Daytime sightings of elusive aardvarks hint at troubled times in the Kalahari



Disappearance of aardvarks from dry ecosystems could have devastating consequences for the many other animals that rely on their burrows.
Kelsey Green

Robyn Hetem, University of the Witwatersrand and Nora Marie Weyer, University of the Witwatersrand

Aardvarks are notoriously elusive, nocturnal mammals. They generally hide in their underground burrows during the day and emerge at night to feed exclusively on ants and termites. Aardvarks are widespread throughout most habitats of Africa south of the Sahara, except deserts. But their actual numbers are not known because they’re so elusive.

Aardvarks top the bucket list of many wildlife enthusiasts, but few have been fortunate enough to see them – until recently. Daytime sightings of aardvarks are becoming more common in the drier parts of southern Africa. But seeing them in the daytime does not bode well because it indicates they might not be finding enough food.

To understand how aardvarks cope with hot and dry conditions, we studied them in the Kalahari, one of the hottest and driest savannah regions in southern Africa in which aardvarks occur. Our study took place at Tswalu, a private reserve in South Africa that supports research through the Tswalu Foundation. We equipped wild, free-living aardvarks with biologgers (minicomputers) that remotely and continuously recorded their body temperature (an indicator of well-being in large mammals), and their activity. Each aardvark also received a radio-tracking device, allowing us to locate them regularly. Tracking the aardvarks provided clues on how they changed their behaviour in relation to environmental stressors in the different seasons and years of our three-year study.

Our study found that in drought periods, aardvarks struggled to find food. It was difficult for them to maintain their energy balance and stay warm during the cool night, so they shifted their active time to the day. Some died from starvation. Given the aardvark’s importance to ecosystems, these findings are a concern.

Comparison of Aardvarks at night and day
Aardvarks usually emerge from their burrows at night (left), but during drought periods, they are increasingly seen during daytime (right).
N. Weyer

Aardvarks are important ecosystem engineers

No other mammal in Africa digs as many large burrows as the aardvark. Dozens of mammals, birds and reptiles use aardvark burrows as shelter from extreme heat and cold, protection from predators, or a place to raise their young. In many of South Africa’s conservation areas, temperatures have already risen by 2℃ over the past 50 years. Further warming by 4-6℃ by the end of the century has been projected.

With deserts and drylands expanding across much of Africa, climate change might threaten the aardvark itself as well as the many animals reliant on aardvark burrows as a cool shelter from rising temperatures.

During typical years, aardvarks were active at night and were able to regulate their body temperature between 35-37℃.

Aardvark active at night during non-drought times
Aardvark active at night during non-drought times.
adapted from Weyer et al., 2020, Frontiers in Physiology, https://doi.org/10.3389/fphys.2020.00637

However, this pattern changed during two severe summer droughts that occurred in the Kalahari during our study. During the droughts, aardvarks shifted their activity to the daytime and their body temperature plummeted below 30°C.

Using remotely-sensed vegetation data recorded by NASA satellites and our own camera trap footage and logger data, we showed that these dramatic changes in body temperature and activity of aardvarks were related to the availability of grass, on which their ant and termite prey rely. When grass was scarce during droughts, the ant and termite prey became inaccessible to aardvarks, preventing them from meeting their daily energy requirements. As their body reserves declined, aardvarks were unable to sustain the energy costs of maintaining warm and stable body temperatures and shifted their activity to the warmer daytime.

Aardvark active in the daytime during drought
Aardvark active in the daytime during drought.
adapted from Weyer et al., 2020, Frontiers in Physiology, https://doi.org/10.3389/fphys.2020.00637

Shifting activity to the warmer daytime while food is scarce can save energy that would otherwise be spent on staying warm during cold nights. But, for our aardvarks, even these energy savings were insufficient during drought, when the ground was bare and the ant and termite prey inaccessible. As a result, seven of our twelve study aardvarks and many others died, presumably from starvation.

A bleak future for aardvarks in a hotter and drier world

On the Red List of Species of the International Union for Conservation of Nature, aardvarks are currently categorised as a species of “Least Concern”. However, we consider aardvarks to be threatened in the drier parts of their distribution in Africa, such as the Kalahari, where climate change brings about droughts. Disappearance of aardvarks from these ecosystems could have devastating consequences for the many other animals that rely on the aardvarks’ burrows.

