environmental adaptation Archives - Page 3 of 4

The FWP weekly digest of wondrous wildlife happenings
and other interesting items from the natural world

Creatures to meet | Things to learn
Things to do

Lisa S. French

2.5-minute read

One aspect of this lockdown situation that we hadn’t anticipated, out of a long list of things that we hadn’t anticipated, because we’ve never done this before, was the staring. The uninterrupted (except by naps), somewhat guilt-inducing house cat staring. Since we’ve been “inside,” we can’t shake the feeling that we’re being watched—and that’s because we are. Watched from the bookshelves, watched from the windowsill—from the stairs, from the hallway, from inside the closet. Those innocent gold-green eyes track our every move and seem to be saying, “We’ve noticed that you are here all of the time now. Since you are here all of the time now—umm, more food?”

The cat staring got us thinking about eyes in general and pupils of eyes in particular and why cat pupils are shaped differently than human pupils. As it turns out, pupil shape is primarily a function of the predator-prey relationship—whether a species hunts or is hunted, is an herbivore or a carnivore, and what time of day it’s active. Through evolutionary adaptation, animals have developed optical superpowers that will maximize the odds of finding food or minimize the odds of becoming food.

According to researchers at UC Berkeley, ambush predators like house cats, tigers, and crocodiles that are either nocturnal or hunt both during day and night are highly likely to have vertically slit or vertically elongated pupils. Animals more likely to become prey like sheep, horses, and goats tend to have horizontally elongated pupils. Pupil shape is an adaptation that increases survival in the environment where a species evolved. Vertically elongated pupils give ambush predators laser-sharp focus on vertical shapes and greater perception of depth and distance so they can choose the ideal path to their next meal. The horizontally elongated pupils of prey species enable them to have a nearly panoramic view ahead and behind to detect approaching predators and make a quick getaway. Both vertically and horizontally slit pupils can expand up to 300 times for better vision in low light.

The location of eyes on an animal’s head also determines how they perceive depth and distance. Ambush predators with frontally-placed eyes like cats and tigers combine visual information from both eyes to home in on their target. Scientists believe some prey animals with lateral eyes that don’t have overlapping fields of view, including pigeons, quails, and doves, bob their heads to visually perceive their environment. However, head movement in ambush predators with lateral eyes like crocodiles would give away their position and potentially cost them their lunch. To compensate, their eyes have a structural advantage that projects images through different parts of the pupil, allowing them to better focus on prey.

Interestingly, height is also a factor in pupil shape. The UC Berkeley study found that in general, the taller the predator, the more rounded the vertically elongated pupils, which is why tiger pupils are closer to oval, and low-lying crocodiles have pupils that are vertical slits.

Bottom line, should you ever find yourself to be an object of intense interest for a wild one with vertically slit pupils, consider proceeding immediately to extreme social distancing.

And what about the vertically slit pupils of the staring house cat then? Well, even if you’re an indoor, purr-prone, domesticated descendant of wildcat predators and your prey comes out of a can and that can has to be opened by non-prey with opposable thumbs—evolutionary optical adaptations still dictate that you keep your eyes on the purveyor of the prize.

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Lisa S. French May 6, 2020

Rescuing Coral Reefs: Cloud Brightening, Bionics, and Super Corals

3.5-minute read

If you’ve not had much mental bandwidth left to ferret out non-COVID-19 news, we totally empathize. In case you missed the story of the third mass bleaching event in five years of Australia’s Great Barrier Reef, here’s a quick what’s what—along with a roundup of some inventive strategies aimed at keeping all of the world’s precious corals out of hot water.

Although some of the creature components of the natural world are currently experiencing a welcome period of rest and recovery, as a result of rising ocean temperatures, the large colonies of thousands of tiny animals that make up coral reefs are facing unprecedented heat stress that is exceeding their ability to adapt and survive. These architecturally complex living structures support beautifully biodiverse undersea communities that encompass up to 25 percent of all marine species, including 4000 types of fish and an estimated 8 million yet-to-be-discovered organisms. As critical parts of our planetary infrastructure, coral reef ecosystems contribute to the livelihoods of 500 million people in 100 countries, adding approximately 30 billion dollars to annual GDP.

