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It’s time to revisit our dear friends, the wombats. Although this blog featured a post about the living wombats in general and a post about the extinct giant wombats which once roamed Australia, we have not concentrated individually on the extant species. Today we will remedy that oversight by writing about the northern hairy-nosed wombat (Lasiorhinus krefftii) which is one of the world’s rarest large mammals. The hairy-nosed wombat is the largest of the world’s three wombat species weighing up to 32 kgs (about 70 pounds). The animal also has longer ears and softer (grayer) fur than other wombats but its behavior and general lifestyle is very similar to its relatives.
Northern Hairy-Nosed Wombat (Lasiorhinus krefftii)
Although the hairy-nosed wombat is one of the most efficient of all mammals in turns of water consumption, the continuing desertification of Australia hit its territory hard and caused the species to decline. The animal was already rare when English settlers came to the island continent and the population dropped even further when forced to compete with European predators and farm animals and contend with habitat loss to farming and development. Perhaps most seriously (and insidiously) the grasses which the wombats prefer to graze are being replaced by invasive species. By the 1970s, the entire species probably only numbered around 20 or 30 individuals.
Range of the Northern Hairy-Nosed Wombat (exaggerated to be visible)
Today the hairy-nosed wombat numbers between 100 and 150 in the wild. The creatures were long confined to a habitat about the size of Central Park (approximately 3 square kilometers) although a second wombat preserve has recently been created for them. Australians are kind people who have been trying hard to save the fetching whisker-nosed marsupial, but the fate of the species is still unclear.
Green Tree Python (Morelia viridis) by bpfischer
The day has completely slipped away from me (as is the way of Mondays in January) but–even though I haven’t written a proper blog post–I wanted to share some photos of an extremely fancy tropical tree python with you. The green tree python (Morelia viridis) is found in southern Indonesia, New Guinea, and the Cape York Peninsula of Australia, all of which sound far preferable to the cold gray pall of Brooklyn. The snake has a long slender body which measures from 1.5 to 1.8 meters (about 5 to 6 feet) and has a pronounced head with a heavy square nose/muzzle.
Green Tree Python (Morelia viridis) by Shannon Plummer
The species is arborial and is notable for coiling up into a saddle position when sleeping or resting. Green tree pythons feed mostly on tree-dwelling mammals (which they catch by hanging their necks and heads into an S-shape and imitating vines) and smaller reptiles which live up in the rainforest. As with the green vine snake, the sinuous almost abstract beauty of the green tree python always makes me think of lush tropical forests on far-away continents and its exquisite green/yellow/chartreuse color reminds me of the beauty of nature.
A Bilby (Macrotis lagotis)
Baby Bilbies in a hat! (image credit: theage.com.au)
Bilbies are blue-gray in color and they grow to about 29–55 centimetres (11–22 in) in length and 3.5 kgs (8 pounds) in weight. They use their sharp claws to unearth a wide diet of insects, arthropods, larvae, small animals, seeds, fungi, bulbs, and fruit. Bilbies rarely drink—they get all the moisture they need from their food.
But wait a minute! Fossorial Marsupials? Arid scrubland? Short gestation? What does any of this have to do with Easter? Well, due to a century of continent-wide ecological disaster caused by a plague of invasive bunnies, Australians hate rabbits with a burning passion (although of course this was not actually the fault of rabbits but was yet another mistake made by nature’s most problematic children). The Easter bunny is not as popular in Australia as elsewhere—giving an Australian child a candy Easter bunny would be like giving a New Yorker a chocolate Easter rat.
The Easter Bunny and the Easter Bilby
Fortunately Bilbies have boldly stepped in to the Easter bunny’s role. In a land where rabbits are regarded as an abomination, the long eared bilby has become the mascot of Easter. Throughout Australia, bilby-shaped confections and related merchandise are sold as an alternative to Easter bunnies. Additionally a number of children’s books have popularized the Easter bilby who seems to have a touch of animist aboriginal magic. For example a passage from Burra Nimu, the Easter Bilby, describes the dyeing of Easter eggs like a dreamtime myth of the desert:
“[The bilby] knew that eggs meant the start of new life and new hope, so he made his especially beautiful. He painted rich red eggs, the colour of the hot desert earth, and splashed them with bright sparkles, because the desert is full of life…Next, he painted soft green eggs and sprinkled them with the colours of the wild flowers he had once seen, soon after the water fell from the sky.
