Australian northern quolls, research and conservation


This May 2014 video from Australia says about itself:

Saving the northern quoll from cane toads

A cane toad invasion is threatening key species in the Northern Territory. Most endangered is the small predatory Northern Quoll, which dies within minutes of being poisoned by the toad.

From the University of Queensland in Australia:

The northern quoll: An amazingly versatile survivor?

August 28, 2020

The northern quoll, one of Australia’s most adorable and endangered native carnivores, appears to be adapted to dramatically different landscapes — which may be key to the species’ survival.

University of Queensland PhD candidate Pietro Viacava co-led a study that found similarities between northern quoll skulls across a 5000 kilometre range, which has raised hopes scientists will be able to cross-breed isolated populations.

“Northern quolls are in danger — a lot has been thrown at them,” Mr Viacava said.

“They’ve been victims of a devastating cane toad invasion, increases in bushfires and habitat fragmentation, all while facing stiff competition from other carnivores such as dingoes and cats.

“The problem we are facing with conserving the northern quoll is that there may be too little genetic diversity in these handful of remaining populations, scattered across Australia.

“If we cross-bred them, we might run the risk that they wouldn’t be ideally suited to these diverse environments.

“Their skulls, for example, might not be properly adapted to eat local prey, as it differs across Australia.

“Luckily, this doesn’t seem to be the case — these quolls seem to be incredibly versatile.”

The research team used a technique known as ‘geometric morphometrics’ to characterise skull shape variation in museum specimens of northern quolls.

They looked for shape differences between populations, or whether environmental conditions coincided with changes in skull shape.

Dr Vera Weisbecker from the Flinders University College of Science and Engineering supervised the study, and said the results appeared to be a win for northern quoll conservation.

“Quoll skull shapes were mostly similar across their entire range, although the shapes did vary with the size of the animals,” Dr Weisbecker said.

“This means, for example, that a quoll skull from Pilbara region in WA looked nearly the same as a similar-sized one from south-eastern Queensland, 5000 kilometres apart.

“Although other parts of the animal’s body and genetic factors need to be considered, we will most likely be able to breed animals from different populations for conservation without losing adaptations to feeding.”

However, there is also a much less positive potential explanation for the results.

“Scientists have long suspected that marsupial mammals — such as quolls, kangaroos and koalas — are seriously limited in the degree to which they can adapt their skull and skeleton,” Dr Weisbecker said.

“This is because newborn marsupials require a specifically shaped snout to be able to latch onto the mother’s teat.

“In that case, what we see may actually be a serious limitation on the ability of quolls to adapt, rather than the much more hopeful multipurpose solution we propose.”

To further explore this possibility, the team is now looking at how closely related species of antechinus — smaller quoll relatives — differ in skull shape.

The team includes researchers from UQ, Flinders University, Queensland University of Technology and the University of New England, with funding from the Australian Research Council.

Tasmanian devils may help in fighting cancer


This 2008 video says about itself:

The odd Tasmanian devil has a huge head to power its massive jaws. It also has an unsettling array of sounds.

From Washington State University in the USA:

Tasmanian devil research offers new insights for tackling cancer in humans

August 6, 2020

A rare, transmissible tumor has brought the iconic Tasmanian devil to the brink of extinction, but new research by scientists at Washington State University and the Fred Hutchinson Cancer Research Center in Seattle indicates hope for the animals’ survival and possibly new treatment for human cancers.

The study, published in Genetics on Aug. 1, found a single genetic mutation that leads to reduced growth of a transmissible cancer in Tasmanian devils in the wild.

“This gene is implicated in human prostate and colon cancers,” said Andrew Storfer, professor of biological sciences at WSU. “While the findings hold the most immediate promise to help save the world’s few remaining Tasmanian devils, these results could also someday translate to human health.”

