Heating up: Why Do Flying Foxes Suffer Through Heatwaves?

A friend of mine posted on my Facebook page asking about the mass flying fox deaths we have seen across the east coast of Australia (and in South Australia) in the past month or so. This is not an uncommon occurrence, particularly in south east Queensland, where the weather is known to maintain high temperatures for long periods of time. I had a bit of prior knowledge on this subject, as a previous Brisbane resident for around seven years, but when I was asked ‘what happened? why? and what can we do about it?’ I wanted to delve a little deeper into peer reviewed articles that address issues of mass death in flying foxes due to heatwaves.

What Happened?

During the last couple of weeks, heatwaves have hit the east coast, toasting the cities of Brisbane, Sydney and Canberra. Luckily in Melbourne, we missed the majority of the heat, but as typical South Australian weather dictates, Adelaide also succumbed to these ultra-sweaty weather events. The Bureau of Meteorology recorded extreme temperatures across the east coast (NSW, south east Queensland, ACT) frequenting the high 30s and reaching the early to mid 40s for days at a time. In this time, tens of thousands of bats were recorded as ‘dropping out of the trees’, with mass flying fox deaths recorded across the country.

It is not just a single species being affected; there are a number of species identified as being particularly at risk from these types of events. The ones we usually hear about are the grey-headed flying fox (Pteropus poliocephalus) and the spectacled flying fox (Pteropus conspicillatus) which are both listed as vulnerable under the EPBC Act(1999). The two more common species are the black flying fox (Pteropus alecto) and the little red flying fox (Pteropus scapulatus), both of which are listed as least concern. These ‘megabat’ species suffer equally from extreme heatwave events – But  why are we seeing such intense heatwaves?


Grey-headed flying fox (Photo: Australian Mammal Learning Zone)


Locally, we can recognise effects such as the urban heat island effect (Manley 1958). This is a well recognised phenomenon where densely urbanised landscapes significantly affect the local climate, with the most recognised of these effects being increased temperature on hot days. Cities can reach up to 12 degrees higher than surrounding rural landscape (Oke 1979; Landsberg 1981), which can seriously affect the geographic distribution of plants and animals, as well as the behaviour of certain animals (Parris and Hazell 2005). Melbourne city has been estimated has averaging approximately 8 degrees higher than the surrounding area (VBC 2017), just as a local example. The loss of vegetation cover and the increase in heat-retentive concrete and bitumen combines to create a potentially devastating increase in temperature, particularly for animals with specific requirements or low tolerances. The lack of flying fox-preferred trees is another concern that is seriously affecting the persistence of these animals within our cities. An increase in human facilities will almost always come at a cost to remnant vegetation, particularly native forest, which has all but disappeared within intensely urban areas. This lack of resources and habitat has had a significant effect on bats worldwide, including here in Australia.

A Conversation article by  Welbergen, Booth and Martin (2014) discusses a particular behavioural trait which may explain why flying foxes tend to suffer greatly during heatwave events. The tendency for flying foxes to stay in roosts, and in groups, is a survival behaviour which would normally be advantageous to an individual’s survival. Unfortunately, when the flying foxes display this behaviour during a heatwave, it results in whole colonies dying, rather than finding shelter out of the sun. Of course, flying foxes are not the only animal that suffers mass casualties during these unprecedented heatwave events; examples of other animals are also linked in the Conversation article, so go and have a look if you are interested.

The overarching explanation of why these mass deaths occur is the elephant in the room; climate change. As most people are now aware, but I will reiterate here anyway, climate change encompasses far more than the typical ‘global warming’ we tend to associate with when hearing the term (hence why the name ‘global warming’ is no longer recognised as accurate). Climate change typically sees the significant increase in extreme weather events, including blizzards, heatwaves, floods and fires, among other weather phenomena. The increase in intense heatwave events is just one consequence we are seeing in Australia. The general consensus is that maximum temperatures and the frequency, intensity and duration of extreme heatwaves are set to increase (Welbergen et al. 2008, IPCC 2007). We are far more likely to see mass heatwave-related deaths of many species, particularly avian species (McKechnie and Wolf 2009). Unfortunately for them, flying foxes are one of the many ‘canaries in the coal mine’. The positive side of which is that the sensitivity of flying foxes to heatwave events can provide scientists with information on climate and weather events, by serving as bioindicator species. This also provides an opportunity for scientists to investigate how we may prevent these mass heatwave deaths into the future.

