Species most likely to go extinct sooner were endemic to islands, lacked the ability to fly, had larger bodies and sharply angled wings, and occupied ecologically specific niches, according to research published this month.

While some of these findings mirror previous research on extinct birds, they are the first to correlate bird traits with the timing of extinctions, said lead author Kyle Kittelberger, a graduate student in the School of Biological Sciences.

“I’ve been very interested in extinctions and understanding the species that we’ve lost and trying to get a sense of how we can use the past to better inform the present and future,” said Kittelberger, who is completing his dissertation on how the bodies and wings of certain species of migratory songbirds have changed in response to climate change.

His team’s analysis tapped into BirdBase, a dataset of ecological traits for the world’s 11,600+ bird species compiled by U biology professor Ça?an ?ekercio?lu and the Biodiversity and Conservation Ecology Lab at the U. The team simultaneously analyzed a broad range of biogeographical, ecological and life history traits previously associated with extinction and extinction risk for bird species that have gone extinct as well as those that lack recent confirmed sightings and have therefore disappeared.

“Importantly, we examine biological correlates of bird extinctions through the lens of when birds went extinct, providing a novel extinction timing element that helps better inform why birds with certain traits disappeared when they did,” Kittelberger wrote in a series of posts on X. By identifying traits that most predispose birds to extinction, the findings can help guide conservation efforts of hundreds of species that are at peril.

“One of the strengths of the approach that we use is we compared all of these traits simultaneously against each other, whereas a lot of previous studies in the literature just look at traits in isolation.”

While only around 2% of the world’s bird species have gone extinct since 1500, the year Kittelberger’s analysis begins, even more had already disappeared by then. Before 1500, however, there is not as reliable a record of the birds that went extinct and data on their traits and characteristics.

This timing coincides with the rise of scientific observation, resulting in a systematic documentation of plant and animal life. It is also the time when European exploration took off, leading to the disruption of ecosystems around the globe as a result of colonization and introduced species.

Today, 1,314 bird species are at risk of extinction, according to the IUCN Red List of Threatened Species, or about 12% of the total.

Many species, such as the ‘Akikiki (Oreomystis bairdi), endemic to the Hawaiian island of Kauai, are so rare that they are functionally extinct. Kittelberger photographed the pictured ‘Akikiki, also called Kauai’s creeper, in the Alaka’i Wilderness Preserve in 2022, when it was believed around 70 or so remained in the wild; today, only one individual remains.

The proportion of 216 bird species globally extinct or likely lost since 1500 that were endemic to a region, found solely on islands, and were either flightless or partially flightless, as well as the breakdown of species by primary habitat or diet.

As with many other Hawaiian bird species, the main threat to the ‘Akikiki comes in the form of introduced species, principally malaria-carrying mosquitoes and habitat-wrecking livestock, according to Hawaii’s Division of Forestry and Wildlife.

The single most critical trait associated with extinction is insularity, those species endemic to islands. Other traits that appear to increase extinction risk, such as body size, wing shape and ecological specialization, are also associated with island insularity.

Pacific islands are home to a vast array of endemic species, many of which are now on the IUCN list. No archipelago has seen more loss of avian biodiversity than Hawaii, which accounts for 34 post-1500 extinctions, according to the study.

The bird family that experienced the most extinctions is Rallidae, or rails, which are globally distributed medium-sized semi-amphibious bird species. This family lost 26 members, while the entire line of the Mohoidae family, small nectar-sipping songbirds commonly known as Hawaiian honeyeaters, is completely gone (the only bird family to go fully extinct in modern times). The family’s last member, the Kauai O’o (Moho braccatus), was last observed in 1987.

The finding that did surprise Kittelberger’s team was the correlation of wing shape to extinction. They found that bird species with a larger hand-wing index, that is more pointed wings, were more likely to have vanished earlier. Since pointier wings indicate stronger flying and dispersal abilities, the team predicted such birds would be better equipped to respond to environmental pressures than those with rounder wings.

Yet birds with rounder wings, those with smaller hand-wing ratios, proved to be more resilient.

“It likely ties with the fact that a lot of these birds that went extinct were on islands. For these species or their ancestors to have arrived at these islands to begin with, they would’ve needed the ability to fly across large, open distances. So a lot of these birds on islands have, not necessarily longer, but more pointed wings,” Kittelberger said. “Think of a swift or a swallow or a bird like an albatross that flies over the ocean. They have really pointy wings that allow them to fly really well, whereas birds in dense tropical rainforests are not flying these large distances, so they have rounded wings because they’re just moving in their local habitat patches.”

Ecological specialists, as opposed to generalists, face great challenges when their specific ecological niche is altered, so they tend to be less able to respond and adapt to disturbances, like invasive species or disruption of a food source.