The research team, led by Storfer and Mark Margres, now a postdoctoral fellow at Harvard University, studied the genomes of cases of devil facial tumor disease, or DFTD, that regressed spontaneously — that is, the cancer began disappearing on its own.

They were surprised to find the mutation contributing to tumor regression doesn’t change the gene function but instead, turns on a gene that slows cell growth in the tumor. At least, it behaves that way in the lab.

Current human cancer therapies focus on removing every trace of a tumor, often through toxic or debilitating treatments, said David Hockenbery, a cancer biologist at Fred Hutch who contributed to the study.

“If there were ways that tumors could be tricked into regressing without having to administer cytotoxic drugs or deforming surgeries, it would be a major advance,” he said.

While infections cause up to 20 percent of all human cancers — such as gastric cancer from Helicobacter pylori and cervical cancer from human papillomavirus — for Tasmanian devils, the cancer is the infection.

DFTD spreads between the animals when they bite each other during common social behaviors. Since the mid-1990s, the disease has decimated the natural population of the carnivorous marsupials, which are now found only on the island state of Tasmania, off the southeastern coast of Australia.

Storfer’s lab leads a National Institutes of Health-funded team of researchers from the U.S. and Australia to improve conservation efforts for Tasmanian devils and increase understanding of the co-evolution of the tumor and its host.

Though ferocious with each other, Tasmanian devils take mild handling by people without much fuss, making it easy for investigators to humanely capture the animals, collect tissue samples and tag them for monitoring before release back into the wild.

As the researchers work to save the devils, they also have an unprecedented opportunity to watch tumors naturally evolve and sometime regress without drugs or surgery.

“Although this disease is largely fatal, we’re seeing tumors just disappear from an increasing number of individual animals,” Storfer said.

The team is looking at the effects of other promising mutations in regressed tumors as well.

“We hope to learn something that could be applied to understanding and possibly treating a number of human cancers in the future,” Storfer said.

This research was supported by the National Institutes of Health, the National Science Foundation and the Washington Research Foundation.

Herbicides threaten kangaroos, new research


This 2015 video says about itself:

Tammar Wallabies

A small wallaby native to South Australia and Western Australia. They were staying close to the dense undergrowth. Notice how the ears can move independently. This video was taken in southwest Western Australia.

From the University of Melbourne in Australia:

Herbicide harming marsupial health and development, research finds

Atrazine impacts reproduction in kangaroos and wallabies

August 6, 2020

Summary: Researchers exposed the adult female tammar wallabies to atrazine contaminated water throughout pregnancy, birth and lactation to help establish the extent of harm being caused by the chemical. They then examined the reproductive development of their young by assessing their growth and development to establish that the herbicide is causing major abnormalities in the male reproductive system in many animals.

The health of wallabies and kangaroos is being affected by the herbicide, atrazine, which is used widely in Australia on cereal crops and in forestation to prevent weeds, according to new research.

Atrazine, which has been banned in the European Union since 2003, may be impacting reproduction in marsupials, the University of Melbourne study found, published today in Reproduction, Fertility and Development.

“Exposures to atrazine is causing major abnormalities in the male reproductive system in many animals, triggering male sterility or even male-to-female sex reversal in frogs,” Professor in Genetics Andrew Pask said.

“With the marsupial’s unique mode of reproduction and the young completing their development in the pouch, mothers are unknowingly passing the toxins on in their breast milk, exposing their young to environmental toxins.”

The study is the first time the impacts of pesticides have been investigated in any marsupial and show that they are able to affect reproductive development.

The research found that concentrations of atrazine have been recorded at disturbingly high levels in Victorian rivers and Tasmanian streams immediately after forestry spraying.

Kangaroos and wallabies are at high risk because they eat the sprayed crops and drink from contaminated water resources where chemicals such as atrazine accumulate from runoff.

Atrazine affects a broad range of animals from mammals such as rats to amphibians, reptiles and even fish.

