Category Archives: blog

Andean hummingbirds take different evolutionary paths to high altitudes —

White-tufted Sunbeam          (© Glenn Bartley)

White-tufted Sunbeam
(© Glenn Bartley)

Scientists have found that multiple hummingbird species have adapted to life at high altitudes in the Andes through distinct genetic mutations that nonetheless affect the same biochemical pathways. This suggests that while the details of molecular adaptation may differ at the amino acid and protein levels, there is predictability in evolution at the level of biochemical pathways.

The transition from living at low elevations to high elevations, such as those found in the Andes, Himalayas, and Tibetan Plateau, comes with many challenges. Extremely high elevations are associated with colder temperatures, increased exposure to ultraviolet radiation, and a lack of oxygen, which is 40% less abundant above 4,000 m than at sea level. Organisms that live at these elevations have developed specific adaptations that allow them to cope with these difficulties. For example, genetic analyses of humans living in the Andes and on the Tibetan Plateau have revealed changes in specific genes that enable them to deal with limited oxygen environments. However, it remains unclear whether such changes are generally predictable across different species or populations, or whether there is some flexibility in what changes occur. In a new article in Genome Biology and Evolution (Lim et al. 2019), a group of researchers from Stony Brook University, the University of New Mexico, and the Swiss Federal Research Institute set out to answer this question.

According to the study’s first author, Marisa Lim, a Ph.D. candidate at Stony Brook University at the time of the research, “The biology and evolutionary history of hummingbirds presented the perfect system to study parallel evolution, as Andean hummingbirds occur at very high elevations and high-altitude species evolved independently across the hummingbird family.” By studying a group of 12 Andean hummingbird species that represent several independent transitions to higher altitudes, the researchers hoped to determine whether changes that confer benefits at high elevations occur in similar amino acids, proteins, or biochemical pathways across species.

The researchers sequenced almost 1,000 genes from each of the 12 species and identified genes and amino acid sites that were under positive selection and were shared across high- or low-elevation hummingbird species. While some changes at particular amino acid sites or in particular genes were shared across species, broadly speaking, the researchers found greater similarity in the overall biochemical pathways and biological functions associated with adaptation to high altitudes. For example, positively selected genes were often involved in pathways or functions related to cellular respiration, metabolism, or mitochondrial biogenesis and translation, with additional genes involved in cell death and immune function.

This finding, that “Andean hummingbirds have converged on the high-altitude phenotype through the evolution of different genetic mechanisms”, is the study’s most exciting result according to Dr. Lim. She believes this indicates that there is “predictability in the evolutionary machinery, primarily across biochemical pathways” and suggests that there is some functional overlap among genes that allows for flexibility in how adaptations evolve.

David Hillis, a professor at the University of Texas at Austin who was not involved in the study and who has studied high-elevation adaptation in Tibetan frogs and lizards (Sun et al. 2018), agrees, stating that the hummingbird study “suggests that even among relatively closely related species that exhibit parallel shifts to high elevations, the details of the molecular adaptations are largely different.” Dr. Hillis notes that the study also suggests that parallel evolution in function is unlikely to confound phylogenetic studies and fits experimental results from laboratory evolution of viruses.

Dr. Lim anticipates future challenges associated with a lack of knowledge about gene function, particularly in non-model organisms, which may limit the ability to “discern true signatures of positive natural selection from statistical and biochemical noise.” While she notes that their results “support and are supported by our current knowledge of genetic adaptation to high-altitude conditions,” she acknowledges that the story does not end here and hopes that future research can build upon the study’s findings. Building upon this study, she is now investigating the adaptive evolution of high- and low-altitude populations using population genomic methods. Dr. Lim recently became a bioinformatics postdoctoral fellow with the Wildlife Conservation Society at the Bronx Zoo, where she develops user-friendly bioinformatics pipelines for wildlife conservation projects. (Phys.org)

Kingfisher’s beak for hydrodynamic designs —

Green and rufous kingfisher (Author - Charles J. Sharp) (CC BY-SA 4.0)

Green and rufous kingfisher (Author – Charles J. Sharp) (CC BY-SA 4.0)

Renowned for their noiseless dive, the kingfisher’s iconic beak-shape has inspired the design of high speed bullet trains. Now scientists have tested beak-shape among some of the birds’ 114 species found world-wide, to assess which shape is the most hydrodynamic.

