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Help from elephants in cooling buildings

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Elephant ears play a crucial role in keep the giant animals cool.  Elephants don’t have significant sweat glands.  Instead, they rely on their large ears to regulate body temperature.  Their ears make up 20% of their body’s surface area.  The ears act like a natural air conditioner, making use of a network of blood vessels close to the surface that help dissipate heat when it’s hot and absorb heat when it’s cold.

Researchers at Drexel University have developed a new approach to passive heating and cooling that has the potential to make buildings more energy efficient.  The idea, published in the Journal of Building Engineering, embeds the equivalent of a vascular network within cement-based building materials.  The network, when filled with paraffin-based material, can help passively regulate the surface temperature of walls, floors, and ceilings.

Building energy demand contributes almost 40% of the production of greenhouse gas from energy use, and about half of building energy use is spent maintaining comfortable temperatures.

The new temperature regulation method puts a grid of paraffin-filled channels in the surface of building concrete.  When temperatures drop, the paraffin transitions from liquid to solid and releases heat energy.  When ambient temperatures rise, the paraffin absorbs heat energy, producing a cooler surface.  This is essentially the same way elephants as well as jack rabbits regulate their temperatures with their large ears.

The Drexel study was a proof-of-concept effort, but the results are promising enough to warrant further work.  With additional testing and scaling, it has the potential to make a significant contribution to ongoing efforts to improve the energy efficiency of buildings.

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Drexel Engineers Want to Make Buildings More Energy Efficient by Making Walls, Floors and Ceilings More Like Elephant Ears

Photo, posted September 1, 2016, courtesy of Nane Kratzke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Elephants have names

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Elephants are considered to be very smart creatures.  They have the largest brain of any land animal and have three times as many neurons as humans.  Of course, a lot of that brain hardware is needed to control those big elephant bodies, but elephants have also demonstrated impressive mental capabilities on many occasions.

A new study by an international team headed by researchers from Colorado State University has found that elephants call each other by name and respond when they hear others call their name.

The researchers analyzed hundreds of elephant calls recorded over more than a year in Kenya.  With machine learning techniques, they were able to identify specific sounds that elephants made when calling each other.  When the researchers played recordings of these sounds, the elephants responded to the sound of their own name by calling back or moving toward the loudspeaker.  Their response to other names was much less enthusiastic.

Very few animals use names at all, and, in most cases, it is more a matter of imitation.  For example, dolphins refer to other dolphins by mimicking their unique sounds.

These findings at least suggest that elephants may be capable of abstract thought and perhaps may have a vocabulary beyond names for each other.  The researchers are investigating whether elephants can identify food, water, or locations using their calls.  The great hope is that it might ultimately be possible to communicate with elephants directly.  It would be wonderful to be able to alert them to poachers or other threats.  The lead author of the study said that he would like to be able to tell elephants things like “Do not come here.  You’re going to be killed if you come here.”

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Elephants Have Names for Each Other, Study Finds

Photo, posted April 24, 2016, courtesy of Neil Ransom via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Elephants and protected areas

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Standing up to 13 feet tall and weighing up to 7 tons, African savanna elephants are the largest species of elephant and the biggest terrestrial animal on Earth.  According to the World Wildlife Fund, African savanna elephants can be found in 23 countries and live in a variety of habitats, including savannas, forests, and deserts.  The largest populations are in Southern and Eastern African countries.

According to assessments from the International Union for Conservation of Nature, the population of African savanna elephants has decreased by at least 60% over the last 50 years.  Poaching and habitat loss are the two main drivers of the population decline.  In 2021, the status of the African savanna elephant was changed from vulnerable to endangered on the IUCN’s Red List of Threatened Species. 

However, according to a new study recently published in the journal Science Advances, conservation measures have successfully stopped African savanna elephant population declines across southern Africa.  The international team of researchers found that the pattern varies regionally, with some elephant populations soaring while others are still facing large declines.

Overall, the study found that there are the same number of elephants now as there were 25 years ago. According to researchers, the key to long-term elephant population growth and sustainability isn’t where a protected area is, but rather how connected it is to other protected or neutral areas around it. 

This isn’t a new concept; in fact, many parks have been connected to one another.  But this study helps prove that the method is effective for elephant conservation.  

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Protected Areas for Elephants Work Best if They Are Connected

African elephant species now Endangered and Critically Endangered – IUCN Red List

African savanna elephant

Photo, posted October 20, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildlife rebounding in Uganda

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The numbers of elephants, rhinos, and other animals in Uganda’s nature preserves is steadily improving, reversing the trend of steady declines previously caused by poachers, wildlife traffickers, and conflict.

