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

Thursday, April 4, 2024

Shy sea anemones are more likely to survive heatwaves

Photo Credit: Praveen Kenderla

Even in nature, pride can prevail. A study with researchers from the University of Gothenburg shows that sea anemones that react more slowly to change can survive a heatwave better than individuals that change their behavior quickly.

Along the Atlantic coasts of Europe, many species are exposed to abrupt shifts in habitat. Tides, storms and rapid temperature changes are commonplace for the marine species that live there. With climate change, heatwaves are expected to become more frequent, and researchers wanted to find out how coastal marine species cope with extreme water temperatures. They chose to study the sea anemone species Actinia equina, a species that exhibits individual behaviors.

Bold or shy

“We call them animal personalities. They are different behavioral life strategies found in the same species. The anemones we studied have two personality traits, bold and shy, and in extreme heat waves the shy anemones do better,” says Lynne Sneddon, a zoophysiologist at the University of Gothenburg and co-author of the study published in the Journal of Experimental Biology.

Wednesday, April 3, 2024

Discovery could end global amphibian pandemic

Panamanian golden frog
Photo Credit: Brian Gratwicke/U.S. Fish & Wildlife Service

A fungus devastating frogs and toads on nearly every continent may have an Achilles heel. Scientists have discovered a virus that infects the fungus, and that could be engineered to save the amphibians.

The fungus, Batrachochytrium dendrobatidis or Bd, ravages the skin of frogs and toads, and eventually causes heart failure. To date it has contributed to the decline of over 500 amphibian species, and 90 possible extinctions including yellow-legged mountain frogs in the Sierras and the Panamanian golden frog. 

A new paper in the journal Current Biology documents the discovery of a virus that infects Bd, and which could be engineered to control the fungal disease.

The UC Riverside researchers who found the virus are excited about the implications of their discovery. In addition to helping them learn about how fungal pathogens rise and spread, it offers the hope of ending what they call a global amphibian pandemic. 

“Frogs control bad insects, crop pests, and mosquitoes. If their populations all over the world collapse, it could be devastating,” said UCR microbiology doctoral student and paper author Mark Yacoub. 

“They’re also the canary in the coal mine of climate change. As temperatures get warmer, UV light gets stronger, and water quality gets worse, frogs respond to that. If they get wiped out, we lose an important environmental signal,” Yacoub said. 

Tuesday, March 26, 2024

Behavior of ant queens is shaped by their social environment

A black garden ant queen caring for her brood
Photo Credit: © Romain Libbrecht)

The queens in colonies of social insects, such as ants, bees, and wasps, are considered the veritable embodiment of specialization in the animal kingdom. The common perception is that the queen's only task is to lay eggs – and that this attribute is an inherent trait, not influenced by external factors. In contrast, recent research undertaken at Johannes Gutenberg University Mainz (JGU) has demonstrated that in certain ant colonies the social environment can play a crucial role in shaping the behavioral specialization of the queens. "With regard to the ant species we studied, it is social factors that control whether queens become specialized or not. Our findings challenge the widely accepted notion of social insect queens as inherently specialized egg-laying machines," stated Dr. Romain Libbrecht.

The research was conducted by the Reproduction, Nutrition, and Behavior in Insect Societies group at JGU under the supervision of Dr. Romain Libbrecht, an evolutionary biologist. The corresponding paper has recently been published in Functional Ecology. Dr. Romain Libbrecht currently works at the Centre National de la Recherche Scientifique (CNRS) in the Insect Biology Research Institute of the University of Tours.

Monday, March 25, 2024

Honey bees at risk for colony collapse from longer, warmer fall seasons

WSU researchers and students collect samples and perform honey bee colony health assessments in orchards near Modesto, CA.
Photo Credit: Brandon Hopkins

The famous work ethic of honey bees might spell disaster for these busy crop pollinators as the climate warms, new research indicates.

Flying shortens the lives of bees, and worker honey bees will fly to find flowers whenever the weather is right, regardless of how much honey is already in the hive. Using climate and bee population models, researchers found that increasingly long autumns with good flying weather for bees raises the likelihood of colony collapse in the spring.