Avian biologist Dr. Kristen Crandell and third year undergraduate student, Rowan Howe, of Bangor University, created 3-D printed models of the beak shapes of several of the diving kingfisher species, at the University’s Pontio Innovation Centre.

Renowned for their hydrodynamic splash and noise free dives, Kristen wanted to test the kingfisher beaks in the lab, and has come up with a top 10 list when it comes to the most efficient design. The lab tests measured how the speed of entry changed as the models hit the water, and found evidence that a longer, narrower shape was more efficient.

This also relates to other diving species such as Gannets, renowned for pulling their wings back and spearing the water with their whole body profile.

The top three kingfishers were the diving species. According to their tests, the top performer was the green-and-rufous kingfisher, a species from the Amazon basin (Brazil and Venezuela), in second place was the Amazon kingfisher, which is widespread through parts of Central and South America, and coming in third was the beach kingfisher, found only in Papua New Guinea and Indonesia. Britain’s native electric blue kingfisher, also found across Eurasia and North Africa, comes in at 6th.

Some kingfishers forage rather than dive for food, so their beaks have not evolved to break the water so seamlessly.

Asked why this research was valuable, Kristen explained that although designers use the natural world as inspiration and that the kingfisher beak shape had been used to redesign bullet trains to remove a sonic boom as they compressed air when entering tunnels, the design solution had come through observation, but no one had actually validated the kingfisher beak shape under lab conditions.

Achieving a greater understanding of how shapes behave could lead to more bio engineering solutions in the future. (Journal of The Royal Society Interface)

Invasive species are Australia’s number-one extinction threat —

Common Myna (pix SShukla) - Copy (Smaller file)According to the UN report from the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) one eighth of the world’s species – more than a million – are threatened with extinction. This startling number is a consequence of five direct causes: changes in land and sea use; direct exploitation of organisms; climate change; pollution; and invasion of alien species.

It’s the last, invasive species that threatens Australian animals and plants more than any other single factor.

Australia’s number one threat

Australia has an estimated 600,000 species of flora and fauna. Of these, about 100 are known to have gone extinct in the last 200 years. Currently, more than 1,770 are listed as threatened or endangered.

While the IPBES report ranks invasive alien species as the fifth most significant cause of global decline, in Australia it is a very different story.

Australia has the highest rate of vertebrate mammal extinction in the world and invasive species are our number one threat.

Cats and foxes have driven 22 native mammals to extinction across central Australia and a new wave of decline – largely from cats – is taking place across northern Australia. Research has estimated 270 more threatened and endangered vertebrates are being affected by invasive species.

Introduced vertebrates have also driven several bird species on Norfolk Island extinct.

The effects of invasive species are getting worse

Although Australia’s stringent bio-security measures have dramatically slowed the number of new invasive species arriving, those already here have continued to spread and their cumulative effect is growing.

Recent research highlights that 1,257 of Australia’s threatened and endangered species are directly affected by 207 invasive plants, 57 animals and three pathogens.

These affect country’s unique biodiversity, as well as the clean water and oxygen – not to mention cultural values.

When it comes to biodiversity, Australia is globally quite distinct. More than 70% of the species (69% of mammals, 46% of birds and 93% of reptiles) are found nowhere else on earth. A loss to Australia is therefore a loss to the world.

Some of these are ancient species like the Wollemi Pine, may have inhabited Australia for up to 200 million years, well before the dinosaurs.

But invasive species are found in almost every part of Australia, from rainforests, to deserts, farms, to cities, national parks and rivers.

The cost to Australia

The cost of invasive species in Australia continue to grow with every new assessment.

The most recent estimates found the cost of controlling invasive species and economic losses to farmers in 2011-12 was 13.6 billion Australian dollars. However this doesn’t include harm to biodiversity and the essential role native species play in the ecosystems, which – based on the conclusions of the IPBES report – is likely to cost at least as much, and probably far more.

Rabbits, goats and camels prevent native desert plant community regeneration; rabbits alone impacting over 100 threatened species. Rye grass on its own costs cereal farmers 93 million Australian dollars a year.

Aquaculture diseases have affected oysters and cost the prawn industry 43 million Australian dollars.

