Emperor penguins face a bleak future – but some colonies will do better than others in diverse sea-ice conditions

Sara Labrousse/French Polar Institute, CC BY-SA Sara Labrousse, Sorbonne Université and Michelle LaRue, University of Canterbury

The long-term future looks bleak for Emperor penguins, but our new research shows some birds may be able to survive in certain conditions, depending on where they live, at least for the next few decades.

Over the past two years, Antarctic sea ice has declined dramatically, prompting scientists to suggest it could reach a “new state”.

A study based on satellite images shows that sea ice broke out early in Antarctica’s Bellingshausen Sea in 2022, potentially resulting in breeding failures across several Emperor penguin colonies in that region.

Our research shows Emperors form colonies in surprisingly diverse environmental conditions that vary depending on location around the continent. Within each of these regions, there is little difference between where birds make their homes and other sites, suggesting they could shift if they had to. This provides a ray of hope in an otherwise bleak outlook.

Emperor penguins may be the only birds to rarely set foot on land. They are unique among penguin species in that they breed on sea ice during the harsh Antarctic winter.

Male Emperor penguins incubate eggs and raise the chicks on sea ice during the Antarctic winter. Sara Labrousse/French Polar Institute, CC BY-SA

We know that they need “fast ice” – the coastal sea ice attached to the Antarctic continent or ice shelves. But they actually inhabit a range of fast-ice locations that differ in the timing of ice formation, how much ice forms and breaks, and even how close they get to other penguin species.

Depending on where they are along the Antarctic coast, Emperors make use of the habitat available to them. Their behaviour may be flexible enough to allow some colonies to cope better in a warming world.

Why fast ice is important

Emperor penguins rely on fast ice as a stable platform for their breeding season. Female Emperors lay their eggs and the males incubate them for about two and a half months.

Even though Antarctica’s sea ice is diminishing, this refers to a measure known as “sea ice extent”, which includes all sea ice covering the polar ocean, whether it is fast ice or drifting pack ice.

A decrease in sea ice extent is not necessary linearly linked to a drop in the area covered by fast ice (although the reverse is true).

If fast ice were to disappear, we would expect more than 90% of Emperor colonies to become functionally extinct by the end of the century. However, our study suggests that in the short to medium term, we should consider the differences in the penguins’ breeding habitats when we think about ways to protect them.

Emperors are unlikely to move far

By looking a little closer at different fast-ice habitats, we found Emperor penguins have certain preferences. The persistence of the ice (how long it lasts into the summer) was important because chicks had more time to develop their water-proof swimming feathers.

In some cases, being close to Adélie penguins made a difference. In other cases, Emperors preferred sites with shallow ocean depths below the colony.

Our results suggest that two of these habitat conditions support larger colonies: stable fast ice that lasts throughout the breeding season (with only small changes in the growth and retreat seasonal cycle) and a good balance between a fast-ice platform that is wide enough to raise chicks but close enough to the ocean to get food for them.

Emperor penguins need access to the ocean to feed their chicks during the breeding season. Sara Labrousse/French Polar Institute, CC BY-SA

We need further studies to clarify these links and the relationship between population size and habitat quality. In our study, we weren’t able to consider prey availability and there may be other factors that play an important role.

Previous research has already shown that Emperor penguins have limited capacity to disperse to find more suitable climate refuges. This is supported by the genetic partitioning among the penguin populations in different Antarctic regions we studied.

It is therefore unlikely Emperors would move far to avoid more severe climate impacts, even if “better” habitats existed and could host larger colonies.

Emperors don’t easily move to other breeding sites, even if the conditions are better. Sara Labrousse/French Polar Institute, CC BY-SA

Protecting penguin habitat

Climate change is currently one of the main pressures driving Emperor penguins closer to extinction.

However, the latest global assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) clearly identified fishing activities as historic and current drivers of the erosion of marine biodiversity worldwide.

This is also true for Antarctica. While fishing pressure there is limited to a fraction of the global fishing fleet, some of the largest vessels target krill, a tiny shrimp-like crustacean consumed by many Antarctic predators, including Emperor penguins.

With climate models predicting further reductions in sea ice extent, new fishing grounds could open and amplify pressure on other Antarctic wildlife.

If we want to live in a world with Emperor penguins, the most important thing to do would be to cut greenhouse gas emissions steeply. Another key action could be to prevent fishing in areas where climate change will have the most impact.

In this respect, truly protected areas are one conservation tool at our disposal. Now that our research provides more detailed information about penguin habitats, we can begin the process of more careful planning for conservation.

The world’s largest marine protected area exists in the Ross Sea, which is home to about 25% of the world’s Emperor penguins. Lessons we learn from protection there could help mitigate future declines of Emperors around Antarctica.

