changes in mean will buffer the negative effects of the extreme warming events.”

However, even for those species that do experience a buffering effect from the climate safety margin, it’s likely to be only temporary as future temperatures continue to rise beyond their optimal temperature range, she adds.

The researchers also studied impacts of extreme events on various age groups of the albatross population. Both models —one which increased temperature mean and the other the variation of sea surface temperatures—in younger populations: an impact with potentially important conservation implications for the species because younger birds are most likely to be those caught in long-line fishing hooks.

“In this special issue of the journal, we developed a roadmap to both advance the research and incorporate what has been learned from related fields,” Jenouvrier adds. “Understanding the behavioral, ecological and evolutionary impacts of extreme climatic events is crucial when these events are rapidly increasing in frequency and intensity due to global climate change.”

Breeding pairs of birds cooperate to resist climate change

(Physorg 5 June ; Photo: Juan. A. Amat )

Most bird chicks need parental care to survive. In biparental species the chicks have greater chances of success if both parents participate in this task, especially under hostile situations. An international team of scientists has revealed that when temperatures rise, males and females in pairs of plovers shift incubation more frequently.

Climate change causes ecological variation and affects the lives of animals. The ever-earlier springs and later autumns caused by rising temperatures cause changes to animals’ physiology, breeding seasons and even population distributions. However, little is still known about how animals behave in response to these disturbances.

A team of scientists, working in collaboration with the Doñana Biological Station (EBD-CSIC), has studied the influence of climate change on incubation in plovers (Charadrius spp.), a genus of shorebirds spread over six continents, with a total of 33 species.

Many plover species nest on the ground in sites where there is no plant cover to detect more easily approaching predators, but where their nests receive direct sunlight.

“This can represent a significant challenge,” as indicated to SINC by Juan A. Amat, a researcher at the EBD and one of the authors of the study, which was published recently in the journal Global Ecology and Biogeography.

The scientist adds that the situation can become complicated for birds in the middle of the day, “when incubating adults may not be able to tolerate the high temperatures.” Typically, the optimum temperature adults provide for embryonic development is 35-39 ºC.

“In many bird species where both mates participate in incubation, one sex, generally the female, incubates by day, while the other (the male) does it by night,” Amat explains. However, under hot conditions greater cooperation would be needed between males and females.

Males participate in daytime incubation

One solution under changing climates would be to shorten the duration of incubation shifts between the sexes. The paper, which was led by the University of Bath (United Kingdom), analysed the behaviour of 36 populations of 12 plover species. Its results reveal that male plovers assist the females during daytime incubation.

“Males’ participation in daytime incubation increases both with ambient temperature and with as the variability of maximum temperatures during the incubation period,” the expert stresses.

The research demonstrates that a rise in temperature changes these bird pairs’ behaviour and their daily routine in terms of nest attendance. “This flexibility of parental cooperation would facilitate responses to the impact of climate change on populations’ reproductive biology,” explains Amat, who considers that the reason behind the male’s increased help is the need to better protect the embryos from extreme conditions.

Previous studies have confirmed that environmental instability has an influence on the early stage of reproduction and the lives of birds, and that unpredictable variations in the environment also affect how bird pairs cooperate in caring for their offspring. The conclusion of this new paper is that climate variations strongly influence parental cooperation.

Sea level rise may drive coastal nesting birds to extinction

Sea level rise may drive coastal nesting birds to extinction

(Australian National University 1 June 2017; Photo: Andreas Trepte)

Rising sea levels and more frequent flooding events may drive coastal nesting birds around the world to extinction, a team of international researchers say following their 20-year study of Eurasian oystercatchers.

Lead researcher Dr Liam Bailey from The Australian National University (ANU) said one of the main reasons for the strong decline in birds that used coastal habitats was because they had shown no response to tidal floods, which are predicted to become more frequent and severe due to climate change.

He said this view was corroborated by other international research.

“Sea level rise and more frequent flooding are major drivers of this steep decline in coastal birds,” said Dr Bailey, a PhD graduate from the ANU Research School of Biology.

“Our study species, the Eurasian oystercatcher, lives in an area where flooding is becoming more common, posing a threat to the survival of the population.

“Our study found no evidence that Eurasian oystercatchers have increased the elevation of their nests, even among birds that lost a nest during a flood. Factors including the presence of predators or unsuitable vegetation might discourage birds from nesting higher.”

The team will investigate other possible strategies that birds may use to avoid flooding, such as encouraging birds to lay their nests earlier in the year when floods are less common.

A recent study using thousands of bird surveys along the east coast of the United States found consistent declines in coastal marsh birds.

“Researchers predict that rising sea levels and increased flooding events may drive the saltmarsh sparrow, a coastal species in the US, to extinction, possibly even within the next 20 years,” Dr Bailey said.

“Like the Eurasian oystercatcher, this species does not appear to be adapting to the changing tidal conditions.”

A similar study in Europe showed strong declines in coastal bird species along the coast of Northern Europe.

“Our work is part of a growing amount of research that shows the vulnerability of coastal bird species. These species may need additional conservation focus in the future,” he said.

