Scammed! Animals 'led by the nose' to leave plants alone

University of Sydney researchers have shown it is possible to shield plants from the hungry maws of herbivorous mammals by fooling them with the smell of a variety they typically avoid.

Findings from the study published in Nature Ecology & Evolution show tree seedlings planted next to the decoy smell solution were 20 times less likely to be eaten by animals.

"This is equivalent to the seedlings being surrounded by actual plants that are unpalatable to the herbivore. In most cases it does trick the animals into leaving the plants alone," said PhD student Patrick Finnerty, the study's lead author from the School of Life and Environmental Sciences Behavioural Ecology and Conservation Lab.

"Herbivores cause significant damage to valuable plants in ecological and economically sensitive areas worldwide, but killing the animals to protect the plants can be unethical," he said.

"So, we created artificial odours that mimicked the smell of plant species they naturally avoid, and this gently nudged problematic herbivores away from areas we didn't want them to be.

"Given that many herbivores use plant odour as their primary sense to forage, this method provides a new approach that could be used to help protect valued plants globally, either in conservation work or protecting agricultural crops."

The experiment, conducted in Ku-ring-gai Chase National Park in Sydney, used the swamp wallaby as model herbivore.

The researchers selected an unpalatable shrub in the citrus family, Boronia pinnata, and a palatable canopy species, Eucalyptus punctata, to test the concept.

The study compared using B. pinnata solution and the real plant and found both were equally successful at protecting eucalyptseedlings from being eaten by wallabies.

As part of his doctoral research, Mr Finnerty has also tested the method successfully with African elephants, but that fieldwork does not form part of this research paper.

Previous attempts to use repellent substances, such as chilli oil or motor oil, to control animal consumption of plants have inherent limitations, Mr Finnerty said.

"Animals tend to habituate to these unnatural cues and so deterrent effects are only temporary," he said.

"By contrast, by mimicking the smell of plants herbivore naturally encounter, and avoid in day-to-day foraging, our approach works with the natural motivators of these animals, with herbivores less likely to habituate to these smells."

Researchers took this idea and used solutions that produce these undesired aromas.

"As a management tool to protect palatable plants, our technique offers many advantages over real plants as a repellent," Mr Finnerty said.

"Our approach should be transferable to any mammalian, or potentially invertebrate, herbivore that relies primarily on plant odour information to forage and could protect valued plants globally, such as threatened species."

Current solutions to herbivore-related problems often involve costly and environmentally impactful measures such as lethal control or fencing.

The new research introduces an alternative low-cost, humane strategy based on understanding herbivores' foraging cues, motivations and decisions.

"Plant browsing damage caused by mammalian herbivore populations like deer, elephants and wallabies is a growing global concern," said senior study author Professor Clare McArthur.

"This damage is one of the greatest limiting factors in areas of post-fire recovery and revegetation, destroying more than half the seedlings in these areas. It also threatens endangered plants and causes billions of dollars of damage in forestry and agriculture globally.

Read more at Science Daily

Protected areas for elephants work best if they are connected

Conservation measures have successfully stopped declines in the African savanna elephant population across southern Africa, but the pattern varies locally, according to a new study.

The evidence suggests that the long-term solution to elephant survival requires not only that areas are protected but that they are also connected to allow populations to stabilize naturally, an international research team says.

Their study, published on January 5th in the peer-reviewed journal Science Advances, collected survey estimates and calculated growth rates for more than 100 elephant populations in southern Africa between 1995 and 2020, accounting for an estimated 70% of the global savanna elephant population.

"This is the most comprehensive analysis of growth rates for any large mammal population in the world," said co-author Rob Guldemond, director of the Conservation Ecological Research Unit (CERU) at the University of Pretoria, in South Africa.

Overall, the survey's results are positive: There are the same number of elephants now as there were 25 years ago, a rare conservation win at a time when the planet is rapidly losing biodiversity.

However, the pattern is not consistent across regions. Some areas, such as south Tanzania, eastern Zambia, and northern Zimbabwe, experienced severe declines due to illegal ivory poaching.

In contrast, populations in other regions like north Botswana are booming.

"Unchecked growth isn't necessarily a good thing, however," says study co-author Stuart Pimm, the Doris Duke Professor of Conservation at Duke University in North Carolina.

"Rapidly increasing populations can outgrow and damage their local environment and prove hard to manage -- introducing a threat to their long-term stability," Pimm says.

In addition to documenting local growth rates, the team also looked at the features of the local populations to identify what makes them stable, that is neither growing nor declining.

Elephant populations in well-protected but isolated parks, sometimes called "fortress conservation," grow rapidly in the absence of threats but are unsustainable in the long term.

These elephants will likely need future conservation interventions, such as translocation or birth control, which are both costly and intensive endeavors.

The team found that the most stable populations occur in large, core areas that are surrounded by buffer zones.

The core areas are defined by their strong levels of environmental protection and minimal human impact, whereas the buffers allow some activities such as sustainable farming, forestry, or trophy hunting.

Unlike the insular fortresses, core areas are connected to other parks, allowing herds to move naturally.