From island to savannah

Globally, invasive species have a disproportionately higher effect on offshore islands – and Australia has more than 8,000 of these. One of the most notable cases is the case of the yellow crazy ants, which killed 15,000,000 red land crabs on Christmas Island.

Nor are the country’s deserts immune. Most native vertebrate extinctions caused by cats have occurred in dry inland deserts and savannas, while exotic buffel and gamba grass are creating permanent transformation through changing fire regimes.

Australia’s forests, particularly rainforests, are also under siege on a number of fronts. The battle continues to contain Miconia weed in the country – the same weed responsible for taking over 70 per cent of Tahiti’s native forests. Chytrid fungus, thought to be present in Australia since 1970, has caused the extinction of at least four frog species and dramatic decline of at least ten others in the sensitive rainforest ecosystems.

Myrtle rust is pushing already threatened native Australian Myrtaceae closer to extinction, notably Gossia gonoclada, and Rhodamnia angustifolia are changing species composition of rainforest understories, and Richmond birdwing butterfly numbers are under threat from an invasive flower known as the Dutchman’s pipe.

Australia’s rivers and lakes are also under increasing domination from invasive species. Some 90% of fish biomass in the Murray Darling Basin are European carp, and tilapia are invading many far north Queensland river systems pushing out native species.

Invasive alien species are not only a serious threat to biodiversity and the economy, but also to human health. The Aedes aegypti mosquito found in parts of Queensland is capable of spreading infectious disease such as dengue, zika, chikungunya and yellow fever.

And it’s not just Queensland that is under threat from diseases spread by invasive mosquitoes, with many researchers and authorities planning for when, not if, the disease carrying Aedes albopictus establishes itself in cooler and southern parts of Australia.

What solutions do we have?

Despite this grim inventory, it’s not all bad news. Australia actually has a long history of effectively managing invasive species.

Targeting viruses as options for controlling rabbits, carp and tilapia; the country has successfully suppressed rabbit populations by 70% in this way for 50 years.

Weeds too are successful targets for weed biological control, with over a 65% success rate controlling more than 25 targets.

The IPBES report calls for “transformative action”. Here too Australia is at the forefront, looking into the potential of gene-technologies to suppress pet hates such as cane toads.

Past and current invasive species programs have been supported by governments and industry. This has provided the type of investment we need for long-term solutions and effective policies.

Australia is better placed now, with effective bio-security policies and strong bio-security investment, than many countries. We will continue the battle against invasive species to stem biodiversity and ecosystem loss. (Phys.org)

Due to humans, extinction risk for 1,700 animal species to increase by 2070 —

Pale-browed_Treehunter (Author - Hector Bottai) (CC BY-SA 3.0)As humans continue to expand our use of land across the planet, we leave other species little ground to stand on. By 2070, increased human land-use is expected to put 1,700 species of amphibians, birds, and mammals at greater extinction risk by shrinking their natural habitats, according to a study by Yale ecologists published in Nature Climate Change.

To make this prediction, the ecologists combined information on the current geographic distributions of about 19,400 species worldwide with changes to the land cover projected under four different trajectories for the world scientists have agreed on as likely. These potential paths represent reasonable expectations about future developments in global society, demographics, and economics.

“Our findings link these plausible futures with their implications for biodiversity,” said Walter Jetz, co-author and professor of ecology and evolutionary biology and of forestry and environmental studies at Yale. “Our analyses allow us to track how political and economic decisions—through their associated changes to the global land cover—are expected to cause habitat range declines in species worldwide.”

The study shows that under a middle-of-the-road scenario of moderate changes in human land-use about 1,700 species will likely experience marked increases in their extinction risk over the next 50 years: They will lose roughly 30-50% of their present habitat ranges by 2070. These species of concern include 886 species of amphibians, 436 species of birds, and 376 species of mammals—all of which are predicted to have a high increase in their risk of extinction.

Among them are species whose fates will be particularly dire, such as the Lombok cross frog (Indonesia), the Nile lechwe (South Sudan), the pale-browed treehunter (Brazil) and the curve-billed reedhaunter (Argentina, Brazil, Uruguay) which are all predicted to lose around half of their present day geographic range in the next five decades. These projections and all other analyzed species can be examined at the Map of Life website.

