<a href="https://www.earth.com/news/sex-impacts-gene-expression/" target="_blank" rel="noreferrer noopener">Sexual dimorphism</a>, which is the observable difference in appearance between male and female members of a species, occurs widely across the animal kingdom, including in humans. An interesting variation of this is sex-limited polymorphism, where one sex exhibits more variation in a certain trait compared to the other. 



An international team of scientists has explored this concept by examining the genetic basis for color polymorphism in adult female <a href="https://www.earth.com/news/cuckoos-are-unable-to-change-their-migrations-in-response-to-climate-change/" target="_blank" rel="noreferrer noopener">cuckoos</a> of the genus Cuculus, which are known for their brood parasitic behavior. The research provides insights into the evolutionary development and practical implications of this trait variation.



<h2 class="wp-block-heading" id="h-genetic-basis-of-female-cuckoo-colors">Genetic basis of female cuckoo colors</h2>



The scientists examined why adult female cuckoos, unlike their uniformly gray male counterparts, may exhibit either gray or rufous (reddish-brown) plumage. This variability is not only evident across different cuckoo species but also within populations of the same species.



Using genome-wide association analysis on nuclear DNA from both Common and Oriental cuckoos, the researchers aimed to pinpoint the genetic factors behind the females' diverse plumage in an attempt to understand the underlying pigmentation mechanisms and the evolutionary history of these <a href="https://www.earth.com/news/scientists-wonder-evolutionary-success/" target="_blank" rel="noreferrer noopener">traits</a>.



In <a href="https://www.earth.com/news/untold-story-of-bird-evolution-revealed-through-genetics/" target="_blank" rel="noreferrer noopener">birds</a>, unlike in mammals, it is the females that are heterogametic (ZW), differing from the homogametic males (ZZ). This led researchers to speculate that the observed color variation in female cuckoos might be linked to genes on the W chromosome. 



“We found that, instead of a single gene or set of genes, nearly all variations in the gray or rufous coloration were associated with the full length of the female-limited W chromosome,” said co-author Mark Haber, the executive director of the <a href="https://asrc.gc.cuny.edu/" target="_blank" rel="noreferrer noopener">CUNY Advanced Science Research Center</a> (CUNY ASRC) and a psychology professor at the <a href="https://www.gc.cuny.edu/" target="_blank" rel="noreferrer noopener">CUNY Graduate Center</a>.



<h2 class="wp-block-heading" id="h-biochemical-processes-of-cuckoo-colors">Biochemical processes of cuckoo colors</h2>



The scientists also examined the biochemical processes of coloration, revealing that both the Common and Oriental cuckoos use two forms of melanin-based pigmentation - similar to that in human skin - to produce their <a href="https://www.earth.com/news/for-songbirds-bright-colors-are-a-blessing-and-a-curse/" target="_blank" rel="noreferrer noopener">color</a> variations. 



Further genomic analysis of these species traced the origin of the color polymorphism in female cuckoos to a mutation that occurred over one million years ago, long before these species diverged around 140,000 years ago.



<h2 class="wp-block-heading" id="h-potential-advantages-of-female-cuckoo-coloration-nbsp">Potential advantages of female cuckoo coloration&nbsp;</h2>



The implications of these color variations are profound. For instance, female cuckoos with the rarer rufous plumage might benefit from mimicking juvenile cuckoos to avoid male harassment during mating seasons.&nbsp;



Moreover, as brood parasites who lay their eggs in the nests of other bird species, rufous females could potentially escape detection by host species better than their gray counterparts, which might reduce the risk of being attacked by host parents.



“The fascinating idea that many other sex-specific traits, which are harder to study, might also be genetically determined in the matrilinear genome, similar to the color polymorphism in female cuckoos,” concluded senior author Jochen Wolf, an expert in evolutionary biology at LMU Munich.



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



Cuckoo birds are known for their distinctive calls and unique breeding behavior, particularly their practice of brood parasitism. This involves laying their eggs in the nests of other bird species, leaving the unsuspecting host birds to raise the cuckoo's offspring.&nbsp;



As a result, the host species may inadvertently neglect their own young due to the demanding nature of the cuckoo chick, which often grows larger than its foster siblings.



Cuckoos are found across the world and are highly adaptable to various environments. The family Cuculidae, to which they belong, includes both brood-parasitic cuckoos as well as species that raise their own young. Their diet varies from insects to caterpillars, and some species also consume fruits and seeds.