What can we do about it?

Even with events this seemingly widespread and catastrophic, there is always something everyone can do to support wildlife during heatwaves. As for flying foxes, there are some small things, and some not-so-small things we can all do to prevent the loss of these exceptionally important animals.

Flying foxes are critically important to a variety of ecosystems, particularly because they are highly mobile pollinators. Many fruits, in particular, are bat-pollinated and would not exist without the natural skill of flying foxes. It is in our own best interest to support flying fox colonies by establishing native gardens, particularly large native trees (if your property allows it). The increase in vegetation within our cities will be critical in combating the heat island effect, whether it be grass, shrubs or eucalyptus – any vegetation is better than none at all. More so than this, large native trees provide habitat and resources for flying foxes (amongst many other native animals). So if you are considering planting a garden, or renovating your existing one – think native! Some people may not want to encourage a colony of native bats onto their property, so alternatives to this may include assisting community groups to revegetate public areas, or writing to your local Minister and encourage them to increase the amount of native greenspace in your local area. Re-establishing flying fox habitat will help to support these fantastic animals, as well as kickstart cooling in your city.

There are a number of other contributions you can make to assist flying foxes, such as supporting positive State and Federal legislation which protects flying foxes, while if you find yourself in the company of one too many flying foxes at your orchard, garden or property, there are appropriate ways of dealing with flying fox colonies peacefully and respectfully. During heatwave days, it is difficult to provide much immediate assistance for flying fox colonies, but you can always try heading outside and watering them down! Seriously though, make sure you leave plenty of water out on hot days, not just for flying foxes, but for other wildlife.

The ultimate gift you may give your resident flying foxes is to become a carer with a wildlife organisation. All States will have a wildlife carer training program, which will equip you with the skills to care for animals that have been injured or displaced. Many States have very limited carers, and the less cuddly species such as flying foxes and reptiles are often the least staffed. Organisations such as WIRES (NSW), Wildlife ACT and wildlife Victoria will have regular training sessions where you can become a carer if you have the spare time. Of course, being a bat carer also requires a significant number of vaccinations, so keep this in mind if you are going to volunteer -but you only have to take a look at the Bats QLD Facebook page to see how rewarding this role is. Alternatively, there are a number of Bat Caring organisations you can donate to – I am sure you can google some in your area.

I hope this has provided you all with a little background information into one of the saddest events we see during extreme heat days, and has given you all a little confidence to give some of your time, effort, money or outdoor space to helping prevent heatwave deaths in the future. If we all contribute a little, there is nothing we can’t achieve.

Dr Mel.

Featured image: Buzzfeed Australia


Environmental Protection and Biodiversity Act (EPBC) (1999). http://www.environment.gov.au/epbc.

Intergovernmental Panel on Climate Change (IPCC) (2007). http://www.ipcc.ch.

Landsberg, H. (Ed.), 1981. The Urban Climate. International Geophysics Series, vol. 28. Academic Press, New York.

Manley, G., 1958. On the frequency of snowfall in metropolitan
England. Quarterly Journal of the Royal Meteorological Society
84, 70–72.

Oke, T.R., 1979. Review of urban climatology, 1973–1976. World Meteorological Organization Technical Note No. 169. Secretariat of the World Meteorological Organization, Geneva.

McKechnie, A.E. and Wolf, B.O. (2009). Climate change increases the likelihood of catastrophic avian mortality events during extreme heat waves. Biology letters. Available at: http://rsbl.royalsocietypublishing.org/content/6/2/253.short.

Parris, K.M. and Hazell, D.L. (2005) Biotic effects of climate change in urban environments: The case of the grey-headed flying-fox (Pteropus polopcephalus) in Melbourne, Australia. Biological Conservation, 267-276.

Victorian Biodiversity Conference (VBC) (2017).

Welbergen, J.A., Klose, S.M., Markus, N. and Eby, P. (2008) Climate change and the effects of temperature extremes on Australian Flying-foxes. Proceedings of the Royal Society, B, 419-425.

