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

Wednesday, February 28, 2024

Aerial surveys reveal ample populations of rays in southeast Florida

The giant manta ray is designated as threatened under the U.S. Endangered Species Act and is protected in Florida waters.
Photo Credit: Steve Kajiura, Florida Atlantic University

The whitespotted eagle ray (Aetobatus narinari) and the giant manta ray (Mobula birostris) are rapidly declining globally. Both species are classified by the International Union for Conservation of Nature as endangered worldwide and the giant manta ray is designated as threatened under the United States Endangered Species Act.

In Florida waters, giant manta rays and whitespotted eagle rays are protected species. To provide effective management for these species, it is necessary to gather information on their distribution and abundance.

Using aerial surveys, Florida Atlantic University researchers conducted a unique long-term (2014 to 2021) study to quantify the spatial (latitude) and temporal (month, year) abundance of the whitespotted eagle rays and giant manta rays in Southeast Florida. The researchers conducted 120 survey flights between January 2014 and December 2021 along the Atlantic Coast from Miami north to the Jupiter Inlet. They reviewed the video footage from the flights to quantify the number of rays of each species.

Monday, February 26, 2024

New study uncovers the importance of deepwater ecosystems for endangered species

Hawksbills typically forage on coral reefs where their diet is predominantly sponges.
Photo Credit: Jeanne A Mortimer

Using tracking data, a new study has revealed for the first time that hawksbill turtles feed at reef sites much deeper than previously thought.

Critically endangered hawksbill turtles are found in every ocean and are the most tropical of sea turtles. Adult hawksbills have long been considered to have a close association with shallow (less than 15 meters depth) seas where coral reefs thrive.

Young hawksbills drift in currents during their open water phase of their development before they move to seabed habitats. Hawksbills are usually seen foraging in coral reefs where their diet is predominantly sponges.

To study their feeding habits in more detail, researchers at Swansea, Florida and Deakin universities used high-accuracy GPS satellite tags to track 22 adult female hawksbills from their nesting site on Diego Garcia in the Chagos archipelago in the Indian Ocean to their foraging grounds.

Scientists assemble a richer picture of the plight and resilience of the foothill yellow-legged frog

Foothill yellow-legged frogs live in the flowing water of rivers and streams, so are especially vulnerable when these shrink to isolated pools.
Photo Credit: Brome McCreary / USGS

Up to only a few inches in length, with a lemon-hued belly, the foothill yellow-legged frog may seem unassuming. But its range once stretched from central Oregon to Baja California. In 2023, it was listed under the federal Endangered Species Act. Its rapidly decreasing range is due in part to a fungal pathogen called Batrachochytrium dendrobatidis, or Bd, that has devastated amphibians around the world.

A team of researchers, including UC Santa Barbara’s Andrea Adams, has conducted the most comprehensive study to date of disease dynamics in foothill yellow-legged frogs. The team’s data — sourced from both wild frogs and specimens in museum collections — enabled them to track patterns of infection across a large geographic range. In a study published in Royal Society Open Science, the researchers reveal that drought, rising temperatures and the increasing conversion of land for agriculture appear to be the largest factors driving Bd infection in this species.

The researchers aimed to assemble as much data as they could, both in space and time. They surveyed in the creeks and rivers of California and Oregon, where they swabbed wild yellow-legged frogs for the presence of Bd. It also led them into fluorescent-lit museum collections to sample specimens from as far back as the 1890s.

Sunday, February 25, 2024

Study provides rare glimpse of the ringtail, an important but poorly understood predator

Photo Credit: Jonathan Armstrong, Oregon State University

Secretive species can pose special conservation challenges simply because they are so skilled at staying under the radar that researchers have uncovered comparatively little about their basic needs.

One such species is the ringtail, a relative of the raccoon that has cultural significance to many Indigenous peoples in North America.

A collaboration among scientists from Oregon State University, the Hoopa Valley Tribe, Penn State and Cal Poly Humboldt has shed new light on the cat-like animal known for its large eyes and fluffy, striped tail.

The nocturnal carnivore, known scientifically as Bassariscus astutus, usually weighs between 1 and 2 pounds and is around 24 inches long including its tail.

Ringtails use the cavities of living trees or standing dead ones, called snags, to rest, sleep, avoid bad weather, hide from predators and make dens to raise their young.

