Tag Archives: Climate change

”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.”

Picky fruit-eating birds are more flexible

(Senckenberg Research Institute and Natural History Museum 11 May 2017; Photo Matthias Dehling )

Researchers from Senckenberg and the German Centre for Integrative Biodiversity Research have found that South American birds that are seasonally specialized on particular fruit types are the most flexible in switching to different fruit types in other seasons. This flexibility in their diet is good news in view of the predicted loss of plant species under global change. The study is published in the Journal of Animal Ecology.

The Plumbeous pigeon is a picky eater. Whereas its relatives on European streets and squares feed on whatever they encounter, its South American relative almost exclusively feeds on certain fruits. Together with other birds such as toucans or the turkey-like guans it belongs to a bunch of large fruit-eating birds that are specialized on particular types of fruits. One might think that being peculiar goes hand-in-hand with being inflexible in food choice — however, it does not.

“We compared neotropic fruit-eating birds that are specialized on a small range of fruit resources in a particular season with birds that eat a large ranage of fruits. The specialists are those which are most flexible in adapting their foraging choices across seasons,” explains Irene Bender, Senckenberg Biodiversity and Climate Research Centre and German Centre for Integrative Biodiversity Research (iDiv), lead author of a new study on this topic. She adds “The flexible avian fruit eaters prefer to feed on large fruits. However, their favourite resources are not constantly available throughout the year which forces them to switch.”

The researchers’ surprising observations shed light on the question how species might respond to resource fluctuations that are not naturally determined. “This flexibility of consumer species may be an important, but so far widely neglected mechanism that could stabilize consumer-resource relationships, for instance in response to human disturbance and environmental change. Being flexible might mean that specialized foragers are able to adapt to future changes in resource availability.” says Dr. Matthias Schleuning, Senckenberg Biodiversity and Climate Research Centre.

The study was based on observational records by a team around Irene Bender and Matthias Dehling of the fruit choices of birds in the Manú Biosphere Reserve on the western slopes of the Andes in Peru. The team also measured traits of the plants which provided the fruits, such as plant height and fruit size. The flexibility of bird species was defined as their ability to switch seasonally among plant species with different traits; their specialization was measured by comparing their fruit choices to those of other bird species in the community.

Migratory seabird deaths linked to hurricanes

(Duke University 11 may 2017; Photo Ryan Huang)

Stronger and more frequent hurricanes may pose a new threat to the sooty tern, an iconic species of migratory seabird found throughout the Caribbean and Mid-Atlantic, a new Duke University-led study reveals.

The study, published this week in the peer-reviewed open-access journal PeerJ, is the first to map the birds’ annual migratory path and demonstrate how its timing and trajectory place them in the direct path of hurricanes moving into the Caribbean after forming over the Atlantic.

“The route the birds take and that most Atlantic-forming hurricanes take is basically the same, only in reverse,” said Ryan Huang, a doctoral student at Duke’s Nicholas School of the Environment, who led the study. “That means these birds, who are usually very tired from traveling long distances over water without rest, are flying head-on into some of the strongest winds on the planet.”

“This is worrying because we know that as Earth’s climate changes, we expect to see more frequent and powerful hurricanes in the future — meaning that the chances of sooty terns being hit by storms will likely go up,” Huang said.

Hurricane season typically lasts from June to November, with peak activity occurring in August and September.

A new map produced by the research shows that sooty terns leave their breeding colony at Dry Tortugas National Park in the Florida Keys each June as hurricane season starts. They migrate southward and eastward across the Caribbean through summer and early fall, before skirting the northern coast of South America and arriving at their winter habitat off the Atlantic coast of Brazil in November.

Huang and his colleagues charted the migratory path by recording and mapping the dates and locations of all sooty terns banded for study at the Dry Tortugas since the 1950s but found dead elsewhere. They also mapped locational data retrieved from birds that were fitted with satellite-telemetry tracking tags. When they overlaid all this data with maps of hurricane paths from the same period, they discovered a striking correlation.

“While it’s impossible to say just how many of the birds died as a direct result of the hurricanes, we saw a strong relationship between the numbers and locations of bird deaths and the numbers and locations of hurricanes,” said Stuart L. Pimm, the Doris Duke Professor of Conservation Ecology at Duke’s Nicholas School.

