extinct

Elephants And Global Warming | Earth Wise

March 9, 2023 By EarthWise Leave a Comment

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

A Giant Tortoise Is Not Extinct | Earth Wise

July 4, 2022 By EarthWise Leave a Comment

The Galapagos Islands are famous for their tortoises, among many other things. A few million years ago, some giant tortoises from South America were somehow carried across hundreds of miles of ocean to the islands – perhaps on driftwood during storms. Tortoises don’t swim, so any that made to an island could only breed with others on that same island. The result was rapid evolution of tortoise species in the Galapagos. Today, there are 14 different species of giant tortoises there.

Centuries ago, tortoise populations in the Galapagos were decimated by European sailors who hunted them for food. The giant reptiles could be kept alive on ships with little food or water, so they became a great source of meat.

On the island of Fernandina, there was a species of Galapagos tortoise known as the “fantastic giant tortoise.” Only a single one of these was ever found and that was in 1906. It ended up being preserved as a museum specimen.

In 2019, a female tortoise living on Fernandina was located and genome sequencing has only recently been successfully completed for that living specimen and the century-old one in the museum which compared them to sequences of the other 13 species of Galapagos tortoise. That analysis showed that the two were indeed the same species and are distinct from all the others.

The female tortoise, who has been named Fernanda, now resides at the Galapagos National Park Tortoise Center, which is a rescue and breeding facility. She is well over 50 years old. Recent tracks and scat on Fernandina Island provide evidence that there may still be others of her kind. The experts are trying to do what they can to keep the species alive.

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‘Fantastic giant tortoise,’ believed extinct, confirmed alive in the Galápagos

Photo, posted January 1, 2019, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Ivory-Billed Woodpecker | Earth Wise

May 24, 2022 By EarthWise Leave a Comment

The ivory-billed woodpecker was the largest woodpecker in the US. They were once relatively common, stretching from the Carolinas through the southeast and across to Texas. Their numbers started to drop sharply in the 19th century because of habitat loss and overhunting. Many were taken as valuable specimens; some were even eaten by poverty-stricken people.

The last widely accepted sighting was way back in 1944. For years, the birds were listed as critically endangered with only infrequent and entirely anecdotal reports of sightings. Last year, the U.S. Fish and Wildlife Service finally declared the species extinct.

A multiyear field study by avian researchers from multiple institutions has recently reported that the ivory-billed woodpecker may in fact still exist in a remote swampy region of Louisiana.

The three-year effort to find the woodpecker involved scientists trudging through the remote site to observe birds and take audio recordings. Unmanned trail cameras taking time-lapse photos and a drone were used to capture images. Several members of the team report that they observed the birds. Some photographic images and videos appear to show ivory bills. Based on characteristic markings visible in some of the photos, the birds do appear to be the ivory bill and not, for example, the fairly common but similar looking pileated woodpecker.

The birds are scarce, live in a tough, swampy habitat, and actively avoid getting near people. They live high in trees and are very difficult to spot, much less get clear photographs of. From all indications, however, reports of the demise of the ivory-billed woodpecker may have been premature.

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Back from the dead? Elusive ivory-billed woodpecker not extinct, researchers say

Photo, posted May 3, 2008, courtesy of Michael McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Right Whales And The Warming Atlantic | Earth Wise

October 25, 2021 By EarthWise Leave a Comment

The warming of the Atlantic Ocean has driven the critically endangered North Atlantic right whale population from its traditional and protected habitat. This has exposed the whales to more lethal ship collisions, increased entanglements with commercial fishing gear, and greatly reduced calving rates.

Since 2010, the calving rate has declined, and the right whale population has dropped by an estimated 26%. Ten years ago, there were about 500 North Atlantic right whales; now there are an estimated 356.

These are some of the best studied whales in the oceans; scientists basically recognize each individual whale and when they are the victims of ship collisions or fishing entanglements, it is easy to identify which animal was killed.

Because of the warming climate, the Atlantic Meridian Overturning Circulation – an important system of surface and deep currents – has slowed down, causing the Gulf Stream to move north. This has injected warmer and saltier water into the Gulf of Maine. The warming Gulf of Maine has reduced the abundance of copepods, tiny crustations that are the favorite snack of right whales. This has reduced whale calving rates and forced the whales to move north to the cooler waters of the Gulf of St. Lawrence.

For the past 6 years, more and more right whales have been observed feeding in the Gulf of St. Lawrence, where there were no protections in place to prevent ship strikes and fishing gear entanglement. In 2017 alone, 17 right whale deaths were confirmed.

According to a recent report from Cornell University and the University of South Carolina, unless its management is improved, right whale populations will decline and potentially become extinct in the coming decades.