Welbergen, J., Booth, C. and Martin, J. (2014). Killer Climate: Tens of thousands of flying foxes dead in a day. Available at: http://theconversation.com/killer-climate-tens-of-thousands-of-flying-foxes-dead-in-a-day-23227

The Origin of Evolution Theory

I started writing a different post this morning, one that highlighted some of my own research, but I realised a paragraph and a half into my post that it wasn’t going to happen for me today – so you will have to wait for that one. In the mean time, it was Charles Darwin’s birthday yesterday (in UK time, the day before here in Australia), and seeing as I said I would introduce you to some of the great scientists of the world, it seems only fitting to begin with a man whose legacy is now larger than life. This is less a scientific piece and more of an admiration/reflection, but I hope you enjoy it anyway.

“When on board the H.M.S. Beagle, as a naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and the geological relationships of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species – that mystery of mysteries, as it has been called by one of our greatest philosophers. On my return home, it occurred to me, in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it.” – Charles Darwin, 1859.

This is the introduction to one of the world’s most influential, and indeed most controversial, books of all time. Darwin’s ‘On the Origin of Species by Means of Natural Selection: or, the Preservation of Favoured Races in the Struggle for Life’ – now known simply as ‘The Origin of Species’ transformed our understanding of life on Earth, and established the foundation of evolutionary theory. In 2015 I was lucky enough to partake in the Charles Darwin Scholarship Programme in the UK, which allowed me to visit many places which were key to the creation of The Origin of Species, but also gave me the opportunity to learn about Darwin the way most other people cannot.

On the Origin of Species

Darwin was a true academic and natural philosopher. Coming from a wealthy family he was gifted with a vast amount of property and inheritance, which allowed him to spend much of his time deliberating, arguing and grappling with his ideas, rather than adopting what we would classify now as a ‘job’. From my visit to Shrewsbury, England, it was clear to me that Darwin had somewhat of an enchanted childhood. His family home, The Mont, was littered with exotic plants his father and grandfather had collected from across the globe, while his home backed onto the River Severn (and still does), surrounded by forest, grass paddocks and an incredible view from the top of Shrewsbury. Exploring around his father’s property seemed to spark his interest in the natural world.

I won’t cover much biographical information here, because you can read that on other sites, but just quickly – Darwin dropped out of medical school and instead went on to study at Christ’s College, under the guidance of his father who encouraged him to become a parson. This is where he met his mentor John Stephens Henslow, who recommended he accompany Captain Robert Fitzroy on a five year journey aboard the HMS Beagle. Infamously, this is the trip that cemented Darwin’s interest in what is now evolutionary theory, but there are some misconceptions about how his theories formed – the most persistent of which is the story of the finches. It is a broad misconception that the finches served as Darwin’s ‘aha!’ moment (aha! in this case meaning the point of revelation or epiphany; a celebrated science term, of course). The Finches were undoubtedly an interest of Darwin’s, but far more of his theories and keen interest arose from studying bivalves, geology, fossils and grass (I will revisit this last one in a moment). By the time Darwin’s finch analysing days had begun, his theories on evolution and natural selection were already forming. His collection and study of finches provided further evidence to his theories of natural selection, but were not the smoking gun, as we are often told today. (Pers. comm. Museum of Natural History, London).

Many of Darwin’s collections still reside at the Museum of Natural History in London, where I was lucky enough to visit ‘backstage’ and see his personal collections. One of my favourite stories, told by a museum collections officer, was of the near loss of the Darwin collection during World War 2. During the War, the museum was bombed, and consequently many collections were decimated. The story goes, however, that the Darwin collection was sitting in a stairwell in the museum, awaiting cataloguing and storage when the bombs fell. The strength of the stairwell saved the majority of the Darwin Collection, which we would not have today if someone was more diligent!

The Grass Paddock

One of my favourite moments from my Darwin trip was my visit to Down House to see Darwin’s Thinking Path (the path he walked every day), as well as a big, empty grass paddock. These two things may not seem equally glorious, but let me assure you, I have a selfie with each of them, and I hold them to equal esteem. One of Darwin’s most indisputable collections of evidence to support his theories came from studying the grass paddock across the way from Down House, which he walked past every day when visiting his Thinking Path. He could easily study sections of the grass, recognising that the species richness and abundance of identifiable grasses within certain plots would change often, depending on certain pressures. Darwin spent much of his time intently studying the grass within his plots, which provided substantial evidence for natural selection and succession theory, which was critical to the production of his work.

