With warmer weather showing signs of returning across the country, so too are many of spring’s delights: the flowering of plants, greening of trees and rolling of cuffs all testament to the fact that the worst of winter is behind us.
Unfortunately, it’s not all lamingtons and Cherry Cheer at this time of year. For there is also a suburban menace lurking just over the horizon: a black and white marauder waiting to terrorise unsuspecting picnickers, exercisers and office workers alike.
Yep, September is magpie season.
If this image doesn’t send a primordial chill down your spine, you’ve obviously never spent the month of September in suburban Australia. All around the country, roadsides, reserves and office blocks turn into battlegrounds as the Australian magpie looks to protect its patch from any and every threat it can lay its beak on.
So why do magpies swoop us humans – is it to defend their young, or their territory? Or are they just bird jerks?
And most importantly, is there any way we can guard against them?
There was an illuminating paper co-authored by academics from Deakin and Griffith universities, titled Attacks on humans by Australian Magpies (Cracticus tibicen): territoriality, brood-defence or testosterone? The paper, published in our Emu – Austral Ornithology journal back in 2010, looked to study three common hypotheses behind magpie-human attacks, particularly in suburban areas. Were the attacks triggered by territoriality, brood-defence or (magpie) testosterone, the authors asked?
The response of 10 pairs of aggressive magpies to natural levels of human intrusion was compared with that of 10 non-aggressive pairs. Behavioural observations strongly supported the contention that attacks on humans resemble brood-defence and did not support an association with territoriality. The study also found no support for the suggestion that testosterone levels correlated with aggressiveness towards humans: male testosterone peaked immediately before laying and was significantly lower during the maximum period of attacks directed at people. Moreover, there were no differences in the testosterone levels of aggressive and non-aggressive male magpies. The pattern of testosterone production over a breeding cycle closely resembled that of many other songbirds and appeared not to influence magpie attacks on humans.
So, brood-defence can be identified as the cause of attacks.
But, of more interest to posties, cyclists and small children with blonde hair in particular: what makes magpies more likely to attack some people, and not others?
Enter the brave scientists of CSIRO Black Mountain in Canberra. In 2010 (it must have been a bad year!) a particularly aggressive maggie was nesting on the foot and cycle path between the Australian National University and our Black Mountain site. With all types of magpie-repelling adornments being attached to cycle helmets with varied successes, and (figurative) public service and academia corpses littering the notorious path, our enterprising colleagues decided to add some scientific scrutiny to the debate: how do you deter a mad magpie?
The results can be seen in the following two YouTube clips that, in 2010 terms, broke the Internet.
We can’t really condone the results: we would never advise riding your bike without a helmet. But these videos also do quite clearly dispel the myth that helmet decorations do anything to stop a swooper.
And really, what’s better than seeing public servants being attacked by a magpie to the soundtrack of Tricky’s Maxinquaye?
Want to learn more about this quintessential Aussie which, September aside, we do actually really like? Then check out this great book available through CSIRO Publishing: Australian Magpie – biology and behaviour of an unusual songbird.
And remember, keep your eyes to the sky.
By Ali Green
It has long been suspected that honey bees, being the creatures of habit that they are, simply return to their familial hive homes at the end of a long day of foraging. But it seems for some bees, laying their hat in a particular hive doesn’t necessarily make it their home.
The data already gathered from tiny sensor backpacks placed on bees suggests that for some vagabond bees, sleeping over at a different hive is a regular part of their active social lives. So what does this devil-may-care attitude to bee social structure really mean? Bee Pajama parties? Promiscuous bees? Oh bee nice!
Bee bed jumping is just one of the intriguing insights our researchers are gleaning from the tiny sensors currently monitoring the behaviour of these little swingers… erm, stingers.
Why do we care about bee-haviour?
Honey bees are essential for food production. In fact they are responsible for one third of the food we eat through the pollination services they provide. Yet the health of honey bees on a global scale is under increasing pressure.
To ensure the sustainable production of crops dependent on honey bee pollination, we must protect and improve the health of our honey bee populations.