The study, published in the journal Scientific Reports, focused on the Pacific Northwest but holds implications for hives across the U.S. The researchers also modeled a promising mitigation: putting colonies into indoor cold storage, so honey bees will cluster in their hive before too many workers wear out.

“This is a case where a small amount of warming, even in the near future, will make a big impact on honey bees,” said lead author Kirti Rajagopalan, a Washington State University climate researcher. “It’s not like this is something that can be expected 80 years from now. It is a more immediate impact that needs to be planned for.”

Tuesday, March 12, 2024

Bees master complex tasks through social interaction

Bees can learn complex, multi-step tasks through social interaction, even if they cannot figure them out on their own.
Photo Credit: Michael Hodgins

In a groundbreaking discovery, bumblebees have been shown to possess a previously unseen level of cognitive sophistication.

 A new study, published in Nature, reveals that these bees can learn complex, multi-step tasks through social interaction, even if they cannot figure them out on their own. This challenges the long-held belief that such advanced social learning is unique to humans, and hints at the presence of key elements of cumulative culture in these insects.

Led by Dr Alice Bridges, postdoctoral researcher at the University of Sheffield, the research team designed a two-step puzzle box requiring bumblebees to perform two distinct actions in sequence to access a sweet reward at the end. The temporary reward was eventually taken away, and bees subsequently had to open the whole box before getting the treat. 

While individual bees struggled to solve the puzzle when starting from scratch, those allowed to observe a trained "demonstrator" bee readily learned the entire sequence – even the first step – while only getting a reward at the end.

Saturday, March 9, 2024

What Makes Birds So Smart?

The avian brain is smaller than that of many mammals, but just as capable.
Photo Credit: Kevin Mueller

Researchers at Ruhr University Bochum explain how it is possible for the small brains of pigeons, parrots and corvids to perform equally well as those of mammals, despite their significant differences.

Since the late 19th century, it has been a common belief among researchers that high intelligence requires the high computing capacity of large brains. They also discovered that the cerebral cortex as typical of mammals, is necessary to analyze and link information in great detail. Avian brains, by contrast, are very small and lack any structure resembling a cortex. Nevertheless, scientists showed that parrots and corvids are capable of planning for the future, forging social strategies, recognizing themselves in the mirror and building tools. These and similar aptitudes put them on a par with chimpanzees. Even less gifted birds, such as pigeons, learn orthographic rules that enable them to recognize typos in short words or classify pictures according to categories such as “impressionism”, “water” or “man-made”. How do they do it with such small brains and without a cortex? With their article in Trends in Cognitive Science, Professor Onur Güntürkün, Dr. Roland Pusch and Professor Jonas Rose from Ruhr University Bochum come closer to solving this more than one hundred-year-old puzzle.

Reptile roadkill reveals new threat to endangered lizard species

The western spiny-tailed skink.
Photo Credit: Dr. Holly Bradley

The chance sighting of a dead snake beside a sandy track in remote Western Australia, and the investigation of its stomach contents, has led Curtin University researchers to record the first known instance of a spotted mulga snake consuming a pygmy spiny-tailed skink, raising concerns for a similar-looking, endangered lizard species.

Lead researcher Dr Holly Bradley from Curtin’s School of Molecular and Life Sciences said the discovery of the partially digested pygmy spiny-tailed skink within the snake had implications for the vulnerable western spiny-tailed skink species.

“Found about 300km east of Geraldton and likely killed by a vehicle, the snake’s consumption of the pygmy spiny-tailed skink raises concerns about the susceptibility of similar-sized juvenile western spiny-tailed skinks, which also inhabit the Mid-West region and are classified as endangered,” Dr Bradley said.

“Pygmy spiny-tailed skinks look and act a lot like babies of the endangered western spiny-tailed skink, which live in the same area, so if these snakes are preying on one of them, they are likely also preying on the other.