Sara Labrousse, Chercheuse en écologie polaire, Sorbonne Université and Michelle LaRue, Associate Professor in Conservation Biology, University of Canterbury

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→October 04, 2023

Why Men Find Switching Tasks More Difficult Than Do Women

It has long been known to science that women find it easier than men to multitask and switch between tasks. But identifying exactly which areas of male and female brains respond differently and why has so far been unclear. According to researchers from the HSE Neurolinguistics Laboratory, men need to mobilise additional areas of their brain and use more energy than women when multitasking.

Why Men Find Switching Tasks More Difficult

Needing to switch attention between tasks causes stronger activation in certain brain regions in men compared to women.

Although women find it easier than men to switch between tasks; how exactly their brains function differently in such situations has so far been unknown. Recent research reveals that male brains appear to consume more energy when they need to shift attention. In addition to this, in men there is greater activity in the dorsolateral prefrontal areas of the brain compared to women, as well as activation in some other areas which is not usually observed in women.

Such differences are typical of younger men and women aged 20 to 45, according to findings from experiments conducted by researchers Svetlana Kuptsova and Maria Ivanova of the HSE Neurolinguistic Laboratory, radiologists Alexey Petrushevsky and Oksana Fedina of the Centre for Speech Pathology and Neurorehabilitation, and Ludmila Zhavoronkova, Doctor of Biology and Senior Research Fellow of the RAS Institute of Higher Nervous Activity and Neurophysiology. The study's findings have been published in Human Physiology, an international peer-reviewed journal.

Higher Activity, Slower Speed

Regardless of gender and age, task switching always involves activation in certain areas of the brain, more specifically, bilateral activation of the dorsolateral prefrontal areas, inferior parietal lobes and inferior occipital gyrus.

However, experiments conducted by Kuptsova et al. demonstrate that in women, task switching appears to require less brain power compared to men, who showed greater activation in the dorsolateral prefrontal areas as well as the involvement of supplementary motor areas and insula, which was not observed in women.

"We know that stronger activation and involvement of supplementary areas of the brain are normally observed in subjects faced with complex tasks. Our findings suggest that women might find it easier than men to switch attention and their brains do not need to mobilise extra resources in doing so, as opposed to male brains," explained Kuptsova.

The experiments involved 140 healthy volunteers, including 69 men and 71 women aged between 20 and 65. The subjects were asked to perform a variety of tasks. In one of the experiments using functional MRI, they were asked to perform a test that required switching attention between sorting objects according to shape (round or square) and number (one or two), in a pseudo-random order. In addition to this, neuropsychological tests were conducted, including the D-KEFS Trail Making Test to measure the subjects' ability to switch attention and the Wechsler Memory Scale test to measure their audial and visual memory.

The use of functional MRI allowed the researchers not only to observe the subjects' behaviour, but also to see what was going on in the brain as subjects switched between tasks and detect differences in brain activation between men and women.

Age versus Gender

The researchers found that the gender differences in the extent of brain activation when switching between tasks only occurred in subjects younger that 45-50, while those aged 50 and older showed no gender differences either in brain activation or speed of task switching.

According to the researchers, older men and women - starting at the age of 45 in women and 55 in men - experienced both increased activation of key areas involved and mobilisation of additional brain resources.

Brain Mystery

The study has once again confirmed that young women tend to cope with attention switching better than young men. While the reaction time is demonstrably different, according to Kuptsova, it is barely noticeable in everyday life, except perhaps that, "it might make a difference in really stressful circumstances or in critical situations which require frequent switching of attention."

However, science cannot currently explain the exact reasons for this difference. Any assumptions as to why nature might need it are nothing but speculation, Kuptsova argues.

For example, there is a popular hypothesis by American psychologist Jerre Levy as to why men tend to have better spatial skills while women are often better at more verbal tasks. According to Levy, these differences are caused by both evolutionary and social factors. In ancient times, men spent their time hunting, which required good spatial abilities, while women were caring for children and thus needed good communication skills. In the course of evolution, these survival skills have been passed down to future generations.

"We could continue with the same logic and assume that homemaking and caring for children historically required women to be good at multitasking, but there is no hard evidence to support this theory," Kuptsova concludes.

The study was hosted by the Centre for Speech Pathology and Neurorehabilitation.

Contacts and sources:

National Research University - Higher School of Economics (HSE)

Citation: Sex- and age-related characteristics of brain functioning during task switching (fMRI study) Authors Authors and affiliations S. V. KuptsovaEmail authorM. V. Ivanova, A. G. Petrushevskiy, O. N. FedinaL. A. Zhavoronkova. Human Physiology July 2016, Volume 42, Issue 4, pp 361–370 2016 DOI: 10.1134/S0362119716040101 Source: http://www.ineffableisland.com/

Read More........→November 22, 2016

Scientists shocked to discover new species of green anaconda, the world’s biggest snake

Shutterstock Bryan G. Fry, The University of Queensland

The green anaconda has long been considered one of the Amazon’s most formidable and mysterious animals. Our new research upends scientific understanding of this magnificent creature, revealing it is actually two genetically different species. The surprising finding opens a new chapter in conservation of this top jungle predator.