Enter the Global Initiative for Honey bee Health (GIHH). We’re proud to be leading this international alliance of researchers in a tightly focused, well-coordinated national and international effort to better understand the diverse stresses impacting bee health.
In order to learn more about these tiny creatures and the issues causing their population collapse, we’ve glued thousands of tiny sensor chips to the backs of bees. Don’t worry – the sensors weigh in at 5 mg each – a light load easily managed by honey bees! The little sensor backpacks work in much the same way as a vehicle e-tag system, with strategically placed receivers identifying and recording the movements of individual bees as they fly in and out of their hives, and feeding the information back to an Intel minicomputer that is remotely accessible.
These high-tech micro-sensors are being used to gather a wealth of complex data which is then analysed to determine best management practices for maintaining healthy and productive honey bee colonies.
What is the data telling us?
Here are a few interesting things we’ve learnt so far about the way bees operate – including their preferred sleeping arrangements!
- By correlating bee movement data with environmental data, such as weather stats, we’ve learned that bees, like us, are not overly fond of conducting their outdoor activities in the rain. Instead they choose to forego foraging on inclement days and stay indoors instead. And who would blame them!
- The sensor system has even helped us observe differences between the routine of bees on two continents. We are tracking a colony of bees in Brazil and discovered that, unlike the lazier Tasmanian bees who prefer to sleep in and retire early, the Brazilian bees get to bed and wake up earlier, while indulging in a two hour siesta during the day.
- The data has also demonstrated that bees navigate by colour. Field experiments that involved labelling hives with different colour stickers have shown that individual bees soon identify with the colour on their hive, to the extent that they will follow their particular colour to a different hive if the stickers are moved around. This is terrific news for beekeepers who might use this information to divert healthy honey bees away from a hive in the process of collapse, simply by relocating their colour stickers.
Discoveries like these contribute to a better understanding and management of honey bee health; increase environmental and economic benefits for farmers and beekeepers; and make a valuable contribution to sustainable farming practices and food security. Not bad for a 5 mg backpack!
We’d like to gather as much data as possible through the GIHH project to help us better understand honey bee behaviour and impacts on honey bee health. This means taking the project global. We’re calling on other research institutions around the world to contribute. If you’re interested, visit our GIHH page for more info.
By Ali Green
“You never can tell with bees.”
― A.A. Milne, Winnie-the-Pooh
Australia’s honey and hive product industry is worth a staggering $90 million a year. Not only that, but the humble honey bee is responsible for contributing an estimated $4-6 billion a year to Aussie crop production.
Without these little guys we’d miss out on approximately one third of the foods we currently eat and enjoy – foods like apples, berries, almonds, and… coffee!
Ponder if you will, a world without cafe lattes, blueberry almond friands and fruit salad – indulgences only made possible by the magic pollinating work of our friends the honey bees. Considering the key role that honey bees (Apis mellifera) play in sustaining our pollination-dependent crops, ensuring their health and happiness is critical.
The Global Initiative for Honey bee Health (GIHH)
The health of the honey bee is in jeopardy. Challenges such as Colony Collapse Disorder (CCD) and the Varroa mite pose a global threat to our bees.
In a world first, the Global Initiative for Honey bee Health (GIHH) will seek to address these threats through a world-wide data collection exercise.
Over the next few years we will be leading an international alliance of researchers, in collaboration with beekeepers and farmers, to place tiny sensors onto the backs of honey bees. Data collected through the ‘backpack’ sensor system will provide valuable insights into bee behaviour and inform the development of sustainable long term solutions for bee health.
Our researcher, Saul Cunningham, considers the honey bee to be a ‘super species’ because of its evolutionary success and impact on humans. Although an exotic species in Australia, the feral honey bee provides a valuable biodiversity and ecosystem service to the Australian environment through its pollination practices, as well as having an important role to play in crop production.
Saul describes Australia, with its warm climate and abundance of nectar-rich plants like Eucalypts, as a haven for feral honey bees.
“Australian agriculture gets a particularly generous service of free pollination from these guys,” Saul says.
“This free service will be all but lost when Varroa mites spread to Australia. And I say when, not if, because it is widely accepted that we cannot expect to remain Varroa-free in the long term.”