Monday, March 4, 2024

Study of slowly evolving ‘living fossils’ reveals key genetic insights

The alligator gar, and other gar species, are “living fossils” that it shows little species diversity or physical differences from ancestors that lived tens of millions of years ago.
Photo Credit: David Solomon

In 1859, Charles Darwin coined the term “living fossils” to describe organisms that show little species diversity or physical differences from their ancestors in the fossil record. In a new study, Yale researchers provide the first evidence of a biological mechanism that explains how living fossils occur in nature.

The study, published in the journal Evolution, shows that gars — an ancient group of ray-finned fishes that fit the definition of a living fossil — have the slowest rate of molecular evolution among all jawed vertebrates, meaning their genome changes more slowly than those of other animals.

By linking this finding to the process of hybridization — when two different species produce viable offspring — of gar species in the wild that last shared common ancestry during the age of the dinosaurs, the researchers demonstrate that slow evolution rate of their genome drives their low species diversity.

“We show that gars’ slow rate of molecular evolution has stymied their rate of speciation,” said Thomas J. Near, professor of Ecology and Evolutionary Biology in Yale’s Faculty of Arts and Sciences and the paper’s senior author. “Fundamentally, this is the first instance where science is showing that a lineage, through an intrinsic aspect of its biology, fits the criteria of living fossils.” 

Thursday, February 29, 2024

Oregon State University researchers are first to see at-risk bat flying over open ocean

Hoary bat at sea.
Photo Credit: Courtesy of Will Kennerley / the MOSAIC Project.

On a research cruise focused on marine mammals and seabirds, Oregon State University scientists earned an unexpected bonus: The first-ever documented sighting of a hoary bat flying over the open ocean.

The bat was seen in the Humboldt Wind Energy Area about 30 miles off the northern California coast; the Humboldt area has been leased for potential offshore energy development, and the hoary bat is the species of bat most frequently found dead at wind power facilities on land.

OSU faculty research assistant Will Kennerley, the first to see the bat, and colleagues documented the sighting with a paper in the Journal of North American Bat Research. The bat was spotted just after 1 p.m. on Oct. 3, 2022, in observing conditions rated as excellent.

“I have spent a lot of time at sea in all oceans of the world, and I’ve seen a lot of amazing things,” said Lisa Ballance, director of OSU’s Marine Mammal Institute. “A hoary bat was a first for all of us. It’s a reminder of the wonder of nature, and of its vulnerability.”

Wednesday, February 28, 2024

New Fish Species Discovered at Remote Islands Off Mexico’s Pacific Coast

Two females of the newly discovered species, Halichoeres sanchezi or the tailspot wrasse. The males are larger and have different coloration.
Photo Credit: Allison & Carlos Estape

A team of scientists including Ben Frable of UC San Diego’s Scripps Institution of Oceanography have discovered a new species of tropical fish during an expedition to the remote islands of the Revillagigedo Archipelago off Mexico’s Pacific coast. The fish is likely endemic to these islands, meaning it is found no place else on Earth. The Revillagigedos are sometimes called the “Mexican Galapagos” for their trove of marine biodiversity and rugged beauty. 

The researchers describe the new species, dubbed Halichoeres sanchezi or the tailspot wrasse, in a paper published Feb. 28 in the journal PeerJ. Halichoeres sanchezi was named in honor of marine scientist Carlos Armando Sánchez Ortíz of the Universidad Autónoma de Baja California Sur (UABCS) who collected the first specimen and who organized the 2022 expedition that led to the fish’s discovery.

The eight specimens of the new species collected by the team range in size from around an inch long to nearly six inches. The smaller females of the species are mostly white with reddish horizontal stripes along their top half and black patches on their dorsal fin, behind their gills, and just ahead of their tail fin. Frable described the males as “orangy red up top fading to a yellow belly with a dark band at the base of the tail.” 

Halichoeres sanchezi is a member of the wrasse family, a highly diverse and colorful group of more than 600 species. Most wrasse are less than seven inches long, such as the bluestreak cleaner wrasse (Labroides dimidiatus), but some get much larger like the California sheephead (Semicossyphus pulcher) or the massive humphead wrasse (Cheilinus undulatus), which can reach seven feet in length.

