Limnactinia nuda

<p>A recent study from Japan has revealed that owning a <a href="https://www.earth.com/news/mischievous-dogs-experts-reveal-the-top-ten-naughtiest-breeds/">dog</a> can significantly reduce the risk of developing dementia in old age. The experts found that dog owners over the age of 65 were 40 percent less likely to develop dementia.</p>



<p>The study marks the first scientific establishment of a clear link between dog ownership and a lowered risk of dementia.</p>



<h2 class="wp-block-heading" id="h-studying-dog-owners">Studying dog owners</h2>



<p>The research wad focused on nearly 12,000 residents in Tokyo aged 65 and older. It was conducted over four years by the <a href="https://www.tmig.or.jp/" target="_blank" rel="noreferrer noopener">Tokyo Metropolitan Institute for Geriatrics and Gerontology</a>.&nbsp;</p>



<p>The experts compared the mental health of older adults who were current dog owners, previous owners, and those who never owned a dog.</p>



<p>The researchers meticulously accounted for various factors including gender, marital status, education, income, health history, and exercise habits, regardless of pet ownership. The average age of the participants was 74.2 years, with 51.5% being female.&nbsp;</p>



<h2 class="wp-block-heading" id="h-regular-exercise-and-social-interaction-nbsp">Regular exercise and social interaction&nbsp;</h2>



<p>Dr Yu Taniguchi, the lead author of the study, noted that individuals who owned a dog had therefore exercised, making new connections with people as they walked their pets.</p>



<p>“Having a dog enabled owners to habitually take exercise and avoid social isolation and these were the two key factors in people having a much lower risk of developing dementia,” explained Dr. Taniguchi.</p>



<p>Interestingly, the researchers found that the protective effects against dementia were still present in dog owners who did not regularly exercise or engage socially, though to a lesser extent than those who did.&nbsp;</p>



<p>“Having a dog effectively requires people to get into the habit of physical activity and that makes it much more likely that they will then have interactions and socialize with other people,” said Dr. Taniguchi.</p>



<h2 class="wp-block-heading" id="h-cats-and-dementia-nbsp">Cats and dementia&nbsp;</h2>



<p>The researchers also investigated the relationship between owning cats and dementia. They determined that cat ownership was not effective for preventing dementia</p>



<p>This is due to the fact that owners do not walk their cats and they do not bring people together socially in the way that dogs do, said Dr. Taniguchi, who has a Jack Russell terrier.</p>



<p>He added that he was not surprised by the group’s findings, as earlier research had identified the potential health benefits of pets.</p>



<h2 class="wp-block-heading" id="h-frailty-and-disability-nbsp">Frailty and disability&nbsp;</h2>



<p>Prior research has already hinted at the health benefits of dog ownership, including reduced frailty in old age and delayed onset of disabilities and death</p>



<p>"Although some previous study reported no-significant association of pet ownership with mortality, systematic review and meta-analysis concluded that dog ownership is associated with lower risk of death over the long term," wrote Dr. Taniguchi and his co-authors.</p>



<p>"Our previous study revealed that older adults who had owned a dog and/or cat had lower risk of incident frailty, with dog owners at baseline showing 0.81 times the likelihood of developing incident frailty than never dog owners during 2-year follow-up period."</p>



<h2 class="wp-block-heading" id="h-improved-well-being-of-dog-owners">Improved well-being of dog owners</h2>



<p>During the coronavirus pandemic, dog owners also reported better well-being than those without pets, likely due to increased exercise and social opportunities.</p>



<p>"Dog care might contribute to the maintenance of physical activity, including having an exercise habit, and social participation even in the face of restrictions to interactions such as those experienced during the COVID-19 pandemic," wrote the researchers.&nbsp;</p>



<p>The study is published in the December edition of <a href="https://www.sciencedirect.com/science/article/pii/S221133552300356X" target="_blank" rel="noreferrer noopener"><em>Preventive Medicine Reports</em></a>.</p>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>-----</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/">Eric Ralls</a> and <a href="https://www.earth.com/">Earth.com</a>.</p>

Dog owners are much less likely to develop dementia

A recent study from Japan has revealed that owning a...

Chinstrap,Penguin,,Antarctica,,January,2019

<p>In a new study, researchers have discovered that nesting chinstrap penguins in the wild manage to accumulate over 11 hours of sleep daily, not through extended rest periods, but via thousands of brief microsleeps. </p>



<p>This fascinating sleep behavior underscores the adaptability and resilience of these birds in maintaining continuous vigilance over their nests.</p>



<h2 class="wp-block-heading" id="h-importance-of-sleep-to-animals">Importance of sleep to animals</h2>



<p>Sleep, a state typically marked by immobility and a decreased sensory response to the environment, is a common trait across various species. Sleeping, while restorative, can make animals vulnerable to predators. </p>



<p>In humans, lack of adequate sleep often leads to microsleeps -- brief, seconds-long lapses in wakefulness characterized by eye closure and sleep-like brain activity. These involuntary pauses can be hazardous, especially in activities like driving. </p>



