Excavated dolmen in Sweden one of the oldest in Scandinavia

Peer-Reviewed Publication

UNIVERSITY OF GOTHENBURG

 

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THE CHAMBER UNDER EXCAVATION. EAST SIDE MOULD REMOVED. THE PLASTIC TUBES ARE SAMPLES FOR ENVIRONMENTAL DNA.

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CREDIT: PHOTO: KARL-GÖRAN SJÖGREN

The first analysis results now confirm that the grave in Tiarp is one of the oldest stone burial chambers in Sweden. “It’s an early grave which dates to the Early Neolithic period, about 3500 BCE,” says archaeologist Karl-Göran Sjögren. The researchers also noted that some parts of the people buried in the grave are missing, such as skulls and thigh bones, posing intriguing questions for archaeologists.

Last summer, archaeologists from Gothenburg University and Kiel University excavated a dolmen, a stone burial chamber, in Tiarp near Falköping in Sweden. The archaeologists judge that the grave has remained untouched since the Stone Age. However, the odd thing is that parts of the skeletons of the people buried are missing.

Skulls and large bones are missing and may have been removed from the grave. We don’t know whether that has to do with burial rituals or what’s behind it,” says Karl-Göran Sjögren.

Now that the researchers have examined the material from the grave, they have found that it contains bones from hands and feet, fragments of rib bones and teeth. But skulls and larger bones such as thigh and arm bones are very few.

“This differs from what we usually see in megalith graves, i.e. stone burial chambers  from the Neolithic period,” Karl-Göran Sjögren explains. “Usually, the bones that are missing are smaller bones from feet and hands.”

Torbjörn Ahlström, Professor of Osteology at Lund University, studied the bone finds. His conclusion is that the bones come from at least twelve people, including infants and the elderly. But the archaeologists don’t yet know why they died.

“We haven’t seen any injuries on the people buried so we don’t think violence is involved. But we are continuing to study their DNA and that will show whether they had any diseases,” says Karl-Göran Sjögren.

Falköping has long been known for its many passage graves dating from a somewhat later period, approximately 3300 BCE. Agriculture reached Falbygden in about 4000 BCE, i.e. about 500 years before the grave in Tiarp was built. In all likelihood, the people buried in the dolmen were farmers.

“They lived by growing grain and keeping animals and they consumed dairy products,” says Karl-Göran Sjögren.

Are the people buried in the grave related?

A number of samples were taken at the excavation last summer, including DNA from the skeletal remains.

“The preliminary DNA results show that the DNA in the bones is well preserved. This means we will be able to reconstruct the family relationships between the people in the grave and we are working on that now,” says Karl-Göran Sjögren.

Falbygden is known for its many traces of people from the Stone Age. There are more than 250 passage graves here, large graves built of blocks of stone.

“But this dolmen is older. It’s about 200 to 150 years older than the passage graves, making it one of the oldest stone burial chambers in Sweden and across the whole of Scandinavia,” says Karl-Göran Sjögren.

There is another thing that makes the grave unique.

“It’s the way it is constructed. There’s a little niche at each end. This is unique for graves in Falbygden,” says Karl-Göran Sjögren.

The study is freely available as open access in Journal of Neolithic Archaeology. Tiarp Backgården. An Early Neolithic Dolmen in Falbygden, Sweden and Early Megalithic Tombs in South Scandinavia and Northern Central Europe.

https://doi.org/10.12766/jna.2023.8

The archaeological excavation in Tiarp in summer 2023 was carried out jointly by Gothenburg and Kiel Universities. From left: Julia Dietrich, Ann-Katrin Klein, Malou Blank and Karl-Göran Sjögren.

CREDIT

Photo: Cecilia Sjöberg

ExcavationofdolmenTierpcloseup (IMAGE)

UNIVERSITY OF GOTHENBURG

Last summer, archaeologists from Gothenburg University and Kiel University excavated a dolmen, a stone burial chamber, in Tiarp near Falköping in Sweden.

CREDIT

Photo: Cecilia Sjöberg

Facts

• The grave in Tiarp Backgården in Falköping, was first found in 1929. It was studied by archaeologists at the time, and then again in 2014, which was when it was discovered that the grave was more or less intact and had bodies buried inside it.

• The archaeological excavation in Tiarp in summer 2023 was carried out jointly by Gothenburg and Kiel Universities. 