The cuckoo's call, which gives them their name, is emblematic in culture and often signals the arrival of spring. The most commonly recognized call is that of the common cuckoo in Europe, famously captured in the phrase "cuck-oo." 



This sound has not only embedded them in folklore but also inspired the creation of the cuckoo clock, where the bird's call marks the passing hours.



The study is published in the journal <a href="http://dx.doi.org/10.1126/sciadv.adl5255" target="_blank" rel="noreferrer noopener">Science Advances</a>.



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Female cuckoo colors provide evolutionary advantages

Sexual dimorphism, which is the observable difference in appearance between male and female members of a species, occurs widely across the animal kingdom, including in humans. An interesting variation of this is sex-limited polymorphism, where one sex exhibits more variation in a certain trait compared to the other.  An international team of scientists has explored this concept by examining the genetic basis for color polymorphism in adult female cuckoos of the genus Cuculus, which are known for their brood parasitic behavior. The research provides insights into the...

Sperm are extremely variable in size, ranging from an amazing six centimeters in fruit flies to .002 millimeters in tiny rotifers. In fact, sperm cells are the most variable known cell type in <a href="https://www.earth.com/news/animals-rarely-try-to-avoid-inbreeding/">animals</a>. The diversity of sperm sizes has been a mystery because sperm all perform the same role - fertilization of eggs. 

Depending on the animal, sperm meet their fate in different ways. In corals or sea urchins for instance, the sex cells meet eggs outside the body. In mammals, sperm meet eggs within a female body. 

A new study from <a href="https://www.su.se/cmlink/stockholm-university">Stockholm University</a> has found that the meeting place for sperm and egg may impact the evolution of size in sperm. The research shows that evolution of sperm got a boost, only when sperm swim inside females. 

“Researchers usually try to explain sperm diversity by focusing on how sperm compete to fertilize eggs or how females choose which sperm fertilize their eggs. But it turns out that there is a missing piece of the puzzle - the location where sperm and eggs meet can also influence sperm size," explained study co-author Ariel Kahrl.

The researchers examined the sperm size of 3,200 animals and analyzed where these sex cells meet with the egg. They confirmed that meeting place is important in the evolution of sperm size. 

In animals with internal fertilization such as mammals, sperm were six times longer and increased in size at a faster rate than in animals such as coral with external fertilization. 

The study’s findings make a lot of sense. There’s a trade off when creating large sperm - you can’t create as many. The opposite is true - when creating a large amount of sperm, it usually necessitates making smaller sperm. 

Animals with external fertilization, such as corals, have selection pressure to make a lot of sperm. With coral reproduction in particular it’s a game of chance - sperm and egg are just cast into the water around the sessile animals to fertilize when they come into contact. It’s obvious why so many sperm need to be produced. 

In animals with internal fertilization, the pressure pushes in the opposite direction - to create larger and fewer (relatively speaking) sperm.    

"Our results clearly show that interactions between sperm and females help generate the tremendous diversity in sperm size we see in animals today. The greater the potential for interactions between sperm and females, the faster sperm evolve," said study co-author John Fitzpatrick.

The study is published in the journal <a href="https://www.nature.com/natecolevol/">Nature Ecology &amp; Evolution</a>.

---

By <a href="http://zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

An answer to the mystery of sperm evolution

Sperm are extremely variable in size, ranging from an amazing...

Migratory birds in North America have been getting smaller with longer wings. After making this discovery, a team of experts at the <a href="https://umich.edu/">University of Michigan</a> set out to investigate whether the physical changes in migratory birds are tied to earlier spring migrations.

The researchers theorized that the pressure to migrate faster and arrive at breeding grounds earlier may have driven the morphological changes.

"We know that bird morphology has a major effect on the efficiency and speed of flight, so we became curious whether the environmental pressure to advance spring migration would lead to natural selection for longer wings," said study lead author Marketa Zimova.

The study revealed that the phenological change to earlier spring migration had occurred parallel to the physical changes in birds, but appeared to be unrelated or "decoupled."

"We found that birds are changing in size and shape independently of changes in their migration timing, which was surprising," said Zimova.

The investigation was based on the analysis of 70,000 bird specimens from 52 species at the Field Museum. The birds were collected after colliding with Chicago buildings during spring and fall migrations between 1978 and 2016.