The research, conducted on the Hoopa Valley Reservation northeast of Eureka, California, found ringtails selected tree cavities in mature and older forests, as well as in younger forests with some older trees still present, rather than oak woodlands or other more open areas.

Monday, February 19, 2024

Spy-satellite images offer insights into historical ecosystem changes

A large forest clear-cut from the 1960s in the vicinity of a one-hectare forest research plot in the Southern Black Forest Region. Although much of the area is forested today, historical harvests have changed the forest structure and composition.
Left: Historical spy-satellite image. Right: Current Google Earth Image.
Image Credit: Courtesy of University of Freiburg

A large number of historical spy-satellite photographs from the Cold War Era were declassified decades ago. This valuable remote sensing data has been utilized by scientists across a wide range of disciplines from archaeology to civil engineering. However, its use in ecology and conservation remains limited. A new study led by Dr. Catalina Munteanu from the Faculty of Environment and Natural Resources at the University of Freiburg, Germany, aims to advance the application of declassified satellite data in the fields of ecology and conservation. Leveraging recent progress in image processing and analysis, these globally available black-and-white images can offer better insights into the historical changes of ecosystems, species populations or changes in human influences on the environment dating back to the 1960s, the researchers suggest.

Monday, February 12, 2024

Genetic analysis and archaeological insight combine to reveal the ancient origins of the fallow deer

Fallow deer
Photo Credit: Nick Fewings

Modern populations of fallow deer possess hidden cultural histories dating back to the Roman Empire which ought to be factored into decisions around their management and conservation.

New research, bringing together DNA analysis with archaeological insights, has revealed how fallow deer have been repeatedly moved to new territories by humans, often as a symbol of colonial power or because of ancient cultures and religions.

The results show that the animal was first introduced into Britain by the Romans and not the Normans, as previously believed. They also reveal how British colonial links during the 17th-19th centuries played a key role in spreading the deer around the world, including the Caribbean island of Barbuda, where it is the national animal.

The research, conducted jointly by the University of Exeter and Durham University, compares contemporary fallow deer records with zooarchaeological samples dating back 10,000 years.

Funded by the Arts and Humanities Research Council, the work has been published in two new studies, simultaneously. The 10,000-year biocultural history of fallow deer and its implications for conservation policy is featured in the latest edition of PNAS, while Ancient and modern DNA tracks temporal and spatial population dynamics in the European fallow deer since the Eemian interglacial is published in Scientific Reports.

Thursday, December 21, 2023

How technology and economics can help save endangered species

The gray wolf is among the animals protected by the Endangered Species Act.
Image Credit: Oregon Department of Fish & Wildlife
(CC BY-SA 2.0)

A lot has changed in the world since the Endangered Species Act (ESA) was enacted 50 years ago in December 1973.

Two researchers at The Ohio State University were among a group of experts invited by the journal Science to discuss how the ESA has evolved and what its future might hold.

Tanya Berger-Wolf, faculty director of Ohio State’s Translational Data Analytics Institute, led a group that wrote on “Sustainable, trustworthy, human-technology partnership.”  Amy Ando, professor and chair of the university’s Department of Agricultural, Environmental, and Development Economics, wrote on “Harnessing economics for effective implementation.”

Berger-Wolf and her colleagues wrote, “We are in the middle of a mass extinction without even knowing all that we are losing and how fast.” But technology can help address that.

For example, they note the value of tools like camera traps that survey animal species and smartphone apps that allow citizen scientists to count insects, identify bird songs and report plant observations.

Thursday, December 14, 2023

Bats declined as Britain felled trees for colonial shipbuilding

A western barbastelle.
Photo Credit: Antton Alberdi

Bat numbers declined as Britain’s trees were felled for shipbuilding in the early colonial period, new research shows.

The study, by the University of Exeter and the Bat Conservation Trust (BCT), found Britain’s Western barbastelle bat populations have dropped by 99% over several hundred years.

Animals’ DNA can be analyzed to discover a “signature” of the past, including periods when populations declined, leading to more inbreeding and less genetic diversity.

Scientists used this method to discover the historic decline of Western barbastelles in Britain – and also analyzed modern landscapes to see what helps and harms bats.

They found more genetic diversity among bats in areas rich in broadleaf woodland and diverse habitats.

Artificial light reduced connectivity between populations, probably because bats avoid areas with bright lighting, while rivers and woodlands increased connectivity.