In other findings, the study concluded more than 87% were endemic to islands; nearly two-thirds inhabited forests; 45% ate primarily insects and other invertebrates; and 20% were completely or partially flightless. Finally, species with big bodies were overly represented on the extinct list.

“Heavier birds have been more likely to be targeted for hunting, with several well-known examples of birds being hunted to extinction in part for food, including the Dodo, Great Auk (Pinguinus impennis), and Spectacled Cormorant (Urile perspicillatus),” the study said. “Body mass has also been linked with a species’ inhabitance of islands, as island birds tend to be larger than mainland species.” Of the 43 species whose average body weight exceeded 500 grams, or 1.1 pounds, three-quarters were endemic to an island.

The decade of the 1890s saw the highest number on extinctions, with 21 recorded. The 1980s was another bad decade for bird loss with 20 species, including the Kauai O’o. This latter decade “is noteworthy since focused and targeted conservation efforts were already underway globally before and during this period,” the study said. “Though the rate of extinction declined in the subsequent decades, the number of globally threatened species has only increased.”

The study, “Correlates of avian extinction timing around the world since 1500 CE,” was published Nov. 7 in the journal Avian Research. The research team included Colby J. Tanner, Amy N. Buxton, Amira Prewett and Ça?an ?ekercio?lu. Support for this research came from the University of Utah’s Graduate Research Fellowship.

CTE is a neurodegenerative disease associated with repeated head injuries, often seen in athletes and military personnel, that can lead to mood changes and dementia.

“This appears to be a case where together these risk factors add up to a greater risk for aggression than they each do on their own, where people with CTE and a family history of mental illness are much more likely to have aggressive behavior than those with just CTE or just the family history,” said study author Jesse Mez, MD, MS, of Boston University Chobanian & Avedisian School of Medicine and a member of the American Academy of Neurology.

The study involved 845 men who were exposed to repetitive head impacts through contact sports or military service. A total of 329 of them played professional football. All donated their brains to research after their death, which was at an average age of 60. Of the total group, 589, or 70%, had CTE and 383, or 45%, had a family history of mental illness.

Researchers interviewed family members or spouses of the participants about their aggressive behavior. They were also asked whether the participants’ parents, siblings or children were ever diagnosed with major depression, bipolar disorder, anxiety, post-traumatic stress disorder, obsessive-compulsive disorder or other mood or psychiatric disorders. If any family member had a diagnosis, the participant was considered to have a family history of mental illness.

Researchers then divided participants into four groups: 256 people, or 30%, with CTE and a family history of mental illness; 333 people, or 40%, with CTE and without a family history of mental illness; 127 people, or 15%, without CTE and with a family history of mental illness; and 129 people, or 15%, without CTE and without a family history of mental illness.

Researchers asked family members about the participants’ aggressive behavior, such as whether they had severe arguments with others or got in physical fights, where scores ranged from zero to 44. They found that during adulthood people with CTE and a family history of mental illness had an average score of 19 compared to people with CTE without a family history of mental illness who had an average score of 17.

“This relationship was most striking for participants who died between 40 and 59 years old,” Mez added.

After adjusting for other factors, such as total years playing contact sports and military history, researchers found that those who died between 40 and 59 years old who had CTE and a family history of mental illness scored an average of 0.64 standard deviations higher on a scale measuring aggression when compared to those with CTE, but without a family history of mental illness. For people who did not have CTE, having a family history of mental illness did not increase their risk for aggressive behavior.

“The link between a family history of mental illness and aggression may be through a shared genetic background and also through shared environment and common behaviors, such as childhood experiences with family members,” said Mez. “Identifying people who are more likely to show symptoms of aggression based on family history of mental illness would give us a way to predict the consequences of CTE and identify who may benefit most from treatment options.”

A limitation of the study was that the study relied on past information from family members and spouses who may not have remembered information accurately.

The study was funded by the National Institutes of Health, Department of Veterans Affairs and the Nick and Lynn Buoniconti Foundation.

This study, published in The Astrophysical Journal, was performed by a multi-year cohort of undergraduate researchers in the Penn State branch of the Pulsar Search Collaboratory student club. Maura McLaughlin, Chair, Eberly Distinguished Professor of Physics and Astronomy, West Virginia University, created the Pulsar Search Collaboratory to engage high schoolers and undergraduates in pulsar science, and she helped facilitate access to the data used in this study. Using archival data from the Arecibo Observatory, the student team found patterns that show how pulsar signals change as they move through the interstellar medium (ISM), the gas and dust that fills the space between stars. The team measured scintillation bandwidths for 23 pulsars, including new data for six pulsars not previously studied. The results showed that in almost all cases, measured bandwidths were higher than predictions by widely used models of the galaxy, highlighting a need for updates to current ISM density models.