“What’s really interesting is that it’s not just the big category 4 and 5 storms that can kill large numbers of birds. A series of smaller, weaker storms may have the same impact as that of a single large, strong storm,” Pimm noted. “In September 1973, Tropical Storm Delia, a small storm in the Gulf of Mexico, killed a lot of birds because they were in the wrong place at the wrong time.”

Although sooty terns are neither rare nor endangered — 80,000 or more of them are estimated to breed in the Dry Tortugas each year — they have long been used by scientists as an indicator species to determine the health of the region’s marine environment.

“If there are changes taking place in the ocean, you’ll see corresponding changes taking place in the health of these tern populations, among other indicator species,” Huang said. “That’s what makes our findings somewhat concerning. If these birds are experiencing negative effects from changing ocean conditions, they are unlikely to be the only species affected.”

New report documents dramatic Antarctic penguin population loss

Hundreds of Adélie Penguins gather on Ross Island in Antarctica. Photo by David Grémillet

(Birdwatching Daily; 28 April 2017; Photo David Grémillet)

The inaugural “State of Antarctic Penguins” (SOAP) report, released on World Penguin Day (April 25) by international science-based NGO Oceanites, reveals that at least two species of Antarctic penguin — Adélie and Chinstrap — have suffered dramatic declines in population due to warming on the Antarctic peninsula. The SOAP report also identifies important trends about the keystone Antarctic penguin species — Adélie, Chinstrap, Emperor, and Gentoo — noting future concerns about these populations. Up-to-date data from more than 660 sites across the entire Antarctic continent has been aggregated and summarized for the report, including 3,176 records from 101 sources of on-the-ground colony counts and satellite photo analyses. The results are both significant and alarming, according to Oceanites founder and president Ron Naveen.

“In one generation, I have personally witnessed the precipitous decline of once abundant Adélie and Chinstrap Penguin populations,” said Naveen. “These iconic birds are literally canaries in the coal mine. They provide critical insights into the dramatic changes taking place in the Antarctic. What’s happening to penguin populations can have important implications for all of us.”

Critical scientific expertise for the SOAP report was provided by the Lynch Lab for Quantitative Ecology at Stony Brook University, who partnered with NASA to develop the Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD), a unique open-ended scientific support tool intended to provide “one-stop shopping” for scientists studying penguin populations in the Antarctic.

Heather Lynch, associate professor and director of the Lynch Lab, states, “We can now use advanced satellite technology and data analyses to better understand how these penguin populations are changing. By integrating expert biological field surveys, satellite imagery analyses, and citizen science, we can further enhance our ability to understand the changes taking place in an incredibly important world we are just learning about.”

The SOAP report presents findings both continent-wide and per key Antarctic fishing areas designated by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

Key report findings:

Over the past 60-plus years in the vastly warmed Antarctic Peninsula, Gentoo populations have increased significantly; Adélie Penguin populations have, in general, declined significantly; and Chinstrap Penguin populations have declined — at some locations significantly.

By contrast, in East Antarctica and the Ross Sea, regions that have not experienced a warming trend, Adélie Penguin populations appear to be increasing.

The SOAP 2017 report notes various concerns, all related to climate, potentially affecting these penguin populations — including the potential for ice sheet collapse both in West and East Antarctica.

Key implications:

In the vastly warmed Antarctic Peninsula, there are “winners” (rising numbers of Gentoos) and “losers” (decreasing numbers of Adélies and Chinstraps), foreboding concerns on whether humans will be able to adapt to warming trends.

Limiting warming to no more than 2°C / 3.6° F has become the de facto target for global climate policy; yet the Antarctic Peninsula already has warmed by more than that over the last 60 years — by 3°C / 5°F year-round and by 5°C / 9°F in the austral winter.

Ongoing studies are underway to ascertain whether penguins can maintain “the four vitals” necessary for adaptation and survival: food, habitat, health (disease-free environment), and reproduction (future generations).

Two species are in decline in the Antarctic Peninsula and another is adapting. Food might be an explanation; all the penguins can eat both krill and fish, but Gentoos, at this point in time, appear to have adapted better to reduced krill availability by eating more fish.

Wind, rain play key role in breeding patterns of migratory tree swallows

https://upload.wikimedia.org/wikipedia/commons/d/dc/7Z1E7819.jpg(Physorg, University of Colorado; Photo Wikipedia; 25 April 2017)

Wind and precipitation play a crucial role in advancing or delaying the breeding cycles of North American tree swallows, according to the results of a new University of Colorado Boulder-led study.