Under normal environmental conditions, corals can live forever. Sadly, recurring and prolonged bleaching events caused by changes in water temperature and acidity as a result of oceans absorbing increasing levels of greenhouse gases (GHG’s) from the atmosphere have pushed corals beyond their comfort zone. During a bleaching event, stressed corals expel the symbiotic algae (zooxanthellae) embedded in their tissues, which they rely on for nutrition and which give them their often vibrant color. Without a consistent source of nourishment from their algal occupants, bleached corals slowly become weakened and may die, causing a chain reaction of equally adverse impacts for reef inhabitants. Depending on the amount of damage that occurs during a bleaching event, it can take decades for a coral reef to recover. To date, up to half of the world’s reefs have been severely damaged.

Okay, what’s the good news, you ask? Is there good news? Because we could use more of that. It’s undeniable that earth systems wait for no one, and our oceans have already been committed to a certain degree of warming. Now, one of the most important things we can do to create good news for corals and other marine wildlife is to help prevent bleaching events by reducing the GHG emissions that absorb radiation from the sun and raise ocean temperatures. As we sprint to ramp up mitigation efforts, scientists around the world from biologists to chemists to geophysicists are tackling the coral crisis from a few different angles in hope of changing the current trajectory from despair to repair. Here are some highlights from projects focused on saving our reef ecosystems from extinction:

Brightening Marine Clouds:
Earth scientists are geoengineering cloud parasols for the planet to cool waters around reefs and buy more time for corals. Through a process called marine cloud brightening, clouds are seeded with salt crystals to increase their reflectivity. These artificially enhanced bright clouds reflect solar radiation away from the earth lowering ocean temperatures in targeted reef areas. In late March, researchers at Southern Cross University in Australia conducted the first successful, small-scale cloud brightening experiment over a portion of the Great Barrier Reef. You can watch how they did it here.

Printing 3-D Bionic Corals:
Figuring out the symbiotic relationship between corals and algae will be critical for reef conservation in a warming world. To gain a better understanding of why corals expel algae under stress, bioengineers at the University of Cambridge have created bionic corals that can mimic the behavior of different coral species using biological materials and specialized 3-D printers. The Cambridge researchers also plan to construct large-scale colonies of man-made corals to grow algae for carbon capture and storage.

Breeding Climate Resilient Super Corals:
To create more resilient reef systems in anticipation of future warming, scientists at the Gates Coral Lab Hawaii Institute of Marine Biology are giving nature a helping hand through the breeding of corals that have successfully adapted to environmental stressors. By selecting the hardiest corals for reproduction and replicating various conditions of acidification, pollution, and temperature over time, marine biologists hope to grow more highly stress-tolerant super corals for use in reef restoration. You can learn more about these forward-thinking cultivators of corals in Coral Whisperers: Scientists on the Brink by Irus Braverman.

If you’re concerned about coral reefs and would like to keep tabs on how they’re holding up in near real-time, there are NOAA satellites for that at Coral Reef Watch.

You can also dive in and participate in some armchair ocean conservation by playing NeMO-Net, a new video game that helps train a NASA supercomputer to map the world’s corals.

If you’d like to follow a collaborative community of earth scientists working to maintain the healthy functioning of our planet, check out EarthCube.

And because gazing at marine life is good for you, to help tide you over until you’re free to roam, the Ocean Conservancy has coral reef wallpaper for your phone and desktop. Download away!

As always, hang in, stay safe, and be well!

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Lisa S. French April 29, 2020

The Plight of the Bumblebee

3-minute read

Whether you look forward to the first spring flight of the bumblebee (Bombus) as a reassuring sign of nature’s capacity for renewal or are simply grateful for the fruits of the fuzzy pollinator’s labor, the recent study documenting its climate change-induced decline was a definite buzzkill. The new analysis of 66 bumblebee species across North America and Europe from researchers at the University of Ottawa and University College London reveals that over the last five decades, the growing number of unusually hot days is increasing local bumblebee extinction rates. Heatwaves and rising average temperatures have led to widespread loss of populations—an estimated 46% in North America and 17% in Europe.

Bumblebees evolved in cooler regions of the world over a period of about 100 million years, and scientists now believe that warmer winters and hotter summers resulting from global heating may exceed the iconic insect’s ability to adapt. At the current rate of emissions, it’s estimated that climate change may have greater negative impacts on the bee species than habitat loss, potentially resulting in mass extinction.

Like honey bees (Apis mellifera), wild bumblebees are important pollinators of crops and native plants, providing critical ecosystem and economic benefits for people and planet—absolutely free of charge. Both honey bees and bumblebees are accidental pollinators. In the process of drinking nectar and harvesting pollen for food, they pick up the finely-grained plant dust on their bodies or leg hair and transfer it from the anther to the stigma of the flower.

