Five years ago we launched in Australia a new public-good journalism project. We aimed to replace the increasingly vapid media offerings with a rich new service. Our editors worked to turn the university into a giant Newsroom full of experts who would write with authority borne of deep research and understanding.
Able to explain better and make sense. Offering evidence in place of ideology. Able to correct falsehoods with facts. With a total commitment to transparency, high editorial standards and a Charter to deliver a service that is reliable, credible and worthy of your trust.
It’s an Australian idea that’s gone global with a Newsroom with 100 staff in Australia, UK, US, France and Africa working with 32,000 researchers and scholars from 1,500 universities and research institutes. With more to come.
Our content reaches 3 million users (unique visitors) a month direct to our website while a further 30 million read our copy through the 22,000 websites globally that carry our copy under Creative Commons.
This is dissemination of knowledge on a scale never previously achieved. And since we are committed to equitable access to information, we don’t charge. Our information richness is there for all to share.
In concert with our global university partners we seek nothing less than a better informed world. Able to share the fruits of research and innovation to offer solutions to the world’s increasingly complex problems.
Although we are five years old in Australia (though our other TCs much younger) we’ve barely got started. We’ve got much more planned. But today we salute again our Australian university partners, our strategic partners and you our readers.
PS: If you are in Melbourne on the night of April 7 we have reserved 10 tickets for readers to attend our birthday bash. Enter your name here and we’ll let you know if you’re going to the party.
The fight against antibiotic-resistant bacteria – so-called “superbugs” – is a huge challenge, one that the World Health Organization has described as a grave global problem.
When superbugs hit the headlines it’s often because of hospital outbreaks, such as the outbreak of Vancomycin Resistant Enterococcus that infected babies in Melbourne in 2013. Yet the problem isn’t confined to hospitals – the wider environment can be important in the development and spread of these bugs, and people can be infected through food and water.
The problem of antibiotic resistance is being exacerbated worldwide by the pollution of waste water with leftover drugs, providing breeding grounds for resistant bacteria and their genes. The problem can persist for years, constantly refreshed by new discharges of both drugs and of resistant bacteria themselves, shed by people and animals.
The fact that penicillin was found in soldiers’ urine in the second world war was, in hindsight, an early indication that antibiotics are present in waste water, and that drugs like this might go on to have an afterlife in streams, lakes and other waterways, clinging to sediment particles and upsetting the delicate bacterial balances in soils and aquatic ecosystems.
But no-one gave the issue much thought until chance intervened in 1992, when German scientists looking for herbicides in rivers, groundwater and lakes stumbled across a chemical they didn’t recognise – it turned out to be the cholesterol-lowering drug clofibrate, a cousin of the weedkiller 2-4-D.
No end of pharmaceutical pollution has since been found in the world’s water – analgesics, antibiotics, lipid regulators, antiseptics, beta-blockers, contraceptive hormones, anticonvulsants and X-ray contrast agents. Detectable levels of clofibrate alone are now found throughout the North Sea.
We now know that partially degraded drugs and ointments can be converted back into their active form through chemical reactions once you’ve said goodbye to them in the loo or shower. Many biodegrade, but others can be very persistent in their new environmental home.
Water treatment plants are thus the last barrier to drug residues and other synthetic chemicals being set loose into soils and waterways (meanwhile, there is no barrier at all for freely administered livestock drugs such as the antibiotics sulphasalazine and oxytetracycline).
Crucial treatment
Treatment plants’ ability to strip out waste drugs varies enormously according to age, level of expertise and design standard. Even the best ones don’t remove all foreign chemicals. Advanced treatment processes are designed more for removing pathogens than for breaking down molecules, although chlorination and what’s known in the trade as “ozonation” do have some ability to change the chemistry of drug molecules (to exactly what is unclear).
As the use of recycled water increases, the quality of this water becomes more critical and good management of all sewer inputs by water companies becomes more important. Thus, pharmaceuticals are being identified as a potential risk in recycled water risk-management systems of utilities such as South East Water in Melbourne, Orange County Sanitation District in California, and Singapore’s NEWater scheme.
This is leading to an increased awareness of the waste contributions from domestic catchments and high-concentration point sources such as hospitals.
It is time for the health and water industries to strike a bargain. Health professionals need to be aware of the need for pharmaceuticals to be managed as organic and persistent pollutants. They can help the water treatment industry by being aware of what their activities are putting into the sewerage and waste disposal systems, in view of the limited extent to which these systems can deal with the large number of drugs that are stable. They should consider prescribing less toxic, less environmentally persistent, but equally effective drugs where possible, as well as trying to reduce overall drug use in the community.
Meanwhile, Australia should build on its reputation for innovation in water management by addressing this health issue. Tackling hot spots in “source control” such as hospitals and clinics could make significant inroads on the amount of waste drugs entering treatment plants. Treatment at source may be preferable to facing increased trade waste charges by utilities if they deem hospital wastewater inputs to be problematic. Water firms should discourage hospital staff from emptying half-empty syringes into wash basins (which is probably common despite being against protocols) should also be discouraged. Rubbish disposal systems that minimise medicines ending up in landfill are another must.
The water industry should to ensure that treatment plants are operating under optimal conditions and that the older ones are either replaced or upgraded. Where appropriate, the industry could also help hospitals with in-house waste treatment, and suggest ways for householders to dispose of unwanted drugs – perhaps along the lines of Orange County’s No Drugs Down the Drain” campaign.