We hope that our findings will raise further awareness about the consequences of climate change and inform future wildlife conservation and management decisions. Such steps might include assessments of the actual population status of aardvarks across Africa, or mitigation measures to preserve species that depend on burrows for refuge in regions where aardvarks might go locally extinct. More extensive measures, like water-wise reserve management, increasing sizes and connectivity of nature reserves in semi-arid regions, and reducing emissions to mitigate climate change, are just as urgent.

Finally, any solution to the plight of climate change on free-living animals requires a better understanding of their capacities to cope with drought. Therefore, many more long-term comprehensive studies are needed on the physiology and behaviour of the vulnerable animals living in hot, arid regions of the world.

Nora Marie Weyer’s disclosure statement has been updated.The Conversation

Robyn Hetem, Senior Lecturer, University of the Witwatersrand and Nora Marie Weyer, PhD – Wildlife Conservation Physiology, University of the Witwatersrand

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Friday essay: species sightings


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An echidna in the Western Granites at Jam Tree Gully.
John Kinsella

John Kinsella, Curtin University

A Rare Sight

The bird seen first time here
in forty years sings lightly
on the wire, you turn to touch
the shoulder of a friend
and turning back together
find nothing but sky
and wire trembling.

Brushtail possum evidenced. We had not seen one here in nine years, and there might not have been a sighting long before this. But there might have been. A possum or possums may have been driven out, removed from the roof cavity — there are, sadly, people who will do this and then exterminate them. But this too is conjecture, we’re only going here on the general condition of the bush block when we arrived — the 170 years of colonial erosion, the running of cattle and sheep and horses, the fencing, cropping (to a lesser extent because we are on the rocky northern face of a valley — that happens on the other side of the hills, a couple of kilometres away), and the machinery of colonial domestic presence — house, sheds, driveway, firebreaks.

Once, this area in the Western Australian wheatbelt, like nearby Goomalling (“Place of possums”), was prime habitat for brushtail possums. Even now residual and remnant York gum and jam tree woodland, granite boulders and granite outcrops, in patches of greater and lesser density, provide enough for native fauna to retain a hold.

Since we’ve been at Jam Tree Gully, we have removed internal fences, planted trees and — through not farming animals — allowed the beginning of a return of undergrowth. It’s an agonisingly slow process; this year is the first in nine years that we have actually seen, through self-generation, the reappearance of the shy sun orchid (a single example), scarlet runner (running postman) and a native fern.

Looking south across Jam Tree Gully.
John Kinsella

I am talking about Ballardong Noongar boodja (country), and not “ours” but by the colonial reality of surveys and land titles, “allocated” as our domestic jurisdiction, the act of survey and property hierarchising entitlement (though mining companies believe they have even more entitlement than that, as, of course, does the state, as anyone can tell you who had “their” land reclaimed as part of the Cathedral Avenue widening of the road from York to Quairading and the destruction of hundreds of old-growth salmon gums, wandoos and York gums). As far as I and my family are concerned, we have an obligation to return this land to a health that though distant from its pre-colonial state of health, at least gestures towards it.

One of the dominant linguistic behaviours of our family residency in the area, of our presence, is to discuss what other living things we see every day, and how they relate to the country we see them on. Our son Tim, an avid birdwatcher and naturalist, walks the block every day and reports back, verbally and on film, about what he’s observed. These are intricate and informed observations, cross-referenced with what is likely to be seen, differences in, say, behaviour (mating plumage, nesting processes, shifts in song, etc), numbers, and implication. Like his parents, Tim sees language as part of presence, and these observations are an essential part of his own poetry-making.

John Kinsella.
Tracy Ryan

Similarly, I spend my time out on the block doing restorative tasks and acts, and working their language into the matrix of my writing. The language is in flux because rather than a taxonomy, a nomenclature of seeing and presence, what happens is that experience of habitat loss, and attempts at habitat restoration, place words, syntax and utterance as we have it under pressure.

Something else emerges, an active language of presence that needs to critique the ironies of its own impact, of its own vicarious (and direct) participation in the ongoing dynamics of dispossession and acquisition.