However, compared to its honey-producing cousin, the bumblebee is equipped with a few extra features that make it especially efficient at pollen gathering. Because bumblebees are bigger than honey bees, they can pick up and transfer more pollen per flower fly-by. Some species of bumblebees also have longer tongues than honey bees, not as long as this creature’s, but pretty impressive by bee standards. Longer-tongued bees are particularly skilled at lapping up nectar and pollen from hard-to-reach places in tubular flowers like honeysuckle and salvia. Bumblebees also have another expert tool in their pollen-gathering arsenal—buzz pollination, or sonication. By holding the flower with its legs or mouthparts and rapidly vibrating its flight muscles, the bumblebee can dislodge pollen from plants that can’t be pollinated through garden variety bee pollination methods. About eight percent of plants rely on this shake-and-take method of pollen gathering, including eggplants, tomatoes, potatoes, blueberries, and cranberries. In addition to its bigger size, longer tongue, and sonication skills, the bumblebee has an extended pollination season and can visit twice as many flowers per day as the honey bee.

Although bumblebees have an exceptional aptitude for pollen gathering, like many animal and plant species, their ability to adjust to the unprecedented environmental stressors of climate change is limited. Uncommonly warm winter temperatures can trick queen bumblebees into emerging from the hive well before pollen is available for food, leaving them too weak to return to the hive to lay eggs—no eggs, no bees. Come spring, higher-than-normal temperatures alter the scent, nectar, and pollen production of flowers, making them less attractive to foraging bees. And increased C02 in the atmosphere also reduces the protein level of pollen, resulting in smaller bumblebees. Smaller bees travel shorter distances, carry less pollen, and pollinate fewer flowers. To put these climate change casualties in perspective, 75 percent of the world’s flowering plants rely on pollinators for reproduction, including more than two-thirds of the world’s crops.

Unfortunately, less than one percent of bumblebee hotspots are currently protected. In a rapidly warming world, conservation aimed at maintaining habitats for the 250 species of bumblebees and assisting the insects with colonization beyond their normal range is crucial to their survival. If you’d like to help ensure that bumblebees have a soft landing wherever they roam and continue to contribute to everyday essentials, here are some tips on what to plant on your city or country patch to keep these precious pollinators buzzing:

Bumbles prefer:

Perennials because they produce more nectar than annuals
Native perennials because they produce more nectar and pollen than sterile hybrids
Symmetric two-sided flowers
Pink and violet-colored flowers

And here’s a short list of the bumblebees’ perennial favorites that you can plant from rooftop to roadside:

Daisy family (Asteraceae)
Common daisies, cornflowers, chamomile,
yarrow, fleabane, asters, dahlias, coneflowers

Flowering pea family (Fabaceae)
Lupine, mimosa, wisteria, clover

Mint family (Lamiaceae)
Sage, mint, rosemary, lavender, thyme,
lemon balm, hyssop, chaste, patchouli

You can learn more about what makes the bee bumble and how you can become a citizen conservationist from the Xerces Society and the Bumblebee Conservation Trust. For a deeper drill-down into the fascinating world of bees of all sorts, we highly recommend The Bee, A Natural History.

If you’ve got access to a front, back or side yard, or any other personal patch, you can find out how to grow climate-resilient, environmentally beneficial communities of plants that you, the bees, and other wildlife will love living within the excellent Bringing Nature Home and Planting in a Post-Wild World. And if you’re a city dweller in need of some perennial planting inspiration, visit the elevated gardens at the High Line in NYC (online or in-person) created by Dutch perennial plant master, Piet Oudolf. We may have a slight hometown bias, but as gardens go, it truly is the bee’s knees.

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Lisa S. French February 22, 2020

Preserving the Music of Trees

2.5-minute read

Acoustic or electric, soul-soothing or headbanging, the tonal quality of the guitar music that puts you in the zone is greatly influenced by the types of wood used to craft the body, neck, and fingerboard of the instrument. Whether it’s sourced from a common tree species like ash, spruce, or maple, or an exotic tropical like ebony, rosewood, or mahogany, the wood used to construct guitars, known as tonewood, has unique characteristics—such as density, resonance, texture, and warp resistance—that lend that special something to the sound of the strings. As a result of decades of deforestation, legal and illegal logging for export, and the introduction of invasive insects and disease, many of the trees used to produce the world’s most valuable tonewoods are now under threat.

