Bats cooperate for finding food


This 2014 video says about itself:

Secrets and Mysteries of Bats – Nature Documentary

This 48-minute documentary explores the world of bats and the scientists who study them — including the late Donald Griffin, a Harvard zoologist who was the first to describe their echolocation ability in the 1940s. Using 3-D graphics to recreate the bats’ acoustic vision and shooting with infra-red and high-speed cameras, this film offers an exhilarating “bat’s-eye” journey into the night.

From the University of Maryland in the USA:

Unpredictable food sources drive some bats to cooperatively search for food

December 13, 2018

Summary: With the help of novel miniature sensors, biologists have found that bat species foraged socially if their food sources were in unpredictable locations, such as insect swarms or fish schools. In contrast, bats with food sources at fixed locations foraged on their own and did not communicate with one another while foraging or eating.

Humans aren’t the only species that have dinner parties. Scientists have observed many animals, including bats, eating in groups. However, little was known about whether bats actively help each other find food, a process known as social foraging.

With the help of novel miniature sensors, an international group of biologists that included University of Maryland Biology Professor Gerald Wilkinson found that bat species foraged socially if their food sources were in unpredictable locations, such as insect swarms or fish schools. In contrast, bats with food sources at fixed locations foraged on their own and did not communicate with one another while foraging or eating. The results of the study were published in the November 19, 2018 issue of the journal Current Biology.

“We were able to show that bats who can’t predict where their food will be are the ones that cooperate with each other to forage”, Wilkinson said. “And I don’t think they are unique — I think that if more studies are done, we will find that other bat species do similar things.”

The researchers selected five bat species from around the world for the study — two species with unpredictable food sources and three with predictable food sources. They fit each bat with a small, lightweight sensor that operated for up to three nights. Because the sensor only weighed approximately 4 grams, it did not hinder the bat’s movements. The sensor recorded GPS data to log each bat’s flight path and audio in ultrasonic frequencies to document bat calls. The researchers recaptured each bat to download the data. In all, the researchers tracked 94 bats in this study.

Edward Hurme, a UMD biological sciences graduate student in Wilkinson’s laboratory and a co-lead author of the paper, tracked one of the bat species — the Mexican fish-eating bat, which lives on a remote Mexican island.

“We took a fishing boat to an uninhabited island where these bats live and camped there for a month at a time”, Hurme said. “Field work can be challenging. One time, a hurricane came and all we could do was hide in the tent. Fortunately, we survived and so did our data.”

After collecting data on all five bat species, the researchers charted the bats’ flight paths and analyzed the audio recordings. They listened for the distinctive, species-specific calls the bats make during normal flight and when trying to capture prey. The research team used this information to map where and when the bats found and ate food and whether other bats were nearby.

The results showed that the three species of bats that eat predictable food sources, such as fruits, foraged on their own. When they found food, they also ate alone. This makes sense, according to Wilkinson, because they didn’t need any help finding food. In fact, having other bats around could create harmful competition for food.

In contrast, the two species of bats with unpredictable food sources often flew together with other members of their species. Moreover, when a tracked bat found prey, other individuals nearby also began to forage. The findings suggest that these bats forage cooperatively and socially within their own species.

The researchers also found that socially foraging bats may eavesdrop on one another by staying close enough to hear each other’s feeding calls.

“We tested this hypothesis by playing recordings of white noise, normal calls and feeding calls for these bats to hear”, Hurme said. “We found that bats who heard normal calls became more attracted to the speakers than those who heard white noise. And when we played feeding calls, bats dive-dombed the speakers.”

The next step for this research is to investigate what strategies bats use in social foraging. In particular, Hurme hopes to discover whether these bats pay attention to the identity of their fellow foragers.

“We would like to know if socially foraging bats will follow any member of their own species or if they prefer specific individuals who are the most successful at finding food”, Hurme said. “There is some evidence that bats can recognize each other by voice, so we are working on ways to identify individuals by their calls.”

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Lion cubs born, BBC video


This 13 December 2018 video recorded in Africa says about itself:

Lioness Cuddles Newborn Cubs | BBC Earth

The dry season has finally ended, time for a new generation of lion cubs to take over! Adorable newborn cubs take their first steps into the world.

Australian marsupial lions, new research


This 2011 video from Australia says about itself:

Our World – Bone Diggers – The Marsupial Lion | Storyteller Media

Bone Diggers: Mystery of a Lost Predator

Australia is known for its cute marsupials, the koala, the kangaroo and the wombat among others. Very few people are aware that there was once a marsupial that was a deadly “creep up and get ya” predator that was more ferocious than a sabre tooth tiger. It was Thylacoleo Carnifex — the Marsupial Lion, Australia’s lost predator.

The Nullarbor Plain is a remote treeless desert resting between the Great Australian Bight and the Great Sandy Desert. It is hard, stony country…flat and featureless.