Varroa destructor mite
An external parasite of bees, the Varroa destructor mite is only about the size of a pinhead. The mites use specialised mouthparts to attack developing larvae or adults, resulting in deformed bees, reduced lifespan and ultimately the destruction of the colony or hive. These mites are the most significant pest of honey bees around the world.
Dr John Roberts, who studies the viruses transmitted by the Varroa destructor mite, is equally pessimistic that it will happen. In saying that, he also agrees that Australia is in the enviable position of being able to learn from the damage control strategies of other countries.
“The Varroa destructor does what it says. It destroys – and it’s the feral honey bee population that is always hardest hit.”
According to John, feral honey bees living in tree hollows or natural hives that are not managed by beekeepers would be wiped out. Farmers of strawberries, almonds and other crops that rely on free pollination by the feral honey bees would be left stranded, as they have been in America and China.
“The impact of losing the free pollination done by feral honey bees will be farmers paying for beekeepers to bring bees in to pollinate their crops, resulting in price hikes in everything from cucumbers and cherries, to macadamias and onions,” John said.
“But you never know where technology will lead us. Our scientists or those in other countries might come up with new ways of managing bees somewhere on the planet, so Australia will be able to respond quickly and effectively when the destructive mite does get here.”
We most definitely want to maintain a Varroa-free status in Australia, so getting involved in projects and initiatives that look to increase our ability to detect early incursions is important.
And this is where the GIHH will play its role.
Analysis of the data gathered by the GIHH will provide valuable information to scientists, beekeepers, primary producers, industry groups and governments to achieve impacts around improved biosecurity measures, crop pollination, bee health, food production and better strategies on sustainable farming practices, food security and impacts on ecosystems in general.
As it stands, Saul and John assure us it’s unlikely the Varroa mite will cause a global food crisis… but it could turn apples into an expensive delicacy!
Dwarf galaxies are the most abundant galaxies in the universe. Yet understanding how these systems behave in galaxy group environments is still a mystery.
These objects are notoriously difficult to study because they are very small relative to classic spiral galaxies. They also have low mass and a low surface brightness, which means that, to date, we have only studied the dwarf galaxies in the nearby universe, out to about 35 million light years away.
My collaborators and I have been studying a dwarf galaxy named ESO 324-G024 and its connection to the northern radio lobe of a galaxy known as Centaurus A (Cen A).
The giant radio lobes are comprised of high energy charged particles, mostly made up of protons and electrons, that are moving at extremely high speeds. The lobes were created from the relativistic jet (shown in the image at the top) that is blasting out of the central core of Cen A.
These energetic particles glow at radio frequencies and can be seen as the fuzzy yellow lobes in the centre of the image (above), together with the neutral hydrogen intensity (HI) maps of its companion galaxies. The lobes now occupy a volume more than 1,000 times that of the host galaxy shown in the image at the top, assuming the lobes are as deep as they are wide.
These HI intensity maps are part of a large HI survey of nearby galaxies called the Local Volume HI Survey (LVHIS). These maps have been magnified in size by a factor of 10 so that they can be seen on such a large scale and are coloured by their relative distances to the centre of Cen A.
A green galaxy is at virtually the same distance from Earth as Cen A, while blue galaxies are in front of Cen A (closer to us) and red galaxies are behind it (farther away).
One of the striking things about this image is that out of the 17 galaxies overlaid onto the Cen A field, 14 are dwarf galaxies.
An interesting dwarf
The one object that really interested me after making this image was the dwarf irregular galaxy ESO 324-G024 (just above the black box). It has a long HI gaseous tail that extends roughly 6,500 light years to the northeast of its main body and it is at nearly the same distance as Cen A.
These two pieces of information right away made this a system worthy of investigation because we thought that perhaps there is a connection between this dwarf galaxy and the northern radio lobe of Cen A.
Nothing like this has ever been seen before, probably because galaxies that have giant radio lobes like Cen A are usually hundreds of millions to billions of light years away. Cen A is a special galaxy because it’s only about 12 million light years from Earth.