Green anacondas are the world’s heaviest snakes, and among the longest. Predominantly found in rivers and wetlands in South America, they are renowned for their lightning speed and ability to asphyxiate huge prey then swallow them whole.

My colleagues and I were shocked to discover significant genetic differences between the two anaconda species. Given the reptile is such a large vertebrate, it’s remarkable this difference has slipped under the radar until now.

Conservation strategies for green anacondas must now be reassessed, to help each unique species cope with threats such as climate change, habitat degradation and pollution. The findings also show the urgent need to better understand the diversity of Earth’s animal and plant species before it’s too late.

Scientists discovered a new snake species known as the northern green anaconda. Bryan Fry

An impressive apex predator

Historically, four anaconda species have been recognised, including green anacondas (also known as giant anacondas).

Green anacondas are true behemoths of the reptile world. The largest females can grow to more than seven metres long and weigh more than 250 kilograms.

The snakes are well-adapted to a life lived mostly in water. Their nostrils and eyes are on top of their head, so they can see and breathe while the rest of their body is submerged. Anacondas are olive-coloured with large black spots, enabling them to blend in with their surroundings.

The snakes inhabit the lush, intricate waterways of South America’s Amazon and Orinoco basins. They are known for their stealth, patience and surprising agility. The buoyancy of the water supports the animal’s substantial bulk and enables it to move easily and leap out to ambush prey as large as capybaras (giant rodents), caimans (reptiles from the alligator family) and deer.

Green anacondas are not venomous. Instead they take down prey using their large, flexible jaws then crush it with their strong bodies, before swallowing it.

As apex predators, green anacondas are vital to maintaining balance in their ecosystems. This role extends beyond their hunting. Their very presence alters the behaviour of a wide range of other species, influencing where and how they forage, breed and migrate.

Anacondas are highly sensitive to environmental change. Healthy anaconda populations indicate healthy, vibrant ecosystems, with ample food resources and clean water. Declining anaconda numbers may be harbingers of environmental distress. So knowing which anaconda species exist, and monitoring their numbers, is crucial.

To date, there has been little research into genetic differences between anaconda species. Our research aimed to close that knowledge gap.

Green anaconda have large, flexible jaws. Pictured: a green anaconda eating a deer. JESUS RIVAS

Untangling anaconda genes

We studied representative samples from all anaconda species throughout their distribution, across nine countries.

Our project spanned almost 20 years. Crucial pieces of the puzzle came from samples we collected on a 2022 expedition to the Bameno region of Baihuaeri Waorani Territory in the Ecuadorian Amazon. We took this trip at the invitation of, and in collaboration with, Waorani leader Penti Baihua. Actor Will Smith also joined the expedition, as part of a series he is filming for National Geographic.

We surveyed anacondas from various locations throughout their ranges in South America. Conditions were difficult. We paddled up muddy rivers and slogged through swamps. The heat was relentless and swarms of insects were omnipresent.

We collected data such as habitat type and location, and rainfall patterns. We also collected tissue and/or blood from each specimen and analysed them back in the lab. This revealed the green anaconda, formerly believed to be a single species, is actually two genetically distinct species.

The first is the known species, Eunectes murinus, which lives in Perú, Bolivia, French Guiana and Brazil. We have given it the common name “southern green anaconda”. The second, newly identified species is Eunectes akayima or “northern green anaconda”, which is found in Ecuador, Colombia, Venezuela, Trinidad, Guyana, Suriname and French Guiana.

We also identified the period in time where the green anaconda diverged into two species: almost 10 million years ago.

The two species of green anaconda look almost identical, and no obvious geographical barrier exists to separate them. But their level of genetic divergence – 5.5% – is staggering. By comparison, the genetic difference between humans and apes is about 2%.

The two green anaconda species live much of their lives in water. Shutterstock

Preserving the web of life

Our research has peeled back a layer of the mystery surrounding green anacondas. This discovery has significant implications for the conservation of these species – particularly for the newly identified northern green anaconda.

Until now, the two species have been managed as a single entity. But each may have different ecological niches and ranges, and face different threats.

Tailored conservation strategies must be devised to safeguard the future of both species. This may include new legal protections and initiatives to protect habitat. It may also involve measures to mitigate the harm caused by climate change, deforestation and pollution — such as devastating effects of oil spills on aquatic habitats.

Our research is also a reminder of the complexities involved in biodiversity conservation. When species go unrecognised, they can slip through the cracks of conservation programs. By incorporating genetic taxonomy into conservation planning, we can better preserve Earth’s intricate web of life – both the species we know today, and those yet to be discovered.

Bryan G. Fry, Professor of Toxicology, School of the Environment, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→February 19, 2024