Between the 1960s and 1980s, political conflict and lawlessness in Uganda led to massive declines in some species as poaching, trafficking, and encroachment ran rampant.

Uganda’s population of over 700 northern white and eastern black rhinos was completely wiped out in the early 1980s by people hunting them for their horns.  A charity brought four rhinos in 2005 to a sanctuary called the Ziwa Rhino and Wildlife Ranch and, according to the Uganda Wildlife Authority, there are now 33 in the facility.

Increased conservation efforts have allowed the population of buffalos to increase 77% to over 44,000 since 1983.  The number of elephants has surged almost 300% to nearly 8,000 over that same time period.  There has also been an increase in the number of mountain gorillas in dense forests.

Over the years, the Ugandan government has brought in a string of conservation policies including lengthy jail terms for violations.  As a result, wildlife populations have been on a steady recovery.

It is typical to think about species in terms of how close to extinction they are, but the ultimate goal of conservation is to recover species.  This means not only gaining distance from extinction but also resuming a species’ role in its ecosystem and repopulating its former range.  Whether the wildlife in Uganda is achieving this status remains to be seen, but the trends are very positive.

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Uganda Sees Resurgence of Rhinos, Elephants, Buffaloes

Photo, posted September 15, 2014, courtesy of Rod Waddington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Humanity Weighs On The World | Earth Wise

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There are countless ways in which humankind has had disproportionate effects on our planet and most of those effects have been negative.  A recent study led by the Weizmann Institute of Science in Israel looked at the total combined weight of various groups of mammals on Earth.  The results are that human beings and our domesticated mammals are the overwhelming majority of the total mass of mammals.

We think of large land mammals – elephants, bears, bison, wildebeests, and so on – as adding up to a massive amount of animal matter.  The study determined that all wild land mammals put together add up to about 22 million metric tons. Wild marine mammals – such as dolphins and whales – add up to about 40 million tons in total.  These sound like pretty big numbers until we look at the human and human-created side of the equation.

The study found that humans weigh about 390 million metric tons, while domesticated mammals – like sheep, cows, and pigs as well as dogs and cats – weigh about 630 million metric tons combined.

All told, wild mammals account for only 6% of all mammals by weight.   People and their domesticated animals make up the other 94%.  This enormous imbalance is an indication of how profoundly humans have reshaped life on Earth.  House cats total twice the weight of African elephants and pigs add up to twice the weight of all wild land animals combined.

The conclusion to draw from the big picture here is that wild animals on Earth are not doing very well.  We already knew this from many other perspectives, but this census by weight presents a stark picture of the extent to which we have taken over the planet and its ecosystems.

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Total Weight of Wild Land Mammals Less Than One-Tenth Weight of All Humans

Photo, posted December 27, 2006, courtesy of Nigel Hoult via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Elephants And Global Warming | Earth Wise

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A study by researchers at Saint Louis University has found that elephants play a key role in creating forests that store large amounts of atmospheric carbon and in maintaining the biodiversity of forests in Africa.  Since elephants are endangered, their status represents a significant threat to an ecosystem that is very important to the Earth’s climate.

The African rainforest contains trees with both low carbon density (light wood) and high carbon density (heavy wood).  High carbon density trees grow more slowly and can be crowded out by the faster growing low carbon density trees rising above them.  Elephants affect the relative abundance of these trees by feeding more on the low carbon density trees which are more palatable and nutritious.  This thinning of the forest allows the trees that sequester the most carbon to flourish.

Elephants are also excellent dispersers of the seeds of high carbon density trees.  Essentially, elephants are the gardeners of the forest.  They plant the forest with high carbon density trees and get rid of the weeds – in this case, the low carbon density trees.  According to the study, if elephants were to become extinct, the African rainforest – the second largest on earth – would gradually lose between six and nine percent of its ability to capture atmospheric carbon.

Elephants have been hunted by humans for millennia.   Gaining support for protecting them has mostly been driven by the argument that everybody loves elephants.  Focusing on their role in maintaining forest diversity has not driven much more action.  The hope is that the evidence of how important elephants are for climate mitigation will be taken seriously by policy makers to generate the support needed for improved elephant conservation.

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Can Elephants Save the Planet?

Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Coping With Climate Change | Earth Wise

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Extreme weather events including prolonged drought and heavy rainfall are becoming more common and more severe as global temperatures rise.  As the climate continues to change in the coming decades, how will animals respond? 

Researchers from the University of Southern Denmark have examined how different mammals react to climate change. They analyzed data on population fluctuations from 157 mammal species around the world.  They compared these fluctuations with weather and climate data from the same time period.  The research team had 10 or more years of data for each species studied. 