I always liked the Easter bunny (and don’t get me wrong, I’m still thankful for the baskets of candy and toys he left) but it seems appropriate that his role has been usurped in Australia. By taking over the function of a minor holiday deity, bilbies have gained new prominence as one of the symbols of Australian conservation. Enjoy Easter (or Passover or Mawlid-al-Nabi) and enjoy this little bilbie gallery I have put together!
"I know I'm a symbol, but please put me down!"
Frequent visitors to this blog will know my longstanding fascination with the mammals of Australia. Because of its long geographic isolation, the island continent was mostly free of eutherian (placental) mammals until very recently–meaning that magnificent non-placental oddballs such as platypuses, wombats, echidnas, quolls, and numbats had plenty of time and space to survive and flourish. However there is one order of placental mammals which proved to be a big exception to this general narrative. Bats are eutherian mammals which can fly. They reached Australia in the Oligocene (the Oligocene era lagerstätten at Riversleigh have yielded 35 species of microchiropterans) and have been very successful ever since.
The Spectacled Flying Fox (Pteropus conspicillatus)
Australia has 65 known species of bats, most of which are still fast tiny insect eating microchiropterans. In recent times though a few species of large fruit-eating megabats have showed up and made inroads into the continent. One of these megabats is the subject of this post–the spectacled flying fox (Pteropus conspicillatus), a big handsome bat which is widespread along the coasts of New Guinea and seems to have established a beachhead in Northern Queensland.
A pregnant female Grey-Headed Flying-Fox (photo by Ofer Levy)
Spectacled flying foxes are gregarious social animals which live in huge colonies high in the canopies of the rainforest. At night they feed on nectar and pollen from tropical blossoms or they squeeze the juice from fruits like mangoes and figs. Although large for bats, the animals weigh less than a kilogram (2.2 pounds) and their wingspan is about 1.2 meters (4 feet). They are called spectacled bats because of the strips of yellow-tan fur around their eyes.
Spectacled Bat Close-up (Photo from CSIRO Sustainable Ecosystems)
It is unclear when the bats came to Australia but the fact that they are indigenous to many of the islands around New Guinea indicates that they are powerful fliers. Additionally, like certain other fruit bats, the spectacled flying fox can occasionally sip sea water without any ill effects.
An orphaned baby bat being cared for at Batreach in Kuranda
Even though they are hunted as bush meat in parts of New Guinea, Spectacled flying foxes are doing fairly well in that part of their range. Unfortunately in Australia they are having trouble with deforestation and with the paralysis tick (one of the many horrifying toxic pests which abound in Australia). Kindly and good-natured Australians frequently rescue orphaned bats, and, when not reintroduced into the wild the captive bats can live over 17 years in captivity. The bats are social animals, so the lonely orphans often bond deeply with their human rescuers.
Sam the orphaned spectacled bat
How can some people not like bats? (This image was taken at Tolga Bat Hospital by Steve Amesbury to promote the noble cause of bat conservation: see DontShootBats.com)
Don’t shoot bats! (or otherwise hurt them!)
To borrow a page from the timeless style of Sesame Street, this week Ferrebeekeeper is brought to you by the Roman letter Q. Each post will concern a topic which begins with that rare letter. So quench your thirst with quinine water and wrap up in a quaint quilt. There is a reason that the letter Q is worth 10 points in scrabble but I think we can find 5 relevant topics that are not too quixotic (also I’m going to stop using extra q words for effect immediately—please don’t stop reading).
A Northern Quoll (Dasyurus hallucatus)
For the first q-themed post, we must travel to the ancient arid continent of Australia. For reasons of geology and tectonics, Australia has been a wallflower in the great continental ballet and has been isolated for the last 40 million years. Thanks to this geographic seclusion, the animals of Australia are much different than the creatures which flourish elsewhere, and Austalia’s mammals are dominated by marsupials like the kangaroos, the wombats, the koalas, and the bandicoots. All of those creatures are herbivores, but there are insectivorous marsupials (like the numbat) and there are marsupial carnivores which prey on the others. Some of the larger orders of marsupial predators have died off as Australia dried out, but a major order of predators remain–the catlike quolls.