"What's crucial is that you need a mix of areas with more stable core populations linked to more variable buffer areas," said lead author Ryan Huang, a Duke Ph.D. now doing postdoctoral research at CERU.

"These buffers absorb immigrants when core populations get too high, but also provide escape routes when elephants face poor environmental conditions or other threats such as poaching," Huang said.

Connecting protected areas means elephants can freely move in and out.

This allows a natural equilibrium to occur without human intervention, sparing conservationists from using their limited resources to maintain balance.

"Calling for connecting parks isn't something new. Many have done so," Huang said.

"But surprisingly, there has not been a lot of published evidence of its effectiveness so far. This study helps quantify why this works."

Read more at Science Daily

How shifting climates may have shaped early elephants' trunks

Researchers have provided new insights into how ancestral elephants developed their dextrous trunks.

The study, published today as an eLife Reviewed Preprint, combines multiple analyses to reconstruct feeding behaviours in the extinct longirostrine elephantiforms- elephant-like mammals characterised by elongated lower jaws and tusks. The work is described by the editors as fundamental to our understanding of how the elongated lower jaw and long trunks evolved in these animals during the Miocene epoch, around 11-20 million years ago. It provides compelling evidence for the diversity of these structures in longirostrine gomphotheres, and their likely evolutionary responses to global climatic changes.

The findings may also shed light on why modern day elephants are the only animals able to feed themselves using their trunks.

Longirostrine gomphotheres are part of the proboscidean family -- a group of mammals including elephants and known for their elongated and versatile trunks. Longirostrine gomphotheres are notable as they underwent a prolonged evolutionary phase characterised by an exceptionally elongated lower jaw, or mandible, which is not found in later proboscideans. It is thought that their elongated mandible and trunk may have co-evolved in this group, but this change among early to late proboscideans remains incompletely understood.

"During the Early to Middle Miocene, gomphotheres flourished across Northern China," says lead author Dr. Chunxiao Li, a postdoctoral researcher at the University of Chinese Academy of Sciences, Beijing, China. "Across species there was huge diversity in the structure of the long mandible. We sought to explain why proboscideans evolved the long mandible and why it subsequently regressed. We also wanted to explore the role of the trunk in these animals' feeding behaviours, and the environmental background for the co-evolution of their mandibles and trunks."

Li and colleagues used comparative functional and eco-morphological investigations, as well as a feeding preference analysis, to reconstruct the feeding behaviour of three major families of longirostrine gomphotheres: Amebelodontidae, Choerolophodontidae and Gomphotheriidae.

To construct the feeding behaviours and determine the relation between the mandible and trunk, the team examined the crania and lower jaws of the three groups, sourced from three different museums. The structure of the mandible and tusks differed across the three groups, indicating differences in feeding behaviours. The mandibles of Amebelodontidae were generally shovel-like and the tusks were flat and wide. Gomphotheriidae had clubbed lower tusks and a more narrow mandible, while Choerolophodontidae completely lacked mandibular tusks and their lower jaw was long and trough-like.

Next, the team conducted an analysis of the animals' enamel isotopes to determine the distribution and ecological niches of the three families. The results indicated that Choerolphontidae lived in a relatively closed environment, whereas Platybelodon, a member of the Amebelodontidae family, lived in a more open habitat, such as grasslands. Gomphotheriidae appeared to fill a niche somewhere in between these closed and open habitats.

A Finite Element analysis helped the team determine the advantages and disadvantages of the mandible and tusk structure between each group. Their data indicated that the Choerolophodontidae mandible was specialised for cutting horizontally or slanted-growing plants, which may explain the absence of mandibular tusks. The Gomphotheriidae mandible was found to be equally suited for cutting plants growing in all directions. Platybelodon had structures specialised for cutting vertically growing plants, such as soft-stemmed herbs, which would have been more common in open environments.

The three families also showed differences in their stages of trunk evolution, which could be inferred from the narial structure -- the region surrounding the nostrils. The narial region in Choerolophodontidae suggested that they had a relatively primitive, clumsy trunk. In Gomphotheriidae, the narial region was most similar to modern day elephants, suggesting they had a relatively flexible trunk. The trunks of Platybelodons may be the first example of a proboscidean trunk with the ability to coil and grasp. The evolutionary level of the trunk appeared to relate to the ability of the mandible to cut horizontally, strongly suggesting a co-evolution between the trunk and the mandible in longirostrine gomphotheres.

During the Mid-Miocene Climate Transition, which caused regional drying and the expansion of more open ecosystems, Choerolophodontidae experienced a sudden regional extinction and Gomphotheriidae numbers also declined in Northern China. The study suggests that the development of the coiling and grasping trunk in Platybelodon allowed this group to survive in greater numbers in their open environments. This may also explain why other animals with trunks, such as tapirs, never developed such dextrous trunks as elephants, as they never moved into open lands.

"Our cross-disciplinary team is dedicated to introducing multiple quantitative research methods to explore paleontology," says co-author Ji Zhang, associate professor of structural engineering at Huazhong University of Science and Technology, Wuhan, China. "Modern computational mechanics and statistics have injected new vitality into traditional fossil research."