To identify eco-friendly alternatives to endangered tree species, researchers in Germany and Finland are working to unpick the acoustic properties of rare tonewoods. In the meantime, Taylor and Fender, industry leaders in the art and science of building stringed instruments, have stepped up to launch two propagation and planting projects designed to help save the imperiled ebony and ash trees used to create the distinctive sounds of their guitars.

The jet-black, extremely durable, insect-resistant heartwood of the African ebony tree (Diospyros crassiflora) is one of the most prized and expensive woods on the planet. Ebony heartwood has been used for centuries to make everything from ships and sculptures to furniture and flooring. It is also one of the best woods for stringed instrument fingerboards and the one preferred by many acoustic and electric guitar manufacturers. One of 10,000 tree species currently facing extinction, African ebony trees grow in small, isolated clusters in lowland rainforests from Nigeria to the Democratic Republic of the Congo. During the last century, over 50% of ebony have been cut down. Almost all of the large trees from the slow-growing species have been harvested for export. Researchers at the Naturalis Biodiversity Center in the Netherlands estimate that 10 to 30% of those exports are illegally logged.

Enter Taylor Guitars and the Ebony Project: a pioneering conservation partnership between the guitar manufacturer, UCLA, the Congo Basin Institute, and The Higher Institute of Environmental Sciences. Based in Cameroon, Africa, the Ebony Project was established to protect and conserve the rare tree species, develop livelihoods for rural communities, reforest degraded land, and increase rainforest habitat. Trained by Ebony Project staff, local communities learn to build and maintain nurseries and propagate and grow ebony saplings. The nurseries are donated to the community to grow other valuable food and medicinal trees for sale or personal use, including mango, avocado, and kola. With the ultimate goal of planting 15,000 trees, the Ebony Project aims to create a sustainable model for the production of the exotic tonewood that also provides critical social and economic benefits to local people. Thriving forests, self-sufficient rural communities, and more guitar music for your ears—a conservation triple win.

And in Cleveland Ohio, home of the Rock and Roll Hall of Fame, FWP tree-planting partner American Forests has launched the Roots of Rock initiative with Fender Musical Instruments and researchers at the U.S. Forest Service in an effort to save the ash tree (Fraxinus Americana) from the hungry maw of the emerald ash borer (EAB). Fender has used ash to construct its legendary electric guitars for 70 years, but since the EAB arrived in the U.S. in 2002, the invasive species has destroyed hundreds of millions of ash trees in North America putting the future of rock at risk. To ensure Fender aficionados can continue to practice their musical artistry, the Roots of Rock team is identifying trees that have successfully warded off the voracious insect. Seeds and shoots from those resilient trees are being used to breed an EAB-resistant variety of ash that will help restore the species to its former glory. Knowledge gained from the Roots of Rock initiative to preserve the music of trees will also be used to combat invasive insects and diseases that threaten the survival of other native species to better protect the health and biodiversity of forests in North America and around the world.

You can learn more about the Roots of Rock Initiative here and read a progress report on the Ebony Project here. Oh, and by the way, rock on!

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Lisa S. French February 4, 2020

Adapting to Heartbreak

3-minute read

The rising numbers depicting the catastrophic loss and destruction caused by bushfires across Australia since September of 2019 are painfully difficult to comprehend: at least 28 people have perished, thousands have lost their homes, and an estimated one billion animals and at least 18 million acres (an area equivalent in size to the state of South Carolina) have been affected. Yet, even those heartbreaking figures fail to adequately reflect the long-term environmental impacts that may forever change the lives of many of the inhabitants of one of our most naturally beautiful and biologically rich island continents.

Australia is “megadiverse,” one of 18 countries representing 36 recognized global biodiversity hotspots and home to 600,000-700,000 species, including many which cannot be found anywhere else in the world. There are some you may have never heard of like the northern hairy-nosed wombat, spotted-tail quoll, and Julia Creek dunnart, as well as one you definitely recognize, the cuddly-looking creature most readily identified as a symbol of wildlife down under—the koala. A native resident of Australia for approximately 25 million years, the much-loved marsupial occupies the eucalyptus forests and woodlands of Queensland, Southern Australia, and two of the states hardest hit by the fires, Victoria, and New South Wales.

At the start of the 20th century, millions of koalas could be found across eastern Australia. As of 2018, the population was estimated to be somewhere between 47,000 at the low end and what is believed to be an overly optimistic 100,000. According to recent assessments, the number of koalas that have died or been injured in the 2019-2020 fires stands at approximately 30,000. The ongoing natural disaster that may have reduced the total koala population by more than one third in just a few short months has accelerated the decline of an animal species already facing urgent multiple threats to its survival.