With marsupials already experiencing devastating population declines across Australia, and 21 per cent of native mammals currently threatened with extinction, researchers say the potential impacts of environmental toxins are of major concern.

Researchers exposed the adult female tammar wallabies to atrazine contaminated water throughout pregnancy, birth and lactation to help establish the extent of harm being caused by the chemical.

They then examined the reproductive development of their young by assessing their growth and development.

Lead author on the research and PhD student Laura Cook said it is hoped the study will lead to more stringent guidelines around the use of atrazine in Australia.

“Endocrine-disrupting chemicals, such as atrazine, have the ability to impact development and increase disease susceptibility,” she said.

“With increased habitat destruction, marsupials are being pushed onto farmland, attracted to the food resources and rare permanent water sources where they may be vulnerable to agricultural contaminants, such as pesticides.”

How baby marsupials and monotremes drink milk


This 2019 video says about itself:

Mom Platypuses Laying Eggs And Cute Platypuses Moments

The platypus, sometimes referred to as the duck-billed platypus, is a semiaquatic egg-laying mammal endemic to eastern Australia, including Tasmania. Together with the four species of echidna, it is one of the five extant species of monotremes, the only mammals that lay eggs instead of giving birth to live young.

The animal is the sole living representative of its family and genus, though a number of related species appear in the fossil record. The first scientists to examine a preserved platypus body judged it a fake, made of several animals sewn together.

From eLife:

Hints at jaw evolution found in marsupials and monotremes

June 30, 2020

Infant marsupials and monotremes use a connection between their ear and jawbones shortly after birth to enable them to drink their mothers’ milk, new findings in eLife reveal.

This discovery by researchers at King’s College London, UK, provides new insights about early development in mammals, and may help scientists better understand how the bones of the middle ear and jaw evolved in mammals and their predecessors.

Marsupials such as opossums, and monotremes such as echidnas, are unusual types of mammals. Both types of animal are born at a very early stage in development, before many bones in the body have started to form. Opossums latch on to their mother’s nipple and stay there while they finish developing. Monotremes, which hatch from eggs, lap milk collected near their mother’s milk glands as they grow. But how they are able to drink the milk before their jaw joint is fully developed was previously unclear.

“Given the lack of a jaw joint in marsupials and monotremes at birth, scientists have previously suggested that the animals may use a connection between the middle ear bones and jaw bones to allow them to feed,” explains lead author Neal Anthwal, Research Associate at the Centre for Craniofacial & Regenerative Biology, at King’s College London’s Faculty of Dentistry, Oral & Craniofacial Sciences in the UK.

To find out if this is true, Anthwal and his colleagues compared the jaw bones in platypus, short-beaked echidnas, opossums and mice shortly after birth. Their work revealed that, soon after echidnas hatch, their middle ear bones and upper jaw fuse, eventually forming a joint that is similar to the jaws of mammal-like reptile fossils. The team found a similar connection in mouse embryos, but this disappears and the animals are born with functioning jaw joints.

Opossums, by contrast, use connective tissue between their middle ear bones and the base of their skull to create a temporary jaw joint that enables them to nurse shortly after birth. “This all shows that marsupials and monotremes have different strategies for coping with early birth,” Anthwal says.

The findings suggest that the connection between the ear and jaw dates back to an early mammal ancestor and persisted when mammals split into subgroups. Marsupials and monotremes continue to use these connections temporarily in early life. In other mammals, such as mice, these connections occur briefly as they develop in the womb but are replaced by a working jaw joint before birth.

“Our work provides novel insight into the evolution of mammals,” concludes senior author Abigail Tucker, Principal Investigator and Professor of Development & Evolution at the Centre for Craniofacial & Regenerative Biology, King’s College London. “In particular we highlight how structures can change function over evolutionary time but also during development, with the ear bones moving from feeding to hearing. The recent availability of monotreme tissue for molecular analysis, as showcased here, provides an amazing future opportunity to understand the biology of these weird and wonderful mammals, which we are keen to explore.”