The main limitation of this work is the lack of discussion comparing the team's results with the development of gigantism and long limbs in proboscideans from the same period, according to eLife's editors. The authors add that such analysis could add to our understanding of how changing feeding behaviours related to wider differences in the animals' body shapes and sizes during this time.

Read more at Science Daily

Elephant ancestors´ teeth evolved in response to long term changes in diet and climate in Africa

A new study shows that the cheek teeth of proboscideans (elephants and their ancient relatives) evolved in response to dietary changes due to vegetation changes and climate change in East Africa during the last 26 million years.

The latest study about of proboscideans (elephants and their ancient relatives) from the University of Helsinki provides proof that some proboscideans started to adapt to locally grass-rich environments in East Africa first by changing their behavior and starting to feed more on grasses. This happened in some lineages of proboscideans, such as choerolophodonts, much earlier than has been thought until now, about 23 to 11 million years ago in parts of East Africa

Also, around 7 million years ago in the lake Turkana region, increasingly grass-rich diets of the earliest true elephants were associated with dryer and more grass-rich savanna environments than elsewhere in East Africa.

"This supports the hypothesis of such regions as "species-factories" where evolutionary adaptation to changing environmental conditions first centered around," says Juha Saarinen from the University of Helsinki, who led the research.

Feeding on grasses is more demanding on teeth than feeding on most other kinds of plants due to a high content of mineral grains called phytoliths in their leaves, causing heavy abrasion on teeth.

Nonetheless, during the Early and Middle Miocene the choerolophodont lineage of proboscideans were able to shift to more grass-rich diets with relatively modest changes in the morphology of their teeth.

Since about 10 million years ago, major changes in climate had a more profound effect on the evolution of proboscidean teeth in East Africa, especially the evolution of true elephants (Elephantidae) with highly specialized high-crowned, multi-ridged molar teeth.

"We were able to show that the strongest peaks of drying of the East African climate during the last 7 million years (for example about 4 and 2 million years ago) correspond with evolutionary bursts in the increase of tooth crown height and the number of ridges on the molar teeth, while these evolutionary changes did not reverse during periods of less harsh climatic conditions" says Saarinen.

"This supports earlier suggestions that adaptive traits in organisms are adaptations to extreme rather than average environmental conditions."

Comparing evidence of past vegetation and the diet of elephants during the last 7 million years also showed an increase of grasslands and increasing dominance of grass-feeding elephants with highly specialized teeth throughout that period in most parts of East Africa. However, during the last 100,000 years this situation changed probably because of drastic fluctuations in global climate and eventually only the dietarily more generalist modern African savanna elephant (Loxodonta africana) with less specialized teeth survived in East Africa. Ecological generalism might similarly explain the survival of Asian elephant (Elephas maximus) in Asia, while the African forest elephant (L. cyclotis) was able to find refuge in more forested parts of Central and Western Africa.

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This elephant's self-taught banana peeling offers glimpse of elephants' broader abilities

Elephants like to eat bananas, but they don't usually peel them first in the way humans do. A new report in the journal Current Biology on April 10, however, shows that one very special Asian elephant named Pang Pha picked up banana peeling all on her own while living at the Berlin Zoo. She reserves it for yellow-brown bananas, first breaking the banana before shaking out and collecting the pulp, leaving the thick peel behind.

The female elephant most likely learned the unusual peeling behavior from watching her caretakers peel bananas for her, the study authors report. The findings in a single elephant show that elephants more broadly have special cognitive and manipulative abilities, they say.

"We discovered a very unique behavior," said Michael Brecht of Humboldt-Universität zu Berlin's Bernstein Center for Computational Neuroscience. "What makes Pang Pha's banana peeling so unique is a combination of factors -- skillfulness, speed, individuality, and the putatively human origin -- rather than a single behavioral element."

Like other elephants, Pha eats green or yellow bananas whole. She rejects brown bananas outright. But when it comes to yellow bananas spotted with brown -- the kind one might reserve for banana bread -- she eats after peeling them first.

Brecht and colleagues including Lena Kaufmann, also at Humboldt-Universität zu Berlin, and Andreas Ochs, Berlin Zoological Garden, made the discovery after learning from Pha's caretakers about her unusual banana-peeling talent. At first, they were confused. They brought Pha nice yellow and green bananas, and she never peeled them.

"It was only when we understood that she peels only yellow-brown bananas that our project took off," Brecht said.

When yellow-brown bananas are offered to a group of elephants, Pha changes her behavior, they report. She eats as many bananas as she can whole and then saves the last one to peel later.

Banana-peeling appears to be rare in elephants as far as anyone knows, and none of the other Berlin elephants engage in peeling. It's not clear why Pha peels them. The researchers note, however, that she was hand raised by human caretakers in the Berlin Zoo. They never taught her to peel bananas, but they did feed her peeled bananas.

Based on this, the researchers suggest she acquired peeling through observational learning from humans. Earlier reports on African elephants suggest elephants can interpret human pointing gestures and classify people into ethnic groups, but complex human-derived manipulation behaviors, like banana-peeling, appear rather unique, according to the researchers. The findings in Pha nevertheless suggest that elephants overall have surprising cognitive abilities and impressive manipulative skill.