The experts determined that spring migrants are now arriving nearly five days sooner than they did four decades ago, while the earliest fall migrants are heading south about 10 days earlier.

In addition, the last of the fall migrants are now departing about a week later, which means that the duration of the fall migration season has been stretched considerably.

"It is unusual to have a dataset that can provide insights into multiple aspects of global change - such as phenology and morphology - at the same time," said study senior author Ben Winger.

"I was impressed that the collision data so clearly showed evidence of advancing spring migration. The collision monitors in Chicago have been collecting these data on bird building collisions for 40 years and, meanwhile, the birds have been changing the timing of their migratory patterns in ways that were imperceptible until the dataset as a whole was examined."

Last year, the U-M-led team reported that nearly all of the 52 bird species they examined had experienced declines in body size and increases in wing length over a period of four decades. 

In the current study, the team analyzed whether the changes in body size and wing length were driven by climate-related shifts in migration timing.  They did this by testing for associations between species-specific rates of phenological and morphological change.

The researchers found no evidence that the rates of migratory changes are predictive of rates of concurrent changes in morphological traits.

"Scientifically, this is really the most interesting and novel finding," said study senior author Professor Brian Weeks.

The depth of the Field Museum dataset enabled the U-M-led team to examine multiple responses to climate warming simultaneously and to test for connections between them.

"It is often assumed that morphological changes driven by climate and changes in the timing of migration must interact to either facilitate or constrain adaptive responses to climate change," said Professor Weeks. "But this has never to my knowledge been tested empirically at a significant scale, until now, due to lack of data."

Previous studies suggest that the earlier arrival of migratory birds in Chicago each spring is linked to shorter, less frequent stopovers during the northbound trek may be a factor.

"And there might be other adjustments that allow birds to migrate faster that we haven't thought about--maybe some physiological adaptation that might allow faster flight without causing the birds to overheat and lose too much water," said Zimova.

The study is published in the <a href="https://besjournals.onlinelibrary.wiley.com/journal/13652656">Journal of Animal Ecology</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Physical changes in birds evolved separately from earlier migrations

Migratory birds in North America have been getting smaller with...

Germany has a range of suitable habitats that make it a hotspot for dragonflies and damselflies. Many of these species are suffering from habitat loss and degradation, but not all of them, according to new research from the <a href="https://www.idiv.de/en/index.html">German Center for Integrative Research</a> (iDIV). 

While a growing collection of studies have found evidence of long-term population declines among dragonflies and damselflies throughout Europe, the new study suggests that some species are thriving in a warmer climate.

In collaboration with experts at FSU and UFZ, the iDIV team conducted a nationwide analysis of the occurrence and distribution of dragonflies and damselflies in Germany between 1980 and 2016. 

The study involved over one million occurrence records for 77 species from different regional databases, most of which were collected by citizen scientists.

The researchers determined that dragonfly and damselfly populations have experienced both losses and gains. The largest number of decreases were observed in cold-adapted species that prefer standing water habitats such as bogs and fens. Many of these species are already threatened with extinction. 

"These species are suffering a lot from habitat loss and degradation. Here, we are still facing serious conservation challenges," said study first author Dr. Diana Bowler.

Overall, the analysis suggests that cold-adapted species in standing water habitats are likely to be most vulnerable to climate change and other environmental changes. 

Overall, the experts found increases in the occurrence of 45 percent of all species in warm-adapted species. 

"Formerly rare species such as Crocothemis erythraea and Erythromma viridulum have become much more common across Germany," said Dr. Bowler. "These species prefer warmer temperatures and so their increase in Germany is most probably an outcome of long-term climate change."

The most population gains were found among running-water species, which represents the conservation success that can be achieved by better environmental management. 

"The increase of these species reflects a recovery from the impacts of past water pollution and the almost complete destruction of natural floodplains," said Klaus-Jürgen Conze. 

In Germany, projects were initiated in the 1990s to improve freshwater quality and river restoration. Furthermore, the EU Water Framework Directive was adopted in 2000.

"Our study highlights the great value of these monitoring efforts for assessing changes in species' occurrences," said study senior author Professor Aletta Bonn. "We found some signs of accelerating declines in the last decade, which highlights the need to support the efforts of these societies in the future."

The study is published in the journal <a href="https://onlinelibrary.wiley.com/journal/14724642">Diversity and Distributions</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Some dragonflies are thriving in a warmer climate

Germany has a range of suitable habitats that make it...

