. Scientific Frontline: Conservation
Showing posts with label Conservation. Show all posts
Showing posts with label Conservation. Show all posts

Friday, November 4, 2022

Platypus Populations Impacted by Large River Dams Are More Vulnerable to Threats

Photo Credit: David Clode

The platypus is possibly the most irreplaceable mammal existing today. They have a unique combination of characteristics, including egg-laying despite being mammals, venomous spurs in males, electroreception for locating prey, biofluorescent fur, multiple sex chromosomes, and the longest evolutionary history in mammals.

Platypuses are a threatened species in some Australian states and their conservation is of concern more broadly, due to known decline in their populations.

A new study published in Communications Biology examined the genetic makeup of platypuses in free-flowing and nearby rivers with large dams in New South Wales. These included the free-flowing Ovens River, along with the dammed Mitta Mitta River, and the free-flowing Tenterfield Creek, along with the nearby Severn River regulated by a large dam.

The study found that large dams are significant barriers to platypus movements. This was reflected in greater genetic differentiation between platypuses above and below large dams compared to rivers without dams. Importantly, this genetic differentiation increased over time since the dam was built, reflecting the long-term impacts of the dam.

Tuesday, November 1, 2022

How much microplastic do whales eat? Up to 10 million pieces per day

Humpback whales lunge feed in Monterey Bay. New research shows whales are ingesting plastic in larger quantities than previously thought, and nearly all comes from their prey, not from the enormous volumes of seawater the whales gulp when feeding.
Photo Credit: shadowfaxone

Analysis of ocean plastic pollution and whale foraging behavior tracked with noninvasive tags shows whales are ingesting tiny specks of plastic in far bigger quantities than previously thought, and nearly all of it comes from the animals they eat – not the water they gulp.

The largest animals ever known to have lived on Earth ingest the tiniest specks of plastic in colossal amounts, Stanford University scientists have found.

Published in Nature Communications, the study focuses on blue, fin, and humpback whales and their consumption of plastic fragments no bigger than a few grains of sand, which are commonly called microplastics. The authors combined measures of microplastic concentrations up and down the water column off the coast of California with detailed logs of where hundreds of whales carrying tracking devices foraged for food between 2010 and 2019.

They found the whales predominantly feed 50 to 250 meters below the surface, a depth that coincides with the highest concentrations of microplastic in the open ocean. The planet’s biggest creature – the blue whale – ingests the most plastic, at an estimated 10 million pieces per day as it feeds almost exclusively on shrimplike animals called krill.

“They’re lower on the food chain than you might expect by their massive size, which puts them closer to where the plastic is in the water. There’s only one link: The krill eats the plastic, and then the whale eats the krill,” said study co-author Matthew Savoca, a postdoctoral scholar at Hopkins Marine Station, Stanford’s marine laboratory on the Monterey Peninsula.

Thursday, October 20, 2022

Wildfires drive L.A.’s mountain lions to take deadly risks

  A National Park Service researcher displays the scorched paws of the adult male mountain lion known as P-64. While an NPS tracking collar showed that P-64 survived the Woolsey Fire, he died several weeks later of starvation.
Credit: Santa Monica Mountains National Recreation Area

When the Woolsey Fire roared through the Santa Monica Mountains in fall 2018, it torched half of the available habitat for the area’s mountain lions — a population already hemmed in by freeways and an ocean.

Most survived the blaze, but in a study published today in Current Biology, scientists from UCLA and the National Park Service found that the animals, no longer able to utilize burned areas, engaged in risky behaviors that increased the likelihood of dangerous encounters with human-built infrastructure and rival mountain lions.

Conflicts with other cougars, particularly males, can be deadly, said lead study author Rachel Blakey, a researcher with UCLA’s La Kretz Center for California Conservation Biology. So can crossing busy roads and freeways, something the researchers found occurred with greater frequency in the 15 months after the fire, jumping from about three crossings a month to five.

“The mountain lions we live alongside in L.A. are already taking their chances with roads and other mountain lions,” Blakey said. “The Woolsey Fire, by further limiting the space they have, really intensified those risks.”