“The integration of our analyses with the Map of Life can support anyone keen to assess how species may suffer under specific future land-use scenarios and help prevent or mitigate these effects,” said Ryan P. Powers, co-author and former postdoctoral fellow in the Jetz Lab at Yale.

Species living in Central and East Africa, Mesoamerica, South America, and Southeast Asia will suffer the greatest habitat loss and increased extinction risk. But Jetz cautioned the global public against assuming that the losses are only the problem of the countries within whose borders they occur.

“Losses in species populations can irreversibly hamper the functioning of ecosystems and human quality of life,” said Jetz. “While biodiversity erosion in far-away parts of the planet may not seem to affect us directly, its consequences for human livelihood can reverberate globally. It is also often the far-away demand that drives these losses—think tropical hardwoods, palm oil, or soybeans—thus making us all co-responsible.” (Nature Climate Change)

Darwin’s finches don’t tell the whole story of avian evolution —

Darwin's finches or Galapagos finchesThe connection between bird diet and skull shape is surprisingly weak for most species according to a new study led by UCL and the Natural History Museum, rewriting our understanding of how ecosystems influence evolution.

Charles Darwin’s 19th century observations of finches on the Galápagos Islands concluded that bird speciation was primarily influenced by ecosystem; the way a bird forages and eats forms its skull shape and drives evolutionary change.

However, a new study by UCL and NHM researchers testing a wider range of species than ever before has found that on a global scale, shared ancestry and behaviour are more important factors than diet.

The study, published in Royal Society journal Proceedings B, tested the skull shape of 352 bird species, representing 159 out of the 195 existing families, making it the largest study of its kind.

“If we apply Darwin’s conclusion for different kinds of birds who primarily eat fish, pelicans and penguins should have exactly the same head and beak shape, as they both use their beaks to eat fish. However, pelicans have a long beak and large throat pouch, while penguins’ beaks are comparatively small,” explained Dr. Ryan Felice (UCL Biosciences), one of the authors of the study.

“Although they eat the same thing, pelicans and penguins acquire their prey in different ways, demonstrating the important role behaviour plays in cranial evolution.”

Penguins’ mouths have a series of spines pointing down their throats, so that food stays in there when caught. Pelicans ingeniously catch fish in their pouch and then tip it back to drain out the water and swallow the fish immediately.

“It is evolutionary history, rather than diet, that has most significantly influenced cranial shape. If you are descended from a duck-like ancestor, you will probably have a duck bill, no matter what diet you have. However, shared diet establishes the parameters of skull evolution, determining the range of potential shapes which can evolve,” added Dr. Felice.

The researchers also discovered that birds who eat grains—such as finches and quail—and those who survive on the nectar of flowers—like hummingbirds—exhibit the highest rate of cranial evolution. By contrast, terrestrial carnivores—hawks, falcons, owls and other birds that hunt and eat using their talons—exhibit a very slow rate of cranial change.

“This is where natural selection comes into play,” said Professor Anjali Goswami, a Research Leader at the Natural History Museum and a co-author on the study.

“Birds that eat nectar or seeds are going to experience lots of competition for resources and must evolve in order to survive.”

“Our study focused on the skull, but we hypothesise that other parts of the body could be shaped by diet and ecology, such as wings, talons, and stomachs, as these are the parts of their bodies which are crucial for catching and digesting prey.”

The study used state-of-the-art equipment to build high resolution 3-D digital models of the bird skulls. This allowed researchers to plot many more points on the skull than previously possible, allowing them to make robust and accurate measurements.

“Our next step is to expand this analysis to other groups of animals, like mammals, reptiles, and dinosaurs,” said Dr. Felice. “Our goal is to understand all of the different factors that have shaped skull evolution through time.”

Dr. Felice’s partners on the paper were Dr. Joseph Tobias (Imperial College London), Dr. Alex Pigot (UCL Biosciences) and Professor Anjali Goswami (UCL Biosciences & Natural History Museum). (Royal Society journal Proceedings B)

Birds prefer to live in luxury than in poor areas —

Common Myna (pix SShukla) Chandigarh; (2 June 2019) (6) (Small File)

Common Myna in a tree hole in a housing society (pix SShukla)

A unique study of birdlife in South African cities has found that birds prefer wealthy areas to poorer ones but will move out if things get too cramped. The study was conducted by a team of scientists from the University of Turin, Italy and the Universities of Cape Town (UCT) and the Witwatersrand, South Africa. Their findings were published this week in the international journal of Global Change Biology.