New extinct giant wombat discovery in Australia


This 25 June 2020 video says about itself:

A new extinct family of giant wombat relatives has been discovered in the Australian desert. The giant marsupial that roamed prehistoric Australia 25 million years ago is so different from its wombat cousins that scientists have had to create a new family to accommodate it.

This 27 June 2020 video says about itself:

A MEGA-WOMBAT the size of a bear that lived around 25million years ago has been unearthed. Scientists discovered the massive beast after digging up part of its skull and bones in Lake Pinpa, Australia.

The animal has been named Mukupirna nambensis – with the first part of its name meaning “big bones”. It weighed up to 171kg and was at least four times larger than all currently living wombats – bigger than a giant panda.

The animal has been classed as an entirely new species and is a member of a group of animals called Vombatiformes. The family also includes creatures such as koalas, modern wombats and their ancient relatives.

Scientists have said the discovery increases our understanding of how wombats developed digging and burrowing behaviour. Its teeth show it only ate plants and its arms suggest it would scratch for food on the ground, such as when looking for roots. Despite its massive size, however, it is not even the biggest wombat-like creature every found. Diprotodon has that honour, weighing in at an impressive 2,000kg – two tonnes – and surviving until at least 50,000 years ago.

Dr Robin Beck, from The University of Salford, who led the study, said: “Koalas and wombats are amazing animals. “But animals like Mukupirna show that their extinct relatives were even more extraordinary, and many of them were giants.” He added: “It tells us a lot about the evolution of wombats, koalas and their relatives. “It is remarkable for its large size – this was clearly an impressive, powerful beast.”

The bones were discovered after drought and strong winds blew the surface of the dry salt lake bed. The freak conditions uncovered the remains of animals that died after getting stuck in the mud millions of years ago. Archaeologists used an “acupuncture” method to find the bones, pushing metal rods into the soft mud until they hit something hard before digging it up.

Mukupirna is now the closest known relative of modern wombats, yet it is still so different scientists have given it its own family of creatures – Mukupirnidae. It is likely the mega wombat vanished during a global climate shift which saw its scrubby forest home vanish. Lusher and more diverse forests followed, which will have lead to climate conditions not suited for the Mukupirnids.

Professor Michael Archer of the University of New South Wales, who was part of the team that first uncovered the bones which have only just been identified in 1975, hailed it as a “mysterious new beast”. Julien Louys of Griffith University, who co-authored the study, said: “The description of this new family fills a crucial missing piece to the ancient bestiary of Australia. “It joins other weird and extinct marsupials from 25 million years ago, many of which we wouldn’t recognise today.”

Prehistoric saber-tooth marsupial Thylacosmilus, new research


This December 2017 video says about itself:

Thylacosmilus || A Jaguar sized Saber-tooth Marsupial relative from South America

Thylacosmilus is an extinct genus of saber-toothed metatherian that inhabited South America from the Late Miocene to Pliocene epochs.

Though Thylacosmilus is one of several predatory mammal genera typically called “saber-toothed cats”, it was not a felid placentalian, but a sparassodont, a group closely related to marsupials, and only superficially resembled other saber-toothed mammals due to convergent evolution.

Remains of this animal have been found primarily in Catamarca, Entre Ríos, and La Pampa Provinces in northern Argentina.

Thylacosmilus was described and named by Elmer S. Riggs in 1933. He named two species, T. atrox and T. lentis.

Thylacosmilus had large, saber-like canines. The roots of these canines grew throughout the animal’s life, growing in an arc up the maxilla and above the orbits. Its cervical vertebrae were very strong and to some extent resembled the vertebrae of Machairodontinae.

Body mass estimates of Thylacosmilus suggest this animal weighed between 80 to 120 kilograms (180 to 260 lb), and one estimate suggesting up to 150 kg (330 lb), about the same size as a modern jaguar. This would make it one of the largest known carnivorous metatherians.