Quolls (genus Dasyurus) are solitary, nocturnal mammals which seek shelter in their burrows and dens by day and hunt birds, amphibians, reptiles, and small mammals at night. They are agile all-terrain creatures capable of swiftly moving across the forest floor or through the forest canopy. Quolls kill their prey with a bite to the neck where it joins the head. In addition to being predators, they also scavenge for carrion and they can sometimes be found by picnic areas and rubbish dumps. There are six species of quolls which range in size from 350 grams (12 ounces) to 3.5 kilograms (8 pounds). Four species are located across the Australian mainland while one species inhabits New Zealand. One outlier species, the Bronze Quoll (Dasyurus Spartacus) lives in the savannah of New Guinea. The animals all share a characteristic spotted fur coat and a similar lifestyle. The closest relatives of quolls are the formidable Tasmanian devils (the largest extant marsupial carnivores) and the superficially weasel-like mulgaras.
Unfortunately, quolls are not doing well. Feral cats, dogs, and foxes are much more deft predators and are outcompeting the quolls or eating them outright (although the quolls do get some free meals from the invasive wave of rabbits and rats which have swept Australia). Additionally the quolls are falling victim to an even stranger invasive species. The Cane Toad (Bufo marinus) is a toxic South American toad which was brought to Australia in order to control agricultural pests. The toads secrete a powerful toxin which is potent enough to kill a human (some people ingest cane toad secretions in order to experience the hallucinogenic effects). Cane toads resemble some of the natural amphibian prey species of quolls and the spotted predators eat them voraciously—only to fall sick and die. In order to save the unlucky quolls, a project is afoot to train the predators not to eat cane toads. Wildlife researchers have been dropping small sausages made of cane toad from airplane in quoll habitats. It is hoped that quolls will eat the sausages and become violently sick (but not fatally so). Having had a miserable bad trip, the quolls will then presumably forbear from eating further cane toad flesh.
The Cane Toad (Bufo marinus)
Diprotodon
The largest marsupial known to science is the now extinct diprotodon. Also known as the giant wombat or the rhinoceros wombat, this mighty marsupial grazer stood nearly 2 meters (6 feet) tall and stretched 3 metres (9.8 feet) from nose to tail. The animals flourished throughout much of the Pleistocene. From 1.6 million years ago until about 40,000 years ago, herds of Diprotodonts roamed across all of Australia. These giant wombats were indeed closely related to today’s wombats and koalas: jointly such creatures make up the Vombatiforme suborder Considering how formidable the bulldozer-like living wombat is, diprotodons must have indeed been like rhinoceroses and they probably occupied a similar top spot in the Australian web of life.
Unfortunately, like a substantial portion of Australia’s mega-fauna, the giant wombats disappeared shortly after humankind reached the island continent. The creatures apparently were destroyed by some combination of climate change, human hunting, and slash-and-burn land management. Aboriginal dreamtime lore makes extensive mention of a mighty furred beast called the bunyip–which has led anthropologists and paleontologists to speculate that the diprotodon has lived on in oral tradition for tens of thousands of years.
Fossil Remains of Diprotodon australis
The Eel-tailed Catfish (Tandanus tandanus)
Last week, I wrote about the great builders of the animal world, the beavers. But of course all sorts of other creatures build things. The Eel tailed catfish (Tandanus tandanus) lives in the Murray-Darling river basin of Eastern Australia where the creatures’ nest-building habits are costing them dearly.
The eel-tailed catfish is from the family Plotosidae (in fact it is a close relative of the striped eel catfish) and like other family members its most distinctive feature is a continuous fin margin surrounding the posterior half of their bodies—aka an eel tail! These catfish prefer to live on the gravel or sand at the bottom of lakes or slow-moving rivers. They eat crayfish, yabbies’, worms, mollusks, insect larva, and other smaller fish.