Tuesday, October 18, 2022

Reliably estimating proportion of vaccinated populations in wildlife

Japanese Wild Boar
Credit: KENPEI, CC BY-SA 3.0/Wikimedia Commons

Researchers develop a ground-breaking model to estimate bait vaccination effectiveness in wild animals based on the proportion of immunized animals in a population and the number of vaccine applications.

Wild animals are host to pathogens that cause a wide variety of infectious diseases, including zoonotic diseases such as rabies, influenza and tuberculosis. The control of these diseases in wild animals is an important issue in the fields of public health, livestock health, and conservation biology. One of the most widely used methods of control is vaccination of wildlife via bait containing oral vaccines (bait vaccination). However, assessing the effectiveness of these vaccines has been difficult.

A team of scientists led by Associate Professor Ryosuke Omori at the International Institute for Zoonoses Control, Hokkaido University, has developed a ground-breaking model to estimate the effectiveness of bait vaccination in wild animals. Their model and findings were published in the journal PLOS Computational Biology.

Monday, October 17, 2022

Virologists close gap on unknown viruses affecting amphibians and reptiles

It took three years to identify the virus that all but wiped out the Bellinger River turtle in 2015. It is hoped that amassing new viral data affecting herptiles will allow quicker conservation responses.
Credit: Pelagic, CC BY-SA 4.0

New knowledge about amphibian and reptile viruses will help us act faster to conserve threatened species.

A study of viruses that affect amphibians and reptiles has closed the gap on the knowledge of viruses affecting animals which until now has largely focused on humans and other mammals.

Third year PhD student Emma Harding, who led the study published today in ISME Communications, used the UNSW supercomputer Katana to comb through petabytes (millions of gigabytes) of publicly available amphibian and reptile RNA data in search of new viruses affecting these classes of animals.

“We know a lot about viruses that infect us and livestock, however not many people have investigated viruses that infect amphibians and reptiles, even though there are over 18,000 species globally,” Ms. Harding, lead author on the paper, says.

“We looked through more than 200 RNA datasets from amphibians and reptiles for evidence of new viruses that could lead to disease. We found 26 new viruses from a range of different families and now have a better understanding of what viruses can infect these animals.”

Wednesday, October 12, 2022

Endangered fruit-eating animals play an outsized role in a tropical forest

A view of the Atlantic Forest in Brazil’s Rio de Janeiro state.
Credit: Adriano Gambarini/The Nature Conservancy

A new study by researchers at the University of Washington shows that losing a particular group of endangered animals — those that eat fruit and help disperse the seeds of trees and other plants — could severely disrupt seed-dispersal networks in the Atlantic Forest, a shrinking stretch of tropical forest and critical biodiversity hotspot on the coast of Brazil.

The findings, published Oct. 12 in the Proceedings of the Royal Society B, indicate that a high number of plant species in today’s Atlantic Forest rely on endangered frugivores — the scientific term for animals that eat primarily fruit — to help disperse their seeds throughout the forest. As a result, losing those endangered frugivores would leave a high proportion of plants without an effective means to disperse and regenerate — endangering these plants, reducing diversity in the Atlantic Forest and crippling critical portions of this ecosystem.

“Tropical forests contain this incredible diversity of trees,” said lead author Therese Lamperty, a UW postdoctoral researcher in biology. “One of the main processes forests use to maintain this diversity is dispersal. If you’re not dispersed, you’re in a crowd of trees that are just like you – all competing for resources. And there are a lot of plant enemies already in the area or that can be easily recruited, like harmful animals or plant diseases. Your chance of survival is higher when you get transported away from your mother tree to an area without trees like you.”

Monday, October 10, 2022

Taking a biochemical snapshot of sea turtle health

Green Sea Turtle 
Photo credit: Randall Ruiz

New Griffith research is using biochemical profiles from the blood of sea turtles as a tool to monitor the health of populations in the wild.

Published in Comparative Biochemistry and Physiology, the researchers used metabolomics, which measures the by-products of physiological processes, to determine if environmental conditions or the way in which they were captured can affect their health.