The search for new antibiotics to beat superantibiotics goes on. The discovery of one of the very few new candidate antibiotics in the past 30 years, teixobactin, while encouraging, is no cause for complacency.
This article was co-authored by David Smith, water quality manager for South East Water, Melbourne.
Recently released government figures show levels of childhood vaccination have fallen to dangerously low levels in some areas of Australia, resulting in some corners of the media claiming re-ignition of “the vaccine debate”.
Well, scientifically, there’s no debate. In combination with clean water and sanitation, vaccines are one of the most effective public health measures ever introduced, saving millions of lives every year.
Those who claim there is a “debate” will cite a series of canards designed to scare people away from vaccinating, but, if you’re not familiar with their claims, you could easily be convinced by anti-vaccine rhetoric.
So what is true and what is not?
Let’s address just a few of the common vaccine myths and explain why they’re wrong.
1. Vaccines cause autism
The myth that vaccines are somehow linked to autism is an unsinkable rubber duck. Initiated in 1998 following the publication of the now notorious Lancet paper, (not-a-Dr) Andrew Wakefield was the first to suggest that the measles mumps rubella (MMR) vaccine might be linked to autism.
What he didn’t reveal was that he had multiple conflicts of interest including that he was being paid by lawyers assembling a class action against the manufacturers of MMR, and that he himself had submitted an application for a patent for a single measles vaccine.
It eventually unravelled for Wakefield when the paper was retracted in 2010. He was struck from the medical register for behaviour classified as “dishonest, unethical and callous” and the British Medical Journal accused him of deliberate fraud.
But once the idea was floated, scientists were compelled to investigate, particularly when it stood to impact public health so dramatically. One of the most powerful pieces of evidence to show that there is no link between vaccines and autism comes from Japan where the MMR was replaced with single vaccines mid-1993. Guess what happened? Autism continued to rise.
We currently don’t know what causes autism. But we do know what doesn’t: vaccines. Image from shutterstock.com
After this door closed, anti-vaxers shifted the blame to thiomersal, a mercury-containing component (not be confused with the scary type that accumulates in the body). Small amounts of thiomersal were used as a preservative in some vaccines, but this never included MMR.
Thiomersal or ethyl-mercury was removed from all scheduled childhood vaccines in 2000, so if it were contributing to rising cases of autism, you would expect a dramatic drop following its removal. Instead, like the MMR in Japan, the opposite happened, and autism continues to rise.
Further evidence comes from a recently published exhaustive review examining 12,000 research articles covering eight different vaccines which also concluded there was no link between vaccines and autism.
Yet the myth persists and probably for several reasons, one being that the time of diagnosis for autism coincides with kids receiving several vaccinations and also, we currently don’t know what causes autism. But we do know what doesn’t, and that’s vaccines.
2. Smallpox and polio have disappeared so there’s no need to vaccinate anymore
It’s precisely because of vaccines that diseases such as smallpox have disappeared.
India recently experienced two years without a single case of polio because of a concerted vaccination campaign.
Australia was declared measles-free in 2005 by the World Health Organization (WHO) – before we stopped being so vigilant about vaccinating and outbreaks began to reappear.
The impact of vaccine complacency can be observed in the current measles epidemic in Wales where there are now over 800 cases and one death, and many people presenting are of the age who missed out on MMR vaccination following the Wakefield scare.
In many ways, vaccines are a victim of their own success, leading us to forget just how debilitating preventable diseases can be – not seeing kids in calipers or hospital wards full of iron lungs means we forget just how serious these diseases can be.
3. More vaccinated people get the disease than the unvaccinated
Although this sounds counter-intuitive, it’s actually true, but it doesn’t mean that vaccines don’t work as anti-vaxers will conflate. Remember that no vaccine is 100% effective and vaccines are not a force field. So while it’s still possible to get the disease you’ve been vaccinated against, disease severity and duration will be reduced.
Those who are vaccinated have fewer complications than people who aren’t. Image from shutterstock.com
With pertussis (whooping cough), for example, severe complications such as pneumonia and encephalitis (brain inflammation) occur almost exclusively in the unvaccinated.
So since the majority of the population is vaccinated, it follows that most people who get a particular disease will be vaccinated, but critically, they will suffer fewer complications and long-term effects than those who are completely unprotected.
4. My unvaccinated child should be of no concern to your vaccinated one
Vaccination is not just a personal issue, it’s a community responsibility, largely because of a concept known as “community immunity”. This describes a level of vaccination that prevents epidemics or outbreaks from taking hold and spreading.
Some people question the validity of this concept, sometimes referred to as herd immunity, but the impact of it breaking down can be easily observed in places where vaccination levels fall dangerously low – take the current measles outbreak in Wales, for example.
The other important factor about community immunity is it protects those who, for whatever reason, can’t be vaccinated or are not fully vaccinated. This includes very young children, immunocompromised people (such as cancer sufferers) and elderly people.
5. Vaccines contain toxins
A cursory search of Google for vaccine ingredients pulls up a mishmash of scary-sounding ingredients that to the uninitiated can sound like “franken-science”.
Some of these claims are patently untrue (there is no anti-freeze in vaccines), or are simple scaremongering (aborted foetuses – in the 1960s some cells were extracted from a foetus to establish a cell line that is still used in labs today). Some of the claimed chemicals (and remember everything is made of chemicals) are present, but are at such low levels as to never reach toxicity.
