Wildlife

Shorebirds in Peril

Across the planet, shorebirds are in serious trouble. In the past 50 years their well-documented North American populations are estimated to have plummeted by at least 70 percent on average, and shorebirds elsewhere are hardly doing better, if not worse.

Reasons are many—the shorelines and mudflats where the birds feed are polluted or disappearing, and many of the migrants among them struggle to find food and resting places in areas where they used to. Some are also targeted by hunters.

For a species to survive in the face of such an onslaught, a large number of healthy baby birds need to enter the population each year. Biologists have long believed this is one of the reasons many birds migrate north to breed; the challenging Arctic climate should keep them from being bothered by nest predators as frequently as birds in the tropics.

The results of a large analysis featuring data on 38,191 nests in 237 shorebird populations around the world that ornithologists have monitored during breeding seasons by looking for signs of predation such as broken egg shells, published last week in Science, are pretty clear: In the 1970s, ‘80s and early ‘90s tropical shorebird nests were indeed suffering the most predation—but since then, as nests around the world have been losing more eggs to predators, the ones in the Arctic have been especially hard-hit. The tropics did see a statistically insignificant increase, but the numbers in the Arctic are staggering: Just a few decades ago only one Arctic egg in three would be lost to predators. Today two out of three are eaten.

The researchers believe climate change is a major culprit. “Our analysis shows that the faster the annual mean temperature has increased, the higher the predation on eggs has become.

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Wildlife

As Arctic ship traffic increases, narwhals and other unique animals are at risk

More than a century ago, Norwegian explorer Roald Amundsen became the first European to navigate the entire Northwest Passage. Due to the short Arctic summer, it took Amundsen’s 70-foot wooden sailing ship three years to make the journey, wintering in protected harbors.

Fast-forward to summer 2016, when a cruise ship carrying more than 1,000 passengers negotiated the Northwest Passage in 32 days. The summer “open-water” period in the Arctic has now increased by more than two months in some regions. Summer sea ice cover has shrunk by over 30 percent since satellites started regular monitoring in 1979.

Arctic seas are home to a specialized group of marine mammals found nowhere else on Earth, including beluga and bowhead whales, narwhals, walruses, ringed and bearded seals and polar bears. These species are critical members of Arctic marine ecosystems, and provide traditional resources to Indigenous communities across the Arctic.

According to ecologists, all of these animals are susceptible to sea ice loss. Research at lower latitudes has also shown that marine mammals can be affected by noise from vessels because of their reliance on sound, as well as by ship strikes. These findings raise concerns about increasing vessel traffic in the Arctic.

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Wildlife

Profound Effects of Pesticides on Bees

Whether it’s foraging for food, caring for the young, using their bodies to generate heat or to fan the nest, or building and repairing nests, a bee colony does just about everything as a single unit.

While recent studies have suggested exposure to pesticides could have impacts on foraging behavior, a new study, led by James Crall, has shown that those effects may be just the tip of the iceberg.

The new study that shows exposure to neonicotinoid pesticides — the most commonly-used class of pesticides in agriculture — has profound effects on a host of social behaviors.

Using an innovative robotic platform to observe bees’ behavior, the study authors showed that, following exposure to the pesticide, bees spent less time nursing larvae and were less social that other bees. Additional tests showed that exposure impaired bees ability to warm the nest, and to build insulating wax caps around the colony. The study is described in a November 9 paper in Science.

Wildlife

Lions Suspected In Drowning Of 400 Buffaloes In Botswana

More than 400 buffaloes believed to have been chased by lions drowned in a river in northern Botswana this week. The mass drowning occurred in Chobe River near the border with Namibia.

Early investigations by authorities in both countries “suggest that an exceptionally large buffalo herd was grazing in Namibia when they stampeded into the Chobe River,” Botswana’s Ministry of Environment, Natural Resources Conservation and Tourism said in a statement late Wednesday. “Initial indications are that they were being chased by a pride of lions,” the ministry said. “It is estimated that more than 400 animals drowned due to the massive movement of buffalo trampling, and falling from steep river banks.”

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Wildlife

Maritime Noise Pollution

Underwater noise created by shipping and recreational boats is making it more difficult for dolphins to talk to each other, according to a new study.

University of Maryland researchers say the complex whistle calls used by the marine mammals are becoming simplified to make sure they can be understood through the din of maritime traffic.

“It’s kind of like trying to answer a question in a noisy bar and after repeated attempts to be heard, you just give the shortest answer possible,” said marine biologist Helen Bailey. She and colleagues made the discovery by analyzing recordings from microphones on the bottom of the Atlantic.

An earlier Japanese study found that humpback whales stop singing or reduce their songs when near loud noise from passing ships.

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Mass Extinction

Earth’s wild animal population has plunged 60 percent since 1970, and the rate of extinction is now 100 to 1,000 times higher due to pressure from human activities, a new report warns.

The World Wildlife Fund’s (WWF) latest Living Planet Index says the global biodiversity needs “life support,” and called on heads of state to step up and fight for the planet.

The group says tackling climate change by advancing renewable energy and boosting environmentally friendly food production would begin taking the pressure off the world’s wildlife.

Wildlife

‘Unprecedented’ Number of Dead Whales Have Washed Up in Scotland and Ireland

A total of 80 deep-water whales have been found dead on the Atlantic coasts of Scotland and Ireland since early August — more than 10 times the usual number over that time in previous years.

Marine mammal scientists say the presence of the washed-up whales suggests an “unusual mortality event,” or UME, that could have killed up to 1,000 Cuvier’sbeaked whales in the North Atlantic Ocean in recent months.

The cause of the whale deaths is unknown, but scientists fear they may be the result of warships using active sonar to hunt for enemy submarines, or naval anti-submarine exercises.