Natural Selection and God

One of the most important aspects of The Origin of Species that many people forget today, is that it took Darwin over 20 years to publish. Apart from taking many years to collect specimens, collate ideas and communicate with his peers, Darwin also struggled substantially with the conflicting nature of his theory of evolution and his identity as a Christian. More so than this, he struggled with the devout nature of his wife, Emma’s dedication to the Church; he was acutely aware of upsetting her, and damaging their reputations in the broader community. One can only imagine the inner conflict that plagued Darwin during this period, but interestingly enough, it was not solely his dedication to his scientific theories that deteriorated, and eventually ended, his Christian identity. While I was in Down House in Kent, not far from London, we heard countless stories from Darwin’s personal life. One of these stories was that of the death of his youngest daughter, Anne. With the passing of Anne, Darwin began to question the legitimacy of a God who would not protect his young child, and ultimately, the grief and anger Darwin felt at the loss of his daughter shredded his faith in God.

The impact of the role of Church and God in Darwin’s life severely bridled the progress of The Origin of Species and the associated theories of evolution by natural selection, particularly when Darwin suggests that apes and people share a common ancestor. It is incredible (to me, at least) to think that this book, which was labelled as inflammatory and deceptive over 150 years ago is still hotly debated and despised in certain parts of today’s community. There are still many religious spokespeople and interest groups, as well as media outlets and organisations who vehemently depose modern evolutionary theory, and often Darwin is blamed. Recently, the current Pope has recognised that evolution is indisputable, though with some notable entanglements with theology. Throughout my posts I will certainly attempt to stay objective about my subject matter, however in some instances I will share my appreciation for certain aspects, and this is certainly one of them. The consolidation between church and science, particularly one that can integrate science into the deep values and beliefs of the religious community, I feel can only be a positive thing.

Alfred Russell Wallace

This aspect of Darwin’s story is perhaps the most debated. One of the stories I was lucky enough to hear while in the UK, came from Darwin’s Great Great Great Grandson (or F4 in his words – genetics joke!) Randal Keynes. The stories surrounding Alfred Russell Wallace vary widely, from Wallace being the first to unravel the origin of species, to being a vicious rival of Darwin’s – racing to complete their manuscripts. Alternatively, you can believe the story we heard from Randal, which seems to hold a little more substance, and certainly more heart than the bitter rivals story. Wallace held Darwin in the highest esteem, which I believe is a notable truth from the many correspondence they shared. It is also recorded that Wallace and Darwin both exchanged ideas and theories  (along with a man called Huxley) while establishing their theories of natural selection together, as well as jointly submitting a tremendous amount of notes and records on the evidence they had collected to support their theory. In the end, it was told to me, Wallace insisted that Darwin submit his manuscript of The Origin of Species to the Academy of Science, as Wallace’s admiration for Darwin outweighed his hunger for scientific and academic kudos. So perhaps all those people who argue that Darwin stole Wallace’s limelight have a point – but in reality, Darwin and Wallace were very close friends. Wallace seems to have been a gentleman in the highest order, and perhaps my Eastern long neck turtle Charlie (Charles!) should have been called Wallace. But I can guarantee that the very next turtle I adopt will certainly be called Wallace, because Darwin without Wallace is no Darwin at all.

Throughout this enormous musing, I assume you have noted my admiration and scientific ‘soft spot’ for Charles Darwin, the father of modern evolution theory. He was a naturalist in the purest sense of the word, in that he could find inspiration from many aspects of his life, and accumulated and devised tremendous thoughts through interacting with the natural world. He was also a dignified and careful scientist, who methodically collected data and observations to carefully craft his theories. He may not have correctly predicted every aspect of evolution (natural selection for example), which we are now coming to recognise, but he certainly blazed a fantastic trail to follow. One of my favourite concepts to consider when thinking about evolution and the theory of natural selection is the concept of chance and the role of chaos, probability and mutation in evolution. This concept is discussed eloquently by my absolute favourite Scientist Dr Greg Graffin, but that is a post for another day.

If you are interested in a little clever writing, I found this google book in my travels this morning. It is on my ‘to read’ list, and from the little I have read, it seems clever. Have a look at Dear Mr Darwin, and see what you think.

