Freshwater Insects Recover While Spiders Decline In UK

February 18, 2020

Many insects, mosses and lichens in the UK are bucking the trend of biodiversity loss, according to a comprehensive analysis of over 5,000 species led by UCL and the UK Centre for Ecology & Hydrology (UKCEH).

The researchers say their findings on UK biodiversity between 1970 and 2015, published in Nature Ecology & Evolution, may provide evidence that efforts to improve air and water quality could be paying off.

“By looking at long-term trends in the distribution of understudied species, we found evidence of concerning declines, but we also found that it’s not all bad news. Some groups of species, particularly freshwater insects, appear to be undergoing a strong recovery,” said the study’s lead author, Dr Charlie Outhwaite (UCL Centre for Biodiversity & Environment Research, UK Centre for Ecology & Hydrology, and the RSPB).

Funded by the Natural Environment Research Council (NERC), the researchers analysed trends in the distribution of invertebrates (such as insects and spiders), bryophytes (such as mosses) and lichens over a 45-year period, to see whether they were following the same declining trends reported in better-studied groups such as mammals, birds and butterflies.

Across all 5,214 species surveyed, overall occupancy (distribution) was 11% higher in 2015 than in 1970. The researchers were not able to estimate the total numbers of each species, but gauged how well each species was doing by whether its geographic range was expanding or shrinking.

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Rare bats in decline

Date: February 14, 2020

Source: City College of New York

A study led by Susan Tsang, a former Fulbright Research Fellow from The City College of New York, reveals dwindling populations and widespread hunting throughout Indonesia and the Philippines of the world's largest bats, known as flying foxes.

Unfortunately, hunting not only depletes the flying foxes, which are already rare, but also potentially exposes humans to animal-borne pathogens (a process known as zoonosis). "For instance, the current case of Wuhan Coronavirus is thought to have been spread from wild bats to humans through an intermediate host at a wildlife market," said CCNY biologist and Tsang's mentor David J. Lohman, an entomologist and two-time Fulbright recipient.

The CCNY experts found that flying foxes originated in a group of islands in Indonesia called Wallacea. They diversified into different species by flying to other islands that presumably lacked competitors and established themselves. Thus, islands are critical to the evolution and conservation of this large group of around 65 mammal species.

"This study provides insight into biodiversity conservation and public health. Islands are frequently home to endemic species found nowhere else," noted Tsang, who earned a PhD in biology from the Graduate Center, CUNY.

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Bogong moth tracker launched in face of 'unprecedented' collapse in numbers

New website asks Australians to record sightings of insect that is main food source of the mountain pygmy possum

Lisa Cox

Tue 17 Sep 2019 09.11 BSTLast modified on Tue 17 Sep 2019 09.13 BST

Every spring, 4.4 billion bogong moths migrate up to 1,000km to the alpine regions of Victoria and New South Wales ahead of the summer heat.

But for the past two years, the number of moths that have made the journey to those areas from breeding grounds in Queensland, NSW and western Victoria has crashed to almost undetectable levels and scientists are turning to the community for help.

A new website, led by Zoos Victoria, is asking Australians to take a photo if they think they see a bogong moth, and to record when and where they saw it.

Called Moth Tracker, the website has been set up to try gather information on the migration routes of the bogong moth and what the coming summer will bring for the species and animals that rely on them.

That includes the mountain pygmy possum, a critically endangered marsupial that hibernates for five to seven months of the year. Just 2,000 of them remain in the wild.

When the possum emerges from under the snow, the bogong moth is its main food source.

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The silent decline of the platypus, Australia’s beloved oddity

Recent studies suggest the duck-billed mammal is not as widespread as thought, in part due to centuries of hunting and habitat loss.

BY CHRISTIE WILCOX

PUBLISHED AUGUST 29, 2019

The platypus is one of Australia’s most beloved species—and, seemingly, one of its most resilient. Even as many of the continent’s native fauna declined or disappeared throughout the 20th century, the quirky duck-billed mammal with webbed feet was seen regularly enough that there was little urgency to monitor the animal’s populations. That is, until biologists began to realize the freshwater dwellers weren’t ok, and they probably weren’t all along.

“The platypus has declined right in front of our noses,” says Tahneal Hawke, a Ph.D. candidate at the University of New South Wales and a researcher with the Platypus Conservation Initiative.

“We have a huge area across the range of the platypus where we literally don't know if they're even there or in what numbers if they are.”

Hawke co-authored a new study that surveyed centuries of historical data and suggests the platypus—found in rivers and streams throughout eastern Australia and Tasmania—has been plummeting in number, due to hunting, habitat loss, and climate change.

Some scientists started sounding alarms of the platypus’ decline as early as the 1980s, but their warnings fell on deaf ears. Then, as more and more data from long-term monitoring programs set up in the 1980s and ‘90s trickled in, the perception of the ever-stalwart platypus began to dim. (Read more about how the venomous, egg-laying platypus evolved.)

“We’ve been monitoring platypus since 1995,” explains Tiana Preston, an environmental water resources planner for the Victoria state agency Melbourne Water, “and the decline is certainly evident.”

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Impact of urbanization on wild bees underestimated

Date:  March 6, 2019

Source:  University of Michigan

Wild bees are indispensable pollinators, supporting both agricultural productivity and the diversity of flowering plants worldwide.

But wild bees are experiencing widespread declines resulting from multiple interacting factors. A new University of Michigan-led study suggests that the effects of one of those factors -- urbanization -- may have been underestimated.

The study, led by a group of current and former U-M students and conducted at sites across southeast Michigan, looks at one aspect of this topic they say has received scant attention from bee researchers: the sex ratio of wild bees and how it changes across a rural-to-urban land-use gradient.

The team found that the sex ratio of wild bees became more male-dominated as urbanization increased, mainly driven by a decline in medium- and large-bodied ground-nesting female bees. The study, published March 6 in the journal Scientific Reports, is believed to be the first investigation of observed sex ratio in a complete wild bee community along a rural-to-urban gradient.

"These findings have potential implications on bee population health and pollination services, since male and female bees often have different pollination behaviors," said Paul Glaum, one of the study's first authors and a postdoctoral researcher in U-M's Department of Ecology and Evolutionary Biology.

Read on

Insect collapse: ‘We are destroying our life support systems’

Scientist Brad Lister returned to Puerto Rican rainforest after 35 years to find 98% of ground insects had vanished

Damian Carrington Environment editor

Tue 15 Jan 2019 06.00 GMTLast modified on Tue 15 Jan 2019 06.02 GMT 

 “We knew that something was amiss in the first couple days,” said Brad Lister. “We were driving into the forest and at the same time both Andres and I said: ‘Where are all the birds?’ There was nothing.”

His return to the Luquillo rainforest in Puerto Rico after 35 years was to reveal an appalling discovery. The insect population that once provided plentiful food for birds throughout the mountainous national park had collapsed. On the ground, 98% had gone. Up in the leafy canopy, 80% had vanished. The most likely culprit by far is global warming.

“It was just astonishing,” Lister said. “Before, both the sticky ground plates and canopy plates would be covered with insects. You’d be there for hours picking them off the plates at night. But now the plates would come down after 12 hours in the tropical forest with a couple of lonely insects trapped or none at all.”

“It was a true collapse of the insect populations in that rainforest,” he said. “We began to realise this is terrible – a very, very disturbing result.”

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Fewer monarch butterflies are reaching their overwintering destination

January 2, 2019, De Gruyter

Arguably, one of the world's most famous insects, the monarch butterfly, is currently experiencing dire problems with its migration in eastern North America. Fewer and fewer monarchs are successfully reaching their overwintering destinations, and scientists aren't sure why. Because of this, the need for research on the migration has never been more urgent. New research published in De Gruyter's Open Access journal Animal Migration, aims to help with this effort.

The dwindling numbers of overwintering monarchs in the mountains of central Mexico have been the subject of debate among researchers, with some arguing it reflects a large-scale drop in numbers of breeding adults, while others point to increasingly perilous migration as the cause. Now, a new research study "Alternate migration strategies of eastern monarch butterflies revealed by stable isotopes" led by Dr. Hannah Vander Zanden, from the University of Florida, throws another potential explanation into the mix—maybe the monarchs are simply travelling elsewhere to overwinter, like to the balmy coast of southern Florida.

Dr. Vander Zanden and her team captured and examined monarchs that wintered in South Florida, using a special analytical technique that can pinpoint where the monarchs came from based on a sample of their wing or body tissue. Amazingly, they discovered that half of the monarchs sampled appeared to originate from the American Midwest, which is typically thought to represent the core breeding range of the eastern population. For years, researchers assumed that monarchs from this region only travel to the mountainous region of Mexico each fall. But, this new discovery means that at least some of the Midwestern monarchs are choosing not to fly to Mexico after all, and instead they appear to fly in nearly the opposite direction until they reach southern Florida.

Read more at: 

Fifty years of decline in Queensland's coastal sharks

Date:  December 13, 2018

Source:  University of Queensland

Queensland's coastal shark numbers are continuing a 50-year decline, in sharp contradiction of suggestions of 'exploding' shark populations, according to an analysis of Queensland Shark Control Program data.

University of Queensland and Griffith University researchers analysed data from the program, which has used baited drumlines and nets since 1962 to minimise human-shark interactions, and now spans 1760 km of the Queensland coastline.

UQ School of Biological Sciences researcher Dr George Roff said historical baselines of Queensland shark populations were largely unknown, despite a long history of shark exploitation by recreational and commercial fisheries.

"Explorers in the 19th century once described Australian coastlines as being 'chock-full of sharks', yet we don't have a clear idea of how many sharks there used to be on Queensland beaches," he said.

"Shark populations around the world have declined substantially in recent decades, with many species being listed as vulnerable and endangered."

By analysing the Queensland Shark Control Program data, the research team reconstructed historical records of shark catches to explore changes in the number and sizes of sharks over the past half century.

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Drying Canadian wetland drives muskrat decline

Date: November 26, 2018

Source: Stanford's School of Earth, Energy & Environmental Sciences

Indigenous communities have used muskrat fur to make clothing for generations and the animal's meat is considered a seasonal delicacy. But it turns out decades of trapping are not primarily responsible for the animal's decline across North America.

Instead, 46 years of satellite imagery show the Peace-Athabasca Delta has been drying since the 1970s, significantly reducing muskrat habitat. Stanford University researchers published their findings in the journal Environmental Research Letters.

"The ecological impacts are not limited to muskrat -- they extend far beyond that," said lead author Ellen Ward, a doctoral candidate in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "These results suggest that maybe the widespread continental-scale decline in this animal is actually being driven by a large-scale loss in wetland and aquatic habitat."

More than just muskrat

Located in northeast Alberta, the Peace-Athabasca Delta is a Ramsar Wetland of International Importance and North America's largest inland freshwater delta. The area comprises habitat for about 200 bird species as well as the threatened wood bison, which is among the largest land animals on the continent. The semi-aquatic muskrat is native to North America and an important ecological indicator since the species is highly sensitive to changing hydrologic conditions.

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Climate impacts amphibians but isn’t main reason for decline - via Herp Digest

Wildlife Society, Dana Kolinsky October 24, 2018

The spotted salamander (Ambystoma maculatum) is one of the amphibian species that has faced declines in the eastern United States and Canada. ©Brad Glorioso/USGS

Researchers know that frogs, toads and salamanders have been facing steep declines in recent decades, but is climate change the main driver?

Putting together data from across North America, including studies of 81 amphibian species, researchers concluded that overall, it’s not.

“Climate does explain why some declines are more severe,” said David Miller, an associate professor of wildlife at Pennsylvania State University and lead author of the study published in Nature Communications. “But it doesn’t explain why amphibians as a whole are declining and whose decline is the worst.”

Miller and his colleagues, as part of a U.S. Geological Survey working group looking at climate and amphibian decline, collected amphibian research from around North America. They included 500,000 observations at more than 5,000 sites.

Then, the team collected climate data from the sites, such as water availability during breeding, summertime heat spells, humidity, snowfall and freezing data.

Using this information, they made predictions of what would happen to amphibian populations if the areas warmed. They found that changes in climate over the past 30 years do not account for amphibians’ steep declines. Changes in climate, especially in temperature, has both positively and negatively affected amphibians, they found.

So what are the reasons for these massive declines? Researchers are focusing more on deadly pathogens such as chytrid fungus and ranavirus, Miller said. But while climate may not be the primary driver, he said, his study has identified species and regions that appear to be more sensitive to climate.

“One of the areas we see this is the high altitude montane sites in the West,” he said. “Yellowstone, Glacier, Banff are all areas that our models would predict have had climate-related declines.”