Neologisms and new nomenclature might be one outcome, but more often it’s a shift in what constitutes the observing eye and voice, what makes the self in the process. In poetics, we talk about the “I” in the context of the unified self and challenging the primacy of personal observation when language itself creates at the very least a simulacrum of self in which the poem is a cybernetic producer of opinions, surprise correlations and yokings, undoings and interjections. The poem itself is alive — made by the writer, it takes on a life of its own.

So, does this mean I am suggesting the poem itself, for example, channels the disturbances and distresses of country? Well, yes, up to a point.

The wasp making its mud cells and inserting caterpillars or spiders, stunned but alive with a wasp egg laid inside their bodies, to be eaten alive — in a state of life suspended — by wasp grubs, which break out of their dark cells into the light.
It’s a poem that needs no explanation if “made” — it works on levels of allegory, symbol, a glimpse of habitat, and so on. Or maybe something a little more acceptable to a readership which ultimately looks for affirmation of connection with the natural world while benefiting from capitalist exploitation of place (look around us), an echidna moving rapidly downhill, its quills liquid in the fractured light of late afternoon sun streaming over the rim of valley, through the York gum canopy.




Read more:
Australia’s species need an independent champion


We don’t see echidnas often here, but we see evidence of their diggings for ants and termites almost daily. And we see their scats. In fact, coming across scats is how we identify so much, including the brushtail possum. Scats, footprints, scratchings and sounds, especially at night. These languages are outside direct encounter, and often outside a description we might offer. Echidna sightings are coming less often, though evidence of their presence remains strong.

The poem interprets this as avoidance and strategy on the part of the echidna — we respect the not-seeing, and delight in the evidence of presence. Same with kangaroos. But in the case of eagles, the (illegal) killing of an eagle in a pair that were resident for many, many years, is an undoing that is hard to resolve under habitat-loss pressure. It is brutal. But writing about this loss, about the wrong done, cannot be a fait accompli — it must believe in the imagined presence as likely “return” as species, at least.

Roos at Jam Tree Gully just before the fences came down.
John Kinsella

All life we see on the block is vulnerable to human violence — thrill-killings of animals are sadly not uncommon, and there seems a strong link between far-right politics of patriotism and shooting around the district.

Scramble-biking, bush-bashing and remorseless clearing are changing habitat around the zone we “protect” at a far greater pace than when we arrived. It’s easy to use the “fly-in fly-out” dynamic as a distraction for the massive abuse that mining is in Australia, and to separate social issues of employment and purpose when discussing the obvious (“clear-cut”) environmental abuses of miners and their protectors, but nonetheless it is a real impact on ecologies that needs to be factored in.

The psychology of the mine

The impact of flying, the obvious impacts of the mines themselves, but also the psychology of purchasing a country property within a couple of hours’ reach of the city airport to use as a base. So many of the farmlets and blocks around where we live appear to have been bought by FIFO (fly in fly out) workers (real estate ads often overtly pitch to FIFO buyers, and I offer anecdotal evidence of conversations direct and indirect with and involving neighbours), and in many circumstances the psychology of the mine looks as if it has been brought to those blocks — substantial bush clearing, clear indifference to wildlife, and a psychology of control, ownership and what manifests by intent or default as a disrespect of Aboriginal land rights.

Of course, such attitudes to country are not unique to FIFO miners, far from it, and they have found around them a context of receptivity to such ways. And I do not blame the individual miners for this per se, but I do blame the mining companies and those who facilitate the abuses of land by those miners. A work psychology too readily becomes a life psychology.

An Inland Thornbill at Jam Tree Gully.
John Kinsella

In creating writing that acts as witness to species loss, we too easily become contributors to the archive, to the seedbank of metaphors that substitute for the real thing. It’s like repugnant natural history collections that give us a record of so many lost species when the very process of collecting has been a part of that species loss. Science bears many moral ironies that I feel an active, restorative poem should not. I am not saying a poem shouldn’t ironise the limitations of its own production, its impacts on ecologies; in fact, the opposite. I am saying it should be aware of them and critique its own role in the destruction.

A poem having a role in destruction? I hear you wonder. How so? Because industrialised consumer life is impacting and many, even the most environmentally-minded, make their art through the tools of exploitation.

It becomes a question of genuinely weighing up the cost in terms of the benefit to the environment. Does getting the message out there regarding habitat destruction cost more morally and literally than not doing so? The notion of “costs” needs to be placed under pressure before we begin. An economics of the figurative needs to be held accountable, scrutinised.