<p>However, the true restorative value of such microsleeps in comparison to longer sleep periods remains a subject of scientific inquiry.</p>



<h2 class="wp-block-heading" id="h-studying-how-chinstrap-penguins-sleep">Studying how chinstrap penguins sleep</h2>



<p>Paul-Antoine Libourel and his team spearheaded a comprehensive study on a colony of chinstrap penguins (<em>Pygoscelis antarcticus</em>) in Antarctica. </p>



<p>These penguins, while nesting, face the constant need to protect their nests from predators and other intruding penguins, especially when their partners are away. This situation demands that one parent remains vigilant, making extended sleep periods impractical and potentially dangerous.</p>



<p>The team employed remote electroencephalogram (EEG) monitoring, along with other noninvasive sensors, to record the sleep patterns of these freely roaming and nesting birds. Continuous video surveillance and direct observations complemented this study.</p>



<p>Contrary to typical sleep patterns observed in many animals, chinstrap penguins did not engage in long sleep sessions. Instead, they were found to frequently fall into microsleeps, each lasting about 4 seconds on average. Remarkably, they accumulated over 11 hours of sleep per day through more than 10,000 of these microsleep episodes.</p>



<h2 class="wp-block-heading" id="h-implications-and-perspectives">Implications and perspectives</h2>



<p>The study's findings suggest that these brief sleep bouts, or microsleeps, can collectively fulfill some of the restorative functions traditionally associated with longer sleep periods. This adaptation appears to be a successful strategy for species like chinstrap penguins that require constant vigilance.</p>



<p>Christian Harding and Vladyslav Vyazovskiy, in a related perspective, highlighted the significance of these findings. They noted that the chinstrap penguins' microsleeps might represent one of the most extreme examples of how the benefits of sleep can accumulate incrementally. This observation opens new avenues for understanding sleep patterns and their variations across different species.</p>



<p>The research conducted by Libourel and colleagues sheds light on the remarkable adaptability of chinstrap penguins in fulfilling their sleep needs through microsleeps. This study adds to our understanding of sleep in wild animals. It also raises intriguing questions about the flexibility and functionality of sleep across different species. </p>



<p>The chinstrap penguins' unique sleep pattern is a testament to the diverse strategies employed by animals to balance the demands of survival and rest.</p>



<h2 class="wp-block-heading" id="h-more-about-chinstrap-penguins">More about chinstrap penguins</h2>



<p>As touched on above, chinstrap penguins are easily recognizable by their distinctive facial markings. They are a fascinating species of penguins that reside primarily in the islands and shores of the Southern Pacific and the Antarctic Ocean. Let's dive deeper into their life, habitat, behavior, and the challenges they face.</p>



<h3 class="wp-block-heading" id="h-physical-characteristics">Physical characteristics</h3>



<p>Chinstrap penguins stand out with their thin black band under the head, resembling a helmet strap, which gives them their name. They are medium-sized penguins, typically weighing between 3 to 6 kilograms. Their bodies are adapted to the aquatic environment. Chinstraps have streamlined shapes, flippers for swimming, and a layer of insulating feathers to protect against the cold.</p>



<h3 class="wp-block-heading" id="h-chinstrap-penguins-habitat">Chinstrap penguins habitat</h3>



<p>Primarily found on the Antarctic Peninsula and surrounding islands, chinstrap penguins thrive in large colonies on ice-free coastal areas. Their choice of habitat is largely influenced by the availability of their primary food source, the krill, which is abundant in these cold waters.</p>



<h3 class="wp-block-heading" id="h-diet-and-feeding-habits">Diet and feeding habits</h3>



<p>Krill constitutes the major part of a chinstrap penguin's diet, although they also consume fish and squid. They are excellent swimmers and can dive to depths of up to 70 meters in pursuit of prey. Their feeding expeditions can last several hours, during which they skillfully navigate through the water.</p>



<h3 class="wp-block-heading" id="h-breeding-and-lifecycle">Breeding and lifecycle</h3>



<p>Chinstrap penguins are monogamous and often return to the same mate each breeding season. The breeding season starts in November when they gather in vast colonies to nest. Females typically lay two eggs, and both parents share the responsibility of incubating the eggs and feeding the chicks. The chicks fledge after about two months and are ready to go to sea.</p>



<h3 class="wp-block-heading" id="h-chinstrap-penguins-social-behavior">Chinstrap penguins social behavior</h3>



<p>These penguins are highly social birds. Their colonies, sometimes consisting of hundreds of thousands of individuals, are a hub of activity. The colonies help provide protection against predators and are also crucial for the birds' social interactions. This includes finding mates and caring for their young.</p>



<h3 class="wp-block-heading" id="h-threats-and-conservation">Threats and conservation</h3>



<p>Chinstrap penguins face several threats. Most notably, climate change, which affects their food supply, and human activities such as fishing and pollution. While they are not currently endangered, their populations are under observation for potential decline due to these environmental pressures.</p>