This was an interesting result and it told us that the northern radio lobe must be inclined toward our line of sight, because ESO 324-G024 was at nearly the same distance as Cen A. This had previously been suggested by studying the jet way down in the core of the host galaxy, but it had never been confirmed in this way before.
A wind in the tail
Next we investigated the mechanism responsible for creating the HI tail in ESO 324-G024. We looked at the likelihood of gravitational forces from the large, central host galaxy of Cen A as a potential culprit for ripping out ESO 324-G024’s gas. But we determined that it is simply too far away from the central gravitational potential for gravity to have created the tail.
So we explored ram pressure stripping, which is thought to be a dominant force for removing gas in galaxies within these kinds of groups. Ram pressure is a force created when a galaxy moves through a dense medium, and thus experiences a wind in its “face”.
It’s similar to holding a dandelion in your hand and then running as fast as you can go and watching the seeds blow away in the wind. At rest, the dandelion feels no wind and the seeds stay intact. But when you run, all of a sudden, the dandelion feels the wind created from your running and this wind blows away the seeds.
In this scenario, ESO 324-G024 is the dandelion and you represent gravity carrying the galaxy through space. We calculated the wind speed required to blow the gas out of ESO 324-G024 and compared this speed to the speed of ESO 324-G024 moving through space. It turns out that the two speeds did not match.
ESO 324-G024 seemed to be moving too slow for all of its gas to have been blown into its long tail. So we went back to our first conclusion about ESO 324-G024 being behind the radio lobe and surmised what may be happening.
We know that the charged particles inside the northern radio lobe of Cen A are moving extremely fast. If ESO 324-G024 is just now coming into contact with the posterior outer edge of the radio lobe of Cen A, which is likely due to its proximity to Cen A, then it is possible that ESO 324-G024 is not only feeling the wind generated from its own motion through space, but also the wind from the charged particles in the radio lobe itself.
This would be like you running with the dandelion and at the same time blowing on it. Therefore, we concluded that ESO 324-G024 is most likely experiencing ram pressure stripping of its gas as it passes close to the posterior edge of the northern radio lobe.
This means that these types of radio lobes must have wreaked havoc on their dwarf galaxy companions in the distant past. This is an interesting case study that showcases how dwarf galaxies may have been knocked about, blasted, by their larger companion galaxies.
Just how common are situations like this and how have they influenced dwarf galaxies over cosmic time? The answer is that we simply don’t know, but I look forward to exploring these questions.
Amid growing demand for seafood, gas and other resources drawn from the world’s oceans, and growing stresses from climate change, we examine some of the challenges and solutions for developing “the blue economy” in smarter, more sustainable ways.
Diving the warm, crystal clear waters of Indonesia’s Raja Ampat Marine Park is an experience for the lucky few. Its coral reefs attract a huge variety of marine life, including turtles, manta rays and countless species of tropical fish – including the now iconic clownfish.
If you’ve gone diving there recently, or are planning a holiday, you may have noticed that the marine park fees have gone up sharply in past 12 months – as they have in many other parts of Indonesia, Malaysia and Thailand.
But you might actually be happy to discover why.
The cost of caring for coral reefs
The dive industry has long been criticised as contributing to declines in coral reef health around the world. Coral reefs globally are under increasing pressure from the cumulative impacts of fishing, shipping, and coastal development, as well as longer-term impacts due to climate change. And unless it’s managed, increased diving and snorkelling tourism can become just another environmental strain.
That’s not in anyone’s interests. Failure to adequately manage activities within reef areas is likely to lead to their degradation, which will make them less attractive to divers and other tourists in the long-term.
But taking better care of our reefs comes at a cost. It requires monitoring and surveillance, as well as ensuring users (such as divers) and beneficiaries (such as local businesses) of the reefs are aware of their impacts and understand how to avoid them.
Across Indonesia, Malaysia and Thailand, dive tourism directly dependent on the health of coral reefs brings in around US$1.5 billion a year to local communities. Most of this is in remote areas, where alternative sources of income are limited.
Those three countries have set up a number of marine parks to protect their reefs. And about 70% of those parks have long had dive fees in place.