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Warming Atlantic forces whales into new habitats, danger

Photo, posted December 8, 2016, courtesy of Sea to Shore Alliance/NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Butterflies And Moths In A Changing World | Earth Wise

July 20, 2021 By EarthWise Leave a Comment

Extinction is a part of life. Plant and animal species disappear all the time. In fact, approximately 98% of all the organisms that have ever existed on planet earth are now extinct. Earth’s so-called ‘normal’ rate of extinction is thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years.

But anthropogenic climate change is bringing about rapid change in nature. Put more simply, human activity is killing nature at an unprecedented rate. According to many scientists, the earth’s sixth mass extinction has already begun. Mass extinctions are defined as times when the Earth loses more than 75% of its species in a geologically short interval.

The changing climate puts immense pressure on species for change. According to a new study by researchers from the University of Helsinki and the Finnish Environment Institute, the few butterfly and moth species capable of adjusting to the changing climate by moving up their flight period and moving further north have fared the best.

In Finland, researchers compared temporal shifts in the flight period and spatial shifts in the northern range boundary of 289 moth and butterfly species, as well as changes in abundance over a roughly 20-year period.

They found that about 45% of species that either moved northward or advanced their flight period fared much better than the roughly 40% of species that did not respond in either way. On average, the populations of these poorly responding species declined. But the 15% of species that did both had the largest increase in abundance.

The ability to adapt to a changing climate is going to be vital for species survival.

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Butterflies and moths have difficulty adjusting to a rapidly changing climate

What is mass extinction and are we facing a sixth one?

Photo, posted August 16, 2017, courtesy of Tero Laakso via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recovering Condors | Earth Wise

August 12, 2020 By EarthWise Leave a Comment

The California condor is the largest North American land bird. Its wingspan is nearly 10 feet and its weight of up to 26 pounds nearly equals that of the trumpet swan, the heaviest native North American bird. California condors can live up to 60 years, making them among the world’s longest-living birds as well. But California condors became extinct in the wild in 1987.

Lead poisoning is the primary threat to condors. The birds are scavengers and feeding on the carcasses of dead animals that contain fragments of lead rifle ammunition is responsible for half of all condor deaths.

Condors historically occupied California’s Sierra Nevada mountains and were known to nest in the cavities of giant sequoia trees. By 1982, the wild population was reduced to just 22 birds, and all of those were eventually trapped and brought into captivity to prevent extinction of the species.

A captive breeding program was undertaken at the Los Angeles Zoo and the San Diego Wild Animal Park. With the success of that program, in 1992 the U.S. Fish and Wildlife Service began releasing condors back into the wild in the mountains of Los Padres National Forest in Southern California. That flock has grown to about 100 birds through both wild reproduction and additional release of captive-bred birds.

The Southern California flock continues to expand its range with birds in 8 California counties and even in Arizona, Utah, and Baja California in Mexico. The total wild population of condors is now estimated to be about 340 birds. Recently, condors have been spotted in Sequoia National Park, a part of its historic range where the birds have been absent for nearly 50 years.

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California Condors Spotted in Sequoia National Park, First Time in Nearly Half a Century

Photo, posted May 20, 2005, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Frogs Are In Big Trouble

May 22, 2019 By EarthWise Leave a Comment

Scientists first noticed in the 1970s that some frog populations were declining rapidly. By the 1980s, some species appeared to be extinct. The loss of frog species was mysterious because many were actually living in pristine habitats that did not face pollution or deforestation.

By the late 1990s, researchers had identified that frogs in widely different places around the world were infected with a deadly fungus called Batrachochytrium dendrobatidis – or Bd for short. The fungus originated on the Korean peninsula, but the pathogen spread throughout the world, probably via the international trade in pet amphibians. By 2007, researchers speculated that Bd might be responsible for all known declines of frogs that had no other apparent cause – about 200 species.

Recently, a group of 41 scientists published the first worldwide analysis of the fungal outbreak and the devastation turns out to be far worse than anyone had previously realized. Populations of more than 500 species of amphibians have declined significantly because of the outbreak, including at least 90 species presumed to have gone extinct. These figures are more than twice as large as earlier estimates.

According to biologists, Bd is now considered to be the deadliest pathogen known to science. But the decimation of frogs peaked in the 1980s. Today, although 39% of the species that suffered population declines in the past are still declining, 12% are showing signs of recovery, possibly because natural selection is favoring resistant animals.

There is cautious optimism for the surviving amphibian species, but scientists worry that another strain of Bd or some different species of fungus altogether may prove even deadlier. The best we can do is not participate in moving pathogens around the world.

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