“These bats usually roost in mature oak and beech trees, and move around every few nights – so they benefit from areas with substantial woodland cover,” said Dr Orly Razgour, from the University of Exeter.

Tuesday, December 12, 2023

Allured by Night Light

Skyglow — how bright the night sky is because of artificial light — is a top predictor of where large numbers of migrating birds are going to stop and rest during their migrations across the U.S.
Image Credit: Jeffrey C. Chase

Billions of migrating birds take flight across North America each fall and spring, heading south to their wintering grounds or north to their breeding grounds. 

Most of these birds are songbirds and they’re on the move at night. At times during their long migration, they need to stop, rest and refuel before they take off again. But instead of landing in their typical habitats such as forests or wetlands, artificial light is drawing them within and around cities. 

That’s a problem, said Jeff Buler, a University of Delaware professor of wildlife ecology, because light pollution can be an “ecological trap” for birds. 

“It lures them into cities where they’re at greater risk of colliding with buildings or mortality from other sources like feral cats,” Buler said. 

New research published in the journal Nature Communications finds that skyglow — how bright the night sky is because of artificial light — is a top predictor of where large numbers of migrating birds are going to stop and rest during their migrations across the U.S.

The study, which uses bird stopover data from 2016 to 2020, is a collaboration between UD’s Buler and researchers at Colorado State University, the National Park Service, the Cornell Lab of Ornithology, Princeton University, University of Massachusetts Amherst and Michigan State University. The research was supported with funding from NASA and the National Science Foundation.

Monday, November 6, 2023

European wildcats avoided introduced domestic cats for 2000 years

A wildcat which is part of the Saving Wildcats conservation breeding for release program which conducted the first release of wildcats to the Cairngorms National Park, Scotland in 2023
Photo Credit: Saving Wildcats

Domestic cats introduced from the Near East and wildcats native to Europe did not mix until the 1960s, despite being exposed to each other for two thousand years.

Two studies published today in Current Biology involving new archaeological and genetic evidence rewrites the history of cats in Europe.

The international team of researchers sequenced and analyzed both wildcats and domestic cats including 48 modern individuals and 258 ancient samples excavated from 85 archaeological sites over the last 8,500 years. They then assessed the patterns of hybridization (or interbreeding) after domestic cats were introduced to Europe over 2,000 years ago, and came into contact with native European wildcats.

The results of the studies demonstrate that, since their introduction, domestic cats and European wildcats generally avoided mating with each other. About 50 years ago in Scotland, however, that all changed and rates of interbreeding between wildcats and domestic cats rose rapidly. This may have happened as a result of dwindling wildcat populations and a lack of opportunity to mate with other wildcats.

Saturday, October 28, 2023

Native waterfall-climbing fish threatened by climate change, human activity

ʻOʻopu nākea is a type of goby fish found only in Hawaiʻi.
Photo Credit: Courtesy of University of Hawaiʻi

New research out of the University of Hawaiʻi at Mānoa is highlighting the importance of the ma uka (mountain) to ma kai (ocean) approach to the stewardship of Hawaiʻi’s natural and cultural resources.

The research focused on ʻoʻopu nākea, a type of goby fish found only in Hawaiʻi. ʻOʻopu nākea spends the larval part of its life in the ocean before returning to the freshwater streams to complete adulthood. It is also one of five freshwater fishes endemic to Hawaiʻi with fused pelvic fins that act as a suction cup to help climb waterfalls as they migrate upstream.

Unfortunately, like so many endemic species to Hawaiʻi, ʻoʻopu nākea are under threat from climate change and human activity and previous research indicated the species no longer needed to reach the ocean to complete their life cycle.

The UH Mānoa-led team utilized the latest microchemistry methods and found that 100% of ʻoʻopu nākea are still using the ocean as an important part of larval development. The study, “Understanding Amphidromy in Hawaiʻi: ʻOʻopu nākea (Awaous stamineus),” was published in the Journal of Fish Biology, and although the findings were positive, they still highlight the importance of preserving Hawaiʻi’s freshwater streams and bodies of water.

Thursday, October 26, 2023

Endangered whales live in area earmarked for gas exploration

Risso's dolphins.
Photo Credit Leonidas Karantzas/Greenpeace

Endangered whales and dolphins live year-round in an area of the Mediterranean earmarked for oil and gas exploration, new research shows.