Like many marsupials indigenous to Australia, koalas have evolved to survive the harsh environmental conditions of the arid and semi-arid landscapes of the driest inhabited continent on Earth. But rising average temperatures across Australia over the past five decades, resulting in more frequent and intense droughts and heatwaves, have severely compromised the koala’s ability to adapt. Exposure to prolonged high temperatures can lead to heat stress, dehydration and eventual death. A December heatwave in 2009 that wiped out an estimated one quarter of the koalas in the town of Gunnedah, New South Wales is just one example.

The tree-dwelling animals are primarily dependent upon various species of eucalyptus, or gum trees, for food, water and shelter. Adult Koalas eat a little over a pound of eucalyptus a day, also extracting moisture from the leaves. Because the leaves of drought-affected trees are less nutritious and produce less moisture, koalas need to eat more leaves to meet their daily dietary requirements, but habitat loss and fragmentation as a result of deforestation reduce the number of eucalyptus trees available to support populations. When forced to leave the safety of a tree-top refuge in search of food, water, or another suitable habitat as a result of climate-change-related impacts, the slow-moving marsupials also face the threat of feral dog attacks and car strikes.

In 2015, Australian researchers publishing in the National Academy of Sciences predicted that the effects of climate change will be magnified over the next few decades resulting in severe to catastrophic losses of wildlife. Just four years later, that prediction has become a reality. As the bushfires rage on, the fate of the koala and other rare and remarkable animal species hangs in the balance. By 2030, average temperatures in Australia are expected to increase by 1.5°C. The country will continue to be challenged by unprecedented physical manifestations of a warming world. Climate change mitigation, adaptation, and initiatives aimed at conserving biodiversity will continue to be critical to help ensure the wellbeing and livelihoods of the billions of people who depend upon the healthy functioning of ecosystems in Australia and around the world.

As the science of climate change evolves, we may take some comfort in its logic while making best efforts to develop adaptation strategies for ourselves and individual species, but when it comes to adapting to heartbreak, science has little to offer because there are many precious living beings on our home planet for which there are no substitutes once lost. Although we can’t reverse the irreversible or replace the irreplaceable, we continue to have hope, because hope may not point to a way back, but it can help guide the way forward. To quote author and historian Rebecca Solnit, “Hope is not a lottery ticket you can sit on the sofa and clutch, feeling lucky. It is an axe you break down doors with in an emergency… To hope is to give yourself to the future, and that commitment to the future makes the present inhabitable.”

You can help give hope to the suffering people and animals in Australia through these Charity Navigator rated organizations. And you can wear your heart on your sleeve for the land down under by purchasing a Fire Relief T-shirt for a limited time from our pals at For Love Of All Things (FLOAT). All proceeds go to support the recovery efforts of the Australia Koala Foundation.

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Lisa S. French January 14, 2020

Saving Saigas

If you were to imagine a cross between Bambi and a snuffleupagus, you might come up with something that looks a lot like the saiga antelope (Saiga tatarica). With its wide doe eyes and large, twin-pipe breathing apparatus, the honey-colored, goat-sized saiga is one of the most whimsical-looking of the spiral-horned antelopes; it is also one of the most threatened animals on Earth. Currently classified as critically endangered, which is the next to last stop on the harrowing road to extinction, the saiga antelope is at very high risk of vanishing from the wild.

Although saigas have roamed the planet since the era of the woolly mammoth, as far back as 2.6 million years, and were abundant across Eastern Europe, Asia, and Alaska throughout the 19th century, their population plummeted from one million in the 1990s to just 60,000 by 2005. Extinct in China for the last five decades, migratory herds of saiga antelopes can now only be found on the vast grassy plains of the Eurasian steppe in remote areas of Kazakhstan, Mongolia, Russia, Turkmenistan, and Uzbekistan. Conservationists working to bring the species back from the brink have faced two major challenges, widespread poaching and climate change-induced vulnerability to viral disease that led to a massive die-off in 2015.