A pear has 600 times more formaldehyde than a vaccine. Image from shutterstock.com
The simple thing to remember is the poison is in the dose – in high enough doses even water can kill you. And there’s 600 times more formaldehyde in a pear than a vaccine.
Also, if you ever read the claim that “vaccines are injected directly into the blood stream” (they’re not), be sceptical of any other claims made.
6. Vaccines will overwhelm kids’ undeveloped immune systems
The concept of “too many too soon” was recently examined in a detailed analysis of the US childhood immunisation schedule by The Institute of Medicine. Experts specifically looked for evidence that vaccination was linked to “autoimmune diseases, asthma, hypersensitivity, seizures, child developmental disorders, learning or developmental disorders, or attention deficit or disruptive disorders”, including autism. The researchers confirmed that the childhood vaccination schedule was safe.
The amount of immune challenges that children fight every day (between 2,000 to 6,000) in the environment is significantly greater than the number of antigens or reactive particles in all their vaccinations combined (about 150 for the entire vaccination schedule).
So the next time you hear these myths about vaccination, hopefully you’ll have some evidence up your sleeve to debunk them.
This month is a great time to catch Jupiter shining brilliantly in the evening sky. And for the next few weeks it will be its best and brightest for the year.
The planet reaches opposition at 5:09am on Saturday morning, February 7 (AEDT). At that time, the sun is located on one side of the Earth and Jupiter is found directly opposite, on the other side of the Earth.
This positions Jupiter opposite the sun and on the the night-side of the Earth. Hence, the planet rises as the sun sets, is overhead around midnight (when the sun is directly below us) and sets as the sun rises. But not only do we get to see Jupiter all night long, we also see it at its brightest.
Being the largest planet, Jupiter is always easy to see. It is only rivalled by Venus, which is brighter than Jupiter because it is much closer and its thick atmosphere reflects sunlight really well.
But around the time of opposition Jupiter really dazzles. This is because, with both Earth and Jupiter located on the same side of the sun, the two planets are closest together for the year. This year they will be separated by 650-million km.
By August, Earth will have swung around the sun, but Jupiter won’t have moved that far. This will bring Jupiter into solar conjunction.The two planets will be found on opposite sides of the solar system, taking them furthest apart for the year. At that time the distance between them will be almost 960-million km. And of course, we won’t see Jupiter because it will appear with the sun in the daytime sky.
Not all oppositions are created equal.
The best oppositions occur when Jupiter is near perihelion or closest to the sun. It makes sense, because if Jupiter is slightly closer to the sun, then opposition will also bring the planet a little closer to Earth.
Jupiter’s last perihelion passage was in March 2011 and the next will be in January 2023, in step with its 11.9 year orbit.
So for the next few years, oppositions aren’t as favourable as they could be. But don’t let this put you off. Look towards the north-east in the evening and it’s a beautiful sight to see Jupiter shining so brightly.
Jupiter is easily the brightest object in the north-eastern sky at sunset. Source: Museum Victoria/Stellarium
It’s also really easy to notice that Jupiter’s light is much steadier than the light from any nearby stars. Jupiter’s increased angular size makes it less susceptible to turbulence in our atmosphere. Or in other words, stars twinkle easily, but planets don’t.
Moon shadows
We now know of 67 moons orbiting Jupiter, but the planet’s four largest moons – Io, Europa, Ganymede and Callisto – are worlds in their own right. They are easily seen in a good pair of binoculars or a small telescope, as tiny star-like objects, strung in a line that can cross either side of Jupiter.
On January 23, the Hubble Space Telescope (HST) captured a rare triple transit shadow – the shadows of Europa, Callisto and Io were seen moving across the surface of Jupiter.
Triple transit shadows can only occur if Callisto is one of the moons involved. This is because, Io, Europa and Ganymede – which all orbit closer to Jupiter than Callisto – are locked in a 1:2:4 orbital resonance. Hence, it is impossible to have all three moons suitably positioned together.
However, there is a problem with needing Callisto for a triple transit. Callisto’s orbit is slightly tilted so that a lot of the time its shadow misses the planet. Shadow transits of Callisto occur in seasons – the current one began in 2013 and will continue until 2016. A list of shadow transits can be found here, although currently they favour North America and are not visible across Australia.
Eclipses and Occultations
What’s more, this triple shadow transit occurred during a period when the Earth and sun are crossing Jupiter’s equatorial plane. This occurs, about every five to six years and during this time Jupiter’s moons can appear to overlap one another.
Sometimes an eclipse is produced when the shadow of one moon passes across another. At other times, the line-up causes an occultation when one moon passes in front of another and obscures it from sight.
Io lines up with Callisto’s shadow. Source: NASA, ESA, Hubble Heritage Team
Just before the HST began observing the triple shadow transit, Io had been eclipsed by Callisto. The first image taken by the telescope shows Io just after it has moved out of Callisto’s shadow.
It’s always interesting to follow the changing positions of Jupiter’s moons through a telescope. I like to imagine what it must have been like for Galileo, as he tracked the moons for the very first time.
On early Saturday morning, around the time of opposition, Europa and Ganymede will be very close together. Europa is set to occult Ganymede (or move in front of it) around 6am (AEDT).
Jupiter’s largest moons appear as four tiny points of light through a telescope. On Saturday morning Europa will pass by Ganymede as shown in the close up on the right. Source: Museum Victoria/Starry Night
The Institute of Celestial Mechanics and Calculation of Ephemerides, in Paris, runs an international campaign to collect data obtained by amateur astronomers during occultations and eclipses of Jupiter’s moons. The observations are used to track how the orbits of Jupiter’s moons are slowly changing over time, as the moons interact gravitationally with each other and Jupiter.