Co-author on the study, UCT Associate Professor Arjun Amar said: “This work is of particular importance because it is one of the few studies conducted in a developing country, and the only study of its kind in Africa, where urbanisation is predicted to occur at a faster rate than any other region on the planet.”

The researchers studied the occurrence of bird species in 22 urban areas across South Africa and found that the number of species present increased according to the income levels of residents, i.e. the more affluent the neighbourhood, the more bird species are found there—provided there are still enough good habitats for the birds to spread their wings. However, this was not true for highly urbanised areas where vegetation has all but disappeared.

The so-called ‘luxury effect,” well-documented in the developed world, also applies to relatively low-density urban areas in South Africa, where wealthy areas have a greater diversity of bird species than found in less wealthy areas. This is probably due to greater investment in gardens, parks and other green spaces which are hot-spots of urban biodiversity in wealthier neighbourhoods. However, birds have no appetite for heavily built-up areas even when they have wealthy inhabitants.

It is the first time the ‘luxury effect’ in birds has been documented for an African country. The study authors believe such findings could help shape future urban planning in the interests of both biodiversity and environmental justice, particularly in the rapidly urbanizing developing world.

Lead author Professor Dan Chamberlain from the University of Turin said: “This study shows that rich, leafy suburbs have more bird species and probably higher biodiversity in general, than poor areas of the city or areas that have too much asphalt and concrete. Understanding the factors which drive the ‘luxury effect’ will help us to design more biodiversity-friendly cities in the future, thus promoting environmental justice for all urban inhabitants.”

The findings were based on careful analysis of four years of data from the Southern African Bird Atlas Project across a range of urban environments, from peri-urban outskirts to high-rise city centres, where average income varied from $1,000 to $30,000 per year according to the South African census.

While researchers also confirmed a predictable link between the amount of urban tree cover and bird diversity, they concluded that tree cover alone does not fully explain the “luxury effect.”

South Africa is described by the authors as “an extremely valuable case study” of the relationship between wealth and biodiversity due to the country’s species richness (10 percent of the world’s terrestrial plants and 7 percent of terrestrial reptiles, birds and mammals) as well as infamous levels of income inequality.

According to the study, “maintaining green space in at least an equal proportion to the built environment is likely to provide a development strategy that will enhance urban biodiversity, and with it, the positive benefits that are manifest for urban dwellers.”

The authors hope that the “findings can form a key contribution to a wider strategy to expand urban settlements in a sustainable way to provide for the growing urban population in South Africa, including addressing imbalances in environmental justice across income levels and racial groups.” (Global Change Biology)

Bird personalities influenced by age and experience, study shows —

Common or Eurasian coot and Common pochard; (pix SShukla); (Representative image)

Common or Eurasian coot and Common pochard; (pix SShukla); (Representative image)

Differences in the personalities of birds are related to both age and experience, according to new research by University of Alberta biologists.

The study examined the red knot, a medium-sized shorebird that breeds in the Canadian Arctic and winters in northwestern Europe. The researchers captured 90 birds and studied them over two years, comparing behavioural and physiological traits of adult and juvenile birds. Studying the two age groups allowed the researchers to determine which changes were due to age as opposed to time in captivity.

“During this time, birds had the same type of life experience, including varied diet,” explained U of A biologist Kim Mathot, who is also Canada Research Chair in Integrative Ecology.

“At the start of the experiments, individuals showed differences in their behaviour. We looked at whether these differences disappeared in the course of the study, which would suggest there is something about individually variable experiences that helps maintain differences, because in our experiments, all these birds had the same experience.”

The individual differences in behaviour were maintained by the birds over the course of the study, but physiological traits—such as the size of each bird’s gizzard—became more similar.

“The world isn’t simple, so it makes sense that there isn’t a straightforward answer for how and why individuals differ,” noted Mathot. “Nature is wonderfully complex. This is yet another example of that at play.”

