Thursday, 2 April 2020

Chimpanzees found to age in ways similar to humans


MARCH 31, 2020 REPORT

by Bob Yirka , Phys.org

A team of researchers from the University of New Mexico and the Kibale Chimpanzee Project in Uganda has found similarities between the way chimpanzees and humans age. In their paper published in Proceedings of the National Academy of Sciences, the group describes their 20-year study of chimps living at Kibale National Park and what they learned about the ways they age.

Prior research has shown that as people age, they undergo changes to their hypothalamic-pituitary-adrenal (HPA) axis—a biological system that plays a major role in how people respond to stress. One of those ways is bumping up levels of cortisol production. Cortisol is a hormone that plays a role in regulating metabolism and blood pressure. Prior research has also shown that excess cortisol can lead to problems such as a reduction in clear thinking, a weakened immune system and inflammation—all symptoms of aging in humans. But now, it appears that chimpanzees undergo a similar process.

The work by the team was part of a large overall effort to study physical and behavioral traits of chimpanzees in a near-natural setting. As part of that effort, team members placed plastic bags in the trees where the chimps reside in the park to collect urine samples from 59 adults. The team has been collecting urine samples from the chimps for approximately 20 years. In analyzing its composition, the researchers have found that the chimps also experience elevated levels of cortisol as they grow older—and furthermore, the higher levels of the hormone could not be attributed to reproductive activity or social status. They claim the increased levels of cortisol suggest chimps age similarly to humans.

The researchers found that cortisol levels were highest in the males when they were making moves on sexually receptive females. They also found that cortisol levels were highest in the females when they were sexually receptive—a time when females are under stress from competing males. They also suggest that rising cortisol levels in hominids are an ancient attribute, and are thus not a byproduct of aging.


About the distribution of biodiversity on our planet


Date: April 1, 2020
Source: University of Bern

Since Charles Darwin, biologists have been using the so-called "biotic interactions" hypothesis to explain, at least in part, why the tropics around the equator are so species rich. The hypothesis focuses on the importance of interactions between species for biodiversity. The geneal idea is that species interactions increase towards the species-rich equator. Such interactions may include interactions such as between parasites and host, or between a predator and its prey. The intuitively appealing hypothesis is: The stronger the interactions between species, the faster evolutionary change, thus resulting in increased species diversity. Strong species interactions should further help maintain a high level of biodiversity. Testing this long-standing hypothesis has proven extremely difficult in the past, and the results from past studies aiming to test the "biotic interactions" hypothesis are mixed.

A new publication in Nature Communications now further challenges the general validity of the "biotic interactions" hypothesis. The study suggests that a specific but fundamental interaction between species -- predation by large fish such as tunas or sharks -- is stronger in the temperate zone than near the equator. According to the "biotic interactions" hypothesis, stronger interactions should be accompanied by a higher diversity of fish species -- a pattern that is also not born out by the study. The study is headed by Dr. Marius Roesti, who began the research work at the University of British Columbia in Vancouver and is now working at the Institute of Ecology and Evolution at the University of Bern.

Elephant welfare can be assessed using two indicators

APRIL 1, 2020



Across the world, animals are kept in captivity for various reasons: in zoos for education and research, in research facilities for testing, on farms for meat and other products, and in people's homes as pets. Maintaining good animal welfare is not only important for ethical reasons; poor welfare can impact human wellbeing and the economy. But how do we assess how animals are feeling?

One way to assess animal wellbeing is to look at stress levels. Vets typically use two biological measures of stress: stress hormone levels and white blood cell ratios. In mammals—including humans—the most important stress hormone is cortisol. When animals are faced with danger, cortisol is produced to help prepare the body for a challenge. However, if high stress and cortisol are experienced constantly, they can impact an animal's health.

In addition to cortisol, scientists can also look at the ratio of two types of white blood cells, heterophils (or neutrophils) and lymphocytes. These cells play an important role in the immune system of mammals, and after animals have experienced a stressful event, their ratio is typically high.

Researchers at the University of Turku, Finland, wanted to find out if these two biological measures of stress were correlated and whether animals with high levels of cortisol also had a high heterophil to lymphocyte ratio. They measured cortisol and heterophil to lymphocyte ratios in 120 Asian elephants from a semi-captive population of working timber elephants in Myanmar. The researchers also weighed each elephant, as body weight is a good indicator of general health.

Wednesday, 1 April 2020

More than 100,000 badgers slaughtered in discredited cull policy

Badger Trust condemns ‘largest destruction of a protected species in living memory’ as government admits failings and focuses on vaccination

Published onSat 28 Mar 2020 16.05 GMT

More than 35,000 badgers were killed during last year’s cull, according to long overdue figures slipped out by the government on Friday at the height of the coronavirus crisis.

The total has dismayed animal rights campaigners, who claim that for the first time since the cull was introduced in 2013, more badgers were shot last year than cattle were slaughtered because they have bovine-TB.

Dominic Dyer, the chief executive of the Badger Trust, said: “The government licensed the killing of 35,034 badgers in 2019 in 40 culling zones stretching from Cornwall to Cumbria in the largest destruction of a protected species in living memory.”

More than 70% of the badgers (24,645) were killed as a result of controlled shooting.

“This is a method of killing which is condemned by the British Veterinary Association as inhumane as it can result in badgers taking more than five minutes to die from multiple bullet wounds, blood loss and organ failure,” Dyer said.

Only 149 (0.6%) of the total 35,034 badgers killed were monitored to establish that they were dispatched humanely.

The total number of badgers killed since the cull policy started now stands at 102,349. It has been estimated that the cull has cost the taxpayer more than £60m.

The figures were supposed to have been published months ago but were delayed as the efficacy of the government’s policy came in for criticism.

“Badgers are now being slaughtered at such a rate across England that they could face local extinction in areas of the country which they have inhabited since the Ice Age,” Dyer said.

Endangered sea turtles hatch on Brazil's deserted beaches

Coronavirus keeps crowds that usually greet hatching of hawksbill turtles away

Tom Phillips in Rio de Janeiro
Published onSun 29 Mar 2020 16.49 BST

Nearly 100 critically endangered sea turtles have hatched on a deserted beach in Brazil, their first steps going almost unnoticed because of coronavirus restrictions that prohibit people from gathering on the region’s sands.

The 97 hawksbill sea turtles, or tartarugas-de-pente as they are known in Brazil, hatched last Sunday in Paulista, a town in the north-eastern state of Pernambuco.

Photographs taken by government workers, the only people to witness the event, showed the tiny creatures making their way down the beach and into the Atlantic waves.

Locals have been forbidden from gathering on Pernambuco’s spectacular shoreline since last weekend, when the state governor, Paulo Câmara, ordered a partial shutdown and urged residents to stay indoors to slow the spread of coronavirus.

Speaking to the Guardian last week, Câmara said such measures – which the country’s president, Jair Bolsonaro, has actively undermined – were vital if Brazil were to avoid a crisis similar to the one that has taken hold in Europe. “Only isolation will stop the curve growing at the speed it is growing in other places,” he said.


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