Western Australia’s marine environment is unique. Two world heritage areas, the largest fringing coral reef in Australia, and more than a thousand kilometres of underwater forests, supporting incredible wildlife, important fisheries, and tourism.
But these precious habitats were decimated in 2011 by a record-breaking marine heatwave, with temperatures rising more than 2°C above normal for ten weeks. The culprit: warm water pushed south by the same La Niña event that caused devastating flooding in Queensland.
Research released this week shows the oceans are continuing to warm steadily despite an a slowdown in the rate of warming at the earth’s surface, increasing the likelihood of extreme heat undersea.
Sadly, these changes could spell the end for large swathes of Western Australia’s underwater forests and much of the marine life that depends on them for food and shelter.
WA’s extreme marine heatwave
La Niña refers to the positive phase of the El Niño–Southern Oscillation (ENSO) climate pattern, which brings cyclones, rain and floods to southeast Asia and Australia. While the devastating impacts of such extreme weather is clearly visible on land, many are unaware of the similarly destructive consequences under water.
The diverse, expansive marine ecosystems along the vast coastline off Western Australia are no strangers to the devastating impacts of La Niña events. In 2011, strong La Niña conditions increased the southward flow of the Leeuwin Current, which pushed warm water from the tropics into cooler temperate latitudes.
At the same time, winds were calmer than normal resulting in unusually high transfer of heat from the air into the upper layers of the ocean. The outcome was an unprecedented marine heatwave which affected more than 2,000 km of the west Australian coastline from north of Ningaloo Reef to Cape Leeuwin on the southwestern corner of the continent. Water temperatures soared past anything recorded for at least 140 years.
Ocean temperatures measured by loggers off Perth, at 10m depth where the seaweed forests are found a) and Sea Surface Temperature anomalies (relative to 1971-2000) measured by satellites throughout Australia during March 2011, the peak of the marine heatwave b). Sources: Thomas Wernberg a) Thomas Wernberg/NASA b)
Climate variability driven by El Niño and La Niña is a natural phenomenon that has influenced Earth’s ecosystems for millennia. However, the recent modelling experiments, which are the most sophisticated to date, suggest that anthropogenic climate change will intensify extreme climate variability driven by El Niño and La Niña events.
The projected increased frequency of extreme La Niñas, from an average of once every 23 years to once every 13 years, will mean that temperate marine ecosystems will have less time to recover in between periods of excessive temperatures.
King hit: the unique west
The west Australian marine environment is unique by global standards. It hosts two World Heritage areas – Ningaloo Reef, Australia’s largest fringing coral reef; and Shark Bay, home to extensive seagrass meadows, turtles, sharks and dugongs.
Seagrass meadows and seaweed forests also fringe more than 1,000 km of coastline from Ningaloo Reef and south to Cape Leeuwin. These underwater forests harbour some of the highest diversity of seagrasses and seaweeds in the world, and hundreds of other species that are found nowhere else on Earth.
Harlequin fish thrive among the kelp covered rocks. They are endemic to western and southern Australia, and are found nowhere else on Earth. Source: Thomas Wernberg, Author provided
Temperate seaweed forests and seagrass meadows are like tropical coral reefs and forests on land – they provide a 3D habitat, food and shelter for a myriad of associated species, many of which have economic importance such as abalone and rock lobsters.
Many of the species found along the coastline of southwestern Australia have evolved to live in cooler temperate waters. When peak summer sea temperatures soar, as they did in early 2011, many species overheat and become physiologically stressed or even die.
Following the 2011 La Niña event, mass deaths occurred in a wide range of species, including seaweeds, seagrasses, shellfish and finfish.
Plants that formed forests such as kelps and seagrasses were particularly hard hit, with knock-on effects on the wildlife that depend on these forests for food and shelter.
One forest-forming seaweed was eradicated from over 100 km of coastline in just a few months as a result of the marine heat wave. Further north, unprecedented levels of coral bleaching and mortality were recorded for a range of reef-building coral species.
Extensive kelp forests a) and seagrass meadows c) were severely impacted by the 2011 marine heatwave, which cased complete canopy loss, population decimation an overgrowth by epiphytes b, d). Sources: Thomas Wernberg a, b), Matt Fraser c) and John Statton d)
Rapid loss of underwater forests in response to recent oceanic warming has also been observed in other temperate regions of the world.
The La Niña also affected important fisheries and tourism. For example, a regional abalone fishery in Kalbarri was decimated and stocks of scallops and blue swimmer crabs in Shark Bay have crashed.
Blue swimmer crabs a) and little penguins b) were heavily impacted by the 2011 marine heat wave. Sources: Thomas Wernberg a) and Belinda Cannell b)
High water temperatures and a lack of available food also killed and reduced the breeding success of Little Penguins, while the highly-valued Western Rock Lobster also suffered many deaths. On the other hand, many warm water species were found further south than usual, presenting opportunities for recreational and commercial fishers alike.
In many cases, species’ populations have not returned to normal in the four years since the marine heat wave, with some species showing no signs of recovery. For example, northern populations of Roe’s abalone have not recovered naturally and a large-scale restocking programme is underway to re-establish the fishery. Similarly, populations of forest-forming seaweeds have not yet bounced back.
The increasing frequency and severity of marine heatwaves set to follow the doubling of La Niña events may eventually sound the death knell for west Australia’s globally significant underwater forests, and will have profound socioeconomic implications.