Like an elephant’s tusks and a pangolin’s scales, the translucent amber horns of the male saiga are highly coveted for use in traditional medicine, making the antelope an especially valuable target for poachers. As a consequence of rampant poaching over a fifteen-year period, the reduction in the number of saiga males available for mating in proportion to females led to a significant decrease in the rate of new births, and ultimately, reproductive collapse. Following a decade of strategic conservation efforts and enforcement of anti-poaching legislation, the saiga population had rebounded to 300,000 by late spring of 2015 when hundreds of thousands of females gathered on the steppe of Kazakhstan to give birth. In a widely documented mass mortality event which has now been linked to a rapid increase in temperature and humidity, over a three week period, 200,000 saiga mothers and newborn calves succumbed to a respiratory virus reducing the total population to 103,000, once again leaving the struggling animals teetering on the edge.

And now for some good and hopeful news, because we can always use a bit more of that in general, but especially when it comes to animals on the verge of extinction: saiga conservation groups working in collaboration with the Royal Veterinary College reported in May 2019 that as a result of ongoing anti-poaching work, disease management, and habitat protection the saiga population doubled to approximately 228,000 between 2016 and 2018. And because lowering vulnerability to climate change-related stressors is key to safeguarding endangered species like the saiga, scientists from the Senckenberg Research Institute and Natural History Museum are also exploring whether the antelopes are flexible enough to relocate. If, like their ice-age ancestors, they are able to survive in colder areas outside of their current semi-arid steppe habitat, the risk of another heat-induced viral infection epidemic may be diminished.

Whether racing against the clock to save the saiga, the right whale, or the rhino, researchers, scientists, and NGOs around the world dedicated to the conservation of the 6,127 species listed as critically endangered have their work cut out for them. Rapid and continuing habitat loss, poaching, and environmental degradation, along with newly emerging viral diseases related to climate change make biodiversity conservation an especially complex and challenging problem that requires unique, ground-breaking, and sustainable solutions.

Speaking of conservation solutions, you can learn about some game-changing innovations from the Nature Conservancy and find out what the next generation of MIT scientists are cooking up on the biodiversity front at the Environmental Solutions Initiative. If you are prone to rooting for the underdog, or the under-antelope, as we are at Weekly Wondrous, you can lend your support to the Saiga Conservation Alliance at the Wildlife Conservation Network. And if you’d like to give a conservation scientist a holiday hug of gratitude for helping to protect and preserve the wild and the wondrous, you may do that wherever you happen to find one.

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Lisa S. French December 10, 2019

Pouched Pademelons

If you’ve never heard of the pademelon, you are not alone. The medium-sized marsupial hopped right under our radar as well. We like to think we’re fairly species-savvy, so when we came across this featured creature courtesy of First Dog on the Moon, initially we thought, well, he’s just making that one up because he’s a cartoon dog, and that’s what they do. As it turns out, while the pademelon (Thylogale) may sound like some newfangled, furry fruit hybrid, it’s actually a long-footed, short-forelimbed, pouched member of the Macropodidae family native to the dense coastal rainforests of Australia and New Guinea.

One of approximately 250 species of Australian marsupials, the pademelon closely resembles its larger cousins, the kangaroo, and wallaby and is also related to quokkas, tree kangaroos, and wallaroos. There are seven distinct pademelon species, ranging in size from about 17 to 20 inches and weighing between 8 and 26 pounds, with grey to dark brown coloration and varied reddish markings. Pademelons are primarily nocturnal herbivores preferring to rest and forage in the safety of dense forest undergrowth during the day, emerging in the evening to feed on leaves, shoots, berries, and ferns, typically not straying far from the forest’s edge.

In contrast to egg-laying mammals (monotremes) like the platypus and spiny anteater, or placental mammals (eutherians) like dingoes and bats which give birth to well-developed offspring, marsupial mammals complete their development in a special maternal pouch following a short gestation period. After just thirty days in the womb, pademelon young are born blind and hairless but with functional forelimbs and mouth, which enable them to crawl into the pouch and attach to the mother to obtain milk. Newborn pademelons, called joeys like their kangaroo cousins, remain inside the pouch for approximately 200 days before being weaned at six to eight months and officially entering the world as independent hoppers.

So why pouches? While some theories suggest that both egg-laying and pouch-percolating mammals represent progressive steps in the evolution toward the eutherian stage of producing well-developed young, researchers at the Australian National University (ANU) offer an alternative explanation: that the marsupial’s unique reproductive ability is not an evolutionary step but instead an advantageous adaptation in response to uncertain and adverse environmental conditions, which has helped them to adjust to the climate of the driest inhabited continent in the world. The ANU scientists believe that the marsupial pouch may play a critical role in the survival of the species by providing developing young with an anti-bacterial, temperature-controlled environment, as well as protection from predators while their mothers forage for food.