• Study participants
  Karl-Göran Sjögren, Malou Blank and Tony Axelsson, Department of Historical Studies, Gothenburg University.
  Torbjörn Ahlström, Lund University
  Stefan Dreibrodt, Institute for Ecosystem Research, Kiel University
  Johannes Müller, Institute of Prehistoric and Protohistoric Archaeology, Kiel University.

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DOI

10.12766/jna.2023.8 

METHOD OF RESEARCH

Case study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Tiarp Backgården. An Early Neolithic Dolmen in Falbygden, Sweden and Early Megalithic Tombs in South Scandinavia and Northern Central Europe

 

Back from the dead: Tropical tree fern repurposes its dead leaves

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU

 

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UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN PLANT BIOLOGY PROFESSOR JAMES DALLING AND HIS COLLEAGUES DISCOVERED THAT SOME TREE FERNS RECYCLE THEIR DEAD FRONDS INTO ROOTS. THE RESEARCHERS CALL THESE REPURPOSED FRONDS “ZOMBIE LEAVES.”

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CREDIT: PHOTO BY FRED ZWICKY

CHAMPAIGN, Ill. — Plant biologists report that a species of tree fern found only in Panama reanimates its own dead leaf fronds, converting them into root structures that feed the mother plant. The fern, Cyathea rojasiana, reconfigures these “zombie leaves,” reversing the flow of water to draw nutrients back into the plant.

Watch a video about the findings.

This weird phenomenon occurs only after the leaves die and droop to the ground, said University of Illinois Urbana-Champaign plant biology professor James Dalling, who made the discovery with his team while studying a different plant in a Panamanian forest reserve. Dalling noticed that the fronds were strongly embedded in the soil and had sprouted a network of rootlets. Laboratory tests revealed that the zombie leaves were drawing nitrogen out of the soil.

Even after they are converted into roots, the wilted fronds look like decayed plant matter, which is probably why generations of plant biologists failed to notice that they were performing a life-sustaining task, Dalling said.

“This is a truly novel repurposing of tissue. And it’s distinct from what we know other ferns do,” he said.

Other plants, including some ferns, send out leaves or shoots that touch the ground and sprout roots to sustain a new plant, he said. But reconfiguring dead tissue to feed the original plant has never been reported. The new findings are detailed in the journal Ecology.

C. rojasiana belongs to an ancient lineage of tree ferns dating back to the Jurassic period, Dalling said. The zombie leaves are most likely an adaptation to the nutrient-poor volcanic soils.

“Panama is a land bridge between North and South America that coalesced 7 million years ago out of an archipelago of islands, and those islands are the result of volcanic activity in the past,” he said. “In one site we discovered, a layer of volcanic ash several meters deep looks like sand that you would dig up on a sandy beach. The plants that grow there are distinct from those that we find elsewhere in that forest reserve.”

The patchiness of the vegetation means soil nutrients also are unevenly distributed.

“And so the tree ferns seem to be putting out tentacles to sample the surrounding soils,” Dalling said. “They’re able to sample a greater range of nutrient environments for the same amount of investment of rootlets than if they just sent out a single rooting structure all around the fern. I think it’s all about the economics of how they use resources in a patchy environment.”

The tree ferns also grow very slowly.

“They’re probably putting on one or two leaves a year, and so they’re adding on the order of a few centimeters of height a year,” Dalling said.

This means each frond is a major investment of resources that the plant repurposes after the leaf dies. The slow growth also means that the tree fern is short enough that when its fronds die, they droop all the way to the ground. The trees reach a maximum height of about two meters, Dalling said.

The finding is “another example of the extraordinary diversity of plant adaptations that exist in resource-poor environments,” he said.

Dalling also is a research associate at the Smithsonian Tropical Research Institute in Panama.

Other plants, including some ferns, send out leaves or shoots that touch the ground and sprout roots to sustain a new plant. But the Panamanian tree fern, Cyathea rojasiana, reconfigures its “zombie leaves,” reversing the flow of water to draw nutrients back into the plant.

CREDIT

Graphic by Camila Pizano, color by Michael Vincent

JOURNAL

Ecology

DOI

10.1002/ecy.4248 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Zombie leaves: novel repurposing of senescent fronds in the tree fern Cyathea rojasiana in a tropical montane forest

ARTICLE PUBLICATION DATE

18-Jan-2024

 

NUS scientists develop novel method to estimate biodiversity loss in Singapore over the past two centuries

Findings underscore the vulnerability of charismatic species in tropical forest environments

Peer-Reviewed Publication

NATIONAL UNIVERSITY OF SINGAPORE

 

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THE GARNET PITTA (PITTA GRANATINA COCCINEA) WAS LAST SEEN IN SINGAPORE IN 1949.