Recent comparative biomechanical analysis have estimated the bite force of T. atrox starting at maximum gape at 38 newtons (8.5 lbf), much weaker than that of a leopard, suggesting its jaw muscles had an insignificant role in the dispatch of prey.

Its skull was similar to that of Smilodon in that it was much better adapted to withstand loads applied by the neck musculature.

Based on studies of its habitat, Thylacosmilus is believed to have hunted in savanna-like or sparsely forested areas, avoiding the more open plains where it would have faced competition with the more successful and aggressive Phorusrhacids it shared its environment with.

Although older references have often stated that Thylacosmilus became extinct due to competition with the “more competitive” saber-toothed cat Smilodon during the Great American Interchange, newer studies have shown this is not the case.

Thylacosmilus died out during the Pliocene (3.6–2.58 mya) whereas saber-toothed cats are not known from South America until the Middle Pleistocene (781-126,000 years ago).

As a result, the last appearance of Thylacosmilus is separated from the first appearance of Smilodon by over one and a half million years.

From the University of Bristol in England:

Bizarre saber-tooth predator from South America was no saber-tooth cat

June 26, 2020

A new study led by researchers from the University of Bristol has shown that not all saber-tooths were fearsome predators.

Saber-tooth cats, such as the North American species Smilodon fatalis, are among the most iconic fossil animals with a reputation for being fierce predators. However, saber-tooths came in all shapes and sizes and nearly a hundred different saber-tooths are known to science so far.

Thylacosmilus atrox (which means ‘terrible pouched knife’) is a well-known animal that lived around five million years ago in Argentina.

A jaguar-sized marsupial, it is popularly known as the ‘marsupial saber-tooth’, compared with the sabertoothed cats elsewhere in the world, and it is often presented as a classic case of convergent evolution — where animals appear similar in form despite having very different evolutionary relationships (such as marsupial flying possums and placental flying squirrels — both, of course, being gliders rather than true fliers).

Thylacosmilus had huge, ever-growing canines, leading people to speculate that it was an even more vicious predator than the placental carnivores it superficially resembled such as Smilodon.

But was it really a fierce predator like the extinct placental saber-toothed cats, which seem to have been much like modern cats but with a different mode of killing their prey?

An international team of researchers, led by Professor Christine Janis from Bristol’s School of Earth Sciences, have performed a series of studies on the skull and teeth of this animal and have come to a different conclusion. Their findings are published in the journal PeerJ.

Professor Janis said: “The title of this paper, ‘An Eye for a Tooth’, sums up how we think this animal has been perceived.

“It has impressive canines, for sure: but if you look at the whole picture of its anatomy, lots of things simply don’t add up. For example, it just about lacks incisors, which big cats today use to get meat off the bone, and its lower jaws were not fused together.

“In addition, the canines of Thylacosmilus were different from the teeth of other saber-toothed mammals, being triangular in shape like a claw rather than flat like a blade.”

A statistical study, comparing aspects of the skull and teeth of Thylacosmilus with both present-day big cats and a diversity of extinct saber-toothed cats, confirmed suspicions about the differences from its placental supposed counterparts.

Co-author Borja Figueirido of the University of Málaga (Spain) added: “The skull superficially looks rather like that of a saber-toothed placental.

“But if you actually quantify things, it becomes clear that Thylacosmilus’ skull was different in many details from any known carnivorous mammal, past or present.”

Detailed biomechanical studies comparing the skulls of Thylacosmilus and Smilodon, simulating performance under different conditions, were also revealing.

Stephan Lautenschlager from the University of Birmingham, the contributing author on the paper who performed these analyses, said: “Previous studies by other researchers have shown Thylacosmilus to have had a weaker bite than Smilodon.