The researchers found that mammals that live for a long time and/or produce less offspring –  like llamas, elephants, bears, and bison – are more climate resilient than small mammals with short lives — like mice, possums, lemmings, and rare marsupials. 

For example, large, long-lived mammals can invest their energy into one offspring, or simply wait for better times if conditions become challenging.  On the other hand, small, short-lived mammals like rodents have more extreme population changes in the short term. In the event of a prolonged drought, large portions of their food base may rapidly disappear, and they are left to starve because they have limited fat reserves.

However, the research team notes that the ability of a species to withstand climate change must not be the only factor when assessing a species’ vulnerability.  In fact, in many cases, habitat destruction, poaching, pollution, and invasive species pose a larger threat to animal species than climate change. 

While the study only examined 157 species, the findings enable researchers to also predict how animals they know less about will react to climate change.

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Which animals can best withstand climate change?

Photo, posted July 8, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Large Mammals And Climate Change | Earth Wise         

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The natural world has an important part to play in mitigating the effects of climate change.  We mostly think about the role of plant life which absorbs carbon in trees, grasses, and other flora.  However, a new study published by Oxford University looks at the role of large wild animals in restoring ecosystems and reducing the effects of climate change.

According to the study, there are three important ways in which large animals such as elephants, rhinos, giraffes, whales, bison, and moose can potentially mitigate the effects of climate change:  carbon stocks, albedo, and fire regimes.

When large herbivores graze, they disperse seeds, clear vegetation, and fertilize soil.  All of these things build more complex and resilient ecosystems which helps to maintain and increase carbon stocks in the soil and in plant tissues thereby helping to reduce CO2 in the atmosphere.

Grazing large animals trample vegetation which opens up areas of dense vegetation to create open mixes of grass and shrubs and can reveal snow-covered ground in cold regions.  Such open habitats are lighter in color (higher in albedo) and reflect more solar radiation into the atmosphere, cooling the Earth’s surface rather than heating it up.

Large grazing animals can lessen wildfire risk by browsing on woody vegetation that would otherwise fuel the fires and also by creating paths that act as firebreaks.

In marine ecosystems, whales and other large animals fertilize phytoplankton, which capture some 37 billion tons of CO2 each year.

Overall, large animals are an important part of the natural world’s ability to reduce the effects of the changing climate by helping with localized adaptation to the changes taking place in ecosystems.

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Large mammals can help climate change mitigation and adaptation

Photo, posted August 20, 2017, courtesy of Jon Niola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Narwhal Tusks And Stories Teeth Can Tell | Earth Wise

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Teeth and particularly narwhal tusks are getting some unusual press recently when one of them was the weapon of choice to fend off the London Bridge attacker, which was a good choice according to Harvard dental researcher Dr. Martin Nweeia.  Turns out that narwhal tusks have some pretty amazing physical features.  They exhibit both extreme strength and flexibility at the same time.  The narwhal is known as the unicorn of the sea, a pale-colored, medium-sized whale found in Arctic coastal waters and rivers.  In males, the more prominent tooth grows into a sword like, spiral tusk up to 8.8 feet long.

Changes in the shape of teeth over time can tell us about climate change. Adaptations in horse teeth 55 million years ago from North America were observed and caused by changes in climate, favoring different food sources.  The horses changed their diets from fruit to more favorable grasses and their teeth changed in response. For this same reason, the teeth of elephants adapting in different environments of Asia and Africa have different tooth forms.  Both eat plants but Asian elephants, with more ridges on their teeth, eat larger amounts of grasses while African elephants, with wider spread ridges, eat more leaves. 

Teeth have been used to link land mass theories like the Bering Land Strait Theory, hypothesizing that North America and Asia were once one land mass. The teeth shape and form of people on both sides of the Bering Land Bridge shared a common “mongoloid dentition” with unique features. And so, can the narwhal tusk tell us something about a changing Arctic?  Scientists have discovered that the narwhal tusk is a giant sensory organ that is able to continually monitor its environment and has the ability to detect ice formation, and melt, both capabilities helpful for surviving in a changing Arctic.

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–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

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Fossil teeth reveal new facts about a mass extinction 260 million years ago

From the Horse’s Mouth: Teeth Reveal Evolution

Photo, posted April 3, 2019, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Room For Wildlife

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Protecting biodiversity is a critical challenge facing humanity.  Global vertebrate populations – from elephants to amphibians – declined by 58% from 1970 to 2012 and losses are expected to reach 67% in the next two years.  Think about it:  at least two-thirds of all vertebrate animals on earth have vanished over the lifetime of anyone fifty years old or over.

[Read more…] about Making Room For Wildlife

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