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CREDIT: KEITA SIN

Scientists from the National University of Singapore (NUS) employed novel statistical methods to reveal the extent of biodiversity loss in Singapore over the past two centuries. The study paints the most accurate picture to date of the ecological impact of deforestation and urban development in the tropical city-state.

Led by Associate Professor Ryan Chisholm from the NUS Department of Biological Sciences,  the research team compiled over 200 years of biodiversity records for Singapore, encompassing more than 50,000 individual records and over 3,000 species across ten major taxonomic groups.

From this comprehensive dataset, the study estimated that Singapore has lost 37 per cent of its species. Importantly, the novel statistical models used by the team considered ‘dark extinctions’ — species that went extinct before they could be discovered and documented. Although 37 per cent is a high extinction rate, it is only half that of a previous 2003 estimate that also attempted to account for dark extinctions. The team also found that certain groups are particularly vulnerable to extinction, including larger mammals, forest-dependent birds, orchids and butterflies.

The findings were detailed in a scientific paper titled “Two centuries of biodiversity discovery and loss in Singapore”, published in the journal PNAS on 11 December 2023.

Using novel statistical models for more accurate estimation

“The use of statistical models developed in my lab allowed us account for species that have disappeared before we even knew they existed. The novel MODGEE (matrix-of-detections-gives-extinction-estimates) model is particularly powerful because it takes into account the entire detection history of each species,” said Assoc Prof Chisholm.

While earlier models estimated extinction rates using just each species’ first and last records, the MODGEE model takes a more detailed approach by using the full species-by-time detection matrix, facilitating a richer analysis. The MODGEE model provides estimated probabilities and dates of extinction for each species, and is suitable for application to groups of species with more comprehensive data records.

Prioritising charismatic species for conservation

The study’s findings are significant not only for Singapore but the broader Southeast Asian region. The researchers extrapolated Singapore’s historical experience to project that if current deforestation trends persist, Southeast Asia may lose 18 per cent of its species by 2100. They describe this as a ‘tropical Europe’ scenario, because although a large majority of species is projected to persist in the future human-dominated landscapes of the region, extinctions will be concentrated among large charismatic species.

Given these findings, the NUS researchers recommended a shift in conservation strategy, prioritising landscape-scale conservation centred around charismatic species — species that garner more public interest due to their aesthetic appeal or cultural significance.

“Adopting this approach not only benefits other species but also aligns with other conservation goals, such as the protection of carbon stocks, crucial in mitigating climate change,” added Assoc Prof Chisholm.

In urban settings like Singapore, the researchers suggested focusing on medium-sized species such as langurs, pangolins, hornbills and butterflies, which can adapt to urbanised landscapes with proper conservation support. For the larger Southeast Asian region, the focus expands to include species such as tigers, orangutans, elephants, rhinoceroses and other endangered large mammals.

 

Half-banded kuhli loach (Pangio semicincta) is extinct in Singapore.

CREDIT

Tan Heok Hui

A Peters’s keelback snake (Hebius petersii) specimen from the NUS Lee Kong Chian Natural History Museum’s collections. The species is extinct in Singapore.

CREDIT

Kelvin Lim

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2309034120 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Two centuries of biodiversity discovery and loss in Singapore

 

Organ donations after MAiD made up 14% of deceased donations in Quebec

Peer-Reviewed Publication

CANADIAN MEDICAL ASSOCIATION JOURNAL

Organ donation after medical assistance in dying (MAiD) represented 14% of Quebec's total deceased donations in 2022, according to a new study in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.230883.

To understand the impact of organ donation after MAiD, Quebec researchers analyzed data on all patients referred to Transplant Québec for possible organ donation after MAiD from January 2018 to December 2022. This represented the first 5 full years when organ donation after MAiD was allowed in the province. Over the 5-year period, Transplant Québec received 245 referrals for donation after MAiD, with an increase in annual referrals from 21 in 2018 to 109 in 2022. The total number of donor patients after MAiD was 64, increasing from 8 in 2018 to 24 in 2022. Donations after MAiD represented 14% of all deceased organ donations in 2022, and the majority of the donors had neurodegenerative diseases, with amyotrophic lateral sclerosis the most common condition. The average age of donors after MAiD was 60 years, and 64% were male.