In May of 2002 an group of cavers, in an Indiana Jones style operation, discovered three caves, which had never been entered by man. The entrance to one of the caves was mere shoulder-width, vertical tube that rapidly expanded to cathedral proportions. In the first cave their head torches illuminated a sight that caused scientific wonderment and a world-wide media frenzy. At the far end of a side tunnel the cavers discovered the pristine and complete skeleton of the fabled marsupial lion, Thylacoleo.

It lay there as if it had died only a year ago. The skeleton was bleach white against the red earth and not a speck of dust on it. Their immediate reaction was to take a photo and get out – their main concern was to preserve the site for scientific analysis.

The photo of Thylacoleo and the cave coordinates ended up on the desk of Dr John Long, vertebrate palaeontologist, a world renowned Bone Digger with the Western Australian Museum. Within a matter of weeks funding and an expedition to recover the remains had been arranged. It would prove a journey full of surprises both during the expedition and later as the remains were studied. The first surprise to take John and his team by surprise was the age of the remains. He was sure the skeleton could only be about 40,000 years old — several dating techniques later and a shattering date of at least 500,000 years suddenly propelled the find into mega-star status.

Bone Diggers – Mystery of a Lost Predator is the amazing story of the dangerous recovery mission and how the remains of the marsupial lion allowed science a unique opportunity to reconstruct the beast and it’s behaviour. From recreating its brain to morphological analysis, the life and form of Thylacoleo began to take shape – this is science at its best!

A co-production between Storyteller Media and the Western Australian Museum.

From PLOS:

First-ever look at complete skeleton of Thylacoleo, Australia’s extinct ‘marsupial lion’

New fossil finds provide insight into biology and behavior of this ancient apex predator

December 12, 2018

Thyalacoleo carnifex, the “marsupial lion” of Pleistocene Australia, was an adept hunter that got around with the help of a strong tail, according to a study released December 12, 2018 in the open-access journal PLOS ONE by Roderick T. Wells of Flinders University and Aaron B. Camens of the South Australia Museum, Adelaide. These insights come after newly-discovered remains, including one nearly complete fossil specimen, allowed these researchers to reconstruct this animal’s entire skeleton for the first time.

A marsupial predator with an estimated weight of over 100kg, Thylacoleo was unlike any living animal, and paleontologists have long tried to interpret its lifestyle from incomplete remains. The new fossils, discovered in Komatsu Cave in Naracoorte and Flight Star Cave in the Nullarbor Plain, include the first known remains of the tail and collarbone of this animal. The authors used this new information to re-assess the biomechanics of Thylacoleo, and by comparing its anatomy to living marsupials, reach new conclusions about the biology and behavior of the “marsupial lion.”

The tail of Thylacoleo appears to have been stiff and heavily-muscled, probably allowing it to be used along with the hind limbs as a “tripod” to brace the body while freeing up the forelimbs for handling food or climbing, as many living marsupials do. The analysis suggests that Thylacoleo had a rigid lower back and powerful forelimbs anchored by strong collarbones, likely making it poorly suited for chasing prey, but well-adapted for ambush hunting and/or scavenging. These features also add to a list of evidence that Thylacoleo was an adept climber, perhaps of trees or steep-walled caverns. Among living marsupials, the anatomy of Thylacoleo appears most similar to the Tasmanian devil, a small carnivore that exhibits many of these inferred behaviors.

The authors add: “The extinct marsupial lion, Thylacoleo carnifex has intrigued scientists since it was first described in 1859 from skull and jaw fragments collected at Lake Colongulac in Victoria Australia and sent to Sir Richard Owen at the British Museum. Although Australia’s largest marsupial carnivore it retains many features indicative of its diprotodont herbivore ancestry and its niche has been a matter of considerable debate for more than 150yrs. Recent cave finds have for the first time enabled a description and reconstruction of the complete skeleton including the hitherto unrecognised tail and clavicles. In this study, Wells and Camens compare the Thylacoleo skeleton with those of range of extant Australian arboreal and terrestrial marsupials in which behaviour and locomotion is well documented. They conclude that the nearest structural and functional analogue to Thylacoleo is to be found in the unrelated and much smaller Tasmanian Devil, Sarcophilus harrisii, a scavenger/hunter. They draw attention to the prevalence of all age classes within individual cave deposits as suggestive of a high degree of sociality. Those ancestral features Thylacoleo shares with arboreal forms are equally well suited to climbing or grasping a prey. They conclude that Thylacoleo is a scavenger, ambush predator of large prey.”

European apes, why extinct?


This 11 December 2018 video says about itself:

Today, our closest evolutionary relatives, the apes, live only in small pockets of Africa and Asia. But back in the Miocene epoch, apes occupied all of Europe. Why aren’t there wild apes in Europe today?

