American pikas fight climate change


This 2018 video from the USA says about itself:

An American Pika runs along his kingdom among the boulders.

From Arizona State University in the USA:

American Pikas show resiliency in the face of global warming

October 13, 2020

The American pika is a charismatic, diminutive relative of rabbits that some researchers say is at high risk of extinction due to climate change. Pikas typically live in cool habitats, often in mountains, under rocks and boulders. Because pikas are sensitive to high temperatures, some researchers predict that, as the Earth’s temperature rises, pikas will have to move ever higher elevations until they eventually run out of habitat and die out. Some scientists have claimed this cute little herbivore is the proverbial canary in the coal mine for climate change.

A new extensive review by Arizona State University emeritus professor Andrew Smith, published in the October issue of the Journal of Mammalogy, finds that the American pika is far more resilient in the face of warm temperatures than previously believed. While emphasizing that climate change is a serious threat to the survival of many species on Earth, Smith believes that the American pika currently is adapting remarkably well.

Smith has studied the American pika for more than 50 years and presents evidence from a thorough literature review showing that American pika populations are healthy across the full range of the species, which extends from British Columbia and Alberta, Canada, to northern New Mexico in the U.S.

Occupancy in potential pika habitat in the major western North American mountains was found to be uniformly high. Among sites that have been surveyed recently, there was no discernible climate signal that discriminated between the many occupied and relatively few unoccupied sites.

“This is a sign of a robust species,” Smith said.

Smith said most of the studies that have raised alarms about the fate of the pika are based on a relatively small number of restricted sites at the margins of the pika’s geographic range, primarily in the Great Basin. However, a recent comprehensive study of pikas evaluating 3,250 sites in the Great Basin found pikas living in over 73% of the suitable habitat investigated. Most important, the sites currently occupied by pikas and the sites where they are no longer found were characterized by similar climatic features.

“These results show that pikas are able to tolerate a broader set of habitat conditions than previously understood,” Smith adds.

Smith’s most interesting finding is that pikas are apparently much more resilient than previously believed, allowing them to survive even at hot, low-elevation sites. Bodie California State Historic Park, the Mono Craters, Craters of the Moon National Monument and Preserve, Lava Beds National Monument, and the Columbia River Gorge (all hot, low-elevation sites) retain active pika populations, demonstrating the adaptive capacity and resilience of pikas. Pikas cope with warm temperatures by retreating into their cool, underground talus habitat during the hot daylight hours and augment their restricted daytime foraging with nocturnal activity.

This doesn’t mean that some pika populations have not been pushed to their limit, leading to their disappearance from some habitats. Smith’s review points out that most documented cases of local loss of pika populations have occurred on small, isolated habitat patches.

“Due to the relatively poor ability of pikas to disperse between areas, those habitats are not likely to be recolonized, particularly in light of our warming climate,” Smith said. “In spite of the general health of pikas across their range, these losses represent a one-way street, leading to a gradual loss of some pika populations. Fortunately for pikas, their preferred talus habitat in the major mountain cordilleras is larger and more contiguous, so the overall risk to this species is low.”

Smith’s work emphasizes the importance of incorporating all aspects of a species’ behavior and ecology when considering its conservation status, and that all available data must be considered before suggesting a species is going extinct. For the American pika, the data conclusively show that rather than facing extinction, American pikas are changing their behaviors in ways that help them better withstand climate change, at least for now.

Mammal-like reptile discovery in Greenland


A team of scientists led by Grzegorz Nied?wiedzki from Uppsala University have investigated the jaw anatomy and tooth structure of a recently described new mammaliaform species named Kalaallitkigun jenkinsi. Credit: Marta Szubert

From Uppsala University in Sweden:

A tiny jaw from Greenland sheds light on the origin of complex teeth

October 13, 2020

A team of scientists led from Uppsala University have described the earliest known example of dentary bone with two rows of cusps on molars and double-rooted teeth. The new findings offer insight into mammal tooth evolution, particularly the development of double-rooted teeth. The results are published in the scientific journal PNAS.