<p>In summary, chinstrap penguins are a remarkable species, adept at surviving and thriving in some of the harshest conditions on Earth. Their unique physical features, social behaviors, and breeding habits make them an important subject of study for understanding the dynamics of marine life in the Antarctic ecosystem. </p>



<p>As they navigate the challenges posed by a changing environment, the continued study and conservation of chinstrap penguins remain crucial for ensuring their survival.</p>



<p>The full study was published in the journal <em><a href="https://www.science.org/doi/10.1126/science.adh0771" target="_blank" rel="noreferrer noopener">Science</a></em>.</p>



<p>---</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>---</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and <a href="https://www.earth.com/" target="_blank" rel="noreferrer noopener">Earth.com</a>.</p>

Chinstrap penguins take over 10,000 micro-sleeps per day

In a new study, researchers have discovered that nesting chinstrap...

Brittle,Stars,Or,Ophiuroids,Are,Echinoderms,In,The,Class,Ophiuroidea

<p>In the quest to understand intelligence and learning, humans have often focused on brain size as a key factor. However, a fascinating study on brainless brittle stars challenges this notion, revealing that these creatures are capable of learning through experience, despite lacking a centralized brain.</p>



<h2 class="wp-block-heading" id="h-enigmatic-brittle-stars">Enigmatic brittle stars</h2>



<p>Brittle stars, related to <a href="https://www.earth.com/news/crown-of-thorns-starfish-are-natures-ultimate-coral-predators-and-they-are-winning/" target="_blank" rel="noreferrer noopener">starfish</a>, are fascinating marine creatures known for their secretive nature. They spend most of their time hidden under rocks or buried in sand, with their bodies consisting of five wiggly arms connected to a nerve ring near their mouth, instead of a traditional brain.</p>



<p><a href="https://jnotar.github.io/" target="_blank" rel="noreferrer noopener">Julia Notar</a>, the lead author of the study conducted at Duke University under <a href="https://scholars.duke.edu/person/sjohnsen" target="_blank" rel="noreferrer noopener">Professor Sönke Johnsen</a>, emphasizes the uniqueness of the brittle star's nervous system. "There's no processing center," explains Notar. "Each of the nerve cords can act independently, functioning more like a committee than under a central boss."</p>



<h2 class="wp-block-heading" id="h-learning-by-association">Learning by association</h2>



<p>Notar's research posits that brittle stars can learn through classical conditioning, a learning process where an organism learns to associate different stimuli.</p>



<p>One example of classical conditioning is demonstrated by Pavlov's famous experiments with dogs. When repeatedly fed at the ringing of a bell, they eventually start drooling at just the sound of the bell, even without food present.</p>



<p>Similarly, humans experience this often. When you repeatedly hear the “ding” of a smartphone alert, the sound eventually takes on a special meaning. The mere ping or buzz of someone's phone, if it matches your phone's chime, can prompt you to reflexively reach for your phone, expecting the next text, email, or Instagram post.</p>



<p>Researchers have demonstrated classical conditioning in starfish in a few previous studies. However, most <a href="https://www.earth.com/news/sea-stars-may-actually-be-walking-heads-with-no-bodies/" target="_blank" rel="noreferrer noopener">echinoderms</a>, a diverse group encompassing around <a href="https://link.springer.com/article/10.3758/s13420-021-00492-3" target="_blank" rel="noreferrer noopener">7,000 species</a> including brittle stars, brainless starfish, <a href="https://www.earth.com/news/sea-urchins-are-struggling-to-survive-because-they-cant-get-a-grip/" target="_blank" rel="noreferrer noopener">sea urchins</a>, and <a href="https://www.earth.com/news/discovery-eating-sea-cucumbers-can-prevent-diabetes/" target="_blank" rel="noreferrer noopener">sea cucumbers</a>, remain untested in this area.</p>



<h2 class="wp-block-heading" id="h-how-the-study-was-conducted">How the study was conducted</h2>



<p>To determine if brittle stars can learn, researchers placed 16 black brittle stars (<em>Ophiocoma echinata</em>) in individual water tanks and recorded their behavior with a video camera.</p>



<p>They trained half of the brittle stars by dimming the lights for 30 minutes at each feeding time. Whenever the lights went out, the researchers placed a morsel of shrimp -- a favorite of the brittle stars -- just out of reach in the tanks.</p>



<p>The researchers fed the other half the same amount of shrimp but did so under lit conditions, never coinciding with the 30-minute dark periods.</p>



<h2 class="wp-block-heading" id="h-watching-brittle-stars-learn">Watching brittle stars learn</h2>



<p>Regardless of light conditions, the animals mostly hid behind the filters in their tanks, emerging only for meals. However, only the brittle stars that received training learned to associate darkness with food.</p>



<p>In the early stages of the 10-month experiment, all the animals remained hidden when the lights dimmed. Over time, the trained brittle stars formed a connection between darkness and feeding time. They began to anticipate food and emerged from hiding whenever the lights went out, even before shrimp was introduced to the tanks.</p>