“As iconic but threatened species, there is considerable interest in adapting cutting-edge analytical techniques to evaluate the health of wild populations of sea turtles,” said Dr Steve Melvin a Research Fellow at the Australian Rivers Institute.

“Nuclear magnetic resonance spectroscopy is a powerful technique that can provide a metabolic fingerprint of the physiological processes taking place in an animal. It gives a direct indication of an organism’s health and how external conditions influence an animal’s physiological response.

“Being non-lethal, metabolomics provides an attractive method for comparing populations of threatened species like sea turtles, and to understand how the environment they are living in impacts their health. However, few studies have used this method to evaluate wild populations of sea turtles.”

Thursday, September 22, 2022

Gut Microbiomes Help Bears with Very Different Diets Reach the Same Size

Photo credit: National Park Service.

A recent study of the gut microbiome of Alaskan brown bears (Ursus arctos) shows that the microbial life in bears’ guts allows them to achieve comparable size and fat stores while eating widely different diets. The work sheds light on the role of the gut microbiome in supporting health in wild omnivores.

“We think of bears as having simple digestive tracts, so it’s easy to slip into thinking that they therefore have simple gut microbiomes,” says Erin McKenney, co-author of the study and an assistant professor of applied ecology at North Carolina State University. “But this study shows there can be tremendous diversity in the gut microbiomes between individual bears, and that this variation can be very important to the physical condition of these animals.”

“For example, the amount of fat that bears are able to store is absolutely critical to the health of wild populations,” says Grant Hilderbrand, co-author of the study and associate regional director for resources for the National Park Service in Alaska. “If female bears are able to reach levels where 19-20% of their body mass in the autumn is fat, they’ll reproduce. And knowing that they can take different dietary paths to reach those fat levels is a valuable insight.”

For this study, researchers collected fecal samples from 51 adult brown bears in three national parks: Katmai National Park and Preserve, Lake Clark National Park and Preserve, and Gates of the Arctic National Park and Preserve.

Wednesday, September 21, 2022

No evidence that dehorning black rhinos negatively impacts the species’ reproduction or survival

A sedated black rhino in the process of being dehorned, with a cap over its eye to protect it from the dust
Credit: Piet Beytell, Namibian Ministry of Environment, Forestry and Tourism

There are no statistically significant differences in key factors of population growth - breeding, birth, survival, life span and death - between dehorned or horned black rhinos new research, conducted by the University of Bristol Vet School, Namibian Ministry of Environment, Forestry and Tourism, and Save the Rhino Trust has found.

The black rhino is critically endangered, with poaching one of several threats to the species’ survival. Many reserves across a number of African countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching but few studies have looked at the impacts of dehorning, particularly in black rhinos.

The study aimed to build on existing knowledge of population productivity between dehorned and horned individuals in four sub-populations of black rhino (of the sub-species Diceros bicornis bicornis) in Namibia.

Three of the populations had undergone some level of dehorning at least once while one of the populations had never been dehorned. The measures investigated included: age of females at the birth of their first calf (age at first reproduction or AFR); average time between the birth of calves for each female (inter-calving interval); birth sex ratios, calf survival, life span and cause of death

Monday, September 19, 2022

Endangered Mouse Study Shares No-Contact Sampling Method

A salt marsh harvest mouse walks across the bulrush at Grizzly Island Wildlife Area in San Francisco.
 Credit: Cody Aylward/UC Davis

From species of marmots to moles, shrews and mice, many of the world’s endangered mammals are small. Genetic sampling is important for understanding how to conserve and protect their populations. But finding efficient, noninvasive ways to collect genetic samples from small animals can be challenging.

A study from the University of California, Davis, describes a new, noninvasive genetic survey technique for the endangered salt marsh harvest mouse, which lives solely within the tidal marshes of the San Francisco Bay Estuary.

In larger mammals, scientists often collect samples from scat, but the poop of small animals can be so small that it is difficult to detect in the wild.

The new technique, published in the Journal of Mammalogy, uses a combination of bait stations and genetics to sample and identify salt marsh harvest mice, or “salties” as researchers affectionately call them. The species has lost more than 90% of its habitat to development and is also threatened by rising sea levels. That’s why it is imperative that the remaining populations are identified accurately and efficiently, the authors note.