Read more:
More sightings of an endangered species don’t always mean it’s recovering


Which brings me back to the language of participation, observation and instruction I intimated when talking of our son Tim and writing what’s happening on the block. My partner Tracy and I are often confronted with the horror of having to say, “We saw a lot of those (birds, mammals, insects, reptiles, trees, shrubs, flowers etc) when we were kids, but not often now, or not at all.”

In many cases, flora and fauna we knew as children are now endangered or verging on extinction, not only within the physical areas with which we were most familiar, but across their range.

An example is the brown bittern, which I used to see and hear as a child when around swampy areas, and which is now almost extinct, certainly in the Northam region. Yet Tracy and I, travelling with Tim, had the remarkable experience of very likely seeing (unconfirmed sighting) a black or brown bittern between Toodyay and Perth last year. Tim, a most observant person, didn’t see it because he was studying something else outside the opposite window, and has been quizzing us about the sighting ever since. He has done a vast amount of research, and we have considered all other possibilities (too big for a little bittern, not the right size and shape for a night heron, a bird I know well), and so on. It was really, a notifiable sighting. Not in the sense of an “invasive species” (the irony!), but as an almost extinct species.

Echidna in the Western Granites.
John Kinsella

Would such notification lead to an invasiveness that affected its habitat more, or would it lead to protection? I consider recent sightings of night parrots in northern Australia, and wonder. The “understanding” to “save” can be so destructive — life, persisting against the odds, suddenly disturbed, fetishised, made vulnerable with over-attention. The “leave alone and stay away” approach can often be more effective. At least until the bulldozers arrive, which I’ve learnt over my life is eventually.

So, what do we do? Write a poem of resistance, of embodying the bird but not appropriating it in a poem, of keeping an eye on habitat and acting if it looks under threat?. Where a creature once was, a creature might be. Belonging and the marks of the endemic cannot be erased entirely with all the brutal means of survey and development, though the modus operandi of the state and its private apparatuses is to achieve that, and to convince us it’s been achieved. They want no comeback, to retrospective protections, and certainly no memorialising that cedes authority.

Brushtail possum evidenced. The nature of our interaction yet to be decided — largely by possum, but also by us. Possum enters poems, enters essays, enters stories. But does it become just a word, just an idea separated from its living life, it’s actuality? So easily, yes. Yet tense has a lot to do with it. As an active presence, not a thing of the past, and as a generator of sounds, movement and language. It is not an addition to here; it is here. It is not an exercise of painting a landscape; it is the land.




Read more:
Hidden housemates: when possums go bump in the night


Language used in the poem needs to be alive to the visceral, to a future in which it is not archival but an active presence, a declaration of rights. How can this be achieved? That poem is trying to write itself at the moment, and is finding its feet, its fur, its eating-places and shitting-places. There is an obligation in how we write, and a social implication in all we write.

In the community of the poem, which is both inside the text and outside, a knowledge of species loss and its prevalence might inform an observing, interaction with and imagining of a creature (or plant) as not only at risk, and on the verge of loss, but also as a resistance to collecting, archiving and relegating. The creature isn’t “was” but “is”, always now. We, the readers and hearers, participate in the speech-making of the poem, participate in this “imagining, and acting, in a world”. There’s one biosphere of many worlds. In our writings we need to make the leaps, the segues, the conversations between the one and the many. Brushtail possum evidenced. Listen, listen — on the roof, now, tomorrow!


The ConversationThis is an edited version of a paper given at the Australian Academy of the Humanities’ 48th Annual Symposium, Humanitarianism and Human Rights, held November 15 to 17, 2017, in Western Australia. The poem A Rare Sight is from John Kinsella’s The Silo: A Pastoral Symphony (Fremantle Press, 1995).

John Kinsella, Professor of Literature and Environment, Curtin University

This article was originally published on The Conversation. Read the original article.

More sightings of an endangered species don’t always mean it’s recovering



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Leadbeater’s possum sightings are up – but that doesn’t mean the critically endangered species is recovering.
David Lindenmeyer, Author provided

David Lindenmayer, Australian National University

If more sightings of an endangered species are recorded, does that mean its numbers are increasing? Australia’s native forest logging industry is arguing yes.