“This work demonstrates the value of large, archived datasets,” said Dr. Sofia Sheikh, SETI Institute researcher and lead author. “Even years after the Arecibo Observatory’s collapse, its data continues to unlock critical information that can advance our understanding of the galaxy and enhance our ability to study phenomena like gravitational waves.”

When radio light from a pulsar travels through the ISM, it gets distorted in a process known as “diffractive interstellar scintillation” (DISS). The same physics that makes light refract into patterns on the bottom of a swimming pool or causes stars to twinkle in the night sky also causes DISS. Instead of water in a pool or air in the atmosphere, DISS occurs when clouds of charged particles in space cause a pulsar’s light to “twinkle” across time and frequency.

Collaborations such as the NANOGrav Physics Frontiers Center use pulsars to study the gravitational wave background, which can help researchers understand the early Universe and the prevalence of gravitational-wave sources such as supermassive black-hole binaries. The pulsar timing measurements must be extremely precise to measure the gravitational wave background correctly. The results from this study will help better model the distortions caused by DISS, which will increase the precision of the pulsar timing measurements of projects like NANOGrav.

The study found that models incorporating galactic structures, such as spiral arms, tend to better fit the DISS data despite the challenge of accurately modeling the Milky Way’s structure. Moreover, the study showed that the models most accurately predicted the bandwidths of pulsars that were used in their development while predictions of newly discovered pulsars were worse. This suggests limitations that reinforce the need for continual updates to galactic structure models.”

This pilot study, part of the AO327 survey from Arecibo, serves as a foundation for future research on pulsar scintillation and gravitational waves. By expanding the pilot study to more recently discovered pulsars in the AO327 dataset in the future, the team hopes to further improve ISM density models for collaborations that observe pulsar timing arrays like NANOGrav.

This research involves the collaboration between authors at the SETI Institute, Penn State, and the NANOGrav Group at West Virginia University. The team includes SETI Institute researcher Michael Lam and former SETI Institute researcher Grayce Brown.

There is evidence that alcohol consumption is influenced by prenatal sex steroids so experts from Swansea University and colleagues from the Medical University of Lodz decided to use a sample of students for their research into the subject.

Their findings have just been published by the online journal American Journal of Human Biology. They found relationships between high alcohol consumption and long 4^th digits relative to 2^nd digits. This showed that high prenatal testosterone relative to oestrogen is linked to high student alcohol consumption.

Professor John Manning, of Swansea’s Applied Sports, Technology, Exercise and Medicine (A-STEM) research team, said: “Alcohol consumption is a major social and economic problem. Therefore, it is important to understand why alcohol use shows considerable differences across individuals.”

The study used a sample of 258 participants — 169 of them female — and it revealed consumption rates varied between the sexes. In comparison to women, men show higher alcohol consumption and higher mortality from alcohol abuse.

He said: “A pattern like this suggests an involvement of sex hormones, such as testosterone and oestrogen. Digit ratio (2D:4D: the relative lengths of the 2^nd [index] and 4^th [ring] fingers) is thought to be an index of early testosterone (long 4^th digit) and oestrogen (long 2^nd digit).

“It is known that alcohol-dependent patients have very long 4^th digits relative to their 2^nd digits, suggesting high testosterone relative to estrogen exposure before birth. As expected, the associations were stronger for men than women.”

Now the researchers hope their conclusions will bring a better understanding of the factors underlying the pattern of alcohol consumption, from abstinence to occasional use to harmful dependence.

This is the latest paper which has highlighted Professor Manning’s work in the field of digit ratios. Previous research has examined how digit ratio may provide vital information concerning outcomes after contracting Covid-19, as well as oxygen consumption in footballers.

All this may not be breaking news to everyone, but amid this upward march in average temperatures, a striking new phenomenon is emerging: distinct regions are seeing repeated heat waves that are so extreme, they fall far beyond what any model of global warming can predict or explain. A new study provides the first worldwide map of such regions, which show up on every continent except Antarctica like giant, angry skin blotches. In recent years these heat waves have killed tens of thousands of people, withered crops and forests, and sparked devastating wildfires.

“The large and unexpected margins by which recent regional-scale extremes have broken earlier records have raised questions about the degree to which climate models can provide adequate estimates of relations between global mean temperature changes and regional climate risks,” says the study.

“This is about extreme trends that are the outcome of physical interactions we might not completely understand,” said lead author Kai Kornhuber, an adjunct scientist at the Columbia Climate School’s Lamont-Doherty Earth Observatory. “These regions become temporary hothouses.” Kornhuber is also a senior research scholar at the International Institute for Applied Systems Analysis in Austria.

The study was just published in the journal Proceedings of the National Academy of Sciences.