“But what we can show is there was probably a difference in behaviour between the two species: Thylacosmilus’ skull and canines are weaker in a stabbing action than those of Smilodon, but are stronger in a ‘pull-back’ type of action. This suggests that Thylacosmilus was not using its canines to kill with, but perhaps instead to open carcasses.”

Finally, the other teeth of Thylacosmilus also pose problems for the interpretation of this animal as a cat-like predator, whether saber-toothed or not. Besides the puzzling lack of incisors, the molars are small, and did not wear down along the sides as seen in an animal feeding on meat.

Larisa DeSantis from Vanderbilt University (USA), who conducted a detailed dental study, added: “The molars tend to wear flat from the top, rather like you see in a bone crusher.

“But if you examine the detailed microwear on tooth surfaces, it’s clear that it was eating soft food. Its wear is most similar to that of cheetahs which eat from fresh carcasses and suggests an even softer diet than fed to captive lions.

“Thylacosmilus was not a bone-crusher and may have instead specialised on internal organs.”

Professor Janis said: “It’s a bit of a mystery as to what this animal was actually doing but it’s clear that it wasn’t just a marsupial version of a saber-toothed cat like Smilodon.

“In addition to the differences in the skull and the teeth, it was also short-legged and stiff-backed, and lacked retractile claws, so it would have had difficulties in pursuing its prey, pouncing on it and holding on to it. I suspect it was some sort of specialised scavenger.

“It may have employed those canines to open carcasses and perhaps also used a big tongue to help extract the innards: other mammals that have lost the incisors, like walruses and anteaters, also have big tongues that they use in feeding.”

When Thylacosmilus lived on the plains of Argentina five million years ago, it would have inhabited a very different type of ecosystem to any modern one. Then the big predators were huge flightless birds, the “terror birds” or phorusrachiformes, now all extinct. Life in the past may have been very different to the present day.

Borja Figueirido added: “In Africa today it’s the mammals who are the killers and the big birds, like vultures, are the scavengers. But perhaps five million years ago in Argentina it was the other way around, and it was the mammals who were the scavengers.”

How koalas drink, new research


This 28 December 2019 video says about itself:

Thirsty koala approaches cyclists for a drink of water | DW News

Fires are threatening the lives of koalas in Australia. It’s feared that thousands of the animals have died in the blazes. Rescuers and good Samaritans are doing what they can to save the endangered koalas. Cyclists in Adelaide stopped in their tracks to give a parched koala some water. After giving water from seven bottles to the animal, the group cycled home thirsty in 40-degree heat.

Australia is the animal’s natural habitat, and the only place where koalas can be found living in the wild. It is estimated that up to 30% of the country’s koalas may have been killed in the fires.

From the University of Sydney in Australia:

Tree trunks take a licking as koalas source water

First study to show koalas drink water by licking tree trunks

May 3, 2020

Koalas are one of the world’s most charismatic animals. But there is a lot we still don’t know about them. For example, how do the marsupials access water in the treetops? Do they only absorb moisture from the gum leaves they eat? Or do they come down from the trees to drink from a waterhole? Until now, no one really knew.

A study published today in Ethology, led by a researcher from The University of Sydney, has captured koala drinking behaviour in the wild for the first time. The paper describes how koalas drink by licking water running down smooth tree trunks during rain.

The news arrives in time to celebrate Wild Koala Day on Sunday 3 May.

“For a long time, we thought koalas didn’t need to drink much at all because they gained the majority of the water they need to survive in the gum leaves they feed on,” said Dr Valentina Mella, in the School of Life and Environmental Sciences. “But now we have observed them licking water from tree trunks. This significantly alters our understanding of how koalas gain water in the wild. It is very exciting.”

Survival

Australia is currently suffering the longest dry period ever documented, with severe rainfall deficits and record maximum temperatures. Koalas experience severe heat-stress and mass mortality events in prolonged hot and dry conditions and they spend more time drinking from artificial water stations if rain is scarce.