"Elephants have truly remarkable trunk skills and that their behavior is shaped by experience," says Brecht.

Read more at Science Daily

Appreciating the value of elephants

New research examining the services and benefits of elephants has revealed many values are often overlooked when deciding how they should be protected.

The collaboration between universities in England and South Africa, including the University of Portsmouth, found conservation strategies often have a narrow focus and tend to prioritise certain values of nature, such as economic or ecological, over moral ones.

When looking specifically at elephants, the study found financial benefits including ecotourism, trophy hunting and as a source of ivory or labour, often conflicts with the animal's ecological, cultural and spiritual contributions.

The authors argue not fully understanding or considering the value systems of all stakeholders involved in conservation, including local people, leads to social inequality, conflict and unsustainable strategies.

Study co-author Antoinette van de Water, from the University of KwaZulu-Natal in South Africa, said: "We chose to look at elephants as the case study because their conservation can be especially challenging and contentious.

"We're not saying economic contributions aren't important, but there's a lot of different values at play and they all need to be considered in conservation strategies if they are going to succeed."

The study also highlights conservation decision makers tend to take a single worldview when considering the value of nature.

Co-author Dr Lucy Bates, from the University of Portsmouth, explained: "Whether it's economic, ecological, or social, a blanket approach to values can impact the success of a conservation strategy.

"Consider something like the ivory trade for example. International trade in ivory is illegal, but many southern African countries want to restart the trade leading to contention across the African continent. If you focus less on the potential economic value of ivory, and turn to other ways elephants can support communities, it can be a game-changer.

"On a smaller scale, you can also apply this framework to defining protected areas and what land could be made available to elephants. By listening to those living in these areas, you can get a clear understanding of how decisions will affect human life as well, and work out ways to resolve any issues."

The paper, published in Ecosystems Services, says nature's non-material benefits include recreation, inspiration, mental health, and social cohesion.

But it points out broader moral values, such as human rights, environmental justice, rights of nature and intergenerational legacy, also have a big part to play in the success of conservation.

The study recommends incorporating moral values related to biodiversity conservation into the valuation framework to create a positive loop between benefits to humans and to nature.

The researchers believe that this approach will help policymakers and managers have a better understanding of what elephants mean to people, why elephants are important in themselves, and what values and interests are at stake. It can also be applied to other species and ecosystems.

"What is really needed is a change of thinking," added Antoinette van de Water.

Read more at Science Daily

Trunk dexterity explained: Scientists decipher facial motor control in elephants

Elephants have an amazing arsenal of face, ear and trunk movements. The trunk consists of far more muscles than the entire human body and can perform both powerful and very delicate movements. A team of scientists from the Humboldt University of Berlin and the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) now examined the facial motor nucleus of African and Asian elephants, the brain structure that controls the facial muscles of these animals. This nucleus contains more facial motor neurons than in any other terrestrial mammal, the scientists show in a paper published in the journal Science Advances. African elephants in particular have particularly prominent neuron clusters for the control of the trunk "fingers."

One of the most remarkable body parts in the animal kingdom is the elephant trunk. It is extremely muscular and strong, containing far more muscles than the entire human body, and yet it is very sensitive and capable of carefully performed, finely tuned motor actions. The way elephants use the tip of their trunk strongly resembles a human hand, and they actually have so-called fingers at the tip. Lena Kaufmann and colleagues in Michael Brecht's laboratory at HU Berlin and Thomas Hildebrandt's Department of Reproduction Management at the Leibniz-IZW for the first time have now studied and described in detail the so-called elephant facial nucleus -- the brain structure responsible for controlling the elephants' facial muscles, from the ears to the tip of the trunk.

"The elephant's facial motor nucleus is unique in several ways. For example, it contains more facial motor neurons than all other terrestrial mammals," says first author Lena Kaufmann (HU Berlin). The scientists counted about 54,000 neurons in the facial nucleus of Asian elephants (Elephas maximus), whereas the African savanna elephant (Loxodonta africana) even has about 63,000. The team attributed the higher number of facial nucleus neurons in African savanna elephants to their larger ears and more elaborate trunk tip. "African savanna elephants have two so-called fingers at the trunk tip with which they grip objects," says Thomas Hildebrandt (Leibniz-IZW). "This kind of pincer grip requires much dexterity with the trunk tip. Not surprisingly, we see in the brains of African elephants prominent neuron clusters for the control of the fingertips." Asian elephants have only one finger and tend to wrap their trunk around objects; hence their finger-tip is less prominently represented in their brain.

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Skin: An additional tool for the versatile elephant trunk

A new study from Georgia Institute of Technology suggests that an elephant's muscles aren't the only way it stretches its trunk -- its folded skin also plays an important role. The combination of muscle and skin gives the animal the versatility to grab fragile vegetation and rip apart tree trunks.

The research, in collaboration with Zoo Atlanta, finds that an elephant's skin doesn't uniformly stretch. The top of the trunk is more flexible than the bottom, and the two sections begin to diverge when an elephant reaches more than 10%. When stretching for food or objects, the dorsal section of the trunk slides further forward.

The findings could improve robotics, which today are typically built for either great strength or flexibility. Unlike an elephant's trunk, the machines can't do both.