The first mammals originated in the latest Triassic period, around 205 million years ago. An ancestor to mammals were the therapsids, “mammal-like reptiles” referred to as stem mammals or proto-mammals, which originated about 320-300 million years ago. One unique characteristic of the lineage that included mammals and animals related to mammals (synapsids) was that they developed complex occlusion. Close ancestors to mammals, called mammaliaforms, developed rows of cusps on molar-like teeth adapted for more omnivorous feeding. The origin of this multicusped pattern and double-rooted tooth has thus far remained unclear.

A team of scientists led by Grzegorz Niedzwiedzki from Uppsala University have investigated the jaw anatomy and tooth structure of a recently described new mammaliaform species named Kalaallitkigun jenkinsi. It was discovered on the eastern coast of Greenland and was a very small, shrew-like animal, probably covered with fur. It would have been the size of a large mouse and lived during the Late Triassic, around 215 million years ago.

“I knew it was important from the moment I took this 20 mm specimen off the ground,” says Niedzwiedzki, researcher at Uppsala University and the corresponding author of the publication.

Kalaallitkigun jenkinsi exhibits the earliest known dentary with two rows of cusps on molars and double-rooted teeth. The anatomical features place Kalaallitkigun jenkinsi as an intermediate between the mammals and the insectivorous morganucodontans, another type of mammaliaform.

The researchers believe that the structural changes in the teeth are related to changed feeding habits. In this case study, the animals were switching to a more omnivorous/herbivorous diet and the tooth crown was expanding laterally. Broader teeth with “basins” on the top surface are better for grinding food. This development also forced changes in the structure of the base of the tooth.

The biomechanical analysis that was carried out within the study found that multi-rooted teeth are better able to withstand mechanical stresses, including those of upper and lower tooth contact during biting, compared to single-rooted teeth. Human teeth, for instance, have this characteristic. The results suggest that the development of molar-like teeth with complex crowns may have developed together with biomechanically optimised dual roots.

“The early evolution of mammals is a particularly interesting topic in evolutionary studies. This tiny jaw from Greenland shows us how complex mammalian teeth arose and why they appeared,” says Niedzwiedzki.

“Our discovery of the oldest mammalian ancestor with double-rooted molars shows how important the role of teeth was in the origin of mammals. I had this idea to look at the biomechanics and the collaboration with the engineers turned out great,” says Tomasz Sulej, researcher at the Polish Academy of Sciences, first author of the publication.

“It seems that the fossils of close mammalian ancestors must be looked for in even older rocks,” says Sulej.

Jurassic mammals lived more like reptiles


This May 2019 video is called The Mammals that Lived Alongside the Dinosaurs.

From the University of Bristol in England:

Ancient tiny teeth reveal first mammals lived more like reptiles

October 12, 2020

Pioneering analysis of 200 million-year-old teeth belonging to the earliest mammals suggests they functioned like their cold-blooded counterparts — reptiles, leading less active but much longer lives.

The research, led by the University of Bristol, UK and University of Helsinki, Finland, published today in Nature Communications, is the first time palaeontologists have been able to study the physiologies of early fossil mammals directly, and turns on its head what was previously believed about our earliest ancestors.

Fossils of teeth, the size of a pinhead, from two of the earliest mammals, Morganucodon and Kuehneotherium, were scanned for the first time using powerful X-rays, shedding new light on the lifespan and evolution of these small mammals, which roamed the earth alongside early dinosaurs and were believed to be warm-blooded by many scientists. This allowed the team to study growth rings in their tooth sockets, deposited every year like tree rings, which could be counted to tell us how long these animals lived. The results indicated a maximum lifespan of up to 14 years — much older than their similarly sized furry successors such as mice and shrews, which tend to only survive a year or two in the wild.

“We made some amazing and very surprising discoveries. It was thought the key characteristics of mammals, including their warm-bloodedness, evolved at around the same time,” said lead author Dr Elis Newham, Research Associate at the University of Bristol, and previously PhD student at the University of Southampton during the time when this study was conducted.