Researchers encountered the new wrasse species inhabiting an underwater field of volcanic rubble at a depth of around 70 feet near San Benedicto Island.

Monday, February 26, 2024

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.

Thursday, February 22, 2024

Snakes do it faster, better

An Australian “snake-lizard” (Lialis burtonis).This species shares numerous similarities with snakes, including loss of limbs and highly flexible skull. But it is an entirely different type of reptile. It is, in fact, a gecko, and is only distantly related to snakes. The snake-lizard is a specialized predator of other lizards and thus has a diet that is also more similar to snakes than it is to other lizards. With just two known species, the snake-lizard has undergone very little evolutionary diversification. Snakes, in contrast, have diversified into many hundreds of species in Australia alone.
Photo Credit: Pascal Title, University of Michigan/Stony Brook University.

More than 100 million years ago, the ancestors of the first snakes were small lizards that lived alongside other small, nondescript lizards in the shadow of the dinosaurs.

Then, in a burst of innovation in form and function, the ancestors of snakes evolved legless bodies that could slither across the ground, highly sophisticated chemical detection systems to find and track prey, and flexible skulls that enabled them to swallow large animals.

Those changes set the stage for the spectacular diversification of snakes over the past 66 million years, allowing them to quickly exploit new opportunities that emerged after an asteroid impact wiped out roughly three-quarters of the planet’s plant and animal species.

How bats distinguish different sounds

Seba's short-tailed bat (Carollia perspicillata) filters out important signals from ambient sound and distinguishes between echolocation and communication calls.
Photo Credit: Julio Hechavarría, Goethe University Frankfurt

Bats live in a world of sounds. They use vocalizations both to communicate with their conspecifics and for navigation. For the latter, they emit sounds in the ultrasonic range, which echo and enable them to create an “image" of their surroundings. Neuroscientists at Goethe University Frankfurt have now discovered how Seba's short-tailed bat, a species native to South America, manages to filter out important signals from ambient sound and especially to distinguish between echolocation and communication calls. 

Seba's short-tailed bat (Carollia perspicillata) lives in the subtropical and tropical forests of Central and South America, where it mostly feeds on pepper fruit. The animals spend their days in groups of 10 to 100 individuals in hollow trunks and rocky caverns, and at night they go foraging together. They communicate using sounds that create distinct ambient noise in the colony – like the babble of voices at a lively party. At the same time, the bats also use vocalizations to navigate their surroundings: a phenomenon known as echolocation, for which they emit ultrasonic sounds that reflect off solid surfaces. The animals then assemble these echoes into an “image" of their surroundings. 

Caring glass frog fathers have smaller testes

Males of the glassfrog species Hyalinobatrachium valerioi are very dedicated fathers.
Photo Credit: © Francesca Angiolani

An international team of researchers including the University of Bern shows in a new study that male glass frogs that care for their offspring have smaller testes than males of species that do not provide any brood care. This indicates an evolutionary trade-off between sperm production and parenting.

Living in the tropical rainforests of Central and South America, frogs of the glass frog family are fascinating because of their transparent skin on their belly, which reveals their internal organs. However, it is not only the appearance of these amphibians that is remarkable, but also their social behavior. In many - but not all - glass frog species, the males remain with the clutch after mating and guard and care for their offspring. In a new study, an international team, including researchers from the Institute of Ecology and Evolution at the University of Bern, shows that there is a link between this paternal care and the testes size of glass frogs. The results were recently published in the journal Proceedings of the Royal Society B.

Tuesday, February 20, 2024

Physically impaired primates find ways to modify their behaviors to compensate for their disabilities

Infant macaque at the Awajishima Monkey Center.
Photo Credit: Sarah Turner

Primates show a remarkable ability to modify their behaviors to accommodate their physical disabilities and impairments according to a new literature review by Concordia researchers.

Whether the disabilities are the result of congenital malformations or injuries, many primate species exhibited behavioral flexibility and innovation to compensate for their disabilities. They also benefitted from flexible and innovative behavior by their mothers early in life and from their peers within their population group as they aged.