The study looks at heat waves over the past 65 years, identifying areas where extreme heat is accelerating considerably faster than more moderate temperatures. This often results in maximum temperatures that have been repeatedly broken by outsize, sometimes astonishing, amounts. For instance, a nine-day wave that hammered the U.S. Pacific Northwest and southwestern Canada in June 2021 broke daily records in some locales by 30 degrees C, or 54 F. This included the highest ever temperature recorded in Canada, 121.3 F, in Lytton, British Columbia. The town burned to the ground the next day in a wildfire driven in large part by the drying of vegetation in the extraordinary heat. In Oregon and Washington state, hundreds of people died from heat stroke and other health conditions.

These extreme heat waves have been hitting predominantly in the last five years or so, though some occurred in the early 2000s or before. The most hard-hit regions include populous central China, Japan, Korea, the Arabian peninsula, eastern Australia and scattered parts of Africa. Others include Canada’s Northwest Territories and its High Arctic islands, northern Greenland, the southern end of South America and scattered patches of Siberia. Areas of Texas and New Mexico appear on the map, though they are not at the most extreme end.

According to the report, the most intense and consistent signal comes from northwestern Europe, where sequences of heat waves contributed to some 60,000 deaths in 2022 and 47,000 deaths in 2023. These occurred across Germany, France, the United Kingdom, the Netherlands and other countries. Here, in recent years, the hottest days of the year are warming twice as fast the summer mean temperatures. The region is especially vulnerable in part because, unlike places like the United States, few people have air conditioning, because traditionally it was almost never needed. The outbreaks have continued; as recently as this September, new maximum temperature records were set in Austria, France, Hungary, Slovenia, Norway and Sweden.

The researchers call the statistical trends “tail-widening” that is, the anomalous occurrence of temperatures at the far upper end, or beyond, anything that would be expected with simple upward shifts in mean summer temperatures. But the phenomenon is not happening everywhere; the study shows that maximum temperatures across many other regions are actually lower than what models would predict. These include wide areas of the north-central United States and south-central Canada, interior parts of South America, much of Siberia, northern Africa and northern Australia. Heat is increasing in these regions as well, but the extremes are increasing at similar or lower speed than what changes in average would suggest.

Climbing overall temperatures make heat waves more likely in many cases, but the causes of the extreme heat outbreaks are not entirely clear. In Europe and Russia, an earlier study led by Kornhuber blamed heat waves and droughts on wobbles in the jet stream, a fast-moving river of air that continuously circles the northern hemisphere. Hemmed in by historically frigid temperatures in the far north and much warmer ones further south, the jet stream generally confines itself to a narrow band. But the Arctic is warming on average far more quickly than most other parts of the Earth, and this appears to be destabilizing the jet stream, causing it to develop so-called Rossby waves, which suck hot air from the south and park it in temperate regions that normally do not see extreme heat for days or weeks at a time.

This is only one hypothesis, and it does not seem to explain all the extremes. A study of the fatal 2021 Pacific Northwest/southwestern Canada heat wave led by Lamont-Doherty graduate student Samuel Bartusek (also a coauthor on the latest paper) identified a confluence of factors. Some seemed connected to long-term climate change, others to chance. The study identified a disruption in the jet stream similar to the Rossby waves thought to affect Europe and Russia. It also found that decades of slowly rising temperatures had been drying out regional vegetation, so that when a spell of hot weather came along, plants had fewer reserves of water to evaporate into the air, a process that helps moderate heat. A third factor: a series of smaller-scale atmospheric waves that gathered heat from the Pacific Ocean surface and transported it eastward onto land. Like Europe, few people in this region have air conditioning, because it is generally not needed, and this probably upped the death toll.

The heat wave “was so extreme, it’s tempting to apply the label of a ‘black swan’ event, one that can’t be predicted,” said Bartusek. “But there’s a boundary between the totally unpredictable, the plausible and the totally expected that’s hard to categorize. I would call this more of a grey swan.”

While the wealthy United States is better prepared than many other places, excessive heat nevertheless kills more people than all other weather-related causes combined, including hurricanes, tornadoes and floods. According to a study out this past August, the yearly death rate has more than doubled since 1999, with 2,325 heat-related deaths in 2023. This has recently led to calls for heat waves to be named, similar to hurricanes, in order to heighten public awareness and motivate governments to prepare.

“Due to their unprecedented nature, these heat waves are usually linked to very severe health impacts, and can be disastrous for agriculture,vegetation and infrastructure,” said Kornhuber. “We’re not built for them, and we might not be able to adapt fast enough.”

The study was also coauthored by Richard Seager and Mingfang Ting of Lamont-Doherty Earth Observatory, and H.J. Schellnhuber of the International Institute for Applied Systems Analysis.