Category Archives: Earth Science

More trees than we thought on Earth

Agriculture, Biology, Earth Science

Do you know how many trees there are on Earth?

The previous estimate in 2008 was 400 billion, or 61 trees for every person.

Here, a new study used satellite imagery and tree counts on the ground to calculate there are 3 trillion trees on Earth.

This is 7 times the previous estimate and equates to 422 trees for every person.

The distribution around the world is determined by climate and human activity.

Highest tree density is in northern boreal and tundra forests (e.g. Scandinavia, North America), as well as tropical areas, which contain 43% of the planet’s trees.

But it’s not all good news.  15 billion trees are being cut down each year and we have lost nearly half of the World’s trees since farming began around 12,000 years ago.

 

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Background

Trees are essential components of many diverse ecosystems around the world.

They provide shelter, carbon sequestration, oxygen production, food, water quality control and protection against erosion, amongst other benefits.

However, their usefulness for construction timber and fires (cooking, warmth), as well as competition for farming land, means they have been cleared by humans for thousands of years.

Knowing how many trees there are in the world and where they are would help policy makers manage the world’s forests against competing pressures.

A previous estimate of 400 billion trees in 2008 was thrown into doubt when a later study found 390 billion trees in the Amazon basin alone.

So how many trees are there in the world?

Materials and Methods

This study used 429,775 ground-source measurements, as well as satellite imagery, of tree density from every continent on Earth (except Antarctica) to generate a global map of forest trees.  This provided a global tree density map at 1 km2 resolution.  Trees were defined as plants with woody stems larger than 10 cm in diameter at breast height.

Results

This study estimates there are 3.04 trillion trees in the world, equating to 422 trees for each of the 7.2 billion people on Earth.

This is 7 times the previous estimate of 400 billion trees (in 2008), and is also more than the number of stars in the Milky Way galaxy.

1.39 trillion trees (46%) are in tropical and subtropical regions, 0.74 trillion (24%) in boreal regions and 0.61 trillion (22%) in temperate regions.

Tree density generally increases with temperature, with moist, warm conditions optimal for tree growth.

A negative relationship between tree density and moisture availability was discovered.  It is most likely due to competition for productive land between forests and farming.

Current global forest clearing rates are estimated to be 15.3 billion trees or 192,000 km2 cleared each year, with the highest being in tropical regions.

Since the onset of human civilisation and farming (around 12,000), it is estimated that Earth’s tree numbers have fallen by 45.8%.

Discussion

It is hoped this survey of tree numbers will help policy makers manage the forests better, especially against powerful competing interests like agriculture and timber industries.

Article

Mapping tree density at a global scale

Crowther et al., 2015 Nature 525: 201-5

Keywords

Science, Earth, World, planet, biology, ecosystem, tree, forest, rainforest, plant, agriculture, timber, wood, tropical, boreal

Subject

ST1-8ES, ACSSU019, ST1-9ES, ACSSU032, ST1-11LW, ACSSU211, ST2-8ES, ACSSU075, ST2-11LW, ACSSU073, SC4-13ES, ACSSU116, SC5-13ES