“By contrast, our findings clearly show that, although they had bigger brains and more advanced behaviour, they didn’t live fast and die young but led a slower-paced, longer life akin to those of small reptiles, like lizards.”

Using advanced imaging technology in this way was the brainchild of Dr Newham’s supervisor Dr Pam Gill, Senior Research Associate at the University of Bristol and Scientific Associate at the Natural History Museum London, who was determined to get to the root of its potential.

“A colleague, one of the co-authors, had a tooth removed and told me they wanted to get it X-rayed, because it can tell all sorts of things about your life history. That got me wondering whether we could do the same to learn more about ancient mammals,” Dr Gill said.

By scanning the fossilised cementum, the material which locks the tooth roots into their socket in the gum and continues growing throughout life, Dr Gill hoped the preservation would be clear enough to determine the mammal’s lifespan.

To test the theory, an ancient tooth specimen belonging to Morganucodon was sent to Dr Ian Corfe, from the University of Helsinki and the Geological Survey of Finland, who scanned it using high-powered Synchrotron X-ray radiation.

“To our delight, although the cementum is only a fraction of a millimetre thick, the image from the scan was so clear the rings could literally be counted,” Dr Corfe said.

It marked the start of a six-year international study, which focused on these first mammals, Morganucodon and Kuehneotherium, known from Jurassic rocks in South Wales, UK, dating back nearly 200 million years.

“The little mammals fell into caves and holes in the rock, where their skeletons, including their teeth, fossilised. Thanks to the incredible preservation of these tiny fragments, we were able to examine hundreds of individuals of a species, giving greater confidence in the results than might be expected from fossils so old,” Dr Corfe added.

The journey saw the researchers take some 200 teeth specimens, provided by the Natural History Museum London and University Museum of Zoology Cambridge, to be scanned at the European Synchrotron Radiation Facility and the Swiss Light Source, among the world’s brightest X-ray light sources, in France and Switzerland, respectively.

In search of an exciting project, Dr Newham took this up for the MSc in Palaeobiology at the University of Bristol, and then a PhD at the University of Southampton.

“I was looking for something big to get my teeth into and this more than fitted the bill. The scanning alone took over a week and we ran 24-hour shifts to get it all done. It was an extraordinary experience, and when the images started coming through, we knew we were onto something,” Dr Newham said.

Dr Newham was the first to analyse the cementum layers and pick up on their huge significance.

“We digitally reconstructed the tooth roots in 3-D and these showed that Morganucodon lived for up to 14 years, and Kuehneotherium for up to nine years. I was dumbfounded as these lifespans were much longer than the one to three years we anticipated for tiny mammals of the same size,” Dr Newham said.

“They were otherwise quite mammal-like in their skeletons, skulls and teeth. They had specialised chewing teeth, relatively large brains and probably had hair, but their long lifespan shows they were living life at more of a reptilian pace than a mammalian one. There is good evidence that the ancestors of mammals began to become increasingly warm-blooded from the Late Permian, more than 270 million years ago, but, even 70 million years later, our ancestors were still functioning more like modern reptiles than mammals”

While their pace-of-life remained reptilian, evidence for an intermediate ability for sustained exercise was found in the bone tissue of these early mammals. As a living tissue, bone contains fat and blood vessels. The diameter of these blood vessels can reveal the maximum possible blood flow available to an animal, critical for activities such as foraging and hunting.

Dr Newham said: “We found that in the thigh bones of Morganucodon, the blood vessels had flow rates a little higher than in lizards of the same size, but much lower than in modern mammals. This suggests these early mammals were active for longer than small reptiles but could not live the energetic lifestyles of living mammals.”

Oldest non-African monkey fossils discovered


Mesopithecus

From Penn State University in the USA:

Oldest monkey fossils outside of Africa found

October 9, 2020

Three fossils found in a lignite mine in southeastern Yunan Province, China, are about 6.4 million years old, indicate monkeys existed in Asia at the same time as apes, and are probably the ancestors of some of the modern monkeys in the area, according to an international team of researchers.