In the next leg of the research, Ph.D. student Eva Kok will follow a smaller subset of the study’s birds after they’ve been released back into the wild to examine how the traits measured in the lab translate to real life.

“We’re curious to see if physiological differences will reappear after release back into the wild,” explained Mathot. “For instance, if an individual had a relatively large gizzard when we initially captured it but that became smaller in captivity, will it grow to be relatively large again when re-released? Or did we shuffle the deck, and now birds can go on different trajectories than what they were on before?”

The study, “Within-Individual Canalization Contributes to Age-Related Increases in Trait Repeatability: A Longitudinal Experiment in Red Knots,” was published in The American Naturalist. (Phys.org)

Bird beaks did not adapt to food types as previously thought, study suggests —

Various kinds of bird beaks

Various kinds of bird beaks

A study, led by the University of Bristol, has shed some new light on how the beaks of birds have adapted over time.

The observation that Galapagos finch species possessed different beak shapes to obtain different foods was central to the theory of evolution by natural selection, and it has been assumed that this form-function relationship holds true across all species of bird.

However, a new study published in the journal Evolution suggests the beaks of birds are not as adapted to the food types they feed on as it is generally believed.

An international team of scientists from the United Kingdom, Spain and the US used computational and mathematical techniques to better understand the connection between beak shapes and functions in living birds.

By measuring beak shape in a wide range of modern bird species from museum collections and looking at information about how the beak is used by different species to eat different foods, the team were able to assess the link between beak shape and feeding behaviour.

Professor Emily Rayfield, from the University of Bristol’s School of Earth Sciences, and senior author of the study, said: “This is, to our knowledge, the first approach to test a long-standing principle in biology: that the beak shape and function of birds is tightly linked to their feeding ecologies.”

Guillermo Navalón, lead author of the study and a final year Ph.D. student at Bristol’s School of Earth Sciences, added: “The connection between beak shapes and feeding ecology in birds was much weaker and more complex than we expected and that while there is definitely a relationship there, many species with similarly shaped beaks forage in entirely different ways and on entirely different kinds of food.

“This is something that has been shown in other animal groups, but in birds this relationship was always assumed to be stronger.”

Co-author, Dr. Jesús Marugán-Lobón from Universidad Autónoma de Madrid, said: “These results only made sense when you realise birds use the beak for literally everything!

“Therefore, also makes sense they evolved a versatile tool not just for getting food, but also to accomplish many other tasks.”

The study is part of a larger research effort by the team in collaboration with researchers from other universities across Europe and the US to better understand the main drivers of the evolution of the skull in birds.

Dr. Jen Bright, co-author from the University of South Florida, said: “We have seen similar results before in birds of prey, but this is the first time we studied the link between beak shape and ecology across all bird groups.

“We looked at a huge range of beak shapes and feeding ecologies: hummingbirds, eagles, parrots, puffins, flamingos, pretty much every beak you can think of.”

Guillermo Navalón added: “These results have important implications for the study of fossil birds.

“We have to be careful about inferring ecology in ancient birds, which we often assume based solely on the shape of the beak.

“Really, we’re just starting to scratch the surface, and a lot more research is needed to fully understand the drivers behind beak shape evolution.” (Phys.org)

How life in Antarctica thrives on penguin poop —

1982 picture shows a two-million-strong king penguin colony on Ile aux Cochon (Picture -  Henri WeimerskirchFrench National Centre for Scientific Research (Source AFP)

1982 picture shows a two-million-strong king penguin colony on Ile aux Cochon (Picture – Henri WeimerskirchFrench National Centre for Scientific Research (Source AFP)

For more than half a century, biologists studying Antarctica focused their research on understanding how organisms cope with the continent’s severe drought and the coldest conditions on the planet.

One thing they didn’t really factor in, however, was the role played by the nitrogen-rich droppings from colonies of cute penguins and seals—until now.

A new study published in the journal Current Biology found the influential excrement supported thriving communities of mosses and lichens, which in turn sustained vast numbers of microscopic animals like springtails and mites for more than 1,000 meters (yards) beyond the colony.

“What we see is that the poo produced by seals and penguins partly evaporates as ammonia,” said co-author Stef Bokhorst from the Department of Ecological Sciences at Vrije Universiteit Amsterdam.