Although the pouched ones are more plentiful in Australia than in any other place on the planet and the continent’s dominant species, many marsupials are on the decline due to habitat loss, and impacts of global heating, including bushfires. Changes in the distribution of food, water, and shelter in Australia’s fifteen biodiversity hotspots as a result of reduced rainfall and increased drought frequency will continue to threaten their survival. Currently, four of seven species of pademelon are listed as endangered or vulnerable, as are other little known marsupials including the bilby, bettong, and potoroo.

If you would like to read a special WWF Earth Hour report on how a warming world will affect unique Australian wildlife like the pademelon, you can check it out here.

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Lisa S. French November 12, 2019

Exceptionally Eel-ectric

Compared to many of the creatures featured on Weekly Wondrous, the electric eel (Electrophorus electricus) scores relatively low on the cuddlesome quotient, however, what the high-voltage South American river dweller lacks in animal magnetism, it makes up for in shock value. And the most shocking eel of them all, the new species Electrophorus voltai, was discovered this fall by scientists at Smithsonian’s National Museum of Natural History.

But before we get to that electrifying story, perhaps you are wondering, “What are eels, anyway? Reptiles? Amphibians? Fish? Amphishians?” Strictly speaking, electric eels are not true eels but a species of electric fish—long, blade-shaped knifefish to be exact, and more closely related to carp and catfish than eels. The 800-plus species of true eels primarily live in saltwater, while electric eels can only be found in the murky freshwater habitats of the Amazon and Orinoco Rivers. It was there, in the highland waters of the Brazilian Shield, that the approximately 8-foot long, 860-volt-producing Electrophorus voltai was identified—the strongest living bioelectricity generator known to date. To put that impressive eel power into perspective, the human body is only capable of producing and transmitting between 10 and 100 millionths of one volt over a distance of approximately one-millionth of a meter, a fact for which those of us who travel by crowded subway are quite grateful.

Like all species of electric eels, the E. voltai produces its record-breaking current through the stimulation of thousands of synchronized stacked cells called electrocytes in three pairs of electric organs that take up 80% of the length of its body. The Smithsonian researchers theorize that the 30% increase in electricity-generating potential from the highest previously recorded E. electricus measurement of 650 volts may be an adaptation to the reduced conductivity of the waters where the E. voltai species began its evolution about 7.1 million years ago.

Electric eels make full use of their innate ability to self-generate jolts, utilizing their piscine electro-pulses for eel-to-eel communication, navigation, self-defense, and to locate and stun small fish and invertebrate prey. The objects of the carnivorous fish’s shocking attentions are captured through a highly effective two-step strategy, which researchers at Vanderbilt University have compared to a type of remote control. First, the eel transmits an electric pulse, which causes whole-body contractions in its prey, revealing its location, then a second shock is administered to immobilize the target for ease of swallowing.

In case you are curious as to how eels manage to avoid electrocuting themselves when they get down to their meal-zapping business, one hypothesis is that the amount of the electricity flow is small in proportion to the eel’s body but significant to the size of its prey, and of very short duration (about two milliseconds). In addition, a large percentage of the current dissipates into the water, further reducing its impact on the eel’s critical organs.

Studying and understanding how eels generate and transmit electricity has inspired all manner of technological and medical innovations that benefit humankind, ranging from the first electric battery in 1799 to the ongoing development of soft robots, cardiac pacemakers, and artificial organs. While an effort has been made to determine what it would take to run a Tesla Model 3 on eel power for one hour, the estimated requirement of 7,200 eels in 144,000 gallons of water indicates that particular research endeavor to be a non-starter for both the Tesla and the eels.

Two hundred and fifty years after the discovery of the first electric eel species in South America, the recent identification of the E. voltai in the same region is yet another compelling testament to the extreme importance of protecting and maintaining biodiversity hotspots like the Amazon. Given that approximately 85% of our planet’s flora and fauna remain to be discovered, it’s clear that preserving wild spaces is critical to the continued study of the living world. As biologist and naturalist E.O. Wilson writes in The Diversity of Species, “We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.”

Full disclosure: While eels are clearly some of the most remarkable creatures on Earth and can be strikingly beautiful, we empathize if you are somewhat eel-averse as we confess to hyperventilating a bit while researching this one. However, since getting fish-zapped outside of the Amazon is a low probability event, we can rest easy and simply file these slippery fellows under “admire from afar.”