<p>These brittle stars had learned to associate the dimming lights with the likelihood of food. They responded without needing to smell or taste the shrimp. The mere dimming of the lights was sufficient to prompt them to emerge for dinner.</p>



<p>Even after a 13-day break without training, which involved repeatedly dimming the lights without feeding, the brittle stars still remembered this association.</p>



<h2 class="wp-block-heading" id="h-implications-and-future-research">Implications and future research</h2>



<p>Notar finds these <a href="https://rdcu.be/drHJO" target="_blank" rel="noreferrer noopener">results</a> exciting, as they demonstrate classical conditioning in a group of animals previously not known for such learning capabilities. </p>



<p>“Knowing that brittle stars can learn means they’re not just robotic scavengers like little Roombas cleaning up the ocean floor,” Notar said. “They're potentially able to expect and avoid predators or anticipate food because they’re learning about their environment.”</p>



<p>The study opens doors to further explore how creatures with non-standard nervous systems learn and remember. Notar plans to delve deeper into the mechanisms behind the brittle stars' learning abilities, aiming to answer the intriguing question: "How do they do it?"</p>



<p>This research fundamentally challenges our understanding of learning and intelligence in the animal kingdom. It suggests that brain size or structure may not be the sole determinants of an organism's ability to learn and adapt to its environment, paving the way for a broader and more inclusive study of intelligence in nature.</p>



<h2 class="wp-block-heading" id="h-more-about-brittle-stars">More about brittle stars</h2>



<p>As discussed above, brittle stars, fascinating and unique echinoderms, exhibit remarkable features and behaviors in marine ecosystems. Belonging to the class Ophiuroidea, these creatures are close relatives of sea stars, but they stand out due to their distinct physical characteristics and ecological roles.</p>



<h3 class="wp-block-heading" id="h-physical-description-and-diversity">Physical description and diversity</h3>



<p>Brittle stars typically possess a central disc and five slender, highly flexible arms. Unlike sea stars, their arms do not contain vital organs and are sharply demarcated from the central disc. This structure enables them to move swiftly through the water and across the seabed. They exhibit a wide array of colors and patterns, enhancing their appeal.</p>



<p>There are over 2,000 known species of brittle stars, varying greatly in size and form. Some species have smooth arms, while others have spiny or adorned ones. Their size can range from a few centimeters to nearly a meter in arm span, with the central disc usually being relatively small.</p>



<h3 class="wp-block-heading" id="h-habitat-and-distribution">Habitat and distribution</h3>



<p>Brittle stars inhabit diverse marine environments, from shallow coral reefs to the deep sea. They often hide under rocks, in coral crevices, or within seagrass beds during the day. Some species even live in symbiotic relationships with other marine organisms, such as corals.</p>



<p>Their global distribution is impressive, with species found in every ocean and at various depths, some reaching as deep as 6,000 meters. This wide distribution highlights their adaptability to different environmental conditions.</p>



<h3 class="wp-block-heading" id="h-feeding-and-nutrition">Feeding and nutrition</h3>



<p>Brittle stars are mostly scavengers and detritivores, feeding on dead organic material and small organisms. They use their flexible arms to capture food particles, which they then transport to their mouths. Some species are also known to be suspension feeders, using their arms to catch plankton and other small particles from the water column.</p>



<h3 class="wp-block-heading" id="h-reproduction-and-lifecycle">Reproduction and lifecycle</h3>



<p>Brittle stars reproduce both sexually and asexually. In sexual reproduction, they release eggs and sperm into the water, where fertilization occurs. The larvae then go through several planktonic stages before settling on the seafloor and metamorphosing into juveniles.</p>



<p>Asexual reproduction occurs through fragmentation, where a part of an arm breaks off and regenerates into a new individual. This ability also aids in their survival, as they can readily regenerate lost limbs.</p>



<h3 class="wp-block-heading" id="h-ecological-role-and-importance">Ecological role and importance</h3>



<p>Brittle stars play a crucial role in marine ecosystems. As scavengers, they aid in the decomposition process and nutrient cycling. They also serve as prey for various marine animals, including fish and crabs.</p>



<p>Their presence in various habitats makes them good indicators of environmental health. Some species are particularly sensitive to changes in water quality, making them useful in monitoring the impact of pollution and climate change on marine ecosystems.</p>



<h3 class="wp-block-heading" id="h-conservation-status">Conservation status</h3>



<p>While many brittle star species are abundant, some face threats from habitat destruction, pollution, and climate change. Their conservation is essential for maintaining the health and diversity of marine ecosystems.</p>



<p>In summary, brittle stars are not just captivating creatures but also vital components of the ocean's biodiversity. Their unique adaptations and ecological roles make them an important subject of study in marine biology and conservation efforts.</p>



<p>The full study was published in the journal <a href="https://link.springer.com/article/10.1007/s00265-023-03402-x">Behavioral </a><a href="https://link.springer.com/article/10.1007/s00265-023-03402-x" target="_blank" rel="noreferrer noopener">Ecology and Sociobiology</a>.</p>



<p>---</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>---</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and <a href="https://www.earth.com/" target="_blank" rel="noreferrer noopener">Earth.com</a>.</p>

Brittle stars have no brain but still manage to learn

In the quest to understand intelligence and learning, humans have...