As an example, the study's authors point to soft robotics. Their fluid-filled cavities allow flexible movements but can easily break when forces are applied. The researchers say the elephant findings suggest that wrapping soft robotics with a skin-like structure could give the machines protection and strength while continuing to allow flexibility.

The paper is published in the Proceedings of the National Academy of Sciences (PNAS) by the same Georgia Tech team that authored a study last summer about how elephants use their trunk muscles to inhale food and water.

"When people extend their tongue -- a muscle-filled, boneless tissue similar in composition to an elephant's trunk -- it stretches uniformly. We expected the same when we challenged an elephant to reach for food," said Andrew Schulz, the study's lead author and a Ph.D. student in Georgia Tech's George W. Woodruff School of Mechanical Engineering. He and the team filmed two African savanna elephants reaching for bran cubes and apples at Zoo Atlanta.

"But when we looked at our high-speed camera footage and plotted the trunk's movements, we were surprised. The top and bottom weren't the same at all," Schulz said.

After seeing the video, Schulz stretched the tissue of a dissected elephant to better understand the skin's elasticity. That's when he found that the top of the skin, which is folded, is 15% more flexible than the wrinkled bottom side. It's also when the team realized they weren't just seeing muscle movement on the video. They were also tracking a thick sheet of skin.

"Flexible skin folds are the elephant's innovation," said David Hu, Schulz's advisor and a professor in the Woodruff School and the School of Biological Sciences. "They protect the dorsal section and make it easier for the elephant to reach downward, the most common gripping style when picking up items."

The Georgia Tech study also found that an elephant trunk differs in another way from other boneless, muscle-filled appendages found in nature, such as squid and octopus tentacles. Instead of extending evenly, an elephant telescopically stretches its trunk like an umbrella, gradually lengthening in waves.

An elephant first extends the section that includes the tip of its trunk, then the adjacent section and so on, gradually working its way back toward its body. Schulz says the progressive movement towards the base is intentional.

"Elephants are like people: they're lazy," he said. "The section at the end of the trunk is 1 liter of muscle. The section closest to its mouth is 11-15 liters of muscle. An elephant will first stretch the end of its trunk, then the adjacent section, because they're easier to move. If an elephant doesn't have to work very hard to reach something, it won't."

Schulz said he had to rely on a drawing from 1908 when learning about trunk anatomy because scientists and engineers haven't done much research on the biomechanics of elephants during the last century. Part of his curiosity of elephants is based on helping them; he thinks a better understanding of the animals will lead to better conservation efforts. As a mechanical engineer, Schulz also sees the applications of robotics.

Read more at Science Daily

Elephant seal’s map sense tells them when to head ‘home’

Each year, pregnant female elephant seals take an approximately 240-day trek over 10,000 kilometers across the Eastern North Pacific Ocean before returning to their breeding beaches to give birth within five days of their arrival. Now, a study appearing February 28 in the journal biology Current Biology finds that this impressive navigation ability depends on an internal map sense, which functions much like a built-in GPS.

"We found that migrating elephant seals know how far they are from their breeding beach thousands of kilometers away," said Roxanne Beltran of the University of California Santa Cruz. "They also know approximately how long it will take them to get back."

Beltran and her colleagues, including Dan Costa, knew that elephant seals are expert navigators. What they didn't know was how the seals manage to make it back to the beach just in time for the breeding season.

In the new study, the researchers used satellite tracking data collected from more than 100 adult female seals. They figured out when each of them turned around to head back to the beach where they started from.

The data revealed that seals decided to turn around based strongly on how far away they were from where they needed to go. Their decisions to turn around weren't related to their body condition, measured as amount of body fat.

"We were surprised that foraging success or percent body fat was not more strongly related to when seals begin the return portion of the migration," Beltran said. "We expected that highly successful (i.e. fatter) seals might end their foraging trips earlier, but that was not the case; instead, it seems like they are well programmed to turn around strategically based on where they are and in turn how long it will take them to get back."

The researchers don't yet know what sensory cues the elephant seals depend on to keep track of where they are and head in the right direction at the right time, but it's clear that they can adjust the timing of their travels based on an internal perception of time and space.

The results help to better understand elephant seals, with important implications for their conservation, the researchers say. In future studies, they hope to quantify exactly how precise the seals' navigation ability is and determine which cues are most important.

Read more at Science Daily

Understanding human-elephant conflict and vulnerability in the face of climate change

Human-wildlife conflict is a central issue in the conservation sciences. Whether it be reintroducing wolves into key ecosystems of the southwestern U.S. -- which is having an impact on livestock and cattle ranchers -- or the ongoing challenge of elephants living alongside communities on the African savannah, the effects of this conflict on people's livelihoods can be significant. In African landscapes where growing human and elephant populations compete over limited resources, for example, human-elephant conflict causes crop loss, and may even result in human injury and death and subsequent retaliatory killing of wildlife.

Despite all that is known about the challenges of human-wildlife conflict, however, measuring its impact on human livelihoods is complicated. An international team of researchers, including Northern Arizona University professor Duan Biggs, spent three yearsinvestigating the dynamics between wildlife, people and the environment across the Kavango Zambezi Transfrontier Conservation Area, the world's largest terrestrial transboundary conservation area, extending across five African countries.