Researchers at the Primatology and Interdisciplinary Environmental Studies (PIES) Lab looked at 114 studies and published their findings in the American Journal of Primatology.

The survey also revealed something the researchers had not anticipated.

“Brogan Stewart, a PhD candidate and the paper’s lead author, noticed that a high proportion of the papers mentioned a connection to human activity as a potential or actual cause of impairment,” says co-corresponding author Sarah Turner, an associate professor in the Department of Geography, Planning and Environment in the Faculty of Arts and Science.

“The disabilities may be the result of primates being caught in snares intended for other animals, or farmers trying to deter crop foraging. Perhaps they are the result of vehicle collision, or sometimes there are links between a small population’s genetics and the impairments, or diseases transmitted from people or contaminants in the environment.”

Monday, February 19, 2024

Birds have been adapting to human activity for millennia

Coot nesting on bike on a lake in Copenhagen. Birds and humans also co-inhabited specific environments in our prehistory, new research shows.
Photo Credit: Lisa Yeomans

Roughly 14,500 to 10,500 years ago, in the transition from the last glacial period, humans harvesting vegetation from the wetlands of eastern Jordan created a habitat for birds that would otherwise have migrated, a new study reveals. It shows that human activity is not necessarily detrimental to biodiversity but may allow for species to co-inhabit specific environments, the researchers suggest.

The presence of humans is usually associated with negative effects on flora and fauna, and our species has demonstrably influenced biodiversity negatively in the course of history.

But in a new study published in the Journal of Archaeological Method and Theory, a team of researchers from the University of Copenhagen and the University of Turin have discovered that some human activities may have had an encouraging effect on biodiversity through modification of specific ecosystems.

Thursday, February 15, 2024

Scientists are unraveling the secrets of red and grey squirrel competition

Image Credit: Gemini Advance AI

In a first of its kind study, researchers have identified significant differences between the diversity of gut bacteria in grey squirrels compared to red squirrels which could hold the key to further understanding the ability of grey squirrels to outcompete red squirrels in the UK. 

New research, published in the Journal of Medical Microbiology, looked to understand more about the mechanisms by which grey squirrels are able to gain an advantage over red squirrels. Chris Nichols, Conservation Evidence Manager at the Woodland Trust, and co-author of the study, said:

“The more we know about grey squirrels, the more equipped we’re going to be in the future to tackle the threats they pose to red squirrels and our native trees, which is one of the biggest problems for forest conservation in the UK.”

Grey squirrels are an invasive, non-native species introduced from North America to sites in Great Britain and Ireland between 1876 to 1929. They out-compete the native red squirrels and multiply thanks to various traits including their ability to access a broader range of food sources including the bark of UK broadleaved trees. This causes significant damage to the trees, and is a behavior that, prior to this research, was not completely understood. 

Tuesday, February 13, 2024

Desert Ants: The Magnetic Field Calibrates the Navigation System

The desert ant Cataglyphis nodus at its nest entrance - an inconspicuous hole in the ground that cannot be seen from the ant's perspective. To find its way back there, the ant uses the earth's magnetic field during its learning walks.
Photo Credit: Robin Grob

Desert ants find their way during an early learning phase with the help of the Earth's magnetic field. The associated learning process leaves clear traces in their nervous system. This is shown in a new study by a Würzburg research team.

They are only a few centimeters tall and their brains have a comparatively simple structure with less than one million neurons. Nevertheless, desert ants of the Cataglyphis genus possess abilities that distinguish them from many other creatures: The animals are able to orient themselves to the Earth's magnetic field.

Visible Changes in the Nervous System

A research team from Julius-Maximilians-Universität Würzburg (JMU) discovered this a few years ago. However, it was previously unknown where in the ants' brains the magnetic information is processed. This has now changed: In a new study published in the journal PNAS - Proceedings of the National Academy of Sciences, the team shows that information about the Earth's magnetic field is primarily processed in the ants' internal compass, the so-called central complex, and in the mushroom bodies, the animals' learning and memory centers.

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.

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