<p>A recent study by a team of researchers from Italy, Norway, Canada, and the US suggests that before their eventual <a href="https://www.earth.com/news/nuclear-winter-dinosaurs-were-likely-killed-by-dust/">extinction</a>, dinosaurs might have faced repeated "volcanic winters" that left them in a weakened state.&nbsp;</p>



<p>These findings come from an analysis of sulfur and fluorine gasses trapped in ancient volcanic rocks from the <a href="https://www.amnh.org/exhibitions/dinosaurs-ancient-fossils/extinction/deccan-traps-volcanoes#:~:text=The%20Deccan%20Traps%20date%20back,volcanic%20eruption%20ever%20on%20land." target="_blank" rel="noreferrer noopener">Deccan Traps supervolcano</a>, which erupted around 200,000 years before the asteroid impact that is widely believed to have caused the dinosaurs’ extinction.</p>



<h2 class="wp-block-heading" id="h-studying-volcanic-winters">Studying volcanic winters</h2>



<p>The study, which focuses on these gases, reveals that their release could have caused global temperatures to drop by up to 18 degrees Fahrenheit (10 degrees Celsius).&nbsp;</p>



<p>This discovery contributes to the ongoing debate among paleontologists and scientists regarding the precise cause of the dinosaurs’ demise. The research aligns with the "press-pulse extinction model," which suggests that a combination of factors led to the extinction event.</p>



<h2 class="wp-block-heading" id="h-unstable-climate-conditions">Unstable climate conditions</h2>



<p>“Our research demonstrates that climatic conditions were almost certainly unstable, with repeated volcanic winters that could have lasted decades, prior to the extinction of the dinosaurs,” said study co-author Don Baker, a geologist at <a href="https://www.mcgill.ca/" target="_blank" rel="noreferrer noopener">McGill University</a> in Montreal.&nbsp;</p>



<p>“Our work helps explain this significant extinction event that led to the rise of mammals and the evolution of our species.”</p>



<h2 class="wp-block-heading" id="h-how-the-research-was-conducted-nbsp">How the research was conducted&nbsp;</h2>



<p>The team analyzed sulfur and fluorine compounds in samples from the Deccan Traps in India’s Western Ghats, near Bombay. They employed synchrotron radiation x‐ray fluorescence spectrometry to measure these compounds’ concentrations. Baker likened the process to cooking pasta, where a small amount of the salt in boiling water is absorbed by the pasta.&nbsp;</p>



<p>Similarly, the team estimated the volume of sulfur and fluorine gases that entered the atmosphere during the Cretaceous period based on the compounds’ presence in the lava rocks.</p>



<h2 class="wp-block-heading" id="h-critical-insights-nbsp">Critical insights&nbsp;</h2>



<p>Notably, the researchers found that the highest sulfur content, as high as 1,800 parts-per-million, correlated with a drop in temperature during the late Cretaceous period. They estimated that between 86,000 and 466,000 cubic-kilometers of sulfur gas were released into the atmosphere, leading to significant climatic changes.</p>



<p>Although the team did not attribute major climate change to fluorine gases, they noted these gases' toxic local effects, including acid rain, crop failure, and livestock poisoning, as observed in historical accounts of the Laki volcano eruptions in Iceland in the 18th century. These effects might have similarly impacted the dinosaurs’ environment.</p>



<h2 class="wp-block-heading" id="h-multiple-triggers">Multiple triggers</h2>



<p>The researchers conclude that the Deccan Traps’ volcanic activity set the stage for a global biotic crisis by triggering repeated short volcanic winters.&nbsp;</p>



<p>However, they believe the "final blow" was the Chicxulub asteroid impact in Mexico, which caused massive environmental devastation. This impact, combined with the preceding volcanic activity, likely accelerated the dinosaurs’ extinction.</p>



<h2 class="wp-block-heading" id="h-study-implications">Study implications</h2>



<p>The study, published in the journal <a href="https://www.science.org/doi/10.1126/sciadv.adg8284" target="_blank" rel="noreferrer noopener"><em>Science Advances</em></a>, highlights the intricate interplay of environmental factors leading up to one of Earth’s most significant extinction events.&nbsp;</p>



<p>“Our dataset indicates that volcanic-driven climate disturbance was already underway,” the researchers noted, underscoring the complexity of the events that led to the end of the dinosaur era.</p>



<h2 class="wp-block-heading" id="h-more-about-volcanic-winters">More about volcanic winters</h2>



<p>As mentioned above, volcanic winters are climatic events resulting from major volcanic eruptions that inject large amounts of ash and sulfur dioxide (SO2) into the Earth's stratosphere. Let's dig a little deeper.</p>



<h3 class="wp-block-heading" id="h-mechanism-of-volcanic-winters">Mechanism of volcanic winters</h3>