The study, led by Jonathan Salerno of Colorado State University and funded by the National Science Foundation, involved a large team of collaborators, including researchers from the University of Colorado Boulder, the University of Louisville, the University of California Berkeley, the University of North Carolina Wilmington, the University of Botswana, the University of Namibia, Stellenbosch University and Griffith University as well as The Nature Conservancy South Africa and the Department of National Parks and Wildlife of Zambia.

As described in their paper recently published in Current Biology, "Wildlife impacts and changing climate pose compounding threats to human food security," the team used interdisciplinary approaches across a wide study area to better understand how climate change interacts with human-elephant conflict to affect household food insecurity.

The goals of the project were to identify the socio-ecological conditions and patterns that affect household and community vulnerability and to determine leverage points that may aid in mitigating how land-use decisions and land-cover change affect vulnerability in the Kavango Zambezi Transfrontier Conservation Area in southern Africa. The investigators combined household surveys and participatory mapping to characterize how indicators of vulnerability shape smallholders' land use decisions. They integrated data on the environment, market factors, government policy and subsidies, culture and ethnicity and the presence and intervention of non-governmental organizations with remotely sensed imagery to compare trajectories of land-use and land-cover change with underlying socioecological drivers. By advancing the understanding of vulnerability, this research identifies how vulnerability influences and is affected by socioeconomic and biophysical drivers at multiple scales.

"The project as a whole is focused on understanding human vulnerability and adaptive capacity in the context of environmental change," Salerno said. "Taking a systems-level view of this problem is important because we're studying human vulnerability, which can be defined and impacted by many different things."

Another important finding of the study was that the people within these affected communities have the adaptive capacity to gather food resources and buffer the impacts of elephant conflict and short rain seasons. Although the individual communities may be resilient, larger institutions such as governments and aid organizations are not currently sufficiently supporting effective risk mitigation or risk reduction strategies for households. The team also advocates that in addition to habitat protection, there need to be appropriate resources and funding put toward human-wildlife conflict mitigation programs to support the conservation of African savannah elephants.

Biggs was born and raised in southern Africa and has worked extensively on community engagement for conservation and human-wildlife conflict. He contributed his experience from the region and social-ecological expertise to the study.

"Our findings highlighting the dependence of both humans and elephants on the same resources, especially during drought, shows that we need to tackle the challenge of human-elephant co-existence and local adaptations to climatic change simultaneously," Biggs said.

Read more at Science Daily

Study confirms that Gabon is the largest stronghold for critically endangered African forest elephants

The most comprehensive survey conducted of elephant numbers in the Central African nation of Gabon since the late 1980s has found elephants occurring in higher numbers than previously thought.

The study, which was conducted by the Wildlife Conservation Society (WCS), Gabon's National Park Agency (ANPN) and Vulcan using a new non-invasive survey technique, estimates that 95,000 forest elephants (Loxodonta cyclotis) now live in Gabon, confirming it as the principal stronghold for this species, which is considered Critically Endangered by IUCN. The technical improvements enabled a more accurate estimate than previous methods confined to dung counts.

The findings provide hope for the future of the species and the impact that conservation-focused policies can have in encouraging wildlife protection if effectively implemented. The study's results, published in the journal Global Ecology and Conservation, mark the first-known DNA-based assessment of a free-ranging large mammal in Africa.

Said Emma Stokes, WCS Regional Director for Central Africa and a co-author of the study: "These results underscore the importance of Gabon as a critical stronghold for forest elephants -- containing some 60-70 percent of Africa's forests elephants. Gabon, together with the northern Republic of Congo, probably hold as many as 85 percent of remaining forest elephants -- in large and relatively stable populations. With significant declines in forest elephants reported across much of the rest of the Congo Basin, these two nations will determine the future for the forest elephant in Africa."

President Ali Bongo Ondimba of Gabon said: "Managing forests, protecting our parks and fighting organised criminal and terrorist groups, who plunder our natural resources, is not easy.

It requires constant vigilance, technical knowhow, logistical capacity, sustainable funding and most importantly, courageous, dedicated, incorruptible forest managers."

Lee White, Minister of Water and Forests, the Sea, the Environment charged with Climate Planning and Land Use Plan, said: "These results demonstrate that Gabon, under the active leadership of President Ali Bongo Ondimba, has been able to buck the trend of forest elephant decline. This is down to the courage and dedication of our national parks rangers, who are very much in the line of fire. In Africa there is a clear link between healthy elephant numbers and natural resource governance -- most countries that have lost their elephant populations have also experienced civil war and instability."

Christian Tchemambela, ANPN Executive Secretary, said: "The data on the forest elephant population is now clearer. This is a big step forward. Our teams have developed more reliable methods, particularly in our genetics laboratory. This scientific evidence can now be used to support decision-making."

The team used spatial capture-recapture (SCR) techniques based on non-invasive molecular sampling from dung. Unlike savannah elephants (Loxodonta africana), which can be accurately counted by aerial surveys, forest elephants often live deep in rainforests making their populations more difficult to estimate. African forest elephants were recently acknowledged by IUCN as a separate species from savannah elephants.