As millions of people rely on ecological goods and services provided by temperate marine ecosystems, a better understanding of what conditions boost resilience to climate variability is needed to maximise chances of protecting and sustaining them in decades to come. Recent research on coral reefs has shown that tropical ecosystems can recover from extreme warming events, if local conditions are favourable. The capacity of temperate reef ecosystems to recover from marine heatwaves is, however, far less understood.
The question that remains is whether our seaweed forests will have time to recover between the blows dealt by these underwater heatwaves – or shift to a new, more impoverished state.
Two out of three Australians regularly use complementary medicines, which constitute a A$3.5 billion domestic market. But the industry’s marketing strategies are a source of ongoing controversy and pose a significant challenge for regulators.
Products containing containing krill oil provide a good example of the kinds of extravagant claims made by supplement manufacturers. The oil is derived from a tiny, shrimp-like crustacean and, like fish oil, contains omega-3 fatty acids.
Company claims include krill oil’s capacity to “relieve arthritic symptoms [of osteoarthritis and rheumatoid arthritis] within a short period of 7 to 14 days”, as well as its “superior absorption” and the curiously ambiguous “9x [strength]” of the less expensive fish oil. Such claims are found on product packs and manufacturers’ websites, as well as the websites of third-party stockists.
Few companies provide links to research supporting such claims. What research does exist is not easily accessible to most consumers, who, at any rate, can rarely assess its validity.
Claims and science
The widely used claim that krill oil relieves the symptoms of arthritis within seven to 14 days appears to be based on a small 2007 study. The research focused on one specific formulation of krill oil, produced by a Canadian company. Possible conflicts of interest, including the source of funding for the study, are notably absent from the paper.
The study recruited 90 people with a confirmed diagnosis of one or more of cardiovascular disease, rheumatoid arthritis (ten people) and osteoarthritis (30 people). They were compared to placebo groups of 12 and 26. Three patients pulled out of the trial before completion, and 12 didn’t have a diagnosis of either osteoarthritis or rheumatoid arthritis.
While some results at seven and 14 days were deemed statistically significant, the meagre number of people involved raises questions about the clinical significance of its conclusions.
Regardless of this and other details of the report that suggest only people with very severe cases of illness were included, the findings of this early and isolated study can, at best, be considered preliminary. And a search of a comprehensive research database found no evidence that the results had been replicated independently.
The claim of krill oil having “superior absorption” is also dubious and not supported by research evidence. A 2014 review of krill oil absorption actually concluded there was no evidence for krill oil being more easily absorbed by the human body.
Regulatory challenges
Companies that market complementary medicines in Australia are legally required to comply with standards set by the Therapeutic Goods Administration (TGA). These standards relate to both the quality of the product and advertising claims.
But manufacturers self-certify their compliance with TGA requirements. Limited, as well as poorly targeted, post-market surveillance of complementary products means they can contravene standards without fear of reprisal. Then there’s the lack of effective penalties to deter companies from breaching TGA regulations.
In May 2013, the Therapeutic Products Advertising Complaint Resolution Panel determined claims such as “9x stronger” and “reduce[s] pain, stiffness and inflammation caused by arthritis, within a short period of 7 to 14 days” breached a number of sections of the Therapeutic Goods Advertising Code 2007.
It said such statements:
“ought to be supported by a wide body of scientific evidence involving a number of independent studies.”
But the claims continue to be made, even by companies asked to withdraw them.
Numerous reports over the last decade have recommended that the lack of effective penalties for offending companies be redressed. But it seems unlikely any changes will be implemented any time soon as both the industry and government support a deregulation agenda.
Meanwhile, consumers continue to be ripped off by products that cannot deliver on the promises they make.
Feral cats are estimated to eat tens of millions of native animals each night in Australia. But what kinds of wildlife are they eating? In research published today in the Journal of Biogeography, my colleagues and I show that cats kill hundreds of different kinds of animals, including at least 16 species considered globally threatened.
Feral cats are a serious threat to wildlife globally, contributing to the extinction of numerous birds, mammals and reptiles worldwide. In Australia, cats have been implicated in the extinction of at least 20 mammal species and sub-species, including the lesser bilby and desert bandicoot.
Cats are widespread across the country, so it’s likely that their diet varies according to the local environment and fauna community – which might be affected by many factors, such as the amount of rainfall that an area receives or the native plant life.
Knowing what cats eat can help us decide how best to manage them.
Feline feast
What we found supports earlier research – the feral cat is an opportunistic predator – a generalist carnivore that eats a wide range of wildlife across Australia.
A feral cat degustation. Tim Doherty, Author provided
Feral cats help themselves to a phenomenal number of species in Australia – 400 different vertebrates. This includes 123 bird species, 157 reptiles, 58 marsupials, 27 rodents, 21 frogs and nine exotic medium- and large-sized mammals. This is more than double the 179 species of animals that cats have been recorded eating on other islands worldwide.
However, this list only includes those species that have been recorded in diet studies, so it’s likely that there are many other species of native animals that cats kill and eat, that we just don’t know about yet.
We found that cats kill at least 16 globally threatened species and 12 others classed as near-threatened. This include mammals like the critically endangered mountain pygmy-possum and the brush-tailed bettong (woylie); the endangered northern quoll; as well as the critically endangered Christmas Island whiptail-skink and the vulnerable malleefowl.
What feral cats eat varies depending on where they are.