Various cetacean species are known to inhabit the Hellenic Trench off Greece in the summer, but until now little has been known about their winter whereabouts.

This lack of information has been used to justify seismic surveys (which may harm whales and dolphins) in winter.

The new study found that at least four species – including the regionally endangered sperm whale – live in the deep waters of the Hellenic Trench in both summer and winter.

The research was carried out in 2021-22 by the Greenpeace Research Laboratories, University of Exeter, Greenpeace Greece and the Pelagos Cetacean Research Institute.

“The Mediterranean is one of the busiest seas on the planet, and whales and dolphins are already threatened by ship strikes, overfishing, bycatch (accidental catching), pollution with chemicals and plastics, and climate change,” said Dr Kirsten Thompson.

Tuesday, October 24, 2023

Killer whales’ diet more important than location for pollutant exposure

Photo Credit: Thomas Lipke

Both elegant and fierce, killer whales are some of the oceans’ top predators, but even they can be exposed to environmental pollution. Now, in the largest study to date on North Atlantic killer whales, researchers in the American Chemical Society’ Environmental Science & Technology report the levels of legacy and emerging pollutants in 162 individuals’ blubber. The animals’ diet, rather than location, greatly impacted contaminant levels and potential health risks — information that’s helpful to conservation efforts.

As the largest member of the dolphin family, killer whales, also known as orcas, are found worldwide. Marine vessel traffic can disturb the hunting and communication of these black-and-white marine mammals. But they face another type of human threat — legacy and emerging persistent organic pollutants (POPs) in their environments. POPs include chlorinated hydrocarbons and flame retardants, and can accumulate in animals’ fat stores as the contaminants move up the food chain though a process called biomagnification.

Thursday, October 19, 2023

Cut emissions and improve farming to protect wilderness

Photo Credit: Dave Willhite

Humanity must cut carbon emissions and use farmland more efficiently to protect our planet’s remaining wilderness, new research shows.

Climate change is making some wilderness areas more suitable for crop growing, heightening the risk of agricultural expansion, especially in northern areas including Canada, Scandinavia and Russia.

By assessing “future climate suitability” for more than 1,700 crop varieties, the study projects 2.7 million square kilometers of wilderness will become newly suitable for agriculture over the next 40 years.

This is 7% of the world’s total remaining wilderness outside Antarctica.

The study, by the University of Exeter, also projects that the variety of crops that can be grown will decrease on 72% of currently cultivable land worldwide – further driving pressure to expand farming into wilderness.

Wednesday, October 18, 2023

Marine mammals in zoos and aquariums now live 2-3 times longer than in the wild

Photo Credit: Los Muertos Crew

A new study provides compelling evidence that animal care and management practices at zoos and aquariums have significantly improved over time. The study, led by Species360 and University of Southern Denmark Research Scientist Dr. Morgane Tidière in collaboration with 41 co-authors from academic, governmental, and zoological institutions around the world, is the first to examine life expectancy and lifespan equality together as a proxy of population welfare in marine mammal species.

The study also found that marine mammal species live longer in zoological institutions than in the wild as a result of advances in animal care practices centered on animal welfare. The results have been published in Proceedings of the Royal Society B: Biological Sciences.

From SDU the following researchers contributed: Fernando Colchero, Johanna Staerk, Ditte H. Andersen, Kirstin Anderson Hansen and Dalia A. Conde.

The animals in the study
The four species in this study (harbor seal, sea lion, polar bear and bottlenose dolphin) were selected because they represent 63,4% of all marine mammals, registered in the global Species360 Zoological Information Management System (ZIMS).

Critical step made for managing brushtail possums

Researchers say mapping the genetic code of the brushtail possum will benefit those working to both conserve and control the animal.

In a five-year long study, just published in Nature Communications, an international group of researchers led by the University of Otago, has assembled the entire genetic code of the marsupial mammal.

The work also uncovered where and when their genes are expressed, and revealed surprising details about their population diversity, reproduction, and origins.

Study lead Associate Professor Tim Hore, of Otago’s Department of Anatomy, describes possums as “a fascinating animal that is loved in one country and a cause of concern in another”.

“They are hunted in Aotearoa New Zealand for their fur, and controlled for conservation, but treasured and protected in Australia. Having their full genetic code is important for both countries as efforts to manage their respective populations are being held back by the lack of this knowledge,” he says.