"Our analysis of data related to organ donation after MAiD in Quebec shows that organ donation organizations can establish systems that honour the wishes of patients pursuing MAiD to donate their organs after their death," writes Dr. Matthew Weiss, a pediatric critical care physician at Centre Mère-Enfant Soleil du CHU de Québec, Quebec, and medical director at Transplant Québec, with coauthors. "However, much remains to be learned regarding how to optimize the system to ensure that donation requests are treated in the most ethical and medically effective way."

The authors note that it is not known how many patients were offered the choice to donate after MAiD or what the consent rate is in that group, as there is currently no system to track this information.

"Patients considering MAiD are among the most vulnerable patients in the health care system, as they have intractable diseases that cause them immense suffering. The desire of some patients to help others after their death must be honoured, but in doing so, donation professionals must assure the system respects their autonomy and dignity," the authors conclude.

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JOURNAL

Canadian Medical Association Journal

DOI

10.1503/cmaj.230883 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Organ donation after medical assistance in dying: a descriptive study from 2018 to 2022 in Quebec

ARTICLE PUBLICATION DATE

29-Jan-2024

 

Fluvo-aquic soil treated with pig manure present a higher risk of antibiotic-resistant bacteria than black and red soils

Peer-Reviewed Publication

HIGHER EDUCATION PRESS

 

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DISTRIBUTION OF ANTIBIOTIC RESISTANT BACTERIA IN DIFFERENT SOIL TYPES FOLLOWING MANURE APPLICATION. IN THIS IMAGE, CRB COMMUNITY COMPOSITION IN CTC-MANURE OF FLUVO-AQUIC SOIL WAS MORE COMPLEX THAN IN BLACK AND RED SOILS AND MANURE-INDIGENOUS CRB WERE ADAPTED TO THE FLUVO-AQUIC SOIL ENVIRONMENT. MANURE APPLICATION LED TO HIGHER CRB RISK IN FLUVO-AQUIC SOIL COMPARED WITH BLACK AND RED SOILS

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CREDIT: HONGNA LI LAB

In agroecosystems where manure is applied as organic fertilizer, these antibiotic residues exert strong selective pressure on soil microbial communities. Antibiotic-resistant bacteria (ARB) from animal manure would increase the concentration of ARB in soils. The influencing mechanisms of soil types on the distribution of ARB were worthy of further exploration. This study demonstrates that CTC-manure induced more resistance of soil indigenous microbes in fluvo-aquic soil, Lactobacillus, Dyella, Ralstonia, and Bacillus were the key different genera, and manure control is an effective way to reduce the risk of soil ARB. The researchers’ findings appeared December 19, 2023 in Soil Ecology Letters.

 

A series of studies on the risk of ARB and antibiotic-resistant genes (ARGs) have been conducted by Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences. For example, they found that Chloroflexi was closely associated with ARGs removal, and potential host bacteria of ARGs varied with different antibiotics. They also found multidrug resistance genes increased the most in red soil with antibiotics, and ARGs were directly influenced by microbes, indirectly affected by soil properties.

 

Professor Li said, "Agricultural production has caused a heavy burden on the environment, and the overall trend of deterioration is still increasing. This is a contradiction that must be resolved. The results of the second national survey of pollution sources released recently showed that the pollution load from agricultural sources exceeded that of industry and cities, highlighting the importance and urgency of agricultural environmental protection work. Therefore, we chose and explored agricultural and rural environmental protection issues, hoping to contribute to the solution of environmental problems."

 

In this study, they found that a higher shift in the operational taxonomic units and the community composition of chlortetracycline (CTC)-resistant bacteria (CRB) were observed in fluvo-aquic soil than in black and red soils. CTC induced antibiotic resistance development in soil indigenous microorganisms (Streptomyces, Pseudomonas, Bacillus, Rhodococcus, and Paenibacillus), and the induction was most obvious in fluvo-aquic soil. Additionally, the key different genera were Microbacteriaceae (black soil), Lactobacillus, unclassified_c__Bacilli and Paenibacillus (fluvo-aquic soil), and Dyella, Ralstonia and Bacillus (red soil). It was concluded that manure application led to higher CRB risk in fluvo-aquic soil compared with black and red soils. This result suggests appropriate methods according to soil types are important ways to reduce the risk of soil resistant bacteria during manure return.

 

Professor Li said, "The application of manure to the soil increased microbial resistance, which was even stronger when the manure contained antibiotic residues. Moreover, manure application led to higher CRB risk in fluvo-aquic soil compared with black and red soils. As a result, scientific manure return according to soil types is also important for monitoring the risk of resistance in agricultural practice."

 

Soil is relevant to our lives; it is fundamental to food security, water security and entire ecosystem health. Monitoring soil antibiotic risk is more important than ever.