An eel-tailed catfish nest (the parent is in the middle)
A week or two before spawning, pairs of eel-tailed catfish build nests for their eggs. The fish construct these torus-shaped structures out of sand and pebbles and, once the female lays the eggs, one or both parents stay with the nest to guard it and to aerate the eggs until they hatch. Unfortunately, because of drought and agriculture, the Murray basin is rapidly drying out and silting up. As the pebbles and coarse sands which the fish use for nests are smothered with slimy silt, the species has been declining. Additionally, eel-tailed catfish are being out-competed by invasive carp which were introduced in a hare-brained aquiculture scheme.
Obdurodon--A Miocene Platypus which flourished 15 to 20 million years ago
Ferrebeekeeper has an abiding interest in monotremes including both the poisonous platypus and the enigmatic echidnas (with their advanced frontal cortex). But sadly that is about it as far as it goes for the extant egg-laying mammals: there are only two living families of monotremes (with a scanty total of five species split between them). To learn more about these animals one must turn to paleontology. Unfortunately even in the fossil record, monotremes are extremely rare.
Based on genetic evidence, biologists believe that the first monotremes made their advent in the history of life about 220 million years ago during the Triassic era; however the earliest known fossil monotreme so far discovered was a fossil jaw from the early Cretacious era about 120 million years ago. The bones belonged to Steropodon galmani, which seems to have been a beaked swimmer about 50 cm (20 inches) long which lived in Australia. Steropodon was apparently a giant among Cretacious mammals–most of which seem to have been shrew-sized (so as to better avoid attention from their contemporaries, the dinosaurs). Reconstructions of Steropodon all seem to resemble the platypus, and most paleantologists would probably concede that it was a sort of platypus—as apparently were other Mesozoic fossil monotremes such as Kollikodon and Teinolophos (platypuses and these platypus-like forbears are called the Ornithorhynchida). During the Cretaceous era, the land which is now Australia was in the South Polar regions of the world (approximately where Antarctica is today). Although temperatures were much warmer during the Cretaceous, monotremes must still have been able to deal with terrible cold: it is believed that the extremely efficient temperature control and the deep hibernation mechanism which these animals continue to display first evolved during that time.
An artist's reconstruction of Steropodon
The only monotreme fossil which was not found in Australia was from another platypus-like creature named Monotrematus sudamericanum. The creature’s remains were found in a Patagonian rock formation from the Paleocene era (the era just after the fall of the dinosaurs). Monotremes probably flourished across South America and Antarctica, as well as on Australia, but evidence is still scarce. There are most likely many interesting monotreme fossils throughout Antarctica, but, for some reason, paleontologists have not yet discovered them. Additionally, unlike the marsupials (which still quietly flourish throughout South America), the poor monotremes were wiped out on that continent.
Another artist's vision of Steropodon galmani--Notice how peeved the poor creature looks!
Last week I wrote about the Eocene era and the great proliferation of mammalian types which took place during that warm and fecund time. Although most families of mammals alive today first appeared on the scene during the Eocene, obviously the monotremes were already incredibly ancient. The Eocene does however seem to have been significant time for the monotreme order: the aquatic platypuses were apparently the ancestral monotremes, and echidnas (the Tachyglossidae) probably split off from them during the Eocene. Unfortunately we have no Eocene monotreme fossils so this conclusion is based on genetic evidence and on the suffusion of Miocene monotremes which include representatives of both Ornithorhynchida and Tachyglossidae. Some of these latter creatures are spectacular, like Zaglossus hacketti the giant echidna from the Pleistocene which was about the size of a ram! As Australia dried up so did the monotremes and now there is only one species of platypus left…
The Giant Echidna (Zaglossus hacketti) which lived until 20,000 years ago...
Well, that’s a cursory history of the monotremes based on what we know. I wish I could tell you more but unfortunately there is no fossil evidence concerning the first half of the order. Sometimes I like to imagine the first monotremes—which were probably clunky, furry platypus-looking characters with an extra hint of iguana thrown in. These creatures fished in the alien rivers of the Triassic world in a time when dinosaurs and pterosaurs were also still evolving.