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Lisa S. French October 31, 2019

Flourishing Flamingos

If you find yourself sloshing around a lagoon on the coast of southern Africa and happen upon a long-necked, spindly-legged, petite pouf of avian pinkness and think “Hmm, that one’s not quite the full flamingo,” you would be correct. Standing up to three feet tall but weighing only three to six pounds, Phoeniconaias minor, a.k.a. the lesser flamingo, is the smallest and one of the most brightly colored of six species of flamingo. What lesser flamingos lack in size, they make up in numbers, forming million-strong mega-flocks in their African home. These very vocal gatherings also known as stands, colonies, or the aptly named flamboyance, help to ward off a long list of potential predators including lions, leopards, cheetahs, jackals, and hyenas. When you are on everyone’s menu, there is safety in numbers.

Like other wading birds, the lesser flamingo is dependent upon the healthy functioning of biodiverse coastal ecosystems for food. Lesser flamingos are filter feeders, skimming blue-green algae, insects and the occasional crustacean from the water through sieve-like structures called lamellae which line their boomerang-shaped bills. All flamingos stand on both legs when feeding, but tuck one leg under their plumage for up to four hours when sleeping. This famed one-legged posture, which long puzzled scientists, has now been attributed to the wading bird’s need for thermoregulation. Standing around in cold water for hours every day, even in a warm climate, can cause a rapid drop in body temperature. Researchers estimate that keeping one leg high and dry helps flamingos reduce heat loss by up to one-half.

This avian adaptation works in conjunction with the rete mirabile, a rather beautiful-sounding Latin term meaning “wonderful net” which refers to the intricate, fine web of arteries and veins that also serves to minimize heat loss in warm-blooded vertebrates. In flamingos, this arterial net functions to preserve upper body heat when their feet and legs are immersed in cold water during prolonged feeding and sleeping sessions.

These champion waders are also able, if awkward, fliers. Gangly necks and legs outstretched, lesser flamingos are capable of reaching speeds of up to 35 miles per hour. Although non-migratory, the birds do relocate in response to changes in climate that affect water levels and food supplies.

With coloration ranging from pastel to coral to bubble-gum pink, the eminently preen-worthy feathers of the flamingo species are a function of “you are what you eat.” Flamingo chicks are born grey or white, slowly acquiring their happy hue over several years as a result of consuming beta carotenoids. Carotenoids, which are found in foods like carrots, squash, apricots, and the blue-green algae favored by flamingos, are broken down by the liver into yellow, orange, and red fat-soluble pigments which are transmitted to plumage—no carotenoids in the diet, no pink in the flamingos.

While lesser flamingo populations are estimated to be between 1.5 and 2.5 million, the species is listed as near threatened by the IUCN as numbers are decreasing due to predation, habitat loss and illegal poaching. Here’s to hoping the smallest pink feathered ones hang on in there—lesser but not less than.

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Lisa S. French September 16, 2019

Traveling Trees

Like all living things, trees have a comfort zone where they grow best and thrive-an evolutionarily determined combination of sunlight, soil nutrients, water and temperature that supports the structure, bark, and leaves of diverse species. But what happens when a tree no longer gets the moisture and nutrients it needs to put down roots and send up shoots in a hotter, drier world? While the mighty oak in your front yard can’t just up sticks and trot down the block to the yard with the fancy sprinkler system, trees do have the ability to migrate in response to environmental change, about ten miles per decade, through various modes of seed dispersal. In the United States, trees move in two directions, gravitating toward cooler temperatures in the North or increased rainfall in the West. However, when the rate of change in temperature or precipitation exceeds a species ability to adapt or migrate, climate-induced dieback can occur, negatively impacting the resilience and sustainability of forest ecosystems.

In anticipation of increased global warming, researchers at the Schoodic Institute at Maine’s Acadia National Park are conducting experiments in assisted tree migration—planting and monitoring non-native, heat and drought-resistant seedlings to determine which species will adapt best to projected climatic changes in Acadia in the coming decades. Deciding which trees to relocate and which to leave behind is a tricky business. Altering one component of a natural system can result in cascading changes that may impact the survival of interdependent, co-evolved plants, and wildlife. What future forests will look like, who decides and whether or not trees should be assisted to migrate is a matter of ongoing controversy and debate. Time will tell if those tree species that just can’t get there from here will be able to survive in a warming world with a little travel assistance from their friends in forest ecology. You can learn more about the science of trees on the move from our planting partners at American Forests here.

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Lisa S. French August 18, 2019