In our study, cats ate rodents most often in Australia’s tropical north. They ate medium-sized mammals, such as possums and bandicoots, most frequently in the south-east of the country. Still, cats ate rodents three times more often than other small, carnivorous mammals known as dasyurids (like dunnarts for example).
Cats also ate many mammals from a group that has suffered severe declines and extinctions over the past 200 years. These are known as “critical weight range” mammals, and weigh between 0.35 and 5.5 kilograms. Unfortunately, these mammals make suitable sized prey for many predatory species such as the feral cat and the introduced red fox.
What cats eat also depends on the amount of rainfall an area receives. Cats fed on reptiles most frequently in the central deserts, where rainfall is lowest. These deserts are also the most reptile-rich part of Australia (and the world).
Cats commonly feed on another widespread pest species: rabbits. Where cats ate fewer rabbits, the frequency of small mammals (rodents and dasyurids) in their diet increased. In Australia’s tropical north where rabbits are mostly absent, cats ate the highest frequency of rodents and dasyurids of anywhere in the country.
This has important implications for how we manage pest animals. If rabbits are culled from an area, but cats aren’t controlled at the same time, then cats might switch prey and eat more small native mammals.
Past experience tells us how these programs can go awry. For example, when feral cats were eradicated from Macquarie Island in 2000, rabbit numbers exploded because the cats had kept the rabbits in check. Rabbits caused severe damage to the island’s native vegetation before being eradicated themselves in 2014. This suggests that a multi-species approach should be adopted for pest animal control.
Cat control
Large-scale control of feral cats is very difficult, particularly on the mainland, although some programs have been successful on islands. The use of poison baits can reduce cat density, but even low levels of cat predation can exterminate threatened mammal populations, such as when cats killed at least seven bilbies reintroduced outside the Arid Recovery reserve in South Australia.
Predator-free islands and fenced reserves on the mainland are the most effective short-term protection for our threatened mammals. However, fences that exclude predators are very expensive to build, and they require constant monitoring, maintenance and funding.
Non-lethal methods have traditionally been overlooked in the fight against invasive predators, such as the feral cat. However, new research suggests that smart fire and grazing management can help preserve the natural shelters that provide native animals with refuge from predators.
Reducing the impact of feral cats on our native animals is a challenging endeavour, but it is essential in the fight to conserve our unique fauna.
Sharks have been making news yet again, after a spate of sightings in Newcastle, New South Wales, prompted days of beach closures and reports of oceangoers allegedly being “stalked” by “monster” specimens.
Similarly, when West Australian teenager Jay Muscat was killed by a shark on December 29 last year at Cheyne’s Beach, near Albany, the state’s media understandably covered the incident in detail, with an ABC television report claiming that a shark had been seen “stalking” the area for about week before the tragedy.
This term also appeared in subsequent media reports about a local family who, three days before the incident, had reportedly been “stalked” by a shark at the same beach. One family member expressed her guilt at not having informed the Department of Fisheries about the shark, which she described as “menacing”.
“Stalking” and “menacing” are graphic, emotive words, typically reserved for criminal behaviour on a serious scale. Petty thieves don’t stalk; rapists and assassins do. Armed robbers are menacing; shoplifters not so much.
What is also important about this language is that it connotes behaviour which is deliberate, conscious, and calculating. In the wake of human encounters with sharks (and particularly great white sharks), we are used to hearing that a shark has “stalked” an area to “target” a victim. Most people don’t consider this terminology inappropriate, despite the fact that the animal is being crudely demonized.
This characterisation is quite arbitrary, as shown by the fact that a minority of observers choose instead to emphasize the “incidental” and “accidental” nature of the same attacks. But this latter interpretation tends to be buried under the flow of negative and emotive words.
The language of crime
Plenty of other metaphors of criminality are also used to characterize sharks in Australian waters. Great whites are routinely said to “lurk”, “linger”, “prowl”, “maraud” or “loiter” near “innocent” or “unsuspecting” bathers.
Sharks “encroach on”, “intrude into”, and “invade” the water near beaches, marinas and surf breaks. When an attack takes place across these presumed boundaries, whole populations of people are “terrorized” into leaving the water, enduring a summer of fear at the mercy of “rogue” sharks.
Not a good day for a dip. AAP Image/NewZulu/Lucy Alcorn
After a tragedy, the shark is still ascribed with qualities of deliberation and calculation. It is said to have slipped away and avoided capture, even “gone under the radar”. The “elusive” or “evasive” killer shark retreats into the vast, unfathomable ocean like a professional assassin disappearing into the anonymity of the city. The shark takes flight, successfully “giving authorities the slip”. “It’ll be miles away by now” is a frequent complaint.
Descriptions of this kind suggest that, like a fugitive from justice, the animal knows it is at large and is weighing up its options: flee the scene, or return to the place of its initial attack and launch another one.
Why do we treat sharks like criminals?
Among developed world populations, Australians are arguably unique in living alongside a considerable number of indigenous wild animals with the capacity to kill them. (Europeans and North Americans rarely come face to face with bears or wolves these days). Whether it’s the redback spider in the chook shed, the brown snake under the veranda, the pure-bred dingo on Fraser Island, or the vast population of crocodiles across the Top End, Australians know how deadly the local wildlife can be.
But none of these – not even crocodiles – is linguistically maligned with quite the same degree of opprobrium, even hatred, as the great white shark. Why?
There are several reasons, but the most important is that while it is easy to ascribe human characteristics to sharks (as we have seen above), many people find them difficult to love, or even to like.