Young sharks that develop inside of protective egg cases called mermaids' purses will struggle to survive as <a href="https://www.earth.com/news/ocean-circulation-is-key-to-climate-change-predictions/">ocean</a> waters get warmer, according to a new study from the <a href="https://www.manchester.ac.uk/">University of Manchester</a>. According to study lead author Daniel Ripley, rising ocean temperatures are reducing the freeze response time that embryonic sharks use to keep from being eaten by predators. 

When an embryonic shark senses the electrical field of potential predators, it responds with a freeze response and stops moving to avoid detection. The longer an embryo can freeze, the greater its chances of evading predators.

For the investigation, Ripley compared the freeze response time of small spotted catshark embryos at water temperatures of 15 and 20 degrees Celsius. 

The study revealed that embryos exposed to a five-degree jump in temperature had a freeze response that was seven times shorter. This reduced response could have major consequences for embryonic sharks as temperatures continue to rise. 

The researchers noted that if warming means embryonic sharks will not be able to freeze as long, the number of sharks surviving to adulthood will decrease.

About 45 percent of shark and ray species lay their eggs inside of a mermaids purse, where the infants develop for around a year before they hatch.

“This study has shown that many shark and ray species may reduce in number owing to increased predation as the oceans warm," said Ripley.

“It’s hard to say to say how exactly this will impact on the ocean ecosystem, but it’s fair to assume there will be a knock on effect; it’s a major problem which is likely to get worse."

Ripley explained that many marine animals are cold blooded, which means that rising sea temperatures have important consequences for them.

“It’s widely accepted that the worlds’ oceans are likely to warm in the next 100 years. And according to the US Environmental Protection Agency, sea surface temperatures have been higher over the three previous decades than at any other time since 1880."

“So the impact of rising ocean temperatures could be catastrophic on species of egg-laying sharks and rays, such as the Brown banded bamboo shark or the Thornback ray."

“Shark embryos are already very vulnerable in their mermaids purses and our study suggests that one of their key survival strategies - freezing to hide from predators- may be significantly reduced by ocean warming."

“Some species are already threatened, and others, we simply don’t know enough about their numbers. But ocean warming may further harm their conservation and survival.”

The study is published in the <a href="https://academic.oup.com/conphys">Journal of Conservation Physiology</a>. 

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Embryonic sharks will struggle to survive in a warmer ocean

Young sharks that develop inside of protective egg cases called...

More than half of butterfly species in Switzerland are potentially threatened by excess nitrogen from vehicle emissions, industry, and <a href="https://www.earth.com/news/tropical-pollinators-are-70-percent-less-abundant-in-high-intensity-croplands/">agriculture</a>. 

Researchers at the <a href="https://www.unibas.ch/en.html">University of Basel</a> have discovered a link between the unintentional fertilization of soils through nitrogen emissions and low diversity of butterflies. 

Professor Valentin Amrhein, who led the team, says that the impact of nitrogen enrichment on butterflies has been underestimated. When it comes to butterfly diversity, the experts believe that nitrogen appears to play a similarly extensive role as climate change. 

Previous studies have shown that excessive nitrogen levels lead to denser vegetation with fewer plant species. 

"We wanted to find out whether a nitrogen surplus also indirectly affects the diversity of butterflies via this change in vegetation," explained study lead author Dr. Tobias Roth.

The researchers investigated the diversity of plants and butterflies at nearly 400 sites throughout Switzerland by analyzing data from Biodiversity Monitoring Switzerland. The results clearly showed that plots with more nitrogen had lower plant and butterfly diversity. 

"As caterpillars, some butterfly species need certain plant species as food, or are dependent on a certain microclimate," said Dr. Roth. 

With excessive fertilization, warm and dry places become cooler and damper as they are shaded by denser plant growth. The nitrogen surplus limits the prevalence of a large number of butterfly species in Switzerland that prefer open and dry sites, particularly those that are endangered. 

"Nitrogen from the air is likely to be an important factor in the reason why these species are endangered," noted Dr. Roth.

While the researchers do not see a simple approach for improving the situation, there may be some potential in technical advances.

"In the past, slurry was sprayed on farmland, for example, and some of this was transferred to other areas of land by the wind," said Dr. Roth. Today, he says, drag hoses are used increasingly to apply the slurry directly to the soil, which reduces nitrogen input in areas where it is not intended. 