Today (February 3rd, 2011) is the first day of the Chinese year 4709, the year of the metal rabbit. You should go have some dumplings and rice wine and then light a bunch of firecrackers and dance with a giant dragon! If you have any business in China, you should relax—nothing is getting done there for nearly a fortnight. This is by far the biggest and most important holiday of the year. For two weeks, the ceaseless seething all-consuming industry of rising China comes to a stop. Even the meanest factory drudges take time off to leave the manufacturing cities and travel back to the country for some well-earned time with family and loved ones. When you celebrate the year of the rabbit you will be doing so with more than a billion souls.
The Year of the Metal Rabbit
The rabbit is a mythological figure of great standing in the Chinese pantheon. The divine jade rabbit is a sage and a potion master capable of mixing the elixer of immortality. He dwells on the moon with the beautiful and troubling moon goddess Chang’e, but every once in a while he scampers down to earth to perform good deeds and instruct worthwhile students. In the middle ages he reputedly saved the inhabitants of Beijing from a plague!
The Jade Rabbit mixes potions in front of his mansion on the moon.
According to astrologers and geomancers the year of the rabbit is traditionally associated with the family and the homestead. It is a good time for artistic pursuits, diplomatic missions, and for shoring up the peace (which always needs to be shored up after a dramatic and dangerous tiger year). People born in the Year of the Rabbit are ambitious and have excellent taste and fashion sense. They are frequently financially lucky: their ability to sense danger and flee from it gives them an edge in business. It goes without saying that they are cautious and careful, never yielding to impulse. Well—not never–although outwardly reserved, rabbits have their own private life. You can look to the animal kingdom for instruction…
Speaking of the animal kingdom, this week we are celebrating Furry Herbivore Week here at Ferrebeekeeper (I made the text red since it’s not a real thing), and the rabbit has a place of honor. Few animals are more universally known and more universally successful. The family Leporidae consists of over 50 species of rabbits and hares and, together with the family Ochotonidae (the pikas), constitutes the order Lagomorpha. But whereas pikas have a limited range, rabbits and hares are found worldwide except for Antarctica (and possibly Manhattan). The Encyclopedia of Mammals eloquently describes the basic leporidae design:
Leporids are small to moderately sized mammals, adapted for rapid movement. They have long hind legs, with four toes on each foot, and shorter fore legs, with five toes each. The soles of their feet are hairy, to improve grip while running, and they have strong claws on all of their toes. Leporids also have distinctive, elongated and mobile ears, and they have an excellent sense of hearing. Their eyes are large, and their night vision is good, reflecting their primarily nocturnal or crepuscular mode of living.
Together with a quick and fecund reproductive cycle and a taste for readily available vegetation, this is a winning design. Few families of mammal are more bountiful. When rabbits and hares were introduced to the continent of Australia, they overran it completely. Armies of bunnies have subsequently wrecked havoc on the lives of marsupial herbivores with which they compete. It is one of the most disastrous stories of invasive animals in history.
But to the rabbits it was a story of success. It always is. Individual rabbit stories end with jaws or talons or steel snares, but the overall story is always a running leaping thriving tale of victory. You shouldn’t look at one rabbit or hare, you should look at them all. When you do you will be amazed by the luck and resiliency and beauty of the leporids. I hope you think about them sometimes as you embark on your own happy and successful year of the rabbit!
The Short-Beaked Echidna (Source: M McKelvey/P Rismiller/)
Last year featured an in-depth examination of Echidna, the terrifying “mother of monsters” from Greek mythology. To start this year on a glorious high note, here is an essay concerning the actual echidnas (Tachyglossidae), a family of mammals from Australia and New Guinea. The echidnas were much wronged when explorers named them after a hellish demigoddess. Although I have never met—or even seen—a living echidna, they are one of my favorite creatures for many reasons. Combining a gentle temperament with fascinatingly alien intelligence, the echidna is a delightful animal whose taxonomical oddity reveals the strange paths of fate which life takes over great expanses of time.