The study found that Gabon has not only more forest elephants than any other country but also the largest intact habitat in the species' range, with elephants found over more than 250,000 square kilometers (96,500 square miles) which represents some 90 percent of the country.

Although elephants were found across Gabon, the highest elephant densities were found in relatively flat areas where there was more suitable elephant habitat available (i.e. forests or forest-savannah mosaics). The lowest elephant densities were found in more hilly terrain or in areas with less suitable elephant habitat (i.e. near cities, or roads).

The team found low elephant densities immediately adjacent to international borders. Neither protected areas nor human pressure in Gabon strongly predict elephant densities. This means that good elephant habitat is not necessarily restricted to protected areas.

Said the lead author of the study, Alice Laguardia of WCS: "Our findings offer a useful nationwide baseline and status update for forest elephants that will inform adaptive management and stewardship of one of the last remaining forest elephant strongholds. These results are of interest to local, national, and international decision-makers concerned with the conservation of this species and its habitat, with the important ecological role of forest elephants on climate regulation potential of forests, and with forest elephants as a useful indicator for healthy, intact and well-governed forests."

But it was not all good news, with researchers reporting that pockets of low elephant density from recent poaching events remain and have yet to recover.

Across Central Africa, forest elephants have been decimated by ivory poachers in recent years across their range. Gabon is unique in the region in having elephants still distributed at relatively high densities across most of the country. With the exception of Gabon and parts of northern Congo, many other countries have experienced catastrophic declines in forest elephant populations over the last two decades: a WCS-led study released in 2014 documented a 65 percent decline in forest elephant numbers between 2002 and 2013.

Elephants can act as a useful indicator of healthy forests and that good management of forests both inside and outside of protected areas can have benefits for both climate and biodiversity. A 2019 study linked forest elephant presence to significantly greater carbon storage through their browsing that effectively thins the forest of smaller trees, thus promoting growth of larger, more carbon rich trees.

"We believe conservation efforts must be founded on solid data," said Lara Littlefield, Executive Director of Partnerships & Programs at Vulcan. "The 2016 Great Elephant Census of savannah elephants led to support for programs that benefitted threatened populations and communities. We are confident this important new study will lead to targeted efforts to protect endangered forest elephants."

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Fossil elephant cranium reveals key adaptations that enabled its species to thrive as grasslands spread across eastern Africa

A remarkably well-preserved fossil elephant cranium from Kenya is helping scientists understand how its species became the dominant elephant in eastern Africa several million years ago, a time when a cooler, drier climate allowed grasslands to spread and when habitually bipedal human ancestors first appeared on the landscape.

Dated to 4.5 million years ago and recovered from a site on the northeast side of Lake Turkana, it is the only well-preserved elephant cranium -- the portion of the skull that encloses the brain -- from that time. It isabout 85% intact and holds a wealth of previously unavailable anatomical detail, according to University of Michigan paleontologist William Sanders.

Known by its museum number, KNM-ER 63642, the roughly 2-ton cranium belonged to a massive adult male of the species Loxodonta adaurora, an extinct evolutionary cousin of modern African elephants but not a direct ancestor.

KNM-ER 63642 is both impressively immense and unexpectedly modern in aspect, displaying adaptations that likely gave L. adaurora an edge when competing with other large mammals for grasses, according to Sanders, lead author of a study published online Oct. 21 in the journal Palaeovertebrata. Co-authors include Meave and Louise Leakey, who led the recovery effort and who are best known for the discovery of early hominid specimens and artifacts from Lake Turkana and elsewhere.

The L. adaurora cranium is striking because it is raised and compressed from front to back, suggesting a novel alignment of chewing muscles well-suited for the efficient shearing of grasses. In addition, the animal's molars are higher-crowned and had thicker coatings of cementum than other early elephants, making the teeth more resistant to the wear common in animals that feed on grasses close to the ground.

"The evident synchronization of morphological adaptations and feeding behavior revealed by this study of Loxodonta adaurora may explain why it became the dominant elephant species of the early Pliocene," said Sanders, who has studied fossil elephants and their relatives for nearly 40 years in Africa and Arabia.

Eastern Africa was home to seven or eight known species of early elephants at the time, along with horses, antelope, rhinos, pigs and hippos. Many of these animals were becoming grazers and competing for the available grasses.

"The adaptations of L. adaurora put it at a great advantage over more primitive elephants, in that it could probably use less energy to chew more food and live longer to have more offspring," said Sanders, associate research scientist at the U-M Museum of Paleontology and in the Department of Anthropology.

Recovery, conservation, dating, description and identification of the elephant cranium involved collaborative work between researchers and techniciansfrom the Turkana Basin Institute, National Museums of Kenya, University of Michigan, Rutgers University, Smithsonian Institution and University of Utah.

KNM-ER 63642 was discovered in 2013 by a member of the Koobi Fora Research Project from a single molar that was visible at the surface.

Excavation revealed the presence of a nearly complete cranium. The tusks and the jawbone were missing, and no other remains from that individual were recovered. The adult male is estimated to have been 30 to 34 years old at death.