Special thanks to https://AfricanFossils.org for allowing us to use their images of Proconsul and Ekembo fossils.

Small wallaby related to extinct giant kangaroos


This January 2018 video says about itself:

Procoptodon is a genus of giant short-faced kangaroo living in Australia during the Pleistocene epoch.

Procoptodon goliah, the largest-known kangaroo that ever existed, stood approximately 2.7 m tall and weighed about 240 kg. Other members of the genus are smaller, however, and Procoptodon gilli is the smallest of all of the sthenurine kangaroos, standing ~1m tall.

This October 2017 video says about itself:

Historic return to mainland Australia for one of our rarest kangaroo species

One of our most endangered kangaroo species, the Banded Hare-wallaby, has made a historic return to mainland Australia, more than 100 years after the last wild colony disappeared as a result of foxes and cats.

60 Banded Hare-wallabies – 27 males and 33 females – have been successfully translocated to AWC’s Mt Gibson Wildlife Sanctuary in Western Australia, where they have been released into a 7,800 hectare feral predator-free area. Watch the full story above.

From Queensland University of Technology in Australia:

Tiny Australian wallaby the last living link to extinct giant kangaroos

December 10, 2018

A Queensland University of Technology (QUT) led collaboration with University of Adelaide reveals that Australia’s pint-sized banded hare-wallaby is the closest living relative of the giant short-faced kangaroos which roamed the continent for millions of years, but died out about 40,000 years ago.

Published in Systematic Biology, the research involved the first near-complete mitochondrial (mt) genome sequencing from extinct Australian megafauna.

  • DNA was sequenced from inner ear bones (petrous bones) of a 45,000-year-old giant short-faced kangaroo, Simosthenurus occidentalis, part of the Sthenurinae sub-family, found at Mt Cripps in Tasmania
  • These are the longest DNA sequences ever recovered from Australia’s extinct megafauna, with more than 16,000 base pairs of mtDNA, which is used to help understand evolutionary relationships
  • The results support an evolutionary link between giant short-faced kangaroos (Sthenurinae) and the threatened banded hare-wallaby, Lagostrophus fasciatus
  • The study also combined the DNA evidence with fossil and anatomical data to trace body size change over the evolutionary history of kangaroos and wallabies

The analysis was conducted by QUT evolutionary biologists PhD researcher Manuela Cascini and Associate Professor Matthew Phillips, from the Science and Engineering Faculty, in collaboration with University of Adelaide’s Professor Alan Cooper and Dr Kieren Mitchell, who undertook the DNA sequencing at the Australian Centre for Ancient DNA.

Lead author Ms Cascini, a molecular biologist who moved from Italy to undertake her PhD research with Associate Professor Phillips, said her project also involved analysis of mtDNA sequenced from the inner ear bones of another ancient extinct macropod that was found in Tasmania — the giant wallaby, Protemnodon anak, which weighed up to 150 kilograms.

Small fragments of ancient DNA sequenced from this giant wallaby species and from the giant short-faced kangaroo were first reported on by University of Adelaide scientists in 2015.

“Our analysis confirmed their conclusion that the giant wallabies are close relatives of the iconic living ‘Macropus’ genus of kangaroos and wallabies,” Ms Cascini said.

“However that earlier study provided insufficient DNA to confidently place the giant short-faced kangaroos on the evolutionary tree.

“We’ve now been able to show the strongest evidence yet that the closest living relative of these massive Sthenurinae kangaroos, which weighed up to about 240 kilograms, is the tiny, 2-kilogram banded hare-wallaby. These wallabies live in the wild only on islands off Western Australia and are classified as vulnerable.”

Associate Professor Phillips said the larger amount of mtDNA sequenced in this study by the University of Adelaide collaborators helped enable the strong finding on the banded hare-wallaby link.

“This is by far the most genetic data that anyone has extracted out of Australian megafauna, and it was taken from the petrous bones which are denser and often seem to hold DNA better”, he said.

“You find a lot of ancient DNA studies of megafauna from permafrost in northern Europe and northern America because the cold helps preserve the DNA. But in Australia the hotter climate and older age of the megafauna is far less favourable for DNA preservation.”

Dr Mitchell said Tasmania’s cooler climate and higher-altitude caves “make for much better DNA preservation than we find elsewhere in Australia, so we focused our hunt for high-quality megafaunal DNA there.”

Associate Professor Phillips said other findings of the study on the evolution of kangaroos and wallabies (macropods) included:

  • The macropod ancestors diverged from tree-living possums around 41 to 46 million years ago
  • They remained small, in the 2-15 kg range, while Australia was more dominated by rainforest
  • As the climate cooled and dried, and as the forests opened up over the past 10 million years, at least four different kangaroo lineages independently evolved to megafaunal size (more than 44 kg)
  • This includes the short-faced kangaroos, the giant Protemnodon wallabies, and the living red and grey kangaroos.