<p>Eruption Dynamics: Large volcanic eruptions expel ash and gases high into the stratosphere.</p>



<p>Formation of Sulfur Aerosols: The sulfur dioxide reacts to form sulfuric acid aerosols, which reflect sunlight away from Earth, leading to cooling.</p>



<p>Longevity in the Stratosphere: These aerosols can remain in the stratosphere for years, prolonging their cooling effect.</p>



<h3 class="wp-block-heading" id="h-volcanic-winters-impact-on-climate">Volcanic winters' impact on climate</h3>



<p>Global Cooling: Volcanic winters typically result in a noticeable drop in global or regional temperatures.</p>



<p>Weather Pattern Disruptions: These temperature changes can alter normal weather patterns, causing droughts or excessive rainfall.</p>



<p>Agricultural Impact: Reduced sunlight and cooler temperatures adversely affect crop yields, potentially leading to famines.</p>



<h3 class="wp-block-heading" id="h-historical-instances">Historical instances</h3>



<p>The Year Without a Summer (1816): Following the 1815 eruption of Mount Tambora, 1816 experienced dramatically lowered temperatures, leading to widespread crop failures.</p>



<p>The Toba Catastrophe (Around 74,000 Years Ago): The Toba super-volcano eruption is believed to have caused a decade-long volcanic winter, severely impacting early human populations.</p>



<h3 class="wp-block-heading" id="h-modern-concerns-and-future-risks">Modern concerns and future risks</h3>



<p>Today, advanced monitoring and climate modeling allow for better prediction and preparedness for volcanic winters. A major eruption today could significantly impact our globalized society, emphasizing the need for continued vigilance and preparedness.</p>



<p>In summary, volcanic winters, though rare, pose a significant risk due to their ability to alter global climates and disrupt human activities. Understanding and preparing for these events is crucial in our increasingly interconnected world.</p>



<p>-----</p>



<p>Like what you<em> read?</em> <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>-----</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/">Eric Ralls</a> and <a href="https://www.earth.com/">Earth.com</a>.</p>

Volcanic winters weakened the dinosaurs before the asteroid hit

A recent study by a team of researchers from Italy,...

<p>Sentinel warning calls in <a href="https://www.earth.com/news/do-birds-dream-of-flying-scientists-say-they-now-know-the-answer/">birds</a> may be universally understood, transcending continental boundaries, according to a new study.&nbsp;</p>



<p>This discovery not only expands our understanding of animal communication but also hints at an evolutionary convergence in vocal signals related to danger.</p>



<h2 class="wp-block-heading" id="h-signs-of-danger">Signs of danger</h2>



<p>The research was led by Henry Pollock, executive director of the Southern Plains Land Trust, and Jonah Dominguez, a graduate student at the <a href="https://illinois.edu/" target="_blank" rel="noreferrer noopener">University of Illinois Urbana-Champaign</a>.</p>



<p>Sentinel species, like the Paridae family, are pivotal in mixed-species groups for their distinct alarm calls. These calls, like the “chick-a-dee-dee-dee” of chickadees, are recognized by various bird species, emphasizing their role as universal signals of danger.&nbsp;</p>



<h2 class="wp-block-heading" id="h-anti-predator-behavior-nbsp">Anti-predator behavior&nbsp;</h2>



<p>“Many animals form mixed-species groups, and the thought is that this is an anti-predator behavior,” said Pollock. “There is safety in numbers, and there is a benefit to surrounding yourself with a more diverse set of eyes and ears."</p>



<p>"However, you have to be able to understand the information that the others around you give to make use of it.”</p>



<h2 class="wp-block-heading" id="h-focus-of-the-study-nbsp">Focus of the study&nbsp;</h2>



<p>The research team set out to investigate whether bird communities across three continents – North America, Europe, and Asia – could interpret the alarm calls of a previously unknown sentinel, the dusky-throated antshrike, a Central and South American bird known for its sentinel role.</p>



<p>The study included contributions from Mark Hauber (GNDP) and international collaborators from Serbia and China.&nbsp;</p>



<h2 class="wp-block-heading" id="h-surprising-results">Surprising results</h2>



<p>The experts played warning calls of the dusky-throated antshrike to different bird flocks. They theorized that birds would react most strongly to familiar local sentinel calls. But the results were surprising.</p>



<p>“We expected to see some kind of response to the novel antshrike’s calls, but predicted that birds wouldn’t respond as strongly to it as their own local sentinel’s calls,” said Dominguez.&nbsp;</p>



<p>“However, we were surprised to find no statistical difference in how birds responded to the local versus foreign sentinel’s alarm call. Birds were responding to the unfamiliar antshrike’s call as if it was a bird they’ve known their whole lives.”&nbsp;&nbsp;</p>



<h2 class="wp-block-heading" id="h-universal-recognition-nbsp">Universal recognition&nbsp;</h2>



<p>According to the researchers, flocks of birds across all three continents responded equally as strongly to the unfamiliar antshrike’s warning calls as they did to familiar, local sentinel’s warning calls.&nbsp;</p>