“This is significant because they are some of the very oldest fossils of monkeys outside of Africa,” said Nina G. Jablonski, Evan Pugh University Professor of Anthropology, Penn State. “It is close to or actually the ancestor of many of the living monkeys of East Asia. One of the interesting things from the perspective of paleontology is that this monkey occurs at the same place and same time as ancient apes in Asia.”

The researchers, who included Jablonski and long-time collaborator Xueping Ji, department of paleoanthropology, Yunnan Institute of Cultural Relics and Archaeology, Kunming, China, studied the fossils unearthed from the Shuitangba lignite mine that has yielded many fossils. They report that “The mandible and proximal femur were found in close proximity and are probably of the same individual,” in a recent issue of the Journal of Human Evolution. Also uncovered slightly lower was a left calcaneus — heel bone — reported by Dionisios Youlatos, Aristotle University of Thessaloniki, Greece, in another paper online in the journal, that belongs to the same species of monkey, Mesopithecus pentelicus.

“The significance of the calcaneus is that it reveals the monkey was well adapted for moving nimbly and powerfully both on the ground and in the trees,” said Jablonski. “This locomotor versatility no doubt contributed to the success of the species in dispersing across woodland corridors from Europe to Asia.”

The lower jawbone and upper portion of the leg bone indicate that the individual was female, according to the researchers. They suggest that these monkeys were probably “jacks of all trades” able to navigate in the trees and on land. The teeth indicate they could eat a wide variety of plants, fruits and flowers, while apes eat mostly fruit.

“The thing that is fascinating about this monkey, that we know from molecular anthropology, is that, like other colobines (Old World monkeys), it had the ability to ferment cellulose,” said Jablonski. “It had a gut similar to that of a cow.”

These monkeys are successful because they can eat low-quality food high in cellulose and obtain sufficient energy by fermenting the food and using the subsequent fatty acids then available from the bacteria. A similar pathway is used by ruminant animals like cows, deer and goats.

“Monkeys and apes would have been eating fundamentally different things,” said Jablonski. “Apes eat fruits, flowers, things easy to digest, while monkeys eat leaves, seeds and even more mature leaves if they have to. Because of this different digestion, they don’t need to drink free water, getting all their water from vegetation.”

These monkeys do not have to live near bodies of water and can survive periods of dramatic climatic change.

“These monkeys are the same as those found in Greece during the same time period,” said Jablonski. “Suggesting they spread out from a center somewhere in central Europe and they did it fairly quickly. That is impressive when you think of how long it takes for an animal to disperse tens of thousands of kilometers through forest and woodlands.”

While there is evidence that the species began in Eastern Europe and moved out from there, the researchers say the exact patterns are unknown, but they do know the dispersal was rapid, in evolutionary terms. During the end of the Miocene when these monkeys were moving out of Eastern Europe, apes were becoming extinct or nearly so, everywhere except in Africa and parts of Southeast Asia.

“The late Miocene was a period of dramatic environmental change,” said Jablonski. “What we have at this site is a fascinating snapshot of the end of the Miocene — complete with one of the last apes and one of the new order of monkeys. This is an interesting case in primate evolution because it testifies to the value of versatility and adaptability in diverse and changing environments. It shows that once a highly adaptable form sets out, it is successful and can become the ancestral stock of many other species.”

The National Science Foundation, Penn State and Bryn Mawr funded this research.

Ice Age Texas, USA manatees?


This 2018 video is called Manatees Are the “Sea Cows” of the Coasts | National Geographic Wild.

From the University of Texas at Austin in the USA:

Ice Age manatees may have called Texas home

October 1, 2020

Manatees don’t live year-round in Texas, but these gentle, slow-moving sea cows are known to occasionally visit, swimming in for a “summer vacation” from Florida and Mexico and returning to warmer waters for the winter.

Research led by The University of Texas at Austin has found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. The discovery raises questions about whether manatees have been making the visit for thousands of years, or if an ancient population of ice age manatees once called Texas home somewhere between 11,000 and 240,000 years ago.

The findings were published in Palaeontologia Electronica.