But the fees have typically been very low, while government contributions were also relatively constrained – which is why a 2006 study found that only about one in seven marine reserves in south east Asia had adequate financial resources.
That’s where learning from the Australian experience, together with modelling work from an international team of researchers, has helped provide a practical solution.
How tourists help pay to preserve the Great Barrier Reef
The Great Barrier Reef Marine Park is one of Australia’s great tourism international drawcards – for divers in particular – injecting an estimated AUS$5 billion into the economy and generating around 64,000 full-time equivalent jobs.
But right from the early days of establishing the Great Barrier Reef Marine Park, Australia had to grapple with how to pay for crucial conservation work.
That’s why divers and other visitors to the Great Barrier Reef Marine Park each pay an environmental management charge of AU$6 a day. That contributes around 20% of the AU$40 million annual management costs.
Modelling to test what impact this charge has on visitor numbers suggests that it is very small, and the gains in terms of financial resources for management far exceed any potential losses to local businesses – which, after all, also depend on the reef for their continued survival.
Testing a model solution
But until a few years ago, the idea of charging higher fees was opposed by many tourism and related businesses in south east Asian diving communities, concerned that it might cause tourist numbers and earnings fall.
In 2013, a group of international researchers supported by the Asia-Pacific Network for Global Change Research worked with managers, resort owners and dive operators in Indonesia, Malaysia and Thailand to develop options for improved reef management in the region.
This included modelling what might happen if you increased dive fees to pay for reef conservation. That study predicted that even if the conservation fees were more than doubled, it was unlikely to deter many divers, who care about the places they go diving in.
It also predicted that the revenue raised for reef protection would far exceed the loss in tourism expenditure in local communities, and help ensure that the communities as well as the reefs would survive into the future.
What higher diving fees are funding
Since then, as any keen divers reading this might already have seen, user fees in many of their marine parks have been introduced or increased. For example, at the Raja Ampat Marine Park in Indonesia, fees for foreign visitors have doubled in 2015 to 1,000,000 Indonesian Rupiah (about AU$100) for an annual permit.
More modest fee increases (and fee levels) have also been seen in most Thai and Malaysian marine parks this year, with most now charging international visitors between AU$10 and AU$20 a day for access.
So what are you paying for? Among other things, divers are helping by paying more for rangers’ wages and for patrols to keep out illegal fishing, mining and poachers, as well as conservation and reef rehabilitation projects in the parks.
But when you consider how much it costs to go on a diving holiday, being asked to pay the equivalent of a light meal is not too much to ask. Indeed, from the modelling study, most visitors gain substantially much more than this in terms of benefits from diving on these coral reefs, and could potentially contribute greater amounts to protect them for future generations.
By digging a little deeper, divers can do more than just go on holiday: they can contribute to longer-term conservation of some of the most extraordinary places on Earth.
Fisheries Economist, Oceans and Atmosphere Flagship at CSIRO
Professor at James Cook University
A fish that prefers to walk on its ‘hands’ rather than swim is one of the few species that has survived totally unchanged, since dinosaurs walked the earth. Fifty million years ago, handfish were found trotting across the rivers of the world, but now these shallow bottom dwellers are some of the rarest animals on Earth.
The Spotted Handfish, with its unusually large overgrown pectoral fins that look like hands, is the darling of the Derwent estuary and the hero of Hobart. We’re not being hyperbolic. This bizarre fish is an icon in Tassie, so much so that renowned winter art festival Dark MOFO, commissioned Balinese artists to create a giant papier-mâché sculpture of the handfish, known to all as “Jessica the Handfish” or ogoh-ogoh.
Inside the sculpture people had written down their hopes and fears. When Jessica was set alight at the end of the festival, so too were many of Hobart’s fears. This was a truly spectacular celebration of a special fish. Sadly the fiery demise of Jessica mirrors the loss of the handfish which is now, tragically, on the critically endangered species list.
While the handfish may have survived mass extinction events and ice ages, more recent human incursions from pollution, dredging, introduced species and coastal development have cutback their habitat to just nine sites in the Derwent estuary. So why did they end up surviving down here? Well, that’s the $50,000 dollar question.