Around 26 of the carcasses were Cuvier’s beaked whales, a species that lives mainly in the deep ocean, while the rest were either Sowerby’s beaked or northern bottlenose whales.

Typically, just two or three dead beaked whales would wash up on the Irish coast each year.

A similar increase in beaked-whale deaths has been reported along the west coast of Scotland.

The sharp increase in the evidence of whale deaths washing up on the coast implied that a much greater number of whales may have been killed in the open ocean.

Scientific research has shown that Cuvier’s beaked whales are sensitive to the very loud sounds caused by anti-submarine sonar, which is used by warships hunting for enemy submarines and during naval anti-submarine exercises.

Scientists suspect the loud sonar sounds cause intense pain to beaked whales diving at extreme depths, so that they surface too quickly and die from decompression sickness.

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Wildlife

Two rhinos die in Chad after being relocated from SA

Two of six critically endangered black rhinos have died of unknown causes five months after being flown from South Africa to Chad in a pioneering project to re-introduce the animals, officials said Sunday.

Rhinos in Chad were wiped out by poaching nearly 50 years ago, and the six rhinos were intended to establish a new population in the country after intensive anti-poaching measures were put in place to protect them.

The rhinos in Chad had been roaming free in Zakouma National Park since late August after a gradual acclimatisation process that saw them first released into small enclosures.

The carcasses of the cow and bull were discovered on October 15. It is uncertain whether they were poached. The surviving four rhinos are being closely monitored, the statement said.

Wildlife

Disease Outbreak Threatening California Sea Lions

A major outbreak of a deadly disease has sickened more than 200 seas lions along the Northern California coast, the Marine Mammal Center announced Tuesday.

Officials at the center said it was the second largest outbreak of leptospirosis in California sea lions in its recorded history. This year, 220 sea lions at the Marin Headlands-based center have tested positive for the bacterial infection, which affects their kidneys.

Though sea lions diagnosed with leptospirosis are treated with antibiotics and other supportive care, roughly two-thirds of the animals with the infection do not survive.

Other animal species, including humans and dogs, can become infected with the bacteria through contact with contaminated urine, water and soil.

Wildlife

Global insect populations declining at alarming rate

An article in PNAS (National Academy of Sciences) has highlighted research from around the world that has found that insect populations are declining significantly.

A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico’s Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo’s insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.

Research from 2014 estimated that in the last 35 years, populations of insects such as beetles and bees have decreased by 45%, and that the number of insects in Europe is in rapid decline. In a separate study published in 2017, flying insect numbers in German nature reserves were found to have decreased by 76% over 27 years.

Wildlife

Monarch Gains

The Mexican forest reserve where millions of monarch butterflies spend the winter saw deforestation drop by 57 percent this year compared to 2017, the World Wildlife Fund (WWF) reported.

“The forest’s degradation has dropped due to a decrease in large-scale illegal logging operations, the end of the damages caused by the 2016 storms and the absence of weather events,” said Jorge Rickards, head of WWF Mexico.

But small-scale illegal logging in the Monarch Butterfly Biosphere Reserve saw a slight rise, with about 3.5 acres of forest lost.

Wildlife

Squirrel Scourge

Farmers in New England are vexed by unusually large numbers of squirrels that are gnawing their way through pumpkin patches, corn fields and apple orchards this fall.

Robert Randall, who has a 60-acre orchard in Standish, Maine, told The Associated Press: “They’re raising some hell this year. It’s the worst I’ve ever seen.”

The squirrel population boom appears to have been fueled by a bumper crop of acorns and other food, according to the New Hampshire Fish and Game Department.

Growers say one of the more infuriating aspects of the squirrels is that they often take a single bite then move on. But just one bite is all it takes to ruin fruit.

The rodents are now being killed in greater numbers by passing vehicles as they dart to find their next meal.

Wildlife

Invading Crabs

An aggressive breed of green crab is invading Maine’s waters.

The crabs (Carcinus maenas) threaten blue mussels, soft-shell clams and the eelgrass beds off the state’s rocky coast. The crustaceans are also just plain nasty: Researchers who work with the crabs say that instead of hiding from threats, the critters rush forward, pincers waving.

The crabs, which measure about 5 inches (13 centimeters) long, belong to the same species that has long lived in Maine’s waters. But in the past few years, a genetically distinct population of this species has traveled south from Nova Scotia, Canada, according to research led by Markus Frederich, a professor of marine sciences at the University of New England. These non-native crabs chow down on marine animals that are important for Maine’s economy, including mussels and clams, and the invaders shred native eelgrass habitat as they hunt.

Green crabs probably arrived in North America in the 1800s in the ballast water of ships from Europe. In the past decade, Maine’s green crab population has exploded, a cycle probably linked to rising ocean temperatures, according to the marine resources department.

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Wildlife

Whaling Wins

A nearly two-decade effort to create a whale sanctuary across the southern Atlantic was shot down by pro-whaling nations at the fractious International Whaling Commission meeting in Brazil.

While 39 countries backed establishing a haven for the marine mammals, 25 voted against it, including Russia and pro-whaling Japan, along with commercial whaling nations Iceland and Norway. This caused the vote to fall short of the required three-quarters majority.

Wildlife

Omnivorous Shark Discovered

Ruining the reputation of sharks as bloodthirsty predators, California researchers said they have found a shark that enjoys a side of seagrass with its prey.

Bonnethead sharks not only eat grass while chomping fish and squid – they also digest the plant and gain nutrition from it, scientists at the University of California, Irvine announced.

It turns out bonnetheads have high levels of enzymes that break down fiber and carbohydrates, compared with the low amount carnivores typically have. That makes the bonnethead the first known omnivorous shark, researchers said.

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