“This was an unexpected thing for me because I don’t think about manatees being on the Texas coast today,” said lead author Christopher Bell, a professor at the UT Jackson School of Geosciences. “But they’re here. They’re just not well known.”

The paper co-authors are Sam Houston State University Natural History Collections curator William Godwin, SHSU alumna Kelsey Jenkins (now a graduate student at Yale University), and SHSU Professor Patrick Lewis.

The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.

“We have them from one decade to another, so we know it’s not from some old manatee that washed up, and we have them from different places,” Godwin said. “All these lines of evidence support that manatee bones were coming up in a constant way.”

The Jackson Museum of Earth History at UT holds two of the specimens.

A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.

“I decided my collection would be better served in a museum,” Liggio said. “The manatee jaw was one of many unidentified bones in my collection.”

Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin’s eye. But Godwin said he was met with skepticism when he sought other manatee fossils for comparison. He recalls reaching out to a fossil seller who told him point-blank “there are no Pleistocene manatees in Texas.”

But examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.

The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-indian artifacts that have been found on the same beaches.

It’s assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees, Bell said. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.

The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does now, said Jackson School Professor David Mohrig, who was not part of the research team.

“Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times,” said Mohrig, an expert on how sedimentary landscapes evolve.

If there was a population of ice age manatees in Texas, it’s plausible that they would have rode out winters in these warmer river outlets, like how they do today in Florida and Mexico.

How blue whales sing and migrate


This video says about itself:

The following is my best Blue Whale footage from 2020! All of this was filmed off the coast of San Diego, California!

From Stanford University in the USA:

Blue whales switch to daytime singing before migrating

October 1, 2020

Summary: Through the use of two advanced audio recording technologies, researchers have found that blue whales switch from nighttime to daytime singing when they are starting to migrate.

The blue whale is the largest animal on Earth. It’s also among the loudest.

“Sound is a vital mode of communication in the ocean environment, especially over long distances,” said William Oestreich, a graduate student in biology at Stanford University’s Hopkins Marine Station. “Light, or any sort of visual cue, is often not as effective in the ocean as it is on land. So many marine organisms use sound for a variety of purposes, including communicating and targeting food through echolocation.”

Although whale songs have been studied for decades, researchers have had limited success in deciphering their meaning. Now, by recording both individual whales and their greater populations in the Northeast Pacific, researchers from Stanford and the Monterey Bay Aquarium Research Institute (MBARI) have identified patterns in the trills and bellows of blue whales that indicate when the animals are migrating from their feeding grounds off the North American coast to their breeding grounds off Central America. Their research was published Oct. 1 in Current Biology.

“We decided to compare daytime and nighttime song patterns from month to month, and there, in the divergence and convergence of two lines, was this beautiful signal that neither of us really expected,” said John Ryan, a biological oceanographer at MBARI and senior author of the paper. “As soon as that image popped up on the screen, Will and I were both like, ‘Hello, behavior'”.

Further analysis across the five years of hydrophone recordings could reveal new information about blue whale migration, a 4,000-mile journey that ranks among the longest in the world — and which the creatures repeat every year. Despite the immensity of blue whales and their travels, scientists know very little about their behaviors, such as how they are responding to changes in the ecosystem and food supply from year to year. Being able to predict the travel of whales along this important route could also help prevent ship strikes.

Supping and singing

To capture whales singing solo and in chorus, the researchers used two advanced recording technologies: an underwater microphone — or hydrophone — and tags that the researchers placed on individual whales.

In 2015, MBARI deposited a hydrophone 18 miles off the Monterey coast, 3,000 feet (900 meters) under sea level. The hydrophone is wired to their MARS undersea cabled observatory, which provides it with power and communications. This seafloor eavesdropper has recorded the deep ocean soundscape almost continuously for more than five years.

“The hydrophone fits in your hand,” said Ryan, who recommends listening to the hydrophone livestream in fall for optimal whale music (although only the humpback whale song can be heard through ordinary speakers). “It’s a little instrument that produces big data — about two terabytes per month.”