“Then, the ammonia gets picked up by the wind and is blown inland, and this makes its way into the soil and provides the nitrogen that primary producers need in order to survive in this landscape.”

Braving bitter temperatures, the researchers waded through fields of animal waste—not to mention hordes of clamoring elephant seals and gentoo, chinstrap, and Adelie penguins—to examine the surrounding soils and plants using infrared gas analyzers that measured their respiration.

Samples brought back and examined in labs revealed that there were millions of tiny invertebrates per square meter because of the lack of predators in their environment—unlike in European or American grasslands, where the number may typically be between 50,000 and 100,000.

“The more animals we get, the larger the footprint there is, and we’re finding higher diversity in those sites,” Bokhorst told AFP, emphasizing that species’ richness was linked less with how cold or dry the region was and more to the nutrients added by the excrement.

Ultimately, the research allowed the team to map the hotspots across the Antarctic Peninsula, finding penguin colonies to be a proxy for biodiversity.

The maps can be updated in the future using satellite imagery to determine the size and location of breeding colonies, freeing future scientists from having to conduct treacherous fieldwork.

‘Ideal natural laboratory’

For Bokhorst, Antarctica presented an “ideal natural laboratory” to study the relationship between nutrients and biodiversity because of the simplicity of the overall food web, in contrast to other parts of the world where ecosystems were far more complex.

“It makes it a lot easier to find driving factors,” said Bokhorst.

But the study also underscored how interconnected the continent’s ecosystem was—and therefore its vulnerability to human activity.

All countries working on the continent are subject to the Antarctic Treaty System, which obliges them to protect its wildlife, but Bokhorst said the study showed “if you start poking at one end it will have an effect at the other end.”

“You need to keep a good eye that you’re not overfishing the oceans so you’re not harming food supplies, otherwise you’re going to have an impact for biodiversity,” he said.

The peninsula’s vibrant invertebrate communities face few predators, but the advent of tourism means there is an increasing chance people could bring seeds or even insects with them.

These, in turn, could benefit from the soil enrichment and establish themselves, threatening the native species.

“That’s a very good argument for why we should be careful with the Antarctic,” said Bokhorst. (Phys.org)

Humans accelerating extinction of other species : UN report —

Birds fly past a smoking chimney in Ludwigshafen_Germany (AP photo_Michael Probst)

Birds fly past a smoking chimney in Ludwigshafen_Germany (AP photo_Michael Probst)

People are putting nature in more trouble now than at any other time in human history, with extinction looming over 1 million species of plants and animals, scientists said Monday.

But it’s not too late to fix the problem, according to the United Nations’ first comprehensive report on biodiversity.

“We have reconfigured dramatically life on the planet,” report co-chairman Eduardo Brondizio of Indiana University said at a press conference.

Species loss is accelerating to a rate tens or hundreds of times faster than in the past, the report said. More than half a million species on land “have insufficient habitat for long-term survival” and are likely to go extinct, many within decades, unless their habitats are restored. The oceans are not any better off.

“Humanity unwittingly is attempting to throttle the living planet and humanity’s own future,” said George Mason University biologist Thomas Lovejoy, who has been called the godfather of biodiversity for his research. He was not part of the report.

“The biological diversity of this planet has been really hammered, and this is really our last chance to address all of that,” Lovejoy said.

Conservation scientists convened in Paris to issue the report, which exceeded 1,000 pages. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) included more than 450 researchers who used 15,000 scientific and government reports. The report’s summary had to be approved by representatives of all 109 nations.

Some nations hit harder by the losses, like small island countries, wanted more in the report. Others, such as the United States, were cautious in the language they sought, but they agreed “we’re in trouble,” said Rebecca Shaw, chief scientist for the World Wildlife Fund, who observed the final negotiations.

“This is the strongest call we’ve seen for reversing the trends on the loss of nature,” Shaw said.

The findings are not just about saving plants and animals, but about preserving a world that’s becoming harder for humans to live in, said Robert Watson, a former top NASA and British scientist who headed the report.

“We are indeed threatening the potential food security, water security, human health and social fabric” of humanity, Watson told The Associated Press.

It’s also an economic and security issue as countries fight over scarcer resources. Watson said the poor in less developed countries bear the greatest burden.