The fossilized cranium, together with the plaster jacket that protected it and some attached sediment, weighed about 2 tons. Based on a previous study of the skeleton from another L. adaurora adult male with a similar-sized skull, this individual likely weighed about 9 tons and probably stood about 12 feet at the shoulder -- bigger than average male elephants of modern times.

"In my opinion, this elephant skull is by far the most impressive specimen that we have in the Kenyan paleontological collection from Lake Turkana, both in its completeness and in its size," said paleontologist and study co-author Louise Leakey of the Koobi Fora Research Project. "When the teeth were seen on the surface, we had no idea that a complete cranium would be uncovered, and the excavation and recovery operation was both challenging and exciting."

KNM-ER 63642 is now permanently housed at the Turkana Basin Institute's facility in Ileret, Kenya. It is the only well-preserved elephant cranium from the interval beginning with the origin of elephants 8 million years ago and ending 3.5 million years ago, according to Sanders.

In addition to providing a trove of insights about the anatomy of early elephants, the newly described cranium also deepens our understanding of the connections between those creatures and our earliest human ancestors, the habitually bipedal australopithecines.

Loxodonta adaurora and other early elephants coexisted with two well-known australopithecine species in eastern Africa: Australopithecusanamensis, recovered by Meave Leakey in and nearby the Lake Turkana Basin, Kenya, and A. afarensis, found at sites in Hadar, Ethiopia, and Laetoli, Tanzania.

In the early Pliocene, as grassy woodlands and grasslands spread across eastern Africa, the australopithecines would have benefited from the presence of elephants. The animals' feeding activities helped keep grasses low to the ground, which would have allowed our upright ancestors to see over the vegetation and to watch for predators.

Elephants also disrupt closed woodlands and create open areas by knocking over trees, uprooting shrubs, and trampling paths through dense forest. And they spread nutrients and grass seed in their dung.

"The origins and early successes of our own biological family are tied to elephants," Sanders said. "Their presence on the landscape created more open conditions that favored the activities and adaptations of our first bipedal hominin ancestors.

"From this perspective, it is ironically tragic that current human activities of encroaching land use, poaching and human-driven climate change are now threatening the extinction of the mammal lineage that helped us to begin our own evolutionary journey."

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Elephants benefit from having older siblings, especially sisters

A study of semi-captive Asian elephants in Myanmar has found that calves benefit from having older sisters more than older brothers. The findings are published in the British Ecological Society's Journal of Animal Ecology.

Researchers at universities in Finland, the UK and Myanmar have found that Asian elephant siblings influence younger offspring from early through to late-life. Being raised with older siblings strongly increased calves' long-term survival compared to not having a sibling, with elder sisters having a bigger impact than elder brothers.

In female elephants, those raised with older sisters had higher long-term survival and reproduced for the first time an average of two years earlier, compared to those with older brothers. Reproducing at an earlier age is generally associated with more offspring over the course of an elephant's lifetime.

In male elephants, those raised with older sisters had lower survival but higher body weight, compared to those with older brothers. This seemingly detrimental effect may be explained by a 'live-fast, die young' strategy, where the positive early increase in body mass could lead to survival costs later in life.

Dr Vérane Berger at the University of Turku and lead author of the study said: "Our research confirms that sibling relationships shape individual lives, particularly in social species, such as the elephants, where cooperative behaviours are essential to the development, survival and reproductive potential of individuals."

The long-term consequences from sibling effects are understudied in long-lived animals. One of the reasons for this is that the logistic challenges of field studies make it hard to investigate effects over an animal's entire lifespan.

In this study, the researchers were able to overcome this barrier by studying a population of government-owned, semi-captive timber elephants in Myanmar, for which extensive life history records are kept.

These elephants are used during the day as riding, transport and draft animals. At night the elephants live unsupervised in forests and can interact and mate with both wild and tame elephants. Calves are raised by their mothers until the age of five when they are trained for work. The Myanmar Timber Enterprise (MTE) imposes regulations on the daily and annual workload of elephants.

Dr Mirkka Lahdenperä at the University of Turku and co-author of the study said: "Because the elephants live in their natural habitats, there are many similarities to wild elephants, such as natural foraging and no assistance in breeding. While there are differences -- in the wild, family groups are probably bigger -- there are more similarities than differences and we could assume that some of the associations found in our study would also hold true for wild elephants. But of course, these should be studied"

The researchers used a large, multi-generational dataset of semi-captive Asian elephants to look at the influence the presence and the sex of elder siblings on the body mass, reproduction, sex, and survival of the next calf. The records contained precise reproductive and longevity information for 2,344 calves born between 1945 and 2018.

As the study was correlational, the influence of external factors outside sibling effects, such as the quality of maternal care and elephants' workload and management, cannot be excluded.

On the next steps for this research project, Dr Berger said: "By collecting more information on the body mass of mothers at birth, we hope to disentangle maternal effects from sibling effects.

"More data will also let us explore the effects of the environment on sibling relationships and go into more detail on the effects siblings have on specific aspects of a younger calf's health, such as immunity, muscular function and hormonal variations.

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