<p>The experts say this finding suggests there is something to sentinel calls that makes them universally recognizable.&nbsp;</p>



<p>For messages that contain important information, such as a warning call for danger, evolution likely converges on similar sounding calls that help get across the message as quickly as possible, according to the researchers.</p>



<h2 class="wp-block-heading" id="h-central-theme-nbsp">Central theme&nbsp;</h2>



<p>“It’s possible that these calls are more readily recognized across species because they have a central theme – essentially something about them that is unique and conserved despite millions of years in evolutionary history,” explained Dominguez.&nbsp;</p>



<p>“There is research in other animals on specific amplitudes and frequencies of sound that cause innate responses, even in animals that are unfamiliar with those sounds. Our study can help researchers figure out what those acoustic elements might be for birds.”</p>



<h2 class="wp-block-heading" id="h-signal-recognition-nbsp">Signal recognition&nbsp;</h2>



<p>“What’s amazing is that our findings are consistent across three different continents with completely different bird communities, which suggests there is some signal encoded within these sentinel alarm calls that cause birds to respond to them, independent of previous experience with that signaler,” explained Pollock.&nbsp;</p>



<p>“This really highlights that signal recognition is not always something that has to be learned through environmental experience.”</p>



<h2 class="wp-block-heading" id="h-future-research-prospects-nbsp">Future research prospects&nbsp;</h2>



<p>The researchers said the study opens the door to many future research directions. They noted that testing birds with the calls of other sentinels and getting more granular in terms of the behavioral responses are potential next steps.</p>



<h2 class="wp-block-heading" id="h-defining-sentinel-species">Defining sentinel species</h2>



<p>Dominguez wants to find the common thread among sentinel birds in an effort to standardize what is categorized as a sentinel species across the literature.&nbsp;&nbsp;</p>



<p>“Sentinel species are not very well defined, as the term is used nebulously for any animals that engage in mixed-species foraging and signaling,” said Dominguez.&nbsp;</p>



<p>“There’s lots of birds that we don’t typically think of as sentinels being classified as them in the literature, and others that probably are sentinels that are being overlooked. I want to figure out if there’s a common thread between them, and whether the term should be used on the species level or more on a flock level.”</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1098/rsbl.2023.0332" target="_blank" rel="noreferrer noopener"><em>Biology Letters</em></a>.</p>



<p>Like what you<em> read?</em> <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>—-</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/">Eric Ralls</a> and <a href="https://www.earth.com/">Earth.com</a>.</p>

Sentinel warning calls seem to be universally understood by birds

Sentinel warning calls in birds may be universally understood, transcending...

<p>A recently published study reveals fascinating new insights into the history of ancient animals. Researchers Miengah Abrahams and Emese M. Bordy from the <a href="https://uct.ac.za/" target="_blank" rel="noreferrer noopener">University of Cape Town</a>, South Africa, have made a monumental fossil discovery of what seems to be bird tracks. This find indicates that creatures roamed the earth over 210 million years ago on feet resembling those of modern birds.</p>



<h2 class="wp-block-heading" id="h-the-trisauropodiscus-footprints">The <em>Trisauropodiscus</em> footprints</h2>



<p>For years, the enigmatic three-toed footprints known as <em>Trisauropodiscus</em>, prevalent in fossil sites across southern Africa, have puzzled scientists. Debates have centered around the type of animals that might have left these distinct tracks and the exact number of ichnospecies (species identified from trace fossils) of <em>Trisauropodiscus</em>.</p>



<p>In their study, Abrahams and Bordy reevaluated the fossil records of these footprints. They scrutinized physical fossil evidence and reviewed previously published materials. Their focus was on <em>Trisauropodiscus</em> tracks from four sites in Lesotho, dating back to the Late Triassic and Early Jurassic Periods.</p>



<h2 class="wp-block-heading" id="h-detailed-analysis-at-maphutseng">Detailed analysis at Maphutseng</h2>



<p>A significant aspect of their research involved an in-depth field-based examination of footprints at an 80-meter-long tracksite in Maphutseng. Here, they discovered two distinct morphologies among the Trisauropodiscus footprints. The first type bears resemblance to certain non-bird dinosaur tracks, while the second closely matches the size and proportions of bird footprints.</p>



<p>These tracks present a conundrum, as they do not directly correspond to any known fossil animals from this era and region. Intriguingly, the oldest of these footprints, over 210 million years in age, predates the earliest known true bird body fossils by 60 million years.</p>



<h2 class="wp-block-heading" id="h-theories-on-the-bird-track-makers">Theories on the bird track makers</h2>



<p>The researchers propose that these tracks could have been created by early dinosaurs, possibly even <a href="https://www.earth.com/news/how-did-bird-hipped-dinosaurs-evolve/" target="_blank" rel="noreferrer noopener">ancestors of a near-bird lineage</a>. However, they also consider the possibility that other reptiles, related to dinosaurs, might have independently evolved bird-like feet. This discovery pushes back the origin of bird-like feet to at least the Late Triassic Period.</p>