On the basis of an increase in sightings of Leadbeater’s possums, advocates for Victorian native forest logging industry has proposed to downgrade the possum’s conservation status from critically endangered (thus facilitating ongoing logging in and around potential habitat in Victoria’s Central Highlands).

But while this sounds reasonable, increased sightings aren’t always a reliable measure of endangered species’ viability. Often, an increase in sightings can be attributed to two things: either more people are trying to spot the animal in question; or new work that has used different parameters to previous studies.


Read more: Victoria must stop clearfelling to save Leadbeater’s possum


Why more sightings may not mean species recovery

One of the ultimate achievements in successful conservation is to downlist a threatened species – for example from critically endangered to endangered, or from endangered to vulnerable. But this requires high-quality, long-term survey data that shows substantial recovery, as well as proof that the key threats to a species’ persistence have been truly mitigated.

An example of a failure to do due diligence was the woylie in Western Australia, (also known as the brush-tailed bettong). It was downlisted in 1996 but then within 3 years suffered an enormous and still not well understood population crash (from which it has still not recovered). Its conservation status was uplisted in 2008.

There have been more records of Leadbeater’s possum in the last few years, but this growth is most likely a function of a large increase in the amount of effort invested in trying to find them.

In areas zoned for timber harvesting, locations with a confirmed Leadbeater’s possum sighting are excluded from logging. This has motivated large numbers of people who are concerned about the plight of the possum to devote many hours to finding animals.

The detection of more animals with greater searching is a well-known phenomenon in ecology and other disciplines. Last year, for example, sightings of wild tiger populations rose by 22% – but further investigation found that the increase was most likely caused by changes in methodology and greater effort in surveying.


Read more: Australia’s species need an independent champion


In fisheries this relationship is termed catch per unit effort. For example, even with rapidly declining numbers in a fishery, the number of fish caught can stay the same or even go up when more efficient and targeted techniques are adopted. Sadly, this intensified effort can often cause fish stocks to collapse.

The real evidence on Leadbeater’s possum

As stated earlier, the first critical piece of evidence required to justify downlisting is robust evidence of long-term improvement in population size. So what does the evidence tell us about Leadbeater’s possum?

For more than 34 years, the Australian National University has monitored Leadbeater’s possum including at more than 160 permanent sites since 1997. This large-scale, long-term data set shows that the possum is in significant decline. Over the past 19 years, the number of survey sites where the possum was detected has dropped by almost two-thirds.

The second critical requirement for delisting is evidence that the key processes threatening the species have been mitigated.

One of the principal threats facing Leadbeater’s possum is the rapid ongoing decline in large old trees which are the sole form of natural nesting sites for the species.

As part of ecological surveys in the wet forests of Victoria, which have been running since 1983, the Australian National University has been collecting information on hollow-bearing trees. The most recent analysis of this large and long-term data set suggests that if current declines continue, by 2040, populations of large old trees may be less than 10% of what they were in 1997.

Another key threatening processes which has not been addressed is fire. Victoria’s wet ash forests are extremely fire prone, in part because forests that regenerate after logging are significantly more likely to burn at elevated severity.

The significant risks facing the mountain ash forests in which Leadbeater’s possum lives has resulted in the forest itself being classified as critically endangered.

No grounds for reducing the conservation status

Efforts to downlist Leadbeater’s possum are misguided at best. The greater number of records in recent years is most likely a reflection of greater survey effort. In contrast, robust long-term monitoring data clearly shows a significant decline in population.

Most importantly, the key processes causing the decline of Leadbeater’s possum (and other threatened species in the same area, like the greater glider) have not been mitigated; indeed they are intensifying (such as the increasing fire burden with increasing area of logged forest).

There is little room to gamble with these species. Leadbeater’s possum and the greater glider currently do not breed in captivity, so expensive fallback options like captive breeding and reintroduction are not viable possibilities if wild populations crash.

The loss of these animals from ill-informed downlisting would add to Australia’s already appalling record on species loss. Approximately 10% of our mammal fauna has gone extinct – the worst rate in the world, and 30 times worse than places of equivalent size, such as the United States.

The ConversationMore formally protected areas, and not downlisting their conservation status, is the most scientifically robust option for the conservation of this iconic animal.

David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University

This article was originally published on The Conversation. Read the original article.