The research, which appears today in the journal Proceedings of the Royal Society B, sheds new light on how wet, windy weather can affect tree swallow nesting and underscores the importance of considering factors beyond temperature when examining how climate change might affect species’ biological niche.

Over the past decade and a half, the average egg hatching date for tree swallows—a common migratory bird species that winters in temperate southern climates before nesting in the spring at sites across North America, including the sub-Arctic regions covered in the study—has shifted earlier in the year by an average of six days. This change is similar to, but considerably greater than, changes seen in more southerly sites and until now has been believed to correlate with rising temperatures.

However, when CU Boulder researchers tested how swallow nesting data from two different Alaskan sites corresponded with both daily and seasonal climate indicators like the number of windy days, days with measureable precipitation and average daily temperature, they found that windiness (or lack thereof) had the most consistent correlation with swallow breeding patterns over time.

“We expected that temperature and precipitation would be much more strongly predictive than wind,” said Daniel Doak, a professor in CU Boulder’s Environmental Studies Program and the co-author of the new research. “The study demonstrates that fine-scale climate effects are important to consider when thinking about what’s going to affect a species.”

The study developed as a result of a CU Boulder undergraduate’s research efforts. Rachel Irons, then a junior in the Department of Ecology and Evolutionary Biology, received a UROP grant and worked with the Alaska Department of Fish and Game on a long-term tree swallow nesting study to fulfill her senior thesis requirements.

“Swallow phenology in Alaska is shifting at twice the rate of the continental U.S.,” said Irons, who is the lead author of the new paper. “I figured it was related to temperature, but I added in wind and precipitation measurements just to get the whole climate picture.”

The results showed that a long-term decline in windiness (and to a more variable extent, rain) in central Alaska over the past decade-plus correlated with the birds’ earlier breeding much more strongly than temperature, indicating that wet, windy spring weather that may have delayed egg laying in the past is now less of an impediment for the swallows.

The authors noted that while it is not necessarily surprising that wind and rain would affect an aerial foraging species like tree swallows, the findings emphasize the need to broaden the scope of consideration when making predictions about which climate mechanisms will influence population ecology.

“This shows that our initial intuitions are not always good about what’s going to impact these birds and their patterns,” said Doak.

Can barnacle geese predict the climate?

(Netherlands Institute of Ecology; Photo: Thomas Lameris; 18 April 2017)

The breeding grounds of Arctic migratory birds such as the barnacle goose are changing rapidly due to accelerated warming in the polar regions. They won’t be able to keep up with this climate change unless they can somehow anticipate it. A research team from the Netherlands Institute of Ecology (NIOO-KNAW) employed computer models to assess the future of the geese and their young.

It’s the time of year when barnacle geese and many other migratory birds prepare to depart for their breeding grounds above the Arctic Circle. From their wintering grounds in the Netherlands, the geese fly all the way up to the Barentsz Sea in northern Russia, where they should arrive just as the snow has melted. But in the polar regions, the climate is warming much more rapidly than in more temperate areas like the Netherlands — a phenomenon known as ‘Arctic amplification’.

It’s hard enough for humans to get to grips with the accelerated warming, let alone for barnacle geese, as an earlier NIOO-led study showed. After all, how can they tell from their wintering grounds if the snow has begun to melt thousands of kilometres away? So is it possible for the barnacle geese to advance their spring migration nonetheless, to predict climate change?

First study, fewer young

Ecologist Thomas Lameris and his fellow researchers from NIOO, and also the Swiss Ornithological Institute among other institutions, have tried to find the answer. “This is the first study that tests if migratory birds are in any way able to adjust their timing to the accelerated warming in the polar regions. We used a model to show that the availability of enough edible grass to build up reserves for their journey is not a problem for the barnacle geese. It’s the unpredictability of the climatic changes in their breeding grounds that spells trouble for them.”

If the geese continue to mistime their arrival, their reproductive success will be reduced. Lameris: “They miss their optimal breeding window and the peak in local food abundance, so fewer goslings will survive.” Some compensation for this comes from the fact that as well as starting earlier, the breeding season is becoming longer. This gives the goslings more time to grow. But that’s not enough.

To establish the barnacle geese’s potential for anticipating climate change, the researchers built a model that…….

Read more