When wild creatures bear even the vaguest resemblance to humans or domesticated animals, this can afford them a level of protection from untrammelled exploitation. The danger which they might pose is somehow offset by some semblance of similarity in appearance or behaviour. The purely wild dingoes of Fraser Island were treated like domestic dogs until we realised they could be deadly.
It is difficult to think of sharks in this benevolent way. The black and beady eyes, the gaping jaw, the rows of serrated teeth, the seemingly malevolent expression, the immense body size – all seem to justify the final damning characterisation as the “ultimate killing machine”.
It is important for this narrative that the damage wrought on the victim’s body by a great white is immense. Although media reports respectfully attempt to gloss over exactly what happened at the moment of impact, we nevertheless have accounts of bodies being “bitten in half”, limbs eviscerated, and – perhaps most powerful of all – victims who are never found at all.
Fearsome Nature
In other words, what gives sharks their unrivalled symbolic character is the fact that they are a living testament to the destructive capacity of Nature.
The fact that great whites remain beyond our control runs entirely counter to the trajectory of recent history where human-animal relations are concerned.
The UC Berkeley geographer Michael Watts has described this relationship as “a gigantic act of enclosure”. The routine capturing, corralling, and containment of animals by humans has become a dominant pattern.
We kill animals and commodify their bodies and other products in endless ways – in battery chicken farms, piggeries, and even the crocodile farms of Australia’s tropical north.
Exceptionally, the great white shark has so far escaped the ignominies and impacts of enclosure enforced on other animals, including most wild ones.
Under these circumstances, it is hardly surprising that through our ways of speaking we tend to condemn the great white for resolutely remaining well beyond the pale, just as we do with other extreme and uncontrollable elements on the margins of our society.
This is a culturally complex issue, beyond the scope of linguistic fixes like replacing the emotive terms such as “shark attack” with more prosaic ones like “shark bite”. But we should nevertheless start paying as much attention to how we talk about our encounters with sharks as we do to the encounters themselves.
Prime Minister Tony Abbott caused quite a stir when he re-established the appointment of knights and dames under the Order of Australia early in 2014. For this to occur, no law needed to be passed. Instead, Her Majesty The Queen, on the recommendation of the Prime Minister, amended the Letters Patent for the Order of Australia awards.
In 2015, it was the knighthood given to the Duke of Edinburgh, Prince Philip, that proved for many to be the Australia Day barbecue stopper. But how is it that Prince Philip – someone who is not an Australian citizen – is awarded a knighthood? Can foreigners even be awarded honours under the Order of Australia?
To answer these questions, it is necessary to delve into the language of the Letters Patent.
What are Letters Patent?
Letters Patent are a legal document signed by the Monarch (or the Governor-General) that grants some sort of right, status or title.
When a royal commission is established, the appointment of the royal commissioner is done so by Letters Patent. One recent example is the appointment of former High Court judge Dyson Heydon as the royal commissioner to investigate alleged corruption within trade unions. Some not-so-recent examples are the letters patent signed by the monarch establishing each of the Australian colonies during the 1800s.
The Order of Australia – our system for recognising the achievements of outstanding Australians – was established by Letters Patent in 1975. Letters Patent are unique in that the document is approved without reference to parliament. This is how knighthoods and damehoods were re-established without the involvement of parliament. Abbott simply instructed the Queen to amend the letters patent.
How are knights and dames appointed?
Knights and dames are essentially “captain’s picks” of the prime minister. Abbott said he “consulted with the chairman of the [Australia Day] Council for the Order of Australia and … with the Governor-General”.
… with the approval of the Sovereign on the recommendation of the Prime Minister, by Instrument signed by the Governor-General.
To understand the appointment process it is necessary to have a close look at the clauses in the current Letters Patent.
Clause 11 of the Letters Patent states that:
Australian citizens … are eligible to be appointed to the Order.
It also allows non-citizens to be “appointed to the Order as honorary members”. In short, it establishes two categories of eligibility.
There are also important clauses that relate specifically to appointing knights and dames. Clause 11A(1) states that:
Appointments as Knights or Dames, or honorary Knights or Dames, in the General Division shall be made for extraordinary and pre-eminent achievement and merit in service to Australia or to humanity at large.
The other important clause is 11A(2), which deals with non-citizens. It qualifies the previous clause by stating that:
Notwithstanding subsection (1), a distinguished person who is not an Australian citizen may be appointed as an honorary Knight or Dame … where it is desirable that the person be honoured by Australia.
What is unclear from the wording of these clauses is whether non-Australian citizens can only be given honorary knighthoods. On one reading of the clauses, non-citizens can only be given honorary knighthoods. An alternative view is that while this may be the sense of the clause, it is not mandatory: that is, non-citizens may also be awarded the “ordinary” knighthood or damehood.
There is no mention that Prince Philip’s award is an honorary appointment. This raises the question of whether Prince Philip’s award should be viewed solely as “honorary”. However, the distinction is important.
The distinction of “honorary” knights and dames
Why does it matter whether Prince Philip’s award was “honorary” or not? Only four knights and dames can be appointed each year. However, this limitation of four per year does not include “honorary” knights and dames.
If Prince Philip’s award was not an honorary appointment, it has taken the award away from an Australian. If Prince Philip’s was an honorary appointment – and this fact was omitted from the list released on Australia Day – it highlights that while only four Australians can receive knighthoods or damehoods, there is no limit on the number of appointments that the prime minister could make to people who are not Australian citizens. The prime minister could start handing out honorary knighthoods or damehoods to foreign leaders left, right and centre.