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JOURNAL

Soil Ecology Letters

DOI

10.1007/s42832-023-0210-6 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Distribution of antibiotic resistant bacteria in different soil types following manure application

ARTICLE PUBLICATION DATE

19-Jan-2024

 

Key LiDAR sensor elements for autonomous vehicles are now made with our technology

High-performance sensor devices for short- and mid-range LiDAR applications. Expected to localize LiDAR sensor devices by developing based on a semiconductor mass production process.

Meeting Announcement

NATIONAL RESEARCH COUNCIL OF SCIENCE & TECHNOLOGY

 

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KIST SINGLE-PHOTON AVALANCHE DIODE DEVELOPED IN SK HYNIX'S 40 NM BACK-ILLUMINATED CMOS IMAGE SENSOR TECHNOLOGY

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CREDIT: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY(KIST)

LiDAR sensors are indispensable for the realization of advanced technologies such as advanced driver assistance systems (ADAS), autonomous driving, and AR/VR. In particular, short- and mid-range LiDAR used in AR/VR devices and smartphones requires better distance (depth) resolution to detect the shape of a person or object more accurately, and so a single-photon detector with better timing jitter performance is required.

LiDAR measures distance and creates a 3D image by calculating the time it takes for a photon emitted by the transmitter to strike an object, reflect, and arrive back at the receiver. The slight difference in detection time that occurs when the single-photon detector at the receiver converts the light signal into an electrical signal is called "timing jitter," and the smaller the value of this jitter, the more accurately the object can be recognized.

The Korea Institute of Science and Technology (KIST) announced that a team led by Dr. Myung-Jae Lee at the Post-Silicon Semiconductor Institute has developed a "single-photon avalanche diode (SPAD)" that can identify objects at the mm level based on a 40nm back-illuminated CMOS image sensor process.

SPADs, which are ultra-high-performance sensor devices that can detect single photons, are extremely difficult to develop, and to date, only Sony of Japan has successfully commercialized SPAD-based LiDAR based on its 90nm back-illuminated CMOS image sensor process and supplied it to Apple products. Sony's SPAD shows better efficiency than back-illuminated SPADs reported in the literature, but its timing-jitter performance of about 137~222ps is insufficient to realize user discrimination, gesture recognition, and accurate shape recognition of objects required in short- and mid-range LiDAR applications.

The single-photon sensor element developed by KIST has significantly improved the timing-jitter performance by more than two times to 56 ps, and the distance resolution has also been improved to about 8 mm, which has great potential for utilization as a short and mid-range LiDAR sensor element. In particular, since the SPAD was developed based on the 40nm back-illuminated CMOS image sensor process, a semiconductor process for mass production, through joint research with SK hynix, it is expected to be immediately localized and commercialized.

"If commercialized as a core source technology for semiconductor LiDAR and 3D image sensors, it will greatly enhance our competitiveness in next-generation system semiconductors, which are Korea's strategic industries," said Myung-Jae Lee, principal investigator at KIST.

Semiconductor chip with ultra-high-performance sensor elements developed by Dr. Myung-Jae Lee's research team at KIST's Advanced Semiconductor Devices and Systems Laboratory (ADS Lab)

CREDIT

Korea Institute of Science and Technology(KIST)

KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/

The research, supported by the Korea Institute of Science and Technology (KIST) Institution Program (Grant No. 2E32242) and the National Research Foundation of Korea (NRF) (Grant No. 2021M3D1A2046731), was presented on December 12 at the International Electron Devices Meeting 2023 (IEDM 2023), held from December 9 to 13 in San Francisco, USA. IEDM is one of the most prestigious conferences for semiconductor industry and research experts, including major global semiconductor companies such as SK hynix, Samsung Electronics, and Intel.

 

Endangered seabird shows surprising individual flexibility to adapt to climate change

Peer-Reviewed Publication

UNIVERSITY OF OXFORD

 

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A BALEARIC SHEARWATER CARRYING A GEOLOCATOR. CREDIT: JOE PENDER

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CREDIT: JOE PENDER

• New research finds that individual behavioural flexibility and not evolutionary selection is driving the northward shift of Balearic shearwaters.
• The findings were revealed through a decade-long study which tagged individual birds.

• The results indicate that individual animals may have greater behavioural flexibility to respond to climate change impacts than previously thought.