Further research could investigate when and why koalas from different areas need access to free water — not contained in the leaves as moisture but available freely as liquid, such as rain, river water or puddles — and whether water supplementation is necessary for some populations.

“This type of drinking behaviour — licking tree trunks — relies on koalas being able to experience regular rainfall to access free water and indicates that they may suffer serious detrimental effects if lack of rain compromises their ability to access free water,” Dr Mella said.

“We know koalas use trees for all their main needs, including feeding, sheltering and resting. This study shows that koalas rely on trees also to access free water and highlights the importance of retaining trees for the conservation of the species.”

Koalas rarely drink water

Each day, wild koalas eat around 510 grams of fresh succulent eucalyptus leaves, and the water in the foliage they feed on is believed to contribute about three-quarters of their water intake in both summer and winter.

Among their adaptations to the Australian climate, koalas also possess extraordinary urinary concentrating abilities and have restricted respiratory and cutaneous water loss compared to similar-sized mammals.

In captivity, koalas have been observed to drink water, but this behaviour has often been considered unusual and attributed to disease or to severe heat stress.

However, anecdotal reports suggest that koalas in the wild drink from waterholes in summer when temperatures exceed 40 degrees Celsius.

Koalas have also been observed approaching humans to access free water (in bottles, gardens and swimming pools during drought and after fire. But this is considered an unusual occurrence.

Observing licking behaviour

For this study, Dr Mella collated observations of koalas drinking in the wild made by citizen scientists and independent ecologists between 2006 and 2019 at the You Yangs Regional Park in Victoria and the Liverpool Plains in NSW. Each observation was koala behaviour noticed by chance and reported to Dr Mella.

There were 44 observations of free-ranging koalas licking water running down a tree trunk during or immediately after rain in the You Yangs Regional Park.

The other two observations of koala drinking behaviour were recorded between the towns of Gunnedah and Mullaley, in the Liverpool Plains. One was an adult female, with a joey, who drank profusely and uninterruptedly for 15 minutes. The other was an adult male who drank at a steady pace for 34 minutes.

“As koalas are nocturnal animals and observation of their behaviour rarely occurs during heavy rainfall, it is likely that their drinking behaviour has gone largely unnoticed and has therefore been underestimated in the past,” Dr Mella said. “Our observations probably only represent a minority of the drinking that normally takes place in trees during rainfall.”

Koalas were observed accessing water in trees by licking the wet surfaces of branches and tree trunks during rain across a range of weather conditions, even when free-standing water was available in dams.

“This suggests koalas were drinking not as a result of heat stress and that this behaviour is likely to represent how koalas naturally access water,” said Dr Mella.

QUT researchers have published an improved and innovative method for estimating the number of koalas in an area detected by using drones and an artificial intelligent algorithm as they continue the quest of identifying surviving koala populations in bushfire areas: here.

Opossum family at Panama bird feeder


This video says about itself:

Mother Opossum Arrives On The Panama Fruit Feeder With A Pouch Full Of Joeys – April 4, 2020

It’s a near-nightly occurrence to see a Common Opossum on the feeder, though it is not common to see one with a pouch full of young. This female was able to get her fill of bananas before waddling off into the night. Opossum babies are the size of jellybeans at birth and there can be up to 20 of them. At the one minute mark, look for a joey’s tail poking out of the pouch. Given the size of that tail, and the mother’s pouch, these young are certainly past the jellybean stage.

Swamp wallaby reproduction, new research


This 2017 video says about itself:

The swamp wallaby is a small macropod marsupial of eastern Australia.

This wallaby is also commonly known as the black wallaby and inhabits thick undergrowth in forests and woodlands, emerging at night to feed.

From Forschungsverbund Berlin in Germany:

Swamp wallabies conceive new embryo before birth — a unique reproductive strategy

March 2, 2020

Summary: Reproduction specialists recently demonstrated that swamp wallabies ovulate, mate and form a new embryo before the birth of the previous offspring. They thereby continuously support embryos and young at different development stages before and after birth.