Wednesday, September 7, 2022

More than 1.1 million sea turtles poached over last three decades

A new ASU study shows during a 30-year period, 95% of poached sea turtles came from two species — green and hawksbill turtles — both of which are listed under the U.S. Endangered Species Act. Also, Southeast Asia and Madagascar emerged as major hot spots for illegal sea turtle take and trade, particularly for critically endangered hawksbills, which are prized in the illicit wildlife trade for their beautiful shells. The East Pacific hawksbill turtle is among the most endangered sea turtle populations.
 Photo Credit: Lindsay Lauckner Gundlock

One of the most serious threats to wildlife biodiversity, in addition to the climate crisis, is the illegal killing and trafficking of animals and plants. Despite many laws against the black-market wildlife trade, it is considered to be one of the most lucrative illicit industries in the world.

Animals, especially endangered and threatened species, are often exploited and sold for their pelts or used as medicine, aphrodisiacs, curios, food and spiritual artifacts.

In a new study published in “Global Change Biology,” Arizona State University researchers estimate that more than 1.1 million sea turtles have been illegally killed and, in some cases, trafficked between 1990 and 2020. Even with existing laws prohibiting their capture and use, as many as 44,000 sea turtles were exploited each year over the past decade in 65 countries or territories and in 44 of the world’s 58 major sea turtle populations.

Despite the seemingly large number of poached turtles, the study shows that the reported illegal exploitation of sea turtles declined by approximately 28% over the last decade — something that surprised the researchers. They initially expected to see an overall increase in reported poaching.

Tuesday, September 6, 2022

Endangered Amargosa Voles Begin to Repopulate Desert Habitat

This landscape shows the Amargosa Valley at sunset. Amargosa voles are endemic to unique Mojave Desert marshes fed by natural springs and the Amargosa River.
Credit: University of California, Davis

Seven years of carefully planned habitat restoration on private land in the Mojave Desert have yielded hope for the persistence of the endangered Amargosa vole. In early August, a photograph from a wildlife camera placed by researchers from the University of California, Davis, and dated July 3 revealed the presence of one, possibly two, vole pups born from parents that were reintroduced to restored marsh habitat on private land in Shoshone Village, Inyo County.

The Amargosa vole was first discovered in the marshes of Shoshone in the late 1800s but had disappeared by the early 1900s because of habitat conversion to agriculture and other uses that destroyed the marshes. The only other place in the world where the voles persist in the wild is near the town of Tecopa, about 8 miles south of Shoshone.

Restoration of the Shoshone Spring marsh started in 2015 as a joint effort of Shoshone Village, the Amargosa Conservancy, UC Davis and the California Department of Fish and Wildlife (CDFW). The restoration was funded by U.S. Fish and Wildlife Service (USFWS) Section 6 and Partners in Fish and Wildlife grants.

Wednesday, August 31, 2022

Marine Protected Areas in Antarctica should include young emperor penguins, scientists say

A group of Juvenile emperor penguins at Atka Bay on the sea ice edge ready for their first swim. In four years, they will return to breed, spending much of their time in unprotected areas of the Southern Ocean.
Image credit: Daniel P. Zitterbart/ ©Woods Hole Oceanographic Institution

Scientists at the Woods Hole Oceanographic Institution (WHOI) and European research institutions are calling for better protections for juvenile emperor penguins, as the U.S. Fish and Wildlife Service considers listing the species under the Endangered Species Act and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) considers expanding the network of Marine Protected Areas (MPAs) in the Southern Ocean.

In one of the few long-term studies of juvenile emperor penguins–and the only study focused on a colony on the Weddell Sea–research published today in Royal Society Open Science found that the young birds spend about 90 percent of their time outside of current and proposed MPAs. The study, which tracked eight penguins with satellite tags over a year, also found that they commonly traveled over 1,200 kilometers (745 miles) beyond the species range defined by the International Union for Conservation of Nature (IUCN), which is based on studies of adult emperor penguins from a few other colonies.