According to the researchers, there is ultimately no way around environmentally friendly consumer behavior when it comes to reducing unwanted nitrogen input. This could be achieved, for example, through the reduction of vehicle emissions and livestock farming. 

The study is published in the journal <a href="https://conbio.onlinelibrary.wiley.com/journal/15231739">Conservation Biology</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Vanishing butterflies linked to nitrogen surplus

More than half of butterfly species in Switzerland are potentially...

Parrots are known for their remarkable ability to imitate, and they even replicate the signaling calls of other individuals during <a href="https://www.earth.com/news/neotropical-river-otters-have-a-complex-vocal-range/">vocal</a> interactions. 

A team of researchers at the <a href="https://www.ku.dk/english/">University of Copenhagen</a> has determined that this rapid vocal matching has an influence on important social dynamics including flock formation. 

The results of the study suggest that we have been overlooking a key component to understanding the function of vocal imitation in parrots. A single vocal interaction seems to influence whether or not parrots decide to fuse with another flock based on the quality of the individual that produces the vocalization. 

"By using a novel experimental design, we were able to gain valuable insights in the flock decisions of a social parrot, the orange-fronted conure, Eupsittula canicularis," explained study first author Heidi M. Thomsen.

"We conducted a field experiment in which flocks of wild orange-fronted conures were attracted to two loudspeakers simulating two orange-fronted conures engaged in a contact call interaction."

"During the interaction, one simulated individual would act as the leader by calling first, followed by the other individual. We specifically tailored the playback so the contact calls of the follower would imitate those of the leader. The listening wild flocks could now decide to fly after either the leader or the follower to fuse with it."

The study revealed that the parrots chose to follow vocal leaders more often than vocal followers during fusions. 

"Furthermore, flocks responded with higher call rates and matched the stimulus calls closer when subsequently choosing a vocal leader. Interestingly, orange-fronted conures also showed higher contact call rates and closer matches when choosing males over females," wrote the study authors.

"These results suggest that paying attention to conspecific contact call interactions can provide individuals with social information that can be utilized during fission and fusion events, significantly influencing the social dynamics of orange-fronted conures."

Thomsen said that while it is not yet known why leaders are preferred, the findings indicate that orange-fronted conure flocks rely on eavesdropping on vocal interactions to infer the relative quality of unfamiliar individuals.

"While orange-fronted conures frequently engage in contact call imitation during vocal interactions with conspecifics, we here illustrate that vocal imitation also has implications for potential third party listeners."

The study is published in the journal <a href="https://journals.plos.org/plosone/">PLOS One</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Imitation guides important social decisions among parrots

Parrots are known for their remarkable ability to imitate, and...

Gray sharks go surfing when they need a break When gray reef sharks need a break from <a href="https://www.earth.com/news/swimming-ocean-changes-bacteria-skin/">swimming</a>, they go surfing to preserve energy. An international team of researchers led by <a href="https://www.fiu.edu/">FIU</a> Professor Yannis Papastamatiou has witnessed hundreds of gray sharks floating in the southern channel of Fakarava Atoll in French Polynesia.

“During the day, they’re pretty placid and relaxed, swimming with minimal effort,” said Professor Papastamatiou. “It’s interesting because it’s a pretty strong current.” <a href="https://www.bing.com/search?q=north+america&amp;cvid=13b1d1ef5fa544a5b4a5ebc5ef530df5&amp;aqs=edge.0.69i59j69i57j0l3j69i60l2.698j0j9&amp;FORM=ANAB01&amp;PC=HCTS">North America</a> is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be described as the northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Tectonic Plate, Greenland is included as part of North America geographically. North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the Earth's land area and about 4.8% of its total surface

While observing sharks swimming against the current, Professor Papastamatiou noticed that they were barely moving their tails. Furthermore, the sharks were using a system that resembled a conveyer belt. When one shark reached the end of the line, it allowed the current to carry it back to the beginning point. 

Gray sharks go surfing when they need a break The team designed a study which combined acoustic tracking devices, video cameras, and underwater observations to monitor the curious behavior of the whales. 

The researchers found that by hanging out and surfing the slope, the sharks cut their energy usage by at least 15 percent. This provides the<a href="https://www.earth.com/news/killer-whales-have-close-friendships/"> whales</a> with some much-needed rest from constantly swimming. 

Professor Papastamatiou joined experts including marine biologist and underwater photographer Laurent Ballesta to film the French research documentary 700 Sharks in Fakarava, a famous dive site that is home to 500 gray reef sharks.