The report’s 39-page summary highlighted five ways people are reducing biodiversity:

— Turning forests, grasslands and other areas into farms, cities and other developments. The habitat loss leaves plants and animals homeless. About three-quarters of Earth’s land, two-thirds of its oceans and 85% of crucial wetlands have been severely altered or lost, making it harder for species to survive, the report said.

— Overfishing the world’s oceans. A third of the world’s fish stocks are overfished.

— Permitting climate change from the burning of fossil fuels to make it too hot, wet or dry for some species to survive. Almost half of the world’s land mammals—not including bats—and nearly a quarter of the birds have already had their habitats hit hard by global warming.

— Polluting land and water. Every year, 300 to 400 million tons of heavy metals, solvents and toxic sludge are dumped into the world’s waters.

— Allowing invasive species to crowd out native plants and animals. The number of invasive alien species per country has risen 70% since 1970, with one species of bacteria threatening nearly 400 amphibian species.

“The key to remember is, it’s not a terminal diagnosis,” said report co-author Andrew Purvis of the Natural History Museum in London.

Fighting climate change and saving species are equally important, the report said, and working on both environmental problems should go hand in hand. Both problems exacerbate each other because a warmer world means fewer species, and a less biodiverse world means fewer trees and plants to remove heat-trapping carbon dioxide from the air, Lovejoy said.

The world’s coral reefs are a perfect example of where climate change and species loss intersect. If the world warms another 0.9 degrees (0.5 degrees Celsius), which other reports say is likely, coral reefs will probably dwindle by 70% to 90%, the report said. At 1.8 degrees (1 degree Celsius), the report said, 99% of the world’s coral will be in trouble.

“Business as usual is a disaster,” Watson said.

At least 680 species with backbones have already gone extinct since 1600. The report said 559 domesticated breeds of mammals used for food have disappeared. More than 40% of the world’s amphibian species, more than one-third of the marine mammals and nearly one-third of sharks and fish are threatened with extinction.

The report relies heavily on research by the International Union for the Conservation of Nature, or IUCN, which is composed of biologists who maintain a list of threatened species.

The IUCN calculated in March that 27,159 species are threatened, endangered or extinct in the wild out of nearly 100,000 species biologists examined in depth. That includes 1,223 mammal species, 1,492 bird species and 2,341 fish species. Nearly half the threatened species are plants.

Scientists have only examined a small fraction of the estimated 8 million species on Earth.

The report comes up with 1 million species in trouble by extrapolating the IUCN’s 25% threatened rate to the rest of the world’s species and using a lower rate for the estimated 5.5 million species of insects, Watson said.

Outside scientists, such as Lovejoy and others, said that’s a reasonable assessment.

The report gives only a generic “within decades” time frame for species loss because it is dependent on many variables, including taking the problem seriously, which can reduce the severity of the projections, Watson said.

“We’re in the middle of the sixth great extinction crisis, but it’s happening in slow motion,” said Conservation International and University of California Santa Barbara ecologist Lee Hannah, who was not part of the report.

Five times in the past, Earth has undergone mass extinctions where much of life on Earth blinked out, like the one that killed the dinosaurs. Watson said the report was careful not to call what’s going on now as a sixth big die-off because current levels don’t come close to the 75% level in past mass extinctions.

The report goes beyond species. Of the 18 measured ways nature helps humans, the report said 14 are declining, with food and energy production noticeable exceptions. The report found downward trends in nature’s ability to provide clean air and water, good soil and other essentials.

Habitat loss is one of the biggest threats, and it’s happening worldwide, Watson said. The report projects 15.5 million miles (25 million kilometers) of new roads will be paved over nature between now and 2050, most in the developing world.

Many of the worst effects can be prevented by changing the way we grow food, produce energy, deal with climate change and dispose of waste, the report said. That involves concerted action by governments, companies and people.

Individuals can help with simple changes to the way they eat and use energy, said the co-chairman of the report, ecological scientist Josef Settele of the Helmholtz Center for Environmental Research in Germany. That doesn’t mean becoming a vegetarian or vegan, but balancing meat, vegetables and fruit, and walking and biking more, Watson said.

“We can actually feed all the coming billions of people without destroying another inch of nature,” Lovejoy said. Much of that can be done by eliminating food waste and being more efficient, he said. (Phys.org)