Dr Mel.


Natural History Museum Staff, London.
Encyclopaedia Britannica.
Down House and The Mount Staff and Historians.
Mr Randal Keynes.

Standing on the Feat of Giants

As WordPress very clearly points out to me, this is my first Blog post. Ever. So I will start by introducing myself, and then share an experience that I never expected to have (and how it ended up in me getting a WordPress blog). I tend to hate long blog posts, however (particularly the recipe ones), so I will make this as short as I can.

My name is Mel, I am a newly graduated Doctor of Ecology; I have a wonderful partner, a dog called Indiana and watch a (possibly) unhealthy amount of How I met your Mother. I have a deep passion for conservation, advocacy and ecological science which I hope to apply as a postdoctoral researcher here in Melbourne – my new home town as of six months ago. I have been officially thesis free for four months now, and the lack of research-based (or in fact, environment-based) jobs in Australia’s market at the moment is disheartening for an eager, job-seeking, newly-doctored ex PhD student. So in between cleaning up after a six month old puppy and being not very good at Star Wars themed cross stitch, I have been, up to now, failing to find a suitable job.

Which brings me to last night; the night I managed to fulfil a life-long dream I assumed would never come to fruition. I saw Sir David Attenborough. In real life. It was a surreal experience, particularly as the lights went out and the stage lit up. A single man stood centre stage and the crowd erupted. As an avid punk music fan, I have been to my fair share of gigs, but the noise that followed the appearance of Sir David on stage was unrivalled by any performance I have been to. An immediate standing ovation accompanied a deafening noise; the kind of noise where your ears start to not hear sounds anymore, and just hear loud. This one man who has not just touched, but transformed the world, along with literally millions of lives just like mine.

Over three hours, Sir David regaled the audience with stories from decades of exploration; from his early days as assistant to a museum collector, to working with countless film makers and visual/audio talents to produce documentaries as groundbreaking as Planet Earth. One story I remember was when Sir David recounted the night that the presenter for Zoo Quest (the show that saw the birth of his 60+ year career) fell ill, and was to be replaced by an inexperienced sound technician called David Attenborough. He was later recognised on the streets of London by a bus driver who had watched the show the night before and the rest, as they say, is history. Sir David Attenborough, the God-like naturalist and global-phenomenon documentary maker had been discovered by accident. Moreover, he was in his thirties before anyone truly recognised his ability to mesmerise audiences with his dapper charm, quick wit and infectious love of the natural world. It was at this point that I realised, there is no official timeline for success (which is far too personal to let anyone else define for you, at any rate). But furthermore, it was very unlikely that a London bus driver would ever lean out his window and recognise my talent for communicating about the natural world – and not just because I don’t live in London. It is often difficult to find the motivation to continue on in a career when you have not managed to break into it yet – particularly when it is as competitive as early career research. However, self motivation was the only thing that would help me find my career path – and I realised that, to be discovered by accident, I had to dedicate myself to making it happen.

It was between this moment of being in the same room as Sir David, and hearing him tell 4,999 other people that he, his crew and his success needed scientists (just like me) to achieve what he achieved. People. like. me. Thanks to my 90 year old hero, I had rediscovered my drive to ensuring my dream comes true, and that I really become an indispensable ecologist. A scientist without whom people like Sir David could not achieve what they do.

At this point I should probably mention, my friend Dr Kylie Soanes (from the University of Melbourne). She has a facebook page, as well as a website that I encourage you to look at – these also played a big part in encouraging me to start this journey – partly to improve my online and science communication, but also to promote easily understood science, particularly natural science, that can be read, discussed and debated by everyone.

This website will be a challenge – an exciting challenge – that I have now committed myself to for one year. Within it I will be sharing posts on conservation, advocacy, climate change and wildlife ecology for the majority of the time. I will also be covering physical and chemical sciences (when I have the cranial capacity!), politically-tainted science, women in science, as well as discussing and introducing the giants (and not-yet so giants) of science world wide. I am excited to stand on the feat(s) of giants for the next year, as well as establishing some feats of my own – and hopefully in the mean time I can share, discuss, debate and talk a little wild science with you.

Talk wild science with me.

Dr Mel.