The focus of the film was on the sharks’ behavior after dark, when the channel becomes a hunting ground. However, Professor Papastamatiou saw that the sharks were hanging around in the channel during the daytime when they were not hunting. 

Ultimately, the study confirmed that the sharks stayed in the channel during the day to find updrafts to surf. In order to save maximum energy, the sharks also changed how deep down they go to surf the slope, according to the researchers. For example, during the turbulence of outgoing tides, the sharks remained near the surface for a smoother ride.

“This study is a nice demonstration of energy seascapes, a spatial representation of how much energy it costs an animal to move through an environment,” said Professor Papastamatiou. 

“Marine environments are a lot more dynamic because of the water currents, which are much less predictable. They can change seasonally, throughout the day and even minute by minute. Ultimately, the energy seascape helps explains why these animals are in this channel hanging out there during the day. Now we have an answer.”

The study is published in the <a href="https://besjournals.onlinelibrary.wiley.com/journal/13652656">Journal of Animal Ecology</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Gray sharks go surfing when they need a break

Gray sharks go surfing when they need a break When...

Young Weddell seals learn how to swim and navigate before they learn to <a href="https://www.earth.com/news/air-pollution-harms-bees-ability-to-forage-for-food/">forage</a>. A new study from <a href="https://www.calpoly.edu/">California Polytechnic State University</a> suggests that Weddell seal pups may be one of the only types of seals that learn how to swim from their mothers.

Weddell seals are the southernmost born mammal. At just two weeks old, the pups begin diving into freezing Antarctic waters. The researchers say that this extreme environment may explain why Weddell seal pups spend an unusually long time with their mothers.

According to the Seal Conservation Society, female Weddell seals grow to be nearly 11 feet long, which is slightly longer than males. The adult females typically weigh between 800 to 1,300 pounds. Their pups are born about four feet in length and weigh 50 to 65 pounds.

In other species, pups are nursed by their mothers on land for up to four weeks. After they are weaned, they enter the water and teach themselves how to swim and forage. On the other hand, Weddell seal pups stick with their mothers for six to seven weeks.

"Most seals don't get to learn anything from mom, so we wanted to know what are the important lessons that they need in this extremely cold environment," said study co-author Professor Heather Liwanag. 

"We were also interested in understanding how adults become such incredible divers. Where do they start?"

The researchers used tracking devices to measure how deep Weddell seal pups dove and what time of day they were in the water. They compared this information to what was known about the mothers' diving behaviors.

The study revealed that pups were in the water at the same time as their mothers, likely learning style important survival skills. Since the pups were not diving to depths that would be necessary to find prey, the experts determined they were not learning how to forage. 

The findings suggest that Weddell seal pups learn how to swim from their mothers. One of the most important lessons may be how to find a breathing hole while swimming beneath an ice sheet. 

"One of the common causes of death in young Weddell seals is drowning," said Professor Liwanag. "It's important that they learn how to find breathing holes in the ice that allow them to take frequent breaths, until they develop the ability to hold their breath for longer durations like the adults."

By studying the behavior of Weddell seals, experts hope to gain a better understanding of how climate change will affect ice-dependent seals worldwide.

The study is published in the <a href="https://academic.oup.com/jmammal">Journal of Mammalogy</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Young Weddell seals learn how to survive from their mothers

Young Weddell seals learn how to swim and navigate before...

It was once thought the coelacanth - a strange lobe finned <a href="https://www.earth.com/news/young-clownfish-are-struggling-to-survive-under-artificial-lights/">fish</a> related to lungfish - was extinct. For a long time, science only knew this strange order of fishes from the fossil record. Then, as fate would have it, a fisherman accidentally caught one of these rare fish alive. 

Coelacanths are enormous in size, but also live deep in the ocean. The inaccessibility of their habitat combined with their scarcity means that coelacanths are rarely seen or studied. A new study published by <a href="https://www.cell.com/">Cell Press</a> contradicts some of what we thought we knew about these mysterious fish.  

Early research tried to calculate coelacanth age by counting the rings in their scales. This research estimated that the fish only lived for roughly 20 years, which would make them one of the fastest growing of all fishes. This seemed unusual for a fish with a slow metabolism and low reproduction rate, traits usually associated with slower growing fishes.