By focusing on the whale song wavelengths in the hydrophone data, the researchers noticed a distinct change over several months. Through the summers, the whale arias grew louder and were sung mostly at nighttime. Over the five years of data, the whale chorus was loudest around October and November, and singing happened more at nighttime. Following each annual peak in song activity, as the whales began to depart for warmer waters, singing became more of a daytime activity.

While daytime versus nighttime differences in singing behavior had been noted in previous research, the whale-borne tags, developed by the lab of Stanford biologist Jeremy Goldbogen, helped explain what these 24-hour patterns and their inversion in late autumn could mean. Fifteen tags tracked the sounds of their carriers through accelerometer measurements — which monitor vibrations — and, in some cases, integrated hydrophones. In the summer, the whales spent much of the daytime feasting, bulking up for the long journey ahead and reserved their musical interludes for nighttime. When the time came, migration was again accompanied by daytime songs.

“In the hydrophone data, we saw really strong patterns over this enormous spatial domain. When we saw the exact same pattern on individual animals, we realized that what we’d been measuring over hundreds of kilometers is actually a real behavioral signal — and one that represents the behavior of many different whales,” said Oestreich. “As an ecologist, it’s very exciting to observe so many whales, simultaneously, using one instrument.”

Listening and learning

This research lays the groundwork for possibly predicting blue whale migration based on the transitions between the different song schedules — such forecasts could be used to warn shipping lanes further down the coast, like air traffic control but for the ocean. The researchers also hope that further analysis of the acoustic data will reveal more about whale behavior in response to environmental changes, such as warming waters and fickle food supplies.

“If, for example, we can detect differences in migration and foraging in response to changes in the environment, that is a really powerful and important way to keep an eye on this critically endangered species,” said Goldbogen, who is an assistant professor of biology in the School of Humanities and Sciences and also senior author of the paper. “That’s economically important, ecologically important and also culturally important.”

Already, Oestreich is pursuing a related question: If we can use this signal to determine whether whales are foraging or migrating, are whales using it that way too? It’s possible, said Oestreich, that a lone whale might listen around before giving up on feeding and heading south.

“Blue whales exist at incredibly low densities with enormous distances between them but, clearly, are sharing information in some way,” said Oestreich. “Trying to understand that information sharing is one motivation, but also potentially using that signaling as a means to study them is another exciting possibility.”

This research was funded by the National Science Foundation, Stanford University, the David and Lucile Packard Foundation, the Office of Naval Research, the Office of Naval Operations (Living Marine Resources program) and the California Ocean Alliance. This research was conducted under National Marine Fisheries Service permit 16111 and 21678.

How giraffes, elephants impact the African environment


This 2019 video from South Africa says about itself:

Beautiful interaction between Elephant, Impala, Kudu and Giraffe at a waterhole in Kruger National Park.

From the Smithsonian Tropical Research Institute:

How do giraffes and elephants alter the African Savanna landscape?

September 14, 2020

Summary: Through their foraging behavior across the diverse topography of the African savanna, megaherbivores may be unknowingly influencing the growth and survival of vegetation on valleys and plateaus, while preserving steep slopes as habitat refugia.

As they roam around the African savanna in search for food, giraffes and elephants alter the diversity and richness of its vegetation. By studying the foraging patterns of these megaherbivores across different terrains in a savanna in Kenya, scientists from the Smithsonian Tropical Research Institute (STRI) and collaborating institutions discovered that these large mammals prefer to eat their meals on flat ground, potentially impacting the growth and survival of plant species on even savanna landscapes, such as valleys and plateaus.

Megaherbivores are more concerned about eating as much food as possible while expending the minimum amount of effort, than about avoiding potential predators. Elephants may consume as much as 600 pounds of vegetation in a day; giraffes, about 75. This drove scientists to wonder about the impact of these megaherbivores on vegetation across a range of landscapes in the savanna.