Along with the charismatic platypus, the echidna is the last of the egg-laying monotremes. Monotremes are a very different sort of mammal than the other two major divisions of mammals, the eutheria and the metatheria. The teeming eutheria (familiar mammals like shrews, manatees, picas, goats, and humans) nourish their fetal young by means of a placenta. The ancient metatheria (marsupials) sustain their developing young in a special pouch. The monotremes predate both groups and give evidence of mammals’ origins. Genetic studies suggest that the monotremes originated from some reptile-like ancestor about 220 million years ago. The long and tangled family history of the mammals and their antecedents will have to wait for another post–suffice to say that monotremes have been here for an extraordinarily long time. The surviving monotremes, however, are not primitive atavists, but extraordinarily advanced descendants of those ancient progenitor mammals. They have evolved and survived in varying fashions over the long eons. Over those millions and millions of years, the echidna developed a very interesting brain.
Echidnas have the largest neocortex relative to bodymass of any creature. The neocortex (which Hercule Poirot always creepily referred to as “the little grey cells”) is involved in higher brain functions such as spacial cognition, logic, and problem solving. This special tool has taken the echidna far: like humans, and unlike almost all other creatures, echidnas live in very diverse habitats. Actually it is the short-beaked echidna (Tachyglossus aculeatus) which lives in different habitats—the other two extant species live in tropical New Guinea and are little known to science. Although all three species seem to share most traits, I am really writing solely about Tachyglossus aculeatus which ranges from the hot dry desert scrub, to the tropical rainforest, to the coast, to the cold snows of the Australian Alps (where they can lower their body temperature a few degrees above freezing and hibernate). Echidnas live on termites and ants, omnipresent social insects which are evolutionary winners in their own right. Echidnas dig up these insects with powerful razor claws and gobble them down using a long sticky tongue which zips in and out of a toothless tube-like mouth. Echidnas are not known to fight each other or other animals. In the great evolutionary battle they are pacifists (provided you are not an ant or termite) and if approached aggressively they will curl into a ball and trust their sharp spine-like hairs to keep them safe. They are also phenomenal burrowers and can quickly tunnel down through anything other than solid stone.
An orphaned puggle being handraised.
Because of their cleverness, relatively little is known about echidnas. They are difficult to capture since they disdain baits and can figure out most traps. Similarly, in zoos, echidnas have proven extremely gifted at escape. Their mating habits are largely mysterious to us but seem to involve non-confrontational competition. The female echidna is followed for an extended period of time by a train of interested males. In response to an unknown signal, the male echidnas begin frantically digging, trying to nudge one another out of the way. Just how the victor emerges from this competition is unknown, but one the female has chosen, the other males walk away with no obvious rancor. After laying her egg, the female immediately rolls it into a pouch-like fold on her abdomen. Once the puggle has hatched, the mother echidna solicitously tends it for seven months, after which it roams off free and solitary.
Echidnas have an extra sense, electoreceptivity, but for them it is much weaker than it is in their close cousins the platypuses. It has also been noted that echidnas vibrate. Water placed near captive echidnas shows distinct ripples in the surface. Perhaps they vocalize on frequencies beneath the range of human hearing (as do elephants). Speaking of captivity, Echidnas have survived for up to 30 years in zoos even though it is a difficult environment for the blithesome free-roaming animals. It is believed they live twice that long in the wild—but, again, nobody really knows.
Agh! Get away from there! I though you had a large neocortex!
Likewise nobody knows the echidnas’ total population numbers or how healthy the species is. What is known is that, sadly, even the intelligent and peaceful echidnas are running into problems in the modern world. Like other good-hearted pedestrians, echidnas are often killed by careless drivers. Echidnas face increasing habitat destruction from human houses, farms, and roads. Likewise they must deal with new predators, the dingos, which have discovered that urinating on balled-up echidnas will cause the latter to uncurl for a moment in stunned disgust (giving the ruthless dogs a chance to rip into their guts).
I wonder what echidnas think of us. They know of our traps, our radio-tracking devices, and they know how to avoid aborigine hunters. They are becoming wise to our deadly cars and to the dirty tricks of dingos. Still they remain curious about people and will sometimes come out of the wilderness in groups to examine our suburbs and cities before melting back into the wild. Humankind took a long while to understand that echidnas are not dim-witted reptilian pincushions but rather clever and highly developed generalists. Do they generously think the same of us, or do they put humankind from their mind as something foul when they head back to the ancient, open outback?