Saving the Spotted Handfish
Along with our partners at the University of Tasmania (UTAS), we’ve been monitoring these quirky animals for many years. And we continue to do so with support from the Threatened Species Commissioner and funding through the Australian Government’s National Landcare Programme.
But what does monitoring a handfish actually look like?
Our team popped on some fluffy onesies underneath our thick dry suits and proceeded to dive into the cool winter waters of the Derwent estuary. There, we conducted the first ever survey of all nine local populations of the Spotted Handfish. Battling what could only be described as ice cream-like headaches, we completed multiple daily dives at each of the sites for the last three months, to get up close and personal – close enough for a high-five.
So far we’ve found handfish at all of the known sites, many with higher than expected numbers. This is great news. However, at several sites the handfish don’t appear to be as densely populated as we once thought.
Unlike other fish, handfish care for their eggs during the gestation period. These protective parents guard their eggs, which cling to stalked ascidians for up to six weeks, keeping a close eye on them till they hatch. Sadly, stalked ascidians are a favourite food of an introduced species, the North Pacific sea star. The handfish’s ongoing battle for survival will continue as long as these villainous sea stars live in the estuary.
The joint CSIRO/UTAS team is about to get back into the water and help the Spotted Handfish by planting 1000 artificial spawning habitats. These are inedible to the starfish and provide much needed places for the handfish to attach their eggs.
Handfish are like rare jewels when you find them on the sea floor and, besides their beauty, they can tell us a thing or two about resilience and survival – it is in our best interests to make sure they thrive and remain a talisman for Hobart and handfish aficionados around the world.
Find out how we’re protecting marine creatures through our National Fish Collection.
By Eamonn Bermingham
It’s wider than a blue whale is long, weighs as much as 25 Asian elephants and will soon be helping to unlock the secrets of the Universe. Say hello to our new dish: Deep Space Station 36.
Fresh from showing the world the first close encounter images with Pluto last month, our Deep Space Communication Complex in Canberra welcomed the newest member of its dish family to the facility earlier today.
The Canberra Complex is one of three Deep Space Network stations capable of providing two-way radio contact with robotic deep space missions. The complex’s sister stations are located in California and Spain.
The new dish is part of a $120 million NASA investment at the site, adding to our four other antennae – though it will take another 12 months to completely fit out.
“It’s a massive investment by NASA and shows the confidence they have in Australia and our ability to manage these operations,” Facility Director Dr Ed Kruzins said today.
Earlier this year our Deep Space Complex celebrated its 50th birthday. Ed says NASA’s latest investment shows that Australia is here to stay when it comes to space communications.
So what’s so special about Australia when it comes to staring into space?
“Geographically, we’re uniquely placed to look at the southern part of the solar system, which is where many of the space missions are now headed. We’re now tracking 40 different space missions, mostly with NASA and some others with Japan and the European Space Agency, so we need this extra capacity to be able to monitor the skies 24/7, 365 days a year,” says Ed.
What can we expect to find?
As the first images from Pluto demonstrated, the Universe has a habit of surprising us.
“We didn’t expect to see some of the things that came back from Pluto and we’ll no doubt see more that we didn’t expect when signals start returning over the coming months. The Universe is full of things we don’t understand. Pluto is covered in ice and in very deep freeze so should be inert, but it isn’t. Why is that? We just don’t know yet.”
But the fascination doesn’t end with Pluto. From water on Mars to the possibility of life on the icy moons of Jupiter, you get a sense that we’re only beginning to understand our solar system – not to mention further afield.
“Our largest antenna, which is 70 metres in diameter, is the only one in the world that’s covering the Voyager 2 mission, which launched back in 1977. It’s recently gone interstellar, easily further than any manmade object has been before, *17.5 light hours away.”
Wow. Speaking of Interstellar, how about that movie?
“The first half of it was absolutely accurate, in that time does pass more slowly on a planet in higher gravity fields!”
If you’d like to find out more about our space research, gaze over here.
(*That’s very, very far away)