Tag: Species

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Health

Crimson Knots in Steepest Decline in Years, Threatening the Species’ Survival

Red Knots in Steepest Decline in Years, Threatening the Species’ Survival

The number of red knots visiting the beaches of Delaware Bay during this spring’s north migration unexpectedly dropped to its lowest level since counts began nearly 40 years ago, adding to concerns about the survival of the shorebird and a sharp setback for a quarter of a century his efforts meant to save him.

Conservationists found fewer than 7,000 of the bird’s rufa subspecies in extensive land, air and water counts on the New Jersey and Delaware side in May. The number is about a third of that found in 2020; less than a quarter of the level for the past two years; and the lowest since the early 1980s when the population was around 90,000.

The numbers were already well below the level that would ensure the bird’s survival. A previous decline had been halted by years of conservation efforts, including a New Jersey ban on harvesting horseshoe crabs, the eggs of which provide essential nourishment for birds on their long-distance migrations.

The recent decline is making the Rufa subspecies – which has been endangered at the federal level since 2014 – even more susceptible to external shocks such as bad weather in their Arctic breeding areas and bringing them closer to extinction, say naturalists.

“I think we need to think about the red knot as a dying species, and we really need immediate action,” said Joanna Burger, a biologist at Rutgers University. Since the early 1980s, she has been studying the knot and other deciduous shorebirds such as ruddy turnstone and semi-palmate sandpipers in Delaware Bay.

She called for an immediate ban on the fishing of horseshoe crabs as bait, an industry that still operates in Delaware, Maryland and Virginia and is subject to quotas from the Atlantic States Marine Fisheries Commission. Although regulators do not allow female crabs to be harvested, naturalists say the rule will not be strictly enforced, resulting in the loss of some of the egg-laying animals and a consequent reduction in the birds’ food supply.

The recent decline also fueled calls by naturalists to urge the pharmaceutical industry to stop using LAL, an extract from the blood of crabs used to detect bacteria in vaccines, drugs and medical devices. A synthetic alternative, rFC, is available and used by at least one pharmaceutical company, but the industry as a whole has been slow to embrace the new technique, resulting in continued demand for horseshoe crabs in the bay.

Although the crabs are returned to the sea after bleeding, conservationists believe that up to a third will die or be unable to reproduce. Ironically, there were plenty of crab eggs to eat on the beaches of the bay this year, but a long-term decline in egg availability has severely dented the bird population and thinned any cushion that would allow the species to survive natural hazards.

Larry Niles, an independent wildlife biologist who has trapped, monitored, and counted shorebirds on New Jersey’s bay beaches for the past 25 years, said he expected this year’s red knots to decline as there was evidence of a bad breeding season in season 2020 but shocked at the size of the decline.

He said it was likely due to low sea temperatures in the mid-Atlantic during the 2020 migration. The cold water delayed spawning of the horseshoe crabs until early June, when the birds had already left Delaware Bay to complete their migration.

Many of the birds, weighing just 4.7 ounces when fully grown, are emaciated after flying from Tierra del Fuego in southern Argentina on one of the longest bird migrations. Some fly non-stop for seven days before reaching Delaware Bay, where they usually stay for about two weeks to rest and gain weight.

But last year many could not find food in the bay and continued north to reach their breeding grounds. Dr. Niles estimates that about 40 percent of migrants died in the last year before reaching the Arctic simply because they ran out of energy.

In that year he also blamed the predation by peregrine falcons, whose growing coastal population was supported by the construction of nesting platforms in New Jersey. They often hunt over the beaches of the bay, making it harder for flocks of shorebirds to feed and gain weight.

The best hope for the species’ survival lies in a complete ban on harvesting female horseshoe crabs until the crab population has recovered, said Dr. Niles.

“Rufa nodes, especially red long-haul nodes, could be lost,” he said in a message to supporters. “We can’t stop bad winds or cold water, but we can increase the horseshoe crab population so that birds that arrive in most of these conditions will find an abundance of horseshoe crab eggs.”

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Health

Subway Swabbers Discover a Microbe Jungle — And 1000’s of New Species

Subway Swabbers Find a Microbe Jungle — And Thousands of New Species

Teams of researchers and volunteers fanned out across the mass transit systems of 60 cities, collecting thousands of samples from 2015 to 2017. They swabbed a wide variety of surfaces, including turnstiles, railings, ticket kiosks and benches inside transit stations and subway cars. (In a handful of cities that did not have subway systems, the teams focused on the bus or train system.)

