THE FORGOTTEN TASMANIAN EMUS
by Tristan Derham, 10th September at 10:27 AM
If you are from Tasmania you have likely heard your mate’s story about the time they, or their friend’s friend, saw a thylacine. Hiking alone, they saw a big dog on the track – but wait! Those stripes! That tail! And just as they reached for their camera… the animal had slipped away into the deep bush. Clearly the thylacine lives on in the public imagination so strongly that we see it in our waking dreams.
How sad, then, that we do not hear stories of wild emus in the Tasmanian bush. No hikers come around a corner to be faced with an emu and his striped chicks stopping for a drink in a stream. No Tasmanian driver ever saw an emu dash across a gravel road and away into the night. For more than one hundred and fifty years, no Tasmanian farmer has seen the tracks of an emu in the mud by the bush block. The only emus we have now are in wildlife parks and farms. Most Tasmanians that I have spoken to don’t remember that wild emus were ever here at all.
We don’t know much about the Tasmanian emus. We don’t know how big they were, how they behaved, what they ate, whether they were abundant or which habitats they preferred. We don’t know what ecological functions were lost with the emus. For example, emus on the mainland might play an important role as long distance seed dispersers. Disturbingly, we don’t know why they disappeared so quickly.
Europeans began colonising Van Diemens Land in 1803. Thirty years later the emu was almost gone. It may have been extirpated even before Van Diemen’s Land was renamed in 1854. Certainly it was gone by 1870. Compared to the thylacine, which hung on for almost one hundred and fifty years, and the forester kangaroo, which lives on today in a few remnant patches, the emu disappeared very quickly indeed.
Here’s what we do know. The Tasmanian emus were closely related to Australian mainland emus, as well as the King Island and the Kangaroo Island emu populations, both of which were extirpated in the nineteenth century. Recent genetic work shows that they can all be considered members of the same species. This is not surprising given that Tasmania has only been separated from the mainland for about 14000 years.
While we don’t yet know what specific habitats that Tasmanian emus required, my recent (unpublished) research shows that they were widespread. When Europeans arrived, emus could be found from the Derwent River in the south to the Tamar in the north and from the north-east to the mid-north coast.
As on the mainland of Australia, emus and their eggs were eaten by Aboriginal people. They were important to at least some Aboriginal Tasmanians, as evidenced by eggshell remains in ancient cave sites, depictions of emus in art and the celebration of an emu dance. As James Boyce has pointed out, along with kangaroos, wallabies and pademelons, emus were an important food source for early European colonists. That is a very short list of facts for such an iconic species.
For other facts, we have less to go on. Accounts of the size of Tasmanian emus from early settlers are conflicting – some claimed that they were smaller than mainland emus, others claim to have caught large birds on a regular basis. For example, the surveyor George Harris, who recommended the site of Hobart Town, regularly caught emus of 35 to 40 kg. These values are within the normal range of body mass for adult emus on the mainland. Little information has been gleaned from museum specimens, since there are so few. Vicky Thomson and others have hypothesised that the Tasmanian emus were slightly smaller, based on a relationship with island size and measurements from two leg bones. A recent consolidation of Tasmanian emu specimens will hopefully provide more data, so watch this space!
Several authors have assumed that emus preferred open woodland habitat. The tragic explorer Henry Hellyer came across emu tracks near St Valentines Peak in 1827, which he took to indicate ‘better country’, that is, open country suitable for grazing sheep. Archaeologists have assumed that the presence of eggshells in ancient deposits indicates grassy, open vegetation nearby. However, Australian mainland emus are found in many different habitats, from open woodland to timbered areas, from near-desert to alpine scrub, from temperate to tropical climates and at all altitudes.
Importantly, we don’t know why the Tasmanian emus disappeared so quickly. Exploring historical texts and interviewing older Tasmanians in the 1920s, Stuart Dove decided that government-sponsored hunting was to blame. That’s a fair assumption given the intensity with which the animals were hunted: One hunter claimed to have been delivering 1000 lb of emu and kangaroo flesh to the colonial stores every month. Europeans killed emus all year round, regardless of breeding seasons. This prompted a call for restrictions on the hunting of native fauna in the late 1830s but to no avail.
Hunting by colonial towns-folk was likely intense but other groups were pursuing the emu as well. There are several accounts of Aboriginal groups with enormous packs of dogs. Bushrangers were living off the land and likely took much of their sustenance from hunting. Emus were known to feed on grain crops and farmers likely killed them to protect their livelihoods.
Aside from hunting there are several other factors that have not yet been systematically considered. Settlers reported unowned dogs attacking sheep. Those dogs may have also depredated emus far from settled areas, although it is puzzling that emus have lived alongside dingoes on the mainland of Australia for at least three thousand years. Robert Dooley has hypothesised that introduced rats devoured emu eggs. Pigs may have attacked eggs and chicks. Herds of free-roaming cattle and sheep would have competed with emus for food. Tasmanian wedge-tailed eagles are known to be susceptible to having their nests disturbed – perhaps Tasmanian emus were similarly sensitive in some way. No one has considered whether a disease could have affected emus, though there is no particular reason to think so.
A likely factor is the loss of emu habitat. Van Diemen’s Land changed very quickly after colonisation. By the 1830s, large areas around the Derwent River, the Tamar River, the Midlands and the central north coast had been settled. If the land taken for cropping and grazing overlapped with the heart of emu habitat then it may have had a severe impact on the emu population. I’m hoping to test that hypothesis using data collected from the early accounts of settlers, explorers and naturalists.
On the other hand, there were still vast areas of Tasmania, far from settlements, which remained uncleared for decades. If the thylacine could take refuge in the wilder corners of Tasmania then why not the emu? A report by the pioneering Tasmanian botanist Ronald Gunn gives us a clue. In 1860, Gunn stood on a hill near the Leven River and saw that the country had not been burned for twenty-five years or more. What had once been open grassy plains was thick with young eucalypts and would soon be unsuitable for pasture. Gunn wrote that “the want of the usual and regular aboriginal fires to clear the country seems to be the cause.”
Almost immediately upon the arrival of the British in Van Diemen’s Land, Aboriginal people were prevented from caring for their country in ways that had sustained it for millenia. This included burning vegetation to clear pathways, to assist in hunting and to provide feeding grounds for herbivores. Were the Tasmanian emus deprived of refuge? Was that the final straw?
(All posts are personal reflections of the blog-post author and do not necessarily reflect the views of all other DEEP members).