Tuesday, October 17, 2023

How to help save plants from extinction

California lilac, a species whose critical limits were obtained for this project
Photo Credit: Karen Udy Chang/Wikimedia Commons

Now is the time to identify the conditions that cause plants to die. Doing so will allow us to better protect plants by choosing conservation targets more strategically, UC Riverside botanists argue in a new paper. 

Published in the Oxford Academic journal Conservation Physiology, the paper demonstrates how scientists can learn the limits past which plants’ vital functions shut down, and makes the case that not doing so is a mistake in this era of increasing drought and wildfires.

“We can measure the amount of water loss plants can tolerate before they start to wilt, and we can learn the temperature at which photosynthesis stops for different kinds of plants,” said Louis Santiago, UCR botany professor and corresponding author of the paper. 

“It is so important to measure the critical limits of when things will fail, and not just how they’re doing now,” he said.

The UCR team believes understanding the current physiological status of a plant species during stress — which so many are experiencing more often with hotter, drier temperatures in many places — can be very useful for showing how close some plants are to local extinction already. Combined with critical limit data, limited conservation funds could be even more wisely spent, revealing plants’ warning signs before they become visible.

Monday, October 16, 2023

Genomic analysis in snakes shows link between neutral, functional genetic diversity

Eastern massasauga rattlesnake.
Photo Credit: Scott Martin

In the world of threatened and endangered species conservation, the genomic revolution has raised some complicated questions: How can scientists justify assessing species genetic diversity without consulting entire genomes now that they can be sequenced? But then again, how can scientists justify the time and expense of genome sequencing when age-old measures of neutral genetic diversity are much cheaper and easier to obtain?

A new study suggests making a transition from “old school” genetics to “new school” genomics for species conservation purposes probably isn’t necessary in all cases.

Researchers found the functional genetic diversity they detected by analyzing gene variations in fully sequenced genomes of 90 Eastern massasauga rattlesnakes correlated nicely with the neutral genetic diversity seen across broad sections of those same genomes containing no protein-coding genes – similar to the type of genetic material historically used to assess genetic diversity. 

“If we’re worried about the genetic health of populations, neutral diversity can give us a pretty good answer, as has long been argued. We have directly tested that for this species,” said H. Lisle Gibbs, professor of evolution, ecology and organismal biology at The Ohio State University and senior author of the study. 

Study indicates majority of endangered greater glider habitat in QLD unprotected

Greater Glider (Petauroides volans) in a Eucalypt taken by Sam Horton in South East Queensland for the Wildlife Queensland and the Glider Network
Photo Credit: Samrhorton

Researchers at Griffith University have discovered that the majority of critical habitat and movement pathways for southern greater gliders in Queensland lie outside of protected areas.

Dr Patrick Norman and Professor Brendan Mackey used cutting-edge technology to map mature forests to identify potential habitat and corridors that were essential for the survival of the endangered species. It is only these 200+-year-old forests in which tree hollows large enough to support the cat-sized gliders occurred.

Worryingly, the researchers discovered that most of the important remaining glider habitat in the state occurred within privately owned, lease owned land and state forest, leaving it vulnerable to logging, clearing and other threats.

Friday, October 13, 2023

Whaling wiped out far more fin whales than previously thought

The study found current conservation efforts should be enough to help the Eastern North Pacific fin whale population rebound without becoming inbred.
Photo Credit: Aqqa Rosing-Asvid
(CC BY 4.0 DEED)

A new genomic study by UCLA biologists shows that whaling in the 20th century destroyed 99% of the Eastern North Pacific fin whale breeding, or “effective,” population — 29% more than previously thought.

But there is also some good news: Genes among members of this endangered species are still diverse enough that current conservation measures should be be enough to help the population rebound without becoming inbred. The study also found that the health of this group is essential for the survival of highly isolated, genetically distinct fin whales in the Gulf of California.

The study, published in Nature Communications, is among the first to use whole genome information to get a picture of the size and genetic diversity of today’s population. Previous studies had to rely on whaling records or mitochondrial DNA, which is inherited only from the mother, providing limited genetic information.

In the 19th century, whaling decimated most whale species around the world but left the largest ones — blue and fin whales — largely untouched. That changed with the advent of industrial whaling in the 20th century. By midcentury, close to a million fin whales worldwide had been slaughtered, at least 75,000 of these in the Eastern North Pacific.

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