”Biologisk mångfald – vår tids ödesfråga”

(SVT 22 maj 2017; Foto: Kerstin Joensson)

OPINION · ”Vikten av biologisk mångfald fastslås i forskningsrapport efter forskningsrapport, och vi vet att människor mår bättre av att leva nära en artrik natur. Det är hög tid att dessa slutsatser syns tydligare även i politiska och affärsmässiga beslut”, skriver företrädare för WWF, Naturskyddsföreningen, SOF BirdLife, Skydda skogen, Jordens Vänner, Fältbiologerna, Klimataktion Sverige, PUSH Sverige, Älväddarnas samorganisation och Urbergsgruppen Sverige.

I dag den 22 maj är det biologiska mångfaldens dag – en internationell högtidsdag, initierad av FN år 2002 för att öka förståelsen för en artrik natur.

Trots 15 års arbete med att lyfta frågan och trots att forskare anser att vi befinner oss i den sjätte stora massutrotningen av arter får sällan biologisk mångfald den uppmärksamhet som skulle behövas.

Klimatförändringarna och biologisk mångfald är vår tids stora ödesfrågor och det är två frågor som är sammanflätade. Artrik natur utgör hållbara system som lättare kan klara av klimatförändringar.

Bevarandet av naturskogar som lagrar stora mängder kol eller våtmarker som minskar övergödningen och gör samhället mindre sårbart mot översvämningar är bara två kända exempel i en lång rad av liknande exempel.

Samtidigt hotar klimatförändringarna artrikedomen när torrområden breder ut sig, korallrev bleks eller de arktiska istäcket blir allt mindre.

Den främsta anledningen till att den biologiska mångfalden minskar är också en av de största faktorerna bakom klimatförändringarna; vi släpper ut växthusgaser, vi hugger ner skogar och exploaterar naturen för att skapa jordbruksmark, monokulturer eller bebyggelse.

Samtidigt har kunskapen i ämnet aldrig varit så här stor.

Vikten av biologisk mångfald fastslås i forskningsrapport efter forskningsrapport, och vi vet att människor mår bättre av att leva nära en artrik natur.

Det är hög tid att dessa slutsatser syns tydligare även i politiska och affärsmässiga beslut.

Intresse för frågan saknas inte. I samband med den Biologiska mångfaldens dag den 22 maj arrangeras det cirka 60 aktiviteter runt om i landet.

Det invigs naturreservat, ordnas med fågelguidningar, skogsvandringar, naturbingo, naturpoesi i sociala medier och landsomfattande spindelräkningar. Skolor, naturföreningar, museum, naturum, länsstyrelser, turistföreningar och privata företag har engagerat sig för att visa vikten av den biologiska mångfalden.

Trots att kunskapen och intresset finns, tas frågan inte upp på allvar i den politiska debatten. Vi är framme vid ett vägskäl. De politiska besluten måste genomsyras av verklig hänsyn till naturen.

Vi kan inte längre anpassa oss efter de som vill fortsätta i samma hjulspår som om ingenting har hänt. Vi har i ett längre perspektiv inte råd med kortsiktighet.

Det är dags att även samhällets makthavare tar engagemanget och den samlade kunskapen på allvar och börjar agera för att rädda världens arter och livsmiljöer.

Att kunna bada i friska sjöar och vattendrag, att promenera i levande skogar, och att uppleva ett rikt växt- och djurliv som väcks av våren. Det är några av de livskvaliteter vi vill att kommande generationer också ska kunna njuta av, och som kan kräva tuffa politiska beslut.

Det att dags att inse att även det som kan tyckas vara oansenligt, faktiskt är ovärderligt.

Därför firar vi den biologiska mångfaldens dag och hoppas att frågan från och med nu får den uppmärksamhet som den förtjänar.

Wind and rain change breeding patterns for swallows

(Dana Kobilinsky 15 May 2017; Photo: Dan Doak)

Fewer storms that bring wind and rain may be causing North American tree swallows (Tachycineta bicolor) to lay their eggs earlier in the spring, according to new research.

The impacts of this early egg laying isn’t known, but the trend points to what researchers say is an overlooked effect of climate change. Many studies look at the effects of warming temperatures on wildlife, but these researchers took into account the effects that less wind and rain in central Alaska have on the birds.

“In spring when the birds are doing their business, their habitat is not warmer at all,” said Daniel Doak, a professor at the University of Colorado Boulder and the senior author on the recent study that his undergraduate student led. “It’s a weak trend. But the storminess trend is very strong.”

As part of their study published in Proceedings of the Royal Society B, the researchers looked at data collected on swallows in two study sites in central Alaska over the past 15 years.  The swallows are an extremely resilient species, Doak said, which makes them easy to study. “They’re a model species for effects on many different species,” he said. “They’re easy to study because they are less perturbed by human disturbances.”

The researchers recorded phenology information such as when the individual birds were laying eggs, hatching and fledging. Then, they reviewed weather station data from NOAA and the National Park Service and took note of climate data including temperatures, windiness and precipitation.

They found that frequent, small spring windstorms, which tend to slow down the breeding process, have become rarer over the past three decades. As the springs have gotten less windy, the birds are laying eggs earlier.

“Birds fine tune what they’re doing when there’s climate variation year to year,” Doak said. He and the other authors hope to study nest success, fledging and rearing of the species at these sites to determine what effects an earlier breeding time has, but he also hopes the study shows the importance of studying climate change impacts other than temperature.

“Climate change really has multiple dimensions,” he said. “We’ve been simplifying it down to the fact that things are getting warmer.”