How individual animals respond to climate change is key to whether populations will persist or go extinct. Many species are shifting their ranges as the environment warms, but up to now the mechanisms underlying this have been unclear. For Europe’s most endangered seabird, the Balearic shearwater (Puffinus mauretanicus), new research has revealed that individual behavioural flexibility and not evolutionary selection is driving this species’ rapid migratory range shift. The study, led by University of Oxford biologists, has been published today in the journal Proceedings of the National Academy of Sciences.

The findings could help inform conservation strategies for vulnerable migratory bird species. The results also suggest that individual animals may have greater behavioural flexibility to respond to climate change impacts than previously thought, although this behavioural adaptation may have hidden costs, making the long-term impact on this species unclear.

Balearic shearwaters are long-lived but Critically Endangered mainly because of declines driven by fisheries by-catch, as they can get caught on baited longline hooks and gill nets. They breed in remote corners of the Mediterranean’s Balearic Islands, then migrate to spend the summer off the Atlantic coasts of Spain, France, and increasingly the UK.

Since 2010, researchers from Oxford University’s Biology Department and from the University of Liverpool, together with collaborators working in Ibiza, have been tracking colonies in Mallorca using miniature on-board geolocation devices. This revealed that the birds have been migrating further and further north once they leave the Mediterranean.

It was unknown, however, whether this change was being driven by individual birds altering their behaviour, or through natural selection favouring birds that travel further.

To answer this, the researchers compared the migration tracks of the same individuals tagged in multiple years. This revealed that individual birds were shifting their range northwards by an average of 25km per year.

Co-lead author Joe Wynn (Department of Biology, University of Oxford & Institute of Avian Research "Vogelwarte Helgoland"), said: ‘We found that the best predictor of this change in migratory behaviour was the average sea surface temperature in the summering-grounds, suggesting that the birds may well be following changes in underlying marine resources. The fact that individuals can be this flexible in the face of rapid climate change is encouraging.’

But despite this flexibility in their summer destination, Balearic shearwaters are much more constrained in where they breed, so that migrating further north means they have further to fly back in the autumn.

Co-author Professor Tim Guilford (Department of Biology, University of Oxford) added: ‘We found that individuals speed up their return migration the further north they have gone, but this only partially compensates for the extra distance and they still arrive back in the Mediterranean late. We don’t yet know how such delays may affect their breeding success or survival.’

This raises the intriguing question of how the birds know how far away from home they are, when they set off back for the colony. To investigate this, the researchers compared the distance estimates of the different kinds of map that shearwaters might use to guide their migration decisions. 

Co-lead author Patrick Lewin (Department of Biology, University of Oxford), said: ‘We found that the route individual birds took on previous migratory journeys was a much better predictor of return speed than an estimate of the straight line distance back to the colony. This suggests that birds do not rely on a large-scale navigational map on migration, but instead have some memory of the route they have flown in the past.’

‘It is possible that individual route memory plays an important role in the migration of many other long-lived seabirds, but further research is needed to clarify this’ he added.

Balearic shearwaters belong to one of the most threatened groups of birds on earth, and are themselves facing potential extinction as a species. This includes both land-based threats, such as predation by invasive species and habitat degradation, and at-sea threats, such as fisheries bycatch, overfishing, pollution, and windfarm development.

Collaborator Pep Arcos from SEO/Birdlife said: ‘In addition to direct threats both on land and at sea, the increasing threat of climate change poses a challenge for a species that breeds in such a restricted habitat. Results from this study suggest that individual flexibility might help with distribution shifts driven by climate change outside the breeding season, but the question is still open about what might be the consequences of climate change for the birds during breeding, when their movements are constrained by the location of the colony.

Notes to editors:

For media requests, contact the Communications team in the Department of Biology, University of Oxford – comms@biology.ox.ac.uk

The study ‘Climate change drives migratory range shift via individual plasticity in shearwaters’ will be published in Proceedings of the National Academy of Sciences on Monday 29 January at 20:00 GMT/ 15:00 ET at doi.org/10.1073/pnas.2312438121. To view a copy of the paper before this under embargo, contact the Communications team in the Department of Biology, University of Oxford – comms@biology.ox.ac.uk

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the eighth year running, and ​number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

The Department of Biology is a University of Oxford department within the Maths, Physical, and Life Sciences Division. It utilises academic strength in a broad range of bioscience disciplines to tackle global challenges such as food security, biodiversity loss, climate change and global pandemics. It also helps to train and equip the biologists of the future through holistic undergraduate and graduate courses. For more information visit www.biology.ox.ac.uk.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2312438121 

ARTICLE PUBLICATION DATE

29-Jan-2024