Considered immature until about 4 years of age, juvenile emperor penguins are more vulnerable than adults because they have not fully developed foraging and predator avoidance skills. As climate change reduces sea-ice habitat and opens up new areas of the Southern Ocean to commercial fishing, the researchers conclude that greatly expanded MPAs are crucial to protect this iconic, yet threatened, penguin species at every life stage.

Friday, August 19, 2022

Which animals can best withstand climate change?

Masai Mara National Reserve, Kenya
Credit: David Heiling on Unsplash

Extreme weather such as prolonged drought and heavy rainfall is becoming more and more common as the global average temperature rises – and it will only get worse in the coming decades. How will the planet’s ecosystems respond?

That is the big question and the background for our study, said biologist John Jackson.

Together with his biologist colleagues Christie Le Coeur from the University of Oslo and Owen Jones from SDU, he authored a new study, published in eLife.

A clear pattern

In the study, the authors analyzed data on population fluctuations from 157 mammal species from around the world and compared them with weather and climate data from the time the animal data were collected. For each species there are 10 or more years of data.

Their analysis has given them an insight into how populations of animal species have coped at times of extreme weather: Did they become more, or less, numerous? Did they have more or fewer offspring?

We can see a clear pattern: Animals that live a long time and have few offspring are less vulnerable when extreme weather hits than animals that live for a short time and have many offspring. Examples are llamas, long-lived bats and elephants versus mice, possums and rare marsupials such as the woylie, said Owen Jones.

Thursday, July 28, 2022

How elephants adapt to human development in cities versus farm life

Resized Image using AI by SFLORG
Source: Radboud University Nijmegen

The movement of elephants through wildlife corridors is directly impacted by differing forms of human pressures and development, new research by Elephants Without Borders (EWB) and Radboud University shows. Their study, published today in Frontiers in Conservation, is the first that takes an in-depth look at how varying land-use affects elephants and their use of wildlife corridors.

From 2012 to 2019, the researchers monitored elephants' movements through six wildlife corridors using of motion-detected camera traps in two different human-dominated landscapes: the townships of Kasane and Kazungula, and the farming villages of the Chobe Enclave, both located in the Chobe District.

The study shows that various land-use seemingly affects when elephants use wildlife corridors on an hourly basis. Elephants in agricultural areas largely moved through the corridors predominantly nocturnally, when humans are less active, compared to the urban corridors, where humans and elephants actively mostly overlap.

Wednesday, July 27, 2022

Parasites may take a heavier toll on mammal populations than previously thought

Tapeworm infection is caused by ingesting food or water contaminated with tapeworm eggs or larvae.
 Credit: University of Alberta

A new study looking at research on parasitic worms suggests the pesky but pervasive creatures have a far greater impact on the health of mammal populations than previously known.

“Parasites don't have to kill the animal to control a population,” says Kyle Shanebeck, a PhD student in the Faculty of Science’s Department of Biological Sciences who led the research review.

Shanebeck’s analysis shows that helminths — large parasites such as tapeworms, flatworms and flukes — have negative effects on the energetic condition, or total body health, of their mammal hosts that can impair systemic functioning, repair, growth, environmental adaptability and reproduction.

“They can affect the animal’s ability to absorb nutrients, which can affect digestive health and behavior, making them more aggressive and even changing where they forage,” notes Shanebeck, whose research is supervised by assistant professor Stephanie Green. “Helminth parasites also suppress immune action or weaken it, as the body spends energy to mount an immune response to fight them which can make a secondary infection worse.”

As Shanebeck explains, assessing population health in wildlife typically focuses on pathogenic diseases — the often-fatal illnesses that can spread between species, and potentially from animals to humans. Parasites, on the other hand, don’t kill their hosts so they tend to be ignored in conservation and management models.

Wednesday, June 29, 2022

Student helps find world’s largest frog in Equatorial Guinea for first time in almost two decades

Left: Student Sam Hurley (left) with local guide Edu. Right: A goliath frog found in Monte Alén National Park, Equatorial Guinea
Source: University of Bristol

Field researchers from the University of Bristol and Bristol Zoological Society have found the world’s largest frog in Equatorial Guinea for the first time in almost two decades.