<p>The authors add, “Trisauropodiscus tracks are known from numerous southern African sites dating back to approximately 215 million years ago. The shape of the tracks is consistent with modern and more recent fossil bird tracks, but it is likely a dinosaur with a bird-like foot produced Trisauropodiscus.”</p>



<p>In summary, this mysterious research not only sheds light on the evolutionary history of ancient animals but also opens new avenues for understanding the origins of avian traits in non-avian species. Future research in this area promises to unravel more mysteries of our planet's distant past.</p>



<p>The full study was published in the journal <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0293021">PLOS ONE</a>.</p>



<p>---</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>---</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and <a href="https://www.earth.com/" target="_blank" rel="noreferrer noopener">Earth.com</a>.</p>

Bird tracks discovered that predate the oldest birds by 60 million years

A recently published study reveals fascinating new insights into the...

<p>A study led by the <a href="https://www.uzh.ch/en.html" target="_blank" rel="noreferrer noopener">University of Zurich</a> reveals a concerning gap in the conservation efforts for some of the ocean's most endangered species: <a href="https://www.earth.com/news/sharks-household-products/">sharks</a>, rays, and skates.&nbsp;</p>



<p>These creatures, belonging to the elasmobranch group, are crucial for maintaining the ecological balance in marine environments. However, their survival is at risk due to inadequate protection.</p>



<h2 class="wp-block-heading" id="h-functional-diversity-nbsp">Functional diversity&nbsp;</h2>



<p>The research was focused on the functional diversity of sharks, rays and other elasmobranchs. Functional diversity refers to the various ecological roles these creatures play in their ecosystems.&nbsp;</p>



<p>This aspect of biodiversity, along with taxonomy (species variety) and phylogenetics (evolutionary history), forms a comprehensive understanding of biodiversity.&nbsp;</p>



<h2 class="wp-block-heading" id="h-how-the-research-was-conducted-nbsp">How the research was conducted&nbsp;</h2>



<p>The researchers analyzed a global dataset containing the traits of more than 1,000 elasmobranch species to assess their functional diversity including richness, uniqueness, and specialization.</p>



<p>The analysis pinpointed several critically endangered species that are vital for maintaining the functional diversity of elasmobranchs.&nbsp;</p>



<h2 class="wp-block-heading" id="h-critical-insights-nbsp">Critical insights&nbsp;</h2>



<p>“We identified the top endangered species crucial for maintaining the architecture of elasmobranch functional diversity, including the longfin mako shark, Ganges shark, daggernose shark, shortfin mako shark, and scalloped hammerhead shark,” explained Professor&nbsp; Catalina Pimiento, who led the study.</p>



<p>These species contribute significantly to the intricate tapestry of ecological roles within marine environments.</p>



<h2 class="wp-block-heading" id="h-functional-diversity-hotspots-nbsp">Functional diversity hotspots&nbsp;</h2>



<p>Spatial analysis revealed that the richness of elasmobranch functional diversity is predominantly found along continental shelves and around oceanic islands.&nbsp;</p>



<p>The experts identified 18 unique functional diversity hotspots, which only slightly overlap with those identified by other biodiversity facets.&nbsp;</p>



<p>Study co-author Dr. John Griffin of Swansea University noted that many of these hotspots are under severe threat from industrial fishing.</p>



<h2 class="wp-block-heading" id="h-fishing-pressure-nbsp">Fishing pressure&nbsp;</h2>



<p>“Many of the hotspots vital for elasmobranch biodiversity converge with fishing pressure along the coast of China, others fall around oceanic islands and high seas,” said Dr. Griffin.</p>



<p>"In line with previous global analyses we found that hotspots of fishing pressure are mainly distributed along the coasts of China and Europe (both in the Atlantic and the Mediterranean)," wrote the researchers.</p>



<p>"Smaller fishing pressure hotspots occur on the coasts of the US and Canada and along the Atlantic coast of southern South America (southern Brazil, Uruguay, and Argentina), west Africa and in the Sea of Okhotsk in Russia."</p>



<h2 class="wp-block-heading" id="h-lack-of-protection-nbsp">Lack of protection&nbsp;</h2>



<p>Alarmingly, the study revealed that the multiple facets of elasmobranch biodiversity remain inadequately protected within the global Marine Protected Area network, leaving these species vulnerable to various threats.</p>



<p>"Overall, our results highlight acute vulnerability of the world’s elasmobranchs’ functional diversity and reveal global priorities for elasmobranch functional biodiversity previously overlooked."</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1038/s41467-023-43212-3" target="_blank" rel="noreferrer noopener">Nature Communications</a>.</p>



<p>Like what you<em> read?</em> <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>—-</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/">Eric Ralls</a> and <a href="https://www.earth.com/">Earth.com</a>.</p>

Sharks need better protection to maintain functional diversity

A study led by the University of Zurich reveals a...

Limnactinia nuda

Taxonomic tree: