Seeing animals and birds is one of the main draws of spending time in nature. But as researchers who study conservation, wildlife and human impacts on wild places, we believe it’s important to know that you can have major effects on wildlife just by being nearby.
In a recent review of hundreds of studies covering many species, we found that the presence of humans can alter wild animal and bird behavior patterns at much greater distances than most people may think. Small mammals and birds may change their behavior when hikers or birders come within 300 feet (100 meters) – the length of a football field. Large birds like eagles and hawks can be affected when humans are over 1,300 feet (400 meters) away – roughly a quarter of a mile. And large mammals like elk and moose can be affected by humans up to 3,300 feet (1,000 meters) away – more than half a mile.
Many recent studies and reports have shown that the world is facing a biodiversity crisis. Over the past 50 years, Earth has lost so many species that many scientists believe the planet is experiencing its sixth mass extinction – due mainly to human activities.
Protected areas, from local open spaces to national parks, are vital for conserving plants and animals. They also are places where people like to spend time in nature. We believe that everyone who uses the outdoors should understand and respect this balance between outdoor recreation, sustainable use and conservation.
How human presence affects wildlife
Pandemic lockdowns in 2020 confined many people indoors – and wildlife responded. In Istanbul, dolphins ventured much closer to shore than usual. Penguins explored quiet South African Streets. Nubian ibex grazed on Israeli playgrounds. The fact that animals moved so freely without people present shows how wild species change their behavior in response to human activities.
Decades of research have shown that outdoor recreation, whether it’s hiking, cross-country skiing or riding all-terrain vehicles, has negative effects on wildlife. The most obvious signs are behavioral changes: Animals may flee from nearby people, decrease the time they feed and abandon nests or dens.
Other effects are harder to see, but can have serious consequences for animals’ health and survival. Wild animals that detect humans can experience physiological changes, such as increased heart rates and elevated levels of stress hormones.
And humans’ outdoor activities can degrade habitat that wild species depend on for food, shelter and reproduction. Human voices, off-leash dogs and campsite overuse all have harmful effects that make habitat unusable for many wild species.
Effects of human presence vary for different species
For our study we examined 330 peer-reviewed articles spanning 38 years to locate thresholds at which recreation activities negatively affected wild animals and birds. The main thresholds we found were related to distances between wildlife and people or trails. But we also found other important factors, including the number of daily park visitors and the decibel levels of people’s conversations.
The studies that we reviewed covered over a dozen different types of motorized and nonmotorized recreation. While it might seem that motorized activities would have a bigger impact, some studies have found that dispersed “quiet” activities, such as day hiking, biking and wildlife viewing, can also affect which wild species will use a protected area.
Put another way, many species may be disturbed by humans nearby, even if those people are not using motorboats or all-terrain vehicles. It’s harder for animals to detect quiet humans, so there’s a better chance that they’ll be surprised by a cross-country skier than a snowmobile, for instance. In addition, some species that have been historically hunted are more likely to recognize – and flee from – a person walking than a person in a motorized vehicle.
Generally, larger animals need more distance, though the relationship is clearer for birds than mammals. We found that for birds, as bird size increased, so did the threshold distance. The smallest birds could tolerate humans within 65 feet (20 meters), while the largest birds had thresholds of roughly 2,000 feet (600 meters). Previous research has found a similar relationship. We did not find that this relationship existed as clearly for mammals.
We found little research on impact thresholds for amphibians and reptiles, such as lizards, frogs, turtles and snakes. A growing body of evidence shows that amphibians and reptiles are disturbed and negatively affected by recreation. So far, however, it’s unclear whether those effects reflect mainly the distance to people, the number of visitors or other factors.
How to reduce your impact on wildlife
While there’s much still to learn, we know enough to identify some simple actions people can take to minimize their impacts on wildlife. First, keep your distance. Although some species or individual animals will become used to human presence at close range, many others won’t. And it can be hard to tell when you are stressing an animal and potentially endangering both it and yourself.
Second, respect closed areas and stay on trails. For example, in Jackson Hole, Wyoming, wildlife managers seasonally close some backcountry ski areas to protect critical habitat for bighorn sheep and reduce stress on other species like moose, elk and mule deer. And rangers in Maine’s Acadia National Park close several trails annually near peregrine falcon nests. This reduces stress to nesting birds and has helped this formerly endangered species recover.
Getting involved with educational or volunteer programs is a great way to learn about wildlife and help maintain undisturbed areas. As our research shows, balancing recreation with conservation means opening some areas to human use and keeping others entirely or mostly undisturbed.
As development fragments wild habitat and climate change forces many species to shift their ranges, movement corridors between protected areas become even more important. Our research suggests that creating recreation-free wildlife corridors of at least 3,300 feet (1,000 meters) wide can enable most species to move between protected areas without disturbance. Seeing wildlife can be part of a fun outdoor experience – but for the animals’ sake, you may need binoculars or a zoom lens for your camera.
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Jeremy Dertien, PhD Candidate in Forestry and Environmental Conservation, Clemson University ; Courtney Larson, Adjunct Assistant Professor, University of Wyoming, and Sarah Reed, Affiliate Faculty in Fish, Wildlife and Conservation Biology, Colorado State University
Kathy Ann Townsend, University of the Sunshine Coast and Dominique Potvin, University of the Sunshine CoastEnvironmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique photos from the field.
When we opened a box supplied by museum curators, our research team audibly gasped. Inside was a huge Australian magpie nest from 2018.
It was more than a metre wide and made up of the strangest assortment of items, including wire coat hangers, headphones, saw blades and plastic 3D glasses — a mix of detritus reflecting our modern lifestyle.
This was one of almost 900 Australian nest specimens dating back over 195 years that we inspected for our recent, world-first study.
We estimate that today, around 30% of Australian bird nests incorporate human-made materials (primarily plastics). We also noted a steady increase in nest parasites over this period.
It’s clear the types of debris the birds use has reflected changes in society over time. They highlight the unexpected and far-reaching ways Australians impact their environment, and put birds in danger.
The first synthetic item
Birds and humans have been sharing spaces and habitats throughout history.
It’s well known birds incorporate material from their environment into their nests, making them ideal indicators of environmental changes and human activity. It’s also well known, particularly among scientists, that museum collections can provide unique insight into environmental changes through time and space.
With this in mind, our international team investigated Australian museum bird nest specimens collected between 1823 and 2018. Sourced from Museums Victoria and CSIRO’s Crace Site in Canberra, we inspected a total of 892 nests from 224 different bird species.
Australian birds generate an amazing array of nest types. Rufous fantails, for example, build delicately woven structures made of fine grass and spiderwebs, while welcome swallows and white-winged choughs create nests out of mud, which dry incredibly hard and can be used year after year.
Before the 1950s, human-made debris found in the nests consisted of degradable items such as cotton thread and paper.
This changed in 1956, when we found the first synthetic item in a bird nest from Melbourne: a piece of polyester string. This appearance correlates with the increased availability of plastic polymers across Australian society, seven years after the end of the second world war.
Australian magpies earn their name
We also determined, based on collection date and using historical maps, whether the nests came from natural, rural or urban landscapes. And it turns out the nest’s location, when it was built, and the species that made it largely determined whether human-made materials were present.
Our study found nests built close to urban areas or farmland after the 1950s by birds from the families Craticidae (Australian magpies and butcherbirds), Passeridae (old world or “true” sparrows) and Pycnonotidae (bulbuls) had significantly more human-made debris.
Familiar to many an urban bird enthusiast, these species tend to adapt quickly to new environments. The incorporation of human materials in nests is likely one example of this behavioural flexibility.
The research team also had access to ten bowerbird bowers from the family Ptilonorhynchidae, spanning more than 100 years. Male bowerbirds are known for creating elaborate structures, decorated with a range of colourful items to attract a mate.
In the 1890s, the birds decorated their bowers with natural items such as flowers and berries. Newspaper scraps were the only human-produced items we identified.
This changed dramatically 100 years later, where the most sought-after items included brightly coloured plastics, such as straws, pen lids and bottle caps.
But there are tragic consequences
When birds weave non-biodegradable materials — such as fishing line and polymer rope — into their nests, it increases the risk of entanglement, amputation and even accumulation of plastics in the gut of nestlings.
For example, we found evidence of one pallid cuckoo juvenile dying in 1981 after it was entangled in plastic twine used by its adoptive bell miner parents.
Plastic was not the only issue. We found the prevalence of nest parasites that attack the young chicks also increased by about 25% over the last 195 years.
Nest parasites can kill huge numbers of nestlings. Recent research into the forty-spotted pardalote in Tasmania, a threatened species, has shown nest parasites kill up to 81% of its nestlings.
What has caused this increase isn’t clear. However, the team determined it wasn’t directly linked to urban or rural habitat type, or the presence of human-made materials in the nest. This goes against the findings of other studies, which show a decrease of parasites in nests that incorporated items such as cigarettes.
Interestingly, we did find eucalyptus leaves might deter parasites, as nests that incorporated them were less likely to show evidence of parasitism.
It may be, therefore, that sticking with certain natural materials is not only better for the safety of nest inhabitants, but also may have an added effect of pest control.
Stop littering, please
While most are aware of how plastics harm sea life, our study is one of the first to show the impact goes further to harm animals living in our own backyard. If the trend continues, the future for Australian birds looks bleak.
However, we can all do something about it.
The team had access to nests from 224 different species, which equates to only about a quarter of Australia’s total of 830 bird species.
There is still plenty more to discover.
Kate Fraser, University of TasmaniaThis week, international ambassadors will take a snorkelling trip to the Great Barrier Reef as part of the Australian government’s efforts to stop the reef getting on the world heritage “in danger” list.
The World Heritage Centre of UNESCO is set to make its final decision on whether to officially brand the reef as “in danger” later this month.
But the implications of mass coral death are complex — just because coral is dying doesn’t mean marine life there will end. Instead, it will change.
In recent research, my colleagues and I discovered dead coral hosted 100 times more microscopic invertebrates than healthy coral. This means up to 100 times more fish food is available on reefs dominated by dead coral compared with live, healthy coral.
This is a near-invisible consequence of coral death, with dramatic implications for reef food webs.
When coral dies
Tiny, mobile invertebrates — between 0.125 and 4 millimetres in size — are ubiquitous inhabitants of the surfaces of all reef structures and are the main food source for approximately 70% of fish species on the Great Barrier Reef.
These invertebrates, most visible only under a microscope, are commonly known as “epifauna” and include species of crustaceans, molluscs, and polychaete worms.
When corals die, their skeletons are quickly overgrown by fine, thread-like “turfing algae”. Turf-covered coral skeletons then break down into beds of rubble.
We wanted to find out how the tiny epifaunal invertebrates — upon which many fish depend – might respond to the widespread replacement of live healthy coral with dead, turf-covered coral.
I took my SCUBA gear and a box of lab equipment, and dived into a series of reefs across eastern Australia, from the Solitary Islands in New South Wales to Lizard Island on the northern Great Barrier Reef.
Underwater, I carefully gathered into sandwich bags the tiny invertebrates living on various species of live coral and those living on dead, turf-covered coral.
But things really got interesting back in the laboratory under the microscope. I sorted each sandwich bag sample of epifauna into sizes, identified them as best I could (many, if not most, species remain unknown to science), and counted them.
I quickly noticed samples taken from live coral took just minutes to count, whereas samples from dead coral could take hours. There were exponentially more animals in the dead coral samples.
Why do they prefer dead coral?
Counting individual invertebrates is only so useful when considering their contribution to the food web. So we instead used the much more useful metric of “productivity”, which looks at how much weight (biomass) of organisms is produced daily for a given area of reef.
We found epifaunal productivity was far greater on dead, turf-covered coral. The main contributors were the tiniest epifauna — thousands of harpacticoid copepods (a type of crustacean) an eighth of a millimetre in size.
In contrast, coral crabs and glass shrimp contributed the most productivity to epifaunal communities on live coral. At one millimetre and larger, these animals are relative giants in the epifaunal world, with fewer than ten individuals in most live coral samples.
These striking differences may be explained by two things.
First: shelter. Live coral may look complex to the naked eye, but if you zoom in you’ll find turfing algae has more structural complexity that tiny epifauna can hide in, protecting them from predators.
A coral head is actually a community of individual coral polyps, each with a tiny mouth and fine tentacles to trap prey. To smaller epifauna, such as harpacticoid copepods, the surface of live coral is a wall of mouths and a very undesirable habitat.
Second: food. Many epifauna, regardless of size, are herbivores (plant-eaters) or detritivores (organic waste-eaters). Turfing algae is a brilliant trap for fine detritus and an excellent substrate for growing films of even smaller microscopic algae.
This means dead coral overgrown by turfing algae represents a smorgasbord of food options for the tiniest epifauna through to the largest.
Meanwhile, many larger epifauna like coral crabs have evolved to live exclusively on live coral, eating the mucus that covers the polyps or particles trapped by the polyps themselves.
What this means for life on the reef?
As corals reefs continue to decline, we can expect increased productivity at the base level of reef food webs, with a shift from larger crabs and shrimp to small harpacticoid copepods.
This will affect the flow of food and energy throughout reef food webs, markedly changing the structure of fish and other animal communities. The abundance of animals that eat invertebrates will likely boom with increased coral death.
Invertebrate-eating animals are food for a diversity of carnivores on a coral reef, and most fish Australians want to eat are carnivores, such as coral trout, snapper, and Spanish mackerel.
While we didn’t investigate exactly which species are likely to increase following widespread coral death, it’s safe to say populations of fish targeted by recreational and commercial fisheries on Australia’s coral reefs are likely to change as live coral is lost, some for better and some for worse.
The Great Barrier Reef is undoubtedly in danger, and it’s important that we make every effort to protect and conserve the remaining live, healthy coral. However, if corals continue to die, there will remain an abundance of life in their absence, albeit very different life from that to which we are accustomed.
As long as there is hard structure for algae to grow on, there will be epifauna. And where there is epifauna, there is food for fish, although perhaps not for all the fish we want to eat.
Michelle Lim, Macquarie UniversityIt’s no secret the world’s wildlife is in dire straits. New data shows a heatwave in the Pacific Northwest killed more than 1 billion sea creatures in June, while Australia’s devastating bushfires of 2019-2020 killed or displaced 3 billion animals. Indeed, 1 million species face extinction worldwide.
These numbers are overwhelming, but a serious global commitment can help reverse current tragic rates of biodiversity loss.
This week the UN’s Convention on Biological Diversity released a draft of its newest ten-year global plan. Often considered to be the Paris Agreement of biodiversity, the new plan aims to galvanise planetary scale action to achieve a world “living in harmony with nature” by 2050.
But if the plan goes ahead in its current form, it will fall short in safeguarding the wonder of our natural world. This is primarily because it doesn’t legally bind nations to it, risking the same mistakes made by the last ten-year plan, which didn’t stop biodiversity decline.
A lack of binding obligations
The Convention on Biological Diversity is a significant global agreement and almost all countries are parties to it. This includes Australia, which holds the unwanted record for the greatest number of mammal extinctions since European colonisation.
All other, otherwise sensible, provisions of the convention are limited by a series of get-out-of-jail clauses. Countries are only required to implement provisions “subject to national legislation” or “as far as possible and as appropriate”.
The convention has used non-binding targets since 2000 in its attempt to address global biodiversity loss. But this has not worked.
The ten-year term of the previous targets, the Aichi Targets, came to an end in 2020, and included halving habitat loss and preventing extinction. But these, alongside most other Aichi targets, were not met.
In the new draft targets, extinction is no longer specifically named — perhaps relegated to the too hard basket. Pollution appears again in the new targets, and now includes a specific mention of eliminating plastic pollution.
Is this really a Paris-style agreement?
I wish. Calling the plan a Paris-style agreement suggests it has legal weight, when it doesn’t.
The fundamental difference between the biodiversity plan and the Paris Agreement is that binding commitments are a key component of the Paris Agreement. This is because the Paris Agreement is the successor of the legally binding Kyoto Protocol.
The final Paris Agreement legally compels countries to state how much they will reduce their emissions by. Nations are then expected to commit to increasingly ambitious reductions every five years.
If they don’t fulfil these commitments, countries could be in breach of international law. This risks damage to countries’ reputation and international standing.
The door remains open for some form of binding commitment to emerge from the biodiversity convention. But negotiations to date have included almost no mention of this being a potential outcome.
So what else needs to change?
Alongside binding agreements, there are many other aspects of the convention’s plan that must change. Here are three:
First, we need truly transformative measures to tackle the underlying economic and social causes of biodiversity loss.
The plan’s first eight targets are directed at minimising the threats to biodiversity, such as the harvesting and trade of wild species, area-based conservation, climate change and pollution.
While this is important, the plan also needs to call out and tackle dominant worldviews which equate continuous economic growth with human well-being. The first eight targets cannot realistically be met unless we address the economic causes driving these threats: materialism, unsustainable production and over-consumption.
Second, the plan needs to put Indigenous peoples’ knowledge, science, governance, rights and voices front and centre.
An abundance of evidence shows lands managed by Indigenous and local communities have significantly better biodiversity outcomes. But biodiversity on Indigenous lands is decreasing and with it the knowledge for continued sustainable management of these ecosystems.
Indigenous peoples and local communities have “observer status” within the convention’s discussions, but references to Indigenous “knowledges” and “participation” in the draft plan don’t go much further than in the Aichi Targets.
Third, there must be cross-scale collaborations as global economic, social and environmental systems are connected like never before.
The unprecedented movement of people and goods and the exchange of money, information and resources means actions in one part of the globe can have significant biodiversity impacts in faraway lands. The draft framework does not sufficiently appreciate this.
For example, global demand for palm oil contributes to deforestation of orangutan habitat in Borneo. At the same time, consumer awareness and social media campaigns in countries far from palm plantations enable distant people to help make a positive difference.
The road to Kunming
The next round of preliminary negotiations of the draft framework will take place virtually from August 23 to September 3 2021. And it’s likely final in-person negotiations in Kunming, China will be postponed until 2022.
It’s not all bad news, there is still much to commend in the convention’s current draft plan.
For example, the plan facilitates connections with other global processes, such as the UN’s Sustainable Development Goals. It recognises the contributions of biodiversity to, for instance, nutrition and food security, echoing Sustainable Development Goal 2 of “zero hunger”.
But if non-binding targets didn’t work in the past, then why does the convention think this time will be any different?
A further set of unmet biodiversity goals and targets in 2030 is an unacceptable scenario. At the same time, there’s no point aiming at targets that merely maintain the status quo.
We can change the current path of mass extinction. This requires urgent, concerted and transformative action towards a thriving planet for people and nature.
Vigya Sharma, The University of QueenslandIndia is the world’s third largest emitter of greenhouse gases, and its transition to a low-carbon economy is crucial to meeting the goals of the Paris Agreement. But unfortunately, the nation is still clinging firmly to coal.
We found three main factors slowing the energy transition: strong political and community support for coal, a lack of alternative economic activities, and deep ties between coal and other industries such as rail.
India must step away from coal, while maintaining economic growth and not leaving millions of people in coal-mining regions worse off. Our research probes this wicked problem in detail and suggests ways forward.
Why India matters
India’s population will soon reach 1.4 billion and this decade it is expected to overtake China as the world’s most populous nation. This, combined with a young population, growing economy and rapid urbanisation, means energy consumption in India has doubled since 2000.
The International Energy Agency (IEA) estimates India will have the largest increase in energy demand of any country between now and 2040.
An affordable, reliable supply of energy is central to raising the nation’s living standards. A recent World Bank analysis found up to 150 million people in India are poor.
Alongside its massive reliance on coal, India has one of the world’s most ambitious renewable energy plans, including an aim to quadruple renewable electricity capacity by 2030.
The IEA says coal accounts for about 70% of India’s electricity generation. And as the nation rebounds from the coronavirus pandemic this year, the rise in coal-fired electricity production is expected to be three times that from cleaner sources.
Coal-powered generation is anticipated to grow annually by 4.6% to 2024, and coal is expected to remain a major emitter of greenhouse gases to 2040.
While India’s energy trajectory remains aligned with its commitments under the Paris Agreement, the speed and readiness of its transition remains a complex, divisive issue. The World Economic Forum’s 2021 Energy Transition Index ranks India 87th out of 115 countries analysed.
Bottlenecks in the transition
Our research involved visits to the Angul district in Odisha in 2018 and 2019, where we conducted focus groups and interviews. Angul is home to 11 coal mines.
We found three crucial bottlenecks to the energy transition, which arguably exist in India’s other coal belts and could derail the nation’s decarbonisation efforts.
First, the Odisha government has historically been very pro-business. Politicians across the spectrum support coal mining and seek to position it as the region’s primary economic lifeline.
The official pro-coal position receives little pushback from Angul residents, who are largely unaware of Odisha’s contribution to national greenhouse gas emissions. Any local opposition to coal usually stems from concern about environmental degradation such as air, water and land pollution.
Most of Angul’s residents felt a deep connection to coal because their livelihood depends on it. One participant told us:
even if all the water is polluted and five inches of dust settles on our well, we would prefer mining to continue as my family’s survival depends on (the contract with the mining company).
Most participants considered their farming land as an asset to be sold to the mining companies for a significant sum. The money would, in turn, allow them to start a business, buy a car or arrange a marriage in the family.
Second, the heavy reliance on coal means efforts to diversify the region’s economy have been grossly neglected.
In Angul, mining zones and coal-dedicated railway lines passing through paddy fields mean agricultural productivity has declined over time. Rural development agendas have been short-lived, often set within six months of an election deadline then changed or abandoned.
Skill-development programs in non-coal vocations have also been limited. This lack of viable alternatives implicitly generates local support for coal.
And third, a suite of industries in Odisha – such as steel, cement, fertiliser and bauxite – depend on cheap coal for power. This is reflected across India, where coal has deep ties with other industries in ways not seen elsewhere.
For example, in 2016 Indian Railways earned 44% of its freight revenue from transporting coal. Indian Railways is India’s largest employer and coal revenue helps keep passenger fares low. So in this way, a potential coal phaseout in India would have far-reaching effects.
The way forward
We offer these pathways to ensure a steady, just energy transition in India:
- India must help its coal regions diversify their economic activities
- bipartisan support for a coal-free India is needed. Transition champions such as Germany can show India’s leaders the way
- a national taskforce for energy transition should be established. It should include representatives from across industry and academia, as well as climate policymakers and grassroots organisations
- India’s coal regions are endowed with metals needed in the energy transition, including iron ore, bauxite and manganese. With improved regulatory standards, these offer economic alternatives to coal
- concerns about the coal phase-out from communities in coal regions should be addressed fairly and in a timely way.
The world’s emerging economies are responsible for two-thirds of global greenhouse gas emissions. The energy transition in India, if done well, could show the way for other developing nations.
But as new industrial sectors emerge and clean energy jobs grow, India must ensure those in coal-dependent regions are not left behind.
Emily Finch, Monash UniversityRoad tripping with a geologist is a little different. While you’re probably reading road signs and dodging roadkill, we’re reading road cuttings and deciphering the history of the area over the previous millions — or even billions — of years.
Geology has shaped the Australian landscape. In Victoria where I live, for example, the western plains are pockmarked by Australia’s youngest volcanoes, while the east of the state has been pushed up to form the mountains of the Great Dividing Range.
Along the southern margin of the state are fossilised braided rivers, relics of when Australia drifted away from Antarctica. Evidence of this event extends into Tasmania, where dolerite, a rock that signifies this rift, looms in enormous columns over Hobart from Mount Wellington.
This probably won’t surprise anyone who knows me, but I have rocks peppered around my house that I’ve collected on my travels. Every time I look at them, I not only think about how the rocks were formed, I’m also reminded of the trip when I collected them.
With international and even state borders set to remain closed for a while longer, this is the perfect time to take a great Australian road trip, become a rock detective, and build up your rock collection while you’re at it.
To help you get started, I’ve listed five rocks any great Australian rock collection should have.
1. Mantle xenoliths
The youngest rocks in Australia are those that erupted out of Australia’s youngest volcano in Mount Gambier, South Australia, 4,000 to 8,000 years ago. That volcano is the culmination of an enormous field of volcanoes that span central and western Victoria.
In western Victoria, the volcanoes were formed from magma that ascended from the Earth’s mantle — the layer between the Earth’s core and crust. While the magma was rising, it tore off chunks of the surrounding mantle rock and transported it to the surface. We can find these chunks of the mantle — or mantle xenoliths (xeno = foreign, lith = rock) — in cooled lava today in western Victoria.
At first, these rocks look like any other piece of black or brown basalt, but then you turn them over or crack them open and there’s a blob of bright green rock staring back at you. The mantle rock inside is comprised mainly of olivine, which is a green mineral, and some black/brown pyroxene.
Mantle xenoliths are a great place to start your rock collection because not only will they be your very own piece of Earth’s mantle, but you can find them yourself through a bit of fossicking around some of the volcanoes in western Victoria.
The Nullarbor Desert, South Australia and Western Australia
The Nullarbor is a desert plain region which straddles the border of South Australia and Western Australia.
The dry environment is ideal for preserving meteorites that fall to Earth, and the light colour of the limestone country rock and lack of vegetation means the black and brown meteorites are easier to see.
Even if you don’t have a great eye for spotting meteorites hiding in plain sight, you can do as the geologists do and use a magnet on a stick to help you. Most meteorites are iron-rich, so wandering around with a magnet hovering over the surface is a good way to pick them up.
Thousands of meteorites have been found in the Nullarbor, some up to 40,000 years old.
3. Metamorphic rocks
Broken Hill, New South Wales
You’ve probably heard of Broken Hill because of the large silver, lead and zinc mine there. But the geological conditions that created the ore deposit around 1.7 billion years ago also made some beautiful rocks.
A visit to Broken Hill’s Albert Kersten Mining and Minerals Museum will demonstrate the vast array of unusual minerals found in the region, some of them described for the first time at this locality.
If you’re seeking your own chunk of Broken Hill’s geological history, Round Hill is the place for you. Just a short way out of the town centre, you’ll find beautiful red garnets surrounded by patches of white minerals (quartz and feldspar).
These rocks started out as sand and mud, and record the history of being buried and heated to over 700℃ deep below the Earth’s surface. This process caused the rock to start melting and created the striking stripey, garnet-rich rocks we find there today.
4. Banded iron formation
Banded iron formation is a layered sedimentary rock mainly comprised of alternating bands of chert (a sedimentary rock made of quartz) that’s often red in colour and silver to black iron oxide. It is the main host of iron ore, and can be found in several regions in Western Australia.
Geologists believe they formed on a continental shelf, where thick continental crust extends out into the ocean and then drops away to oceanic crust.
Banded iron formation is exciting because it no longer forms on Earth today, meaning it records an ancient process that we no longer see happening.
It is thought to have formed in ancient oceans, which were starting to increase in oxygen content at the time. It records the chemical input of these oceans, as well as sediments from the continent and volcanoes on the ocean floor.
5. Dinosaur fossils
Central and western Queensland
Oh to have been in Queensland 100 million years ago! Judging by the fossils found in parts of the state, it would have been a cornucopia of dinosaur activity.
From an unlikely duo of dinosaurs in a 98-million-year-old billabong in Winton, to fossilised evidence of a dinosaur herd at Lark Quarry, Queensland is the place to go to peer back in time to the Mesozoic Era between 252 and 66 million years ago.
And if you’re really lucky, you might even have dinosaur bones on your property, like the huge, long-necked sauropod discovered just this year on a Queensland cattle farm.
When building your Australian rock collection, remember to check first if fossicking is allowed in the area. When you find an interesting rock, your state or territory geological survey might be able to help with identifying it.