Marsupials such as kangaroos or wallabies are known for their very different reproductive strategy compared to other mammals. They give birth to their young at a very early stage and significant development occurs during a lengthy lactation period in which the offspring spends most of its time in a pouch. Although in some marsupials new ovulation happens only a few hours after giving birth, the regular consecutive stages of ovulation, fertilization, pregnancy and lactation are respected — with one exception: Reproduction specialists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), Germany, and the University of Melbourne, Australia, recently demonstrated that swamp wallabies ovulate, mate and form a new embryo before the birth of the previous offspring. They thereby continuously support embryos and young at different development stages before and after birth. These findings are published in the Proceedings of the National Academy of Sciences of the United States of America.

Using high-resolution ultrasound to monitor reproduction in swamp wallabies during pregnancy, Prof Thomas Hildebrandt (Leibniz-IZW and University of Melbourne), Dr Brandon Menzies and Prof Marilyn Renfree (both from University of Melbourne) were able to confirm what has been suspected for a long time: swamp wallaby females ovulate, mate and form a new embryo whilst already carrying a full-term fetus that they will soon give birth to. The new embryo enters embryonic diapause until the new-born offspring leaves the pouch nine months later. Thus, when the embryonic diapause is included, females are continuously pregnant throughout their reproductive life, a unique reproductive strategy that completely blurs the normal staged system of reproduction in mammals.

This phenomenon is made possible by two anatomically completely separated uteri and cervices connected to ovaries by their oviducts. “This is true for all marsupials, but the unique overlapping reproductive cycles seem to be a special feature of the swamp wallabies,” says Renfree. Normally, ovulation alternates between the two ovaries. “All female macropodid marsupials — essentially kangaroos, wallabies and a few other groups of species — except the swamp wallaby have an oestrous cycle longer than the duration of their pregnancy, so females come into oestrus, ovulate and mate within hours after birth.” It has been suspected for some time that swamp wallabies might conceive during an active pregnancy, because the oestrous cycle of the swamp wallaby is shorter than the duration of their pregnancy and there have been reports about mating before the birth of the previous offspring. Such a “superfetation” has previously been only described (by Leibniz-IZW scientists) for the European brown hare where females copulate again three to four days before the birth of the incumbent young, forming new conceptuses during an active pregnancy.

In order to confirm superfetation in swamp wallabies, the scientists removed the pouch young of ten females to reactivate the dormant blastocysts (early stage embryo). They then monitored the development of the blastocyst in four of these ten females using high-resolution ultrasound. All females gave birth at around 30 days after the young had been removed. Parallel to the embryo development in one uterus, the scientists closely examined the opposite ovary. There, follicles started to appear and grow. At day 26 of the pregnancy the ultrasound examination showed that the conceptus had developed into a fetus with the head, limbs and heartbeat clearly visible — and at day 28 and 29 the largest follicle in the opposite (contralateral) ovary had ovulated and a new corpus luteum was evident. The other six females that were not scanned with ultrasound were regularly examined for sperm. Sperm was identified in the urogenital tract one to two days before birth but at no other time. “These results clearly demonstrate that swamp wallabies ovulate and mate one to two days before birth, during an existing pregnancy,” says Hildebrandt.

Pregnancies of eutherian mammals (most mammals, i.e. the most taxonomically diverse of the three branches of mammals) greatly exceed the length of the oestrous cycle, so during mammalian evolution, there has been selection pressure to extend the duration of pregnancy. Among marsupials (who form a second taxonomic branch of mammals), gestation in most macropodids encompasses almost the entire duration of the oestrous cycle. The swamp wallaby takes this one step further with its pre-partum oestrus, allowing this marsupial’s gestation length to exceed the oestrous cycle length.

Sadly, many of these unique animals have been lost in the current disastrous bushfires in Australia this summer.