Using advanced microscopy techniques, researcher Kélig Mahé and colleagues from IFREMER Channel and North Sea Fisheries Research Unit in Boulogne-sur-mer, France examined 27 coelacanth specimens housed in the world’s largest collection of the fish at the French National Museum of Natural History. 

The researchers found that their oldest specimen was 84 years old, and that coelacanths do not reach maturity around the age of 55.

"Our most important finding is that the coelacanth's age was underestimated by a factor of five," said Mahé. "Our new age estimation allowed us to re-appraise the coelacanth's body growth, which happens to be one of the slowest among marine fish of similar size, as well as other life-history traits, showing that the coelacanth's life history is actually one of the slowest of all fish."

Older studies looked at obviously visible circuli - calcified scale structures - to calculate the age of coelacanths. This new study looks more closely to examine microscopic circuli that are easily overlooked. 

The technique is similar to counting rings on a tree or rings in the otoliths of other fishes but complicated by the necessary imagery technology. 

"We demonstrated that these circuli were actually annual growth marks, whereas the previously observed macro-circuli were not," said Mahé. "It meant that the maximum longevity of coelacanth was five times longer than previously thought, hence around a century."

"Coelacanth appears to have one of, if not the slowest life histories among marine fish, and close to those of deep-sea sharks and roughies."

A new study is already being planned to examine the chemistry of coelacanth scales and determine if the growth rate is related to temperature. It seems this Lazarus fish still has some surprises ahead for us.  

The study is published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a>.

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By <a href="http://zachfitzner@yahoo.com">Zach Fitzner </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Coelacanths live about five times longer than expected

It was once thought the coelacanth - a strange lobe...

Just so there’s no mistake, Tyrannosaurus rex was not a medium-sized predator. A new study shows that <a href="https://www.earth.com/video/how-tyrannosaurs-grew-into-fierce-predators/">Tyrannosaurs</a> were so big, in fact, that the juveniles displaced medium-sized predators. 

A sharp decline in predators is usually related to a corresponding drop in prey species. This is true of living animals such as the snowshoe hare and the Canadian lynx, as well as predators and prey in the fossil record. 

A new study from the <a href="https://www.umd.edu/">University of Maryland</a> has found a different relationship, not between predator and prey but between tyrannosaurs and other predators.

The research, conducted by Thomas Holts, suggests that everywhere tyrannosaurs became dominant, the juveniles took over the ecological role of medium-sized predators.

“Earlier in the history of dinosaurs, in most communities you'd have a bunch of different types of carnivores of various size ranges from small fox-sized all the way up to the occasional giants," said Holts. 

"Then something happens between 95 and 80 million years ago, where we see a shift. The really big carnivores, larger than an elephant, like tyrannosaurs and their kin, become the apex predators, and the middle-sized predators, say leopard to buffalo-sized carnivores, are either missing or very rare.”

Previous research shows that younger tyrannosaurs acted and ate like mid-sized predators, moving with agility and speed that older members of their kind couldn’t match. In Asia and western North America, this means that the role of medium-sized predator fell almost solely to tyrannosaurs. 

It’s hard to say yet whether or not T. rex and their kin actually pushed out the other predators. It could be that something else entirely happened to medium-sized predators and tyrannosaurs just filled a vacant niche. 

To learn the truth, Holtz said the solution is more “boots on the ground," more good old fashioned field work. 

Further research is needed to investigate any changes in prey size during the shift to tyrannosaur domination. In addition, Holtz plans to survey the size distribution of carnivores during the Triassic period. 

"These interactions are important for understanding what life was like during the time of the dinosaurs," said Holtz. "But in the broader sense, having more understanding of changing ecosystems, and in this case, looking at the predator and prey components of an ecosystem, gives us a better and more diverse view of how the interactions of life work in the world, even today."

The study is published in the <a href="https://cdnsciencepub.com/journal/cjes">Canadian Journal of Earth Sciences</a>,

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By <a href="http://zachfitzner@yahoo.com">Zach Fitzner </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Young Tyrannosaurs displaced medium-sized predators

Just so there’s no mistake, Tyrannosaurus rex was not a...

Herring gulls are passing along chemicals used in plastic production to their offspring, according to new research from the <a href="https://www.exeter.ac.uk/">University of Exeter</a>. The study adds to a growing collection which shows that coastal environments are hit particularly hard by plastic pollution. 

Phthalates are chemical compounds that are added to plastics to keep them flexible. In collaboration with experts at the University of Queensland, the Exeter team found up to six types of phthalates in newly laid herring gull eggs.