The scientists’ subterranean sampling expeditions often attracted attention. Some commuters grew so curious that they joined the volunteer swabbing corps, while others insisted that they absolutely did not want to know what was living on the subway poles. Passengers occasionally misunderstood what the researchers were doing with their tiny swabs. “One man effusively thanked us for cleaning the subway,” Dr. Mason said.

The researchers also collected air samples from the transit systems of six cities — New York, Denver, London, Oslo, Stockholm and Hong Kong — for a companion paper on the “air microbiome” that was published on Wednesday in the journal Microbiome.

“This is huge,” said Erica Hartmann, a microbiologist at Northwestern University who was not involved in the study. “The number of samples and the geographic diversity of samples — that’s unprecedented.”

Then the team extracted and sequenced the DNA from each sample to identify the species it contained. In total, across all of the surface samples, they found 4,246 known species of microorganisms. Two-thirds of these were bacteria, while the remainder were a mix of fungi, viruses and other kinds of microbes.

But that was just the beginning: They also found 10,928 viruses and 748 kinds of bacteria that had never been documented. “We could see these were real — they’re microorganisms — but they’re not anywhere in any database,” said Daniela Bezdan, the former executive director of MetaSUB who is now a research associate at the University Hospital Tübingen in Germany.

The vast majority of these organisms probably pose little risk to humans, experts said. Nearly all of the new viruses they found are likely to be bacteriophages, or viruses that infect bacteria, Dr. Danko said. Moreover, genetic sequencing cannot distinguish between organisms that are dead and those that are alive, and no environment is sterile. In fact, our bodies rely on a rich and dynamic community of microbes in order to function properly.

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World News

‘A Social Species’: How Kangaroos Talk With Individuals

‘A Social Species’: How Kangaroos Communicate With People

MELBOURNE, Australia – If they’re hungry, they’ll let you know by walking up to you and looking pleadingly at you and the container of food.

If that doesn’t work, they’ll sniff and paw your leg.

No, we are not talking about dogs. We’re talking about kangaroos.

Researchers at the University of Roehampton in the UK and the University of Sydney in Australia say such behavior led to a surprising discovery: kangaroos can communicate with people in a similar way to dogs, horses and goats, although they have never been domesticated.

Kangaroos are the first in the wild to display behavior that is more common in domesticated species and transmit help from a human, the researchers said. Previously, researchers had assumed that this type of inter-species communication only existed in animals that evolved alongside humans.

The study suggests that Australian marsupials have higher levels of intelligence than expected.

The researchers hoped the results would lead people – especially Australians – to treat kangaroos with greater care. Although featured on the country’s coat of arms and viewed as a national treasure, they are also perceived as disruptive and weeded out annually for their overabundance.

According to official estimates, there were almost 50 million kangaroos across Australia in 2017, twice as many as humans. Farmers complain that kangaroos are eating pastures intended for farm animals, while researchers fear that they pose a threat to endangered wildlife by destroying habitats and eating reptiles.

“There is a section of the population who think they are harmful and stupid and want to shoot them,” said Alan McElligott, the newspaper’s lead author. “I think when the general public understands an animal’s cognitive abilities better, it’s easier to sell the idea that we should treat them with the best possible care.”

The researchers trained and tested 11 kangaroos from Australian zoos over eight days to get food out of a box. Then they locked the box and made it impossible for them to access the food without help.

At first, the kangaroos sniffed and scratched the box. But when they realized they couldn’t open it, they turned to Dr. McElligott who was in the enclosure with them.

“The kangaroos looked up at me and they switched that kind of look – they looked at the box, back at me, back at the box, back at me,” said Dr. McElligott, who previously worked at the University of Roehampton and is now an adjunct professor at the City University of Hong Kong.

“Some of the kangaroos came up to me and sniffed my knee and scratched my knee,” he added. “If it were a dog, you’d call it paws.”

Ten of the eleven kangaroos involved in the study saw Dr. Actively at McElligott, and nine took turns looking at him and the box of food.

“They really tried to purposely communicate their desire to get him to get the food out of the box,” said Alexandra Green, an animal behavior and welfare researcher at the University of Sydney, the newspaper’s co-author.

Dr. Green says that she believes the kangaroo’s behavior is a modification of how they communicate with one another in the wild.

“They are a social species and would use these clues among themselves,” she said. “In a trapped environment where people are present, they can likely adapt this ability to communicate with people.”

The kangaroos used in the study, published on Wednesday in Biology Letters, an expert-reviewed scientific journal from the Royal Society, weren’t entirely wild as it would have been dangerous for the researchers. They had grown up in zoos and were familiar with people, but were still considered non-domesticated.

Dr. McElligott said that in a similar study with wolves, another non-domesticated animal, the wolves simply attacked the feed boxes with their teeth instead of asking humans for help.