The 2015 Australia Day honours may be remembered for many reasons. However, the show-stopper was the decision to add a knighthood to Prince Philip’s long list of titles. We can hardly wait for the Queen’s Birthday honours list.
Are neck, hand or forearm cooling, ice-cube sucking or cold showers effective ways to lose heat on those dog days of summer? Can sports clothing keep you cool by wicking away sweat? When the heat is on, some of us are prepared to entertain even snake-oil solutions for the sake of personal comfort, but do such cooling strategies really work?
Let’s first consider heat loss from a physical perspective, putting aside physiological heat-loss mechanisms, such as sweating and skin blood flow. Cooling down is more easily understood when reduced to this level because the physical properties of heat exchange are well known.
Understanding heat loss
The first of these properties is the temperature gradient; the bigger the temperature difference between two things, the more rapidly heat (thermal energy) flows towards the cooler one.
Substances conduct heat at different rates (thermal conductivity). Water, for instance, is 24 times more conductive than air at the same temperature. Consider walking into the cold room of a bottle shop, which is usually a cool five degrees Celsius, versus swimming in water of the same temperature. The latter is excruciating, with death from hypothermia just around the corner.
We also need to keep in mind the heat retained within various substances, which is known as mass-specific heat. This tells us how heat is required to increase the heat of two objects that weigh the same by one degree Celsius. Water has a specific heat four times that of air, for instance, so a kilogram of water can remove four times as much heat as the equivalent mass of air.
Density is important too, because it determines the mass of a substance that can be contained within a fixed space. Since water is 800 times denser than air, a bath filled with water is many times heavier than one that contains air.
Together, specific heat and mass define the volume-specific capacity of substances to store heat. Going back to our example with water: it has a heat capacity more than 3,000 times that of air because of the combined effects of its mass-specific heat and density.
An object’s mass and surface area are important as well, because heat is stored in its mass and lost through its surface. Spheres have the largest mass for a given surface area, while wafers have the opposite characteristic. In other words, an object’s surface-area-to-mass ratio dictates its heat-exchange potential, with flatter and thinner surfaces (such as hands and feet) losing heat more rapidly.
Cooling solutions
So, to cool an object, maximise the temperature gradient, choose a coolant with a high thermal conductivity and heat capacity (liquids), and modify the shape of your object to resemble a wafer. Without question, water is ideal for cooling non-living objects.
But does it work as well for living bodies? And how is it influenced by the physiological responses that we all experience when exposed to heat?
So far, we have only considered heat conduction, or heat exchanged between objects in direct contact – touching a hot stove for example. But conduction speed is influenced by the distance heat must travel.
Animals enhance cooling by delivering heat closer to the skin surface. This convective mechanism, which involves delivering hotter central-body blood to the cooler skin, shortens the conductive pathway and promotes heat loss.
Natural selection has ensured that naked human skin is ideally suited for evaporative cooling. Obi/Flickr, CC BY
But this mechanism relies on increasing and sustaining skin blood flow, which is dictated by the separate and combined effects of deep-body and local skin temperatures. Maximal skin blood flow occurs only when both the deep-body and local skin tissues are heated, but not if only one region is hot.
When a hot person is placed in very cold water (say of about five degrees Celsius), skin blood flow is dramatically reduced, so heat loss is compromised. Paradoxically, submerging that same person in temperate water (25 degrees Celsius) increases heat dissipation by preventing this blood-flow suppression.
Clothing and comfort
Natural selection has ensured that naked human skin is ideally suited for evaporative cooling, and anything placed on the skin interferes with that process.
The average person has some 110 sweat glands per square centimetre of skin (although this varies with location). When heated, these glands secrete sweat that wets the skin. The ensuing evaporation transfers heat to water molecules, which change from a liquid to a gas, leaving the sweating person cooler.
But, in still conditions, the characteristics of the air in direct contact with the skin change; it rapidly becomes warmer and more humid. This warmer air is less dense and spontaneously rises, taking with it heat (natural convection) and water vapour, and permitting the incoming air to be warmed and humidified.
When we move, or when air moves across the skin (forced convection), convective and evaporative cooling are magnified. Clothing reduces these benefits.
So these are the principles that dictate human heat loss. But we must now distinguish between thermal strain and comfort.
Strain is the physiological impact of heating the body, as quantified through deep-body and skin temperatures; comfort relates to the pleasure derived from different thermal states. We now need to consider whether we wish to feel more comfortable or to reduce thermal strain.
Since comfort follows reduced thermal strain, our energies should be directed accordingly. The first strategy should be to resist counter-evolutionary practices designed to minimise strain (heat avoidance, for instance, and air conditioning), and allow our bodies to adapt to seasonal variations.
So, use natural ventilation whenever possible, dress appropriately and experience the climate. With adaptation, you can improve both physiological heat loss and thermal comfort.
The second strategy is for desperate times, like those dog days of summer: water immersion. Showers help, but are very wasteful. Hand and forearm immersion are good, but time consuming. Neck cooling and ice-cube sucking suck!
Instead, bathe in enough temperate water to just cover yourself, and stay there until you feel cool-cold. Natural water sources are ideal. And as for sports clothing, there is no clothing that can improve the heat-loss capability of your skin; donate your money to a worthy charity!
Andrew Jaspan, Editor, The Conversation
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The Logical Place 