"Herring gull mothers pass on vital nutrients to their offspring via their eggs," said Professor Jon Blount.

"This includes lipids that nourish developing embryos, and vitamin E, which helps to protect chicks from oxidative stress that can occur during development and at hatching."

"Unfortunately, our findings suggest that mothers are inadvertently passing on phthalates and products of lipid damage." 

Professor Blount noted that eggs with higher phthalate contamination also contained greater amounts of lipid damage and less vitamin E. Further research is needed to investigate the consequences this may have for baby chicks. 

The team collected 13 herring gulls eggs from various sites in Cornwall. All of the contained phthalates, which are now found in almost every environment on Earth. The compounds tend to accumulate in the fatty tissues of living organisms. Previous studies have discovered phthalates in birds that herring gulls are known to prey upon. 

"Research on the impact of plastic on animals has largely focussed on entanglement and ingestion of plastic fragments," said Professor Blount. "Far less is known about the impacts of plastic additives on the body."

"By testing eggs, our study gives us a snapshot of the mother's health - and it appears phthalate contamination could be associated with increased oxidative stress, and mothers transfer this cost to their offspring via the egg."

"More research is now needed to discover how developing offspring are affected by being exposed to phthalates before they have even emerged as a hatchling."

"We need to look more deeply into the pervasive threats of plastics - not just the breakdown of plastic items themselves, but also the dispersal of the multiple chemicals they contain.

"Where do these end up, and what effects are they having on wildlife and ecosystems?"

The study is published in the journal <a href="https://www.journals.elsevier.com/marine-pollution-bulletin">Marine Pollution Bulletin</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plastic additives found in the eggs of herring gulls

Herring gulls are passing along chemicals used in plastic production...

In a new study from the <a href="https://www.exeter.ac.uk/">University of Exeter</a>, drone footage has revealed that killer whales have complex <a href="https://www.earth.com/news/social-isolation-impacts-physical-functioning-in-older-adults/">social</a> lives that center around close friendships. The researchers found that killer whales spend the most time interacting with specific individuals of the same sex and similar age.

In collaboration with experts at the Center for Whale Research (CWR), the team also discovered that killer whales become less socially connected as they get older.

"Until now, research on killer whale social networks has relied on seeing the whales when they surface, and recording which whales are together," said lead author Dr. Michael Weiss.

"However, because resident killer whales stay in the social groups into which they're born, how closely related whales are seemed to be the only thing that explained their social structure.'

"Looking down into the water from a drone allowed us to see details such as contact between individual whales." 

According to Dr. Weiss, the findings show that even within their tight-knit groups, whales clearly  prefer to interact with certain individuals.

"It's like when your mom takes you to a party as a kid - you didn't choose the party, but you can still choose who to hang out with once you're there."

While examining patterns of physical contact, the experts found that both females and younger whales play a central social role in the group. The older the whale, the less central they became in the overall social structure.

The study was focused on more than four decades of data on a critically endangered population of southern resident killer whales in the Pacific Ocean. The researchers also analyzed 651 minutes of drone videos that they filmed over ten days.

"This study would not have been possible without the amazing work done by CWR," said Professor Darren Croft. "By adding drones to our toolkit, we have been able to dive into the social lives of these animals as never before."

"We were amazed to see how much contact there is between whales - how tactile they are. In many species, including humans, physical contact tends to be a soothing, stress-relieving activity that reinforces social connection."

"We also examined occasions when whales surfaced together - as acting in unison is a sign of social ties in many species."

"We found fascinating parallels between the behavior of whales and other mammals, and we are excited about the next stages of this research."

The study is published in the journal <a href="https://royalsocietypublishing.org/journal/rspb">Proceedings of the Royal Society B</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Killer whales have close friendships

In a new study from the University of Exeter, drone...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Santiago, Chile in South America

[sendtonews key="JRaP49ISmm-2357509-12187" type="single"] Today’s Video of the Day from the...

Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Interactive map of the universe includes 200,000 galaxies

[sendtonews key="e4ZG0Jawp3-2374785-12187" type="single"] Astronomers at Johns Hopkins University have created...

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



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

Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Two distant planets may be "water worlds"

[sendtonews key="QIoVYJqRBi-2434608-12187" type="single"] Today's Video of the Day from NASA...

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Satellites capture the world's biggest and fastest waves

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...