The most important ashes struggle of the summer: the Mallee Emu-wren

The most important ashes struggle of the summer: the Mallee Emu-wren

You unzip the flysheet of your tent and emerge into the world to be greeted by a morning lit with gold. The sun’s rays course freely across the sky in the absence of clouds. It’s cool, but you know it won’t be for long. As you rise to your feet, you brush the pale, red sand – damp with overnight dew – that has clung to your pants while you were putting your shoes on. The morning air rings with the calls of Yellow-plumed and White-eared Honeyeaters. There is the distant call of a Crested Bellbird, although who knows if you were able to correctly estimate the distance of this master of ventriloquism.

With this much bird activity, there is too much excitement building to justify breakfast at camp. This morning, it will be a muesli bar while out on the search. Before you depart camp you do make time to strap on your gaiters. These are a necessity if you want your calves and shins to escape the worst of the prickly Triodia (commonly referred to as Spinifex or Porcupine Grass). Undoubtedly, you will end up with prickles in your knees and a few pesky spines will score a direct hit straight through your gaiters, but that is the price you pay if you want to spot your target bird. It is dependent on large, mature clumps of Triodia, so there will be no avoiding pain if you are to have any chance of success.

Every time I go in search of mallee emu-wrens, I do it mostly with my ears. I mistakenly chase calls of variegated fairy-wrens and splendid fairy-wrens all morning until I hear it. And once you have heard it, there’s no mistaking it. It’s so high pitched, yet buzzy, that it can be only one thing – a mallee emu-wren. An hour or two of searching in a morning is often all it takes and it is even quicker sometimes. So if it is this easy to find, how can it be one of Australia’s rarest birds?

Rarely venturing out into the open, the high pitched, buzzy call of the Mallee Emu-wren is often the first indication that there is one nearby.

Well, the truth is that you have to look in very specific places to find this bird these days. It would once have been found across large expanses of eastern South Australia, and north-west Victoria. These days it is believed to occur in only a handful of locations in north-west Victoria. Until as recently as 2014, Mallee Emu-wrens were found in South Australia in Ngarkat Conservation Park and near Billiat Conservation Park, but large fires passed through these patches of habitat and in the process, they wiped out Mallee Emu-wrens from South Australia. Some people are optimistic that small numbers of Mallee Emu-wrens may still be hanging on in South Australia. Nevertheless, these fires left the outlook for this species crucially dependent on populations in Victoria, particularly those living in Murray-Sunset National Park and Hattah-Kulkyne National Park.

Murray-Sunset and Hattah-Kulkyne are big national parks in the context of the Victorian reserve network. Yet, they are not so big that a single large fire may not wreak havoc across much, if not all, of the vegetation within these two reserves. If this were to happen, it would take many years for mature clumps of Triodia to establish again and without mature clumps of Triodia, Mallee Emu-wrens don’t breed. As the summer fire season approaches, Simon Verdon, a La Trobe University PhD student researching Mallee Emu-wrens, holds his breath. “Each summer carries the risk of large, reserve-scale wildfires wiping out whole populations or even the whole species,” he explains.

Large, mature clumps of Triodia (commonly referred to as Spinifex or Porcupine Grass) are the favoured habitat of Mallee Emu-wrens.

Australia is an inherently fire-prone landscape and many of our plants and animals are fire-adapted. So much so that many species, including the very Triodia that Mallee Emu-wrens depend on, possess attributes that promote burning. The presence of Mallee Emu-wrens, a species so threatened by fire, in a fire-prone landscapes seems something of a paradox. Verdon says that human modification of the landscape is to blame for the dire situation the Mallee Emu-wren now finds itself in. “Fires have always been a part of this landscape. It is only because land clearing has fragmented the landscape into a series of isolated reserves that fire poses such a threat to this species.”

Mallee Emu-wrens are a small bird with a tiny wingspan. Watching them fly from Triodia clump to Triodia clump, their feeble flight is obvious. This means that recolonisation of habitat after it has recovered from the passage of fire is a very slow process, and may not occur at all if the distance to remaining populations exceeds the very limited dispersal capabilities of the bird.

A fledgling Mallee Emu-wren. If enough of these are to be produced, then fire management will need to ensure enough suitable area of mature Triodia escapes the effects of wildfire.

Despite the potential for catastrophe, Verdon remains optimistic, stating, “Absolutely there is hope for the Mallee Emu-wren! It is locally abundant.” He sees managing the fire regime across the distribution of Mallee Emu-wrens as key to its survival. “As long as we can stop wildfires burning entire reserves in one go the species has a good chance of survival.”

Therein lies the problem for those charged with managing this landscape. According to Verdon, “the challenge is balancing the threat of wildfire in the one hand against the potential damage done by strategic burning in the other.” Prescribed burning remains the best tool land managers have for reducing the likelihood of large-scale fire, but it too removes mature Triodia from the landscape. Too much prescribed burning and you may have an effect similar to a large bushfire. Getting the balance right relies on a thorough understanding of the way Mallee Emu-wrens and the landscape respond to the effects of fire. “The important thing here is that everyone involved has the same goal in mind, which makes progress in this field of research that bit quicker,” explains Verdon. We can only hope that Verdon’s optimism is well-founded and that his research is able to provide us with the ability to better protect this charismatic species.

Mallee Emu-wrens are not alone in being threatened by fire. Some other bird species that reside in the mallee, such as Black-eared Miners and Red-lored Whistlers, also require mature habitat that only occurs after many years without fire. Western Ground Parrots, which reside in a tiny area of habitat in southern Western Australia, face similar challenges to mallee emu-wrens because of their very limited range. Whereas fire is a threat for some species, lack of fire can be detrimental to others. In the north of Australia, changes to natural fire regimes are threatening Golden-shouldered Parrots. A reduction in the number of fires means that fire-stimulated seeding does not occur, leaving these seed-eating parrots with critical food shortages. Furthermore, reduced fire frequency has led to the grasslands in which the parrots forage being invaded by woody tea-tree vegetation that provides hiding places for predators of the Golden-shouldered Parrot.

Nothing quite compares to the excitement of seeing Mallee Emu-wrens. They’re a special bird in a special environment.

For those lucky enough to know the Mallee Emu-wren well, it would be such a tragedy if they were to disappear into the annals of history. As Verdon puts it, “That a bird so small and seemingly delicate can thrive in a landscape which seems so harsh – especially in summer – is a humbling thought.” With the total population estimated to comprise fewer than 17,000 individuals and population strongholds confined largely to two reserves, the survival of the Mallee Emu-wren hangs on a knife-edge. A single bad fire season could see the survival prospects of this species quite literally go up in smoke. Like Verdon, I will be watching for reports of bushfires in Victoria’s north-west this summer and hoping that the region escapes unscathed. If it does, I will breathe a sigh of relief knowing that for another year I will likely have the chance of hearing that distinctive, high-pitched buzz – a call that will forever take me back to the magic of the mallee, regardless of what the future holds for the Mallee Emu-wren.

Rowan Mott

Rowan is a Monash University PhD graduate and now works there as an ecologist. His research interests are broad, spanning seabird foraging ecology to plant invasions. When not in his office, he will most likely be in a woodland with binoculars around his neck and camera in hand.

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