“Previous studies have demonstrated that megaherbivores adjust their movement patterns to avoid costly mountaineering,” said co-author David Kenfack, STRI staff scientist, coordinator of the ForestGEO network forest monitoring plots in Africa and recently elected Fellow of the African Academy of Sciences. “We wanted to know the extent to which fine-scale variations in topography may influence browsing damage by these charismatic megaherbivores and evaluate whether seasonal shortages in food availability would force the megaherbivores to venture into areas with rugged terrain.”

Their observations conducted within a 120-hectare Smithsonian ForestGEO long-term vegetation monitoring plot located at Mpala Research Center in Kenya confirmed that giraffes and elephants prefer flat ground while foraging. They compared the damage on Acacia mellifera trees, which grow all over the savanna landscape and are a common meal for megaherbivores. They found that the trees growing on steep slopes were taller and had fewer stems than those in valleys and plateaus, suggesting that elephant and giraffes tend to avoid feeding in these less accessible habitats.

This behavior did not change during the dry season, when resources become scarce, indicating that these two species would rather disperse to new areas with more favorable conditions than climb up a nearby slope to feed.

For the authors, these feeding patterns may help preserve steep slopes as habitat refugia, with a greater diversity and density of vegetation than more frequently visited areas. Their findings support this argument: the number and variety of trees encountered on the steep slopes was higher than in the valleys and plateaus.

“This study has broadened our understanding of the role of topography in explaining diversity patterns of plants,” said Duncan Kimuyu, a Smithsonian Mpala postdoctoral fellow, lecturer at Karatina University in Kenya and main author of the study. “Further research is warranted to understand how other factors such as differences in soil properties may interact with topography and megaherbivores to influence the growth and survival of vegetation in the African savanna.”

Members of the research team are affiliated with STRI, Karatina University, Mpala Research Center and Wildlife Foundation and the National Museums of Kenya. Research was funded by the Smithsonian Tropical Research Institute, ForestGEO and the International Foundation for Science (D/5455-2).

How male, female leopards live in Tanzania


This 2019 video says about itself:

Pula, a female leopard, hunts and takes down an impala for a meal.

From the University of Copenhagen in Denmark:

The surprising rhythms of Leopards: Females are early birds, males are nocturnal

September 10, 2020

Summary: After 10 months of camera surveillance in the Tanzanian rainforest, researchers have concluded that female and male leopards are active at very different times of the day. The discovery contradicts previous assumptions and could be used to help protect the endangered feline, whose populations have dwindled by 85 percent over the past century.

Tanzania’s Udzungwa Mountains are carpeted by dense rainforest, making the area impossible to reach by jeep or other vehicles. As such, the leopards in this area have never been subject to the prying eyes of researchers. Until now.

After covering 2,500 square kilometers on foot, setting up 164 game camera traps and collecting more than 5000 days worth of footage from the area, the Natural History Museum of Denmark’s Rasmus W. Havmøller has discovered new and surprising knowledge about these spotted predators.

“I’m the first person to study leopards in this area, simply because it is so inaccessible. It took several pairs of good hiking boots, let me put it that way,” says Havmøller, who never actually got to see one of the shy leopards with his own eyes. Instead, he had to “settle” for buffalo and elephants.

While Havmøller never caught a glimpse of a leopard himself, his 164 camera traps most certainly did. Using motion sensors, the cameras captured the leopards, as well as forest antelopes, baboons and other leopard prey on film. Camera observations revealed leopard behaviour that contradicts previous assumptions.

“In the past, leopards were thought to be most active at dusk. Very surprisingly, the study shows that leopards hunt and move around at very different times of the day depending on whether they are females or males,” says Rasmus W. Havmøller, who adds:

“Females are typically active from early through late morning, and then a bit before sunset, while males only really wake up at night.”

This is the first time that differences in activity patterns between male and female leopards have been studied.

Differences between male and female leopards have only recently begun to be studied, so there is still much to learn about the animal. But researchers need to hurry. Rapidly growing human populations in Africa and India are the greatest threat to these animals, which are forced from their habitats and shot when they near livestock.

“Globally, things are going awfully for leopards, with sharp declines in their populations over the past 100 years. Furthermore, these animals aren’t monitored all that well. In part, this is because it is difficult. But also, because there has been a greater focus on species that are even more endangered, including lions, tigers and cheetahs. Therefore, it might be that the leopards in Udzungwa present the last chance to study these creatures in a diversified environment, one that has only been lightly impacted by humans, before they end up becoming highly endangered” explains Rasmus W. Havmøller.

The researcher believes that the results will provide a better understanding of the lives of wild leopards — an understanding that may help prevent their complete extinction.

“The fact that female leopards are active well into the morning makes them more vulnerable to human activities, since this is when we as humans are most active. To protect something, one needs to have some knowledge about it. During my study, we also discovered that a leopard from the rainforest doesn’t move into semi-arid areas or onto the savannah, or vice versa. It’s very strange. Why they don’t is the next big question,” concludes Havmøller.

Intact Pleistocene cave bear discovered in Siberia


This 14 September 2020 video says about itself:

Another Ice mummy has been uncovered in Russia. An adult cave bear and cub have been found fully intact with all original organs in the place they were when the critter died!

From the North-Eastern Federal University in Yakutsk in Siberia, by Anna Baisakova:

NEFU scientists to study cave bear found on the Lyakhovsky Islands

First-ever preserved grown up cave bear – even its nose is intact – unearthed on the Arctic island

Separately at least one preserved carcass of a cave bear cub found on the mainland of Yakutia, with scientists hopeful of obtaining its DNA.

More details of the finds are to be announced soon.

Until now only the bones of cave bears have been discovered.

The new finds are of ‘world importance’, according to one of Russia’s leading experts on extinct Ice Age species.

Scientist Lena Grigorieva said of the island discovery of the adult beast: ‘Today this is the first and only find of its kind – a whole bear carcass with soft tissues. ‘It is completely preserved, with all internal organs in place including even its nose. «Previously, only skulls and bones were found. This find is of great importance for the whole world».

The remains were found by reindeer herders on the island and the remains will be analysed by scientists at the North-Eastern Federal University (NEFU) in Yakutsk, which is at the forefront of research into extinct woolly mammoths and rhinos.

Russian and foreign colleagues will be invited to join the study.

The cave bear (Ursus spelaeus) is a prehistoric species or subspecies that lived in Eurasia in the Middle and Late Pleistocene period and became extinct about 15,000 years ago.

Preliminary analysis suggests the bear to be between 22,000 and 39,500 years old.

«It is necessary to carry out radiocarbon analysis to determine the precise age of the bear,» said senior researcher Maxim Cheprasov from the Mammoth Museum laboratory in Yakutsk. The finder transferred the right to research to the scientists of NEFU, he said.

Unique discovery of perfectly preserved extinct cave bear showing its teeth after up to 39,000 years.

Bolshoy Lyakhovsky Island, or Great Lyakhovsky, is the largest of the Lyakhovsky Islands belonging to the New Siberian Islands archipelago between the Laptev Sea and the East Siberian Sea in northern Russia.

A scientific programme for its comprehensive study will be prepared. We will have to study the carcass of a bear using all modern scientific research methods – molecular genetic, cellular, microbiological and others.

«The research is planned on as large a scale as in the study of the famous Malolyakhovsky mammoth,» said Dr Grigorieva, leading researcher of the International Centre for Collective Use of Molecular Paleontology at the NEFU’s Institute of Applied Ecology of the North.

Recent years have seen major discoveries of mammoths, woolly rhinos, Ice Age foal, several puppies and Cave Lion cubs as the permafrost melts in Siberia.

Reference:

The International Center for Collective Use “Molecular Paleontology” was opened in March 2015 on the basis of the laboratory “Mammoth Museum named after P.A. Lazarev” RIAEN as a separate structural unit of the institute. The opening of the ICCU became possible due to the agreement on scientific cooperation on the project “Revival of the mammoth and other fossil animals”, concluded between NEFU and the South Korean Sooam Biotechnological Institute on September 23, 2012. One of the priority areas of cooperation is joint research in the field of studying the genome of ancient animals.