The most recent amphibian survey in the country’s Monte Alén National Park, which is one of the goliath frog's few known habitats, recorded no sign of it.

Goliath frogs can be as big as some housecats, measuring up to 34cm in length and weighing more than 3kg.

Concerned by the lack of recent evidence of the species in the national park, conservationists travelled to Equatorial Guinea to find evidence that the giant amphibian was not lost to the region.

Working in partnership with INDEFOR-AP, the national park service of Equatorial Guinea, the researchers conducted a survey along the Benito River.

Over 10 days in the forest, the researchers spotted the amphibian in a small waterfall. They had hoped to collect vocal recordings of the frog, however, the animal was not heard calling, perhaps confirming previous accounts that it is indeed a quiet, if not silent, amphibian. More study is needed.

Monday, June 27, 2022

Southern resident killer whales not getting enough to eat since 2018

A southern resident killer whale.
Credit: NOAA, Ocean Wise

The endangered southern resident killer whale population isn’t getting enough to eat, and hasn’t been since 2018, a new UBC study has determined.

The animals have been in an energy deficit, averaging across spring, summer and fall, for six of the last 40 years—meaning the energy they get from food is less than what they expend. Three of those six years came in the most recent years of the study, 2018 to 2020. The average difference in energy is 28,716 calories, or about 17 per cent of the daily required energy for an average adult killer whale, the authors say.

“With the southern resident population at such a low level, there’s a sense of urgency to this kind of research,” says lead author Fanny Couture, a doctoral student at the Institute for the Oceans and Fisheries (IOF) and Ocean Wise. “Both killer whales and Chinook salmon, the southern resident’s main prey, are important, iconic species for the west coast of Canada. Studying what is happening to the population may help offer solutions, both for the southern residents and potentially other killer whale populations in the future.”

The southern resident population, which feeds mainly on Chinook salmon, numbered 73 individuals as of October 2021, compared with the increasing northern resident population of about 300. Studies have posited that the growth of the southern resident population may be impeded by a lack of food.

Thursday, June 16, 2022

Scientists fail to locate once-common CA bumble bees

The Western bumble bee, a once-common bee in California, was not found in the recent UCR-led survey.
resized using AI by SFLORG
Credit: Rich Hatfield/Xerces Society

Several species of California bumble bees have gone missing in the first statewide census of the fuzzy pollinators in 40 years. If they can be found, a recent court ruling could help save them.

Smaller-scale studies have documented significant declines in bumble bee populations around the world due to climate change, development of wild habitat, and the use of bee-killing pesticides.

Led by UC Riverside, this study was an effort to document changes in bumble bee populations across large geographic areas in California since the last such study was done in the 1980s.

It is important to have data that substantiates the bees’ health. Bumble bees can fly in cooler temperatures and lower light levels than many other bees, and help pollinate crops worth $3 billion annually in the U.S. They perform a type of pollination required for plants including tomatoes, peppers and cranberries.

For the updated data, UCR entomologist Hollis Woodard’s research group collected bees from 17 total sites representing six different ecosystems previously known to host a large variety of bumble bees.

Tuesday, June 14, 2022

Right Whales’ Survival Rates Plummet After Severe Injury from Fishing Gear

Source: Duke University

Most North Atlantic right whales that are severely injured in fishing gear entanglements die within three years, a new study led by scientists at the New England Aquarium and Duke University finds.

North Atlantic right whales are a critically endangered species whose population has shrunk in recent decades. Scientists estimate fewer than 350 of the iconic whales are still alive in the wild today.

To examine the role fishing gear entanglements have played in the species’ decline, the researchers tracked the outcomes of 1,196 entanglements involving 573 right whales between 1980 and 2011 and categorized each run-in based on the severity of the injury incurred

The data revealed that male and female right whales with severe injuries were eight times more likely to die than males with minor injuries, and only 44% of males and 33% of females with severe injuries survived longer than 36 months.

Females that did survive had much lower birth rates and longer intervals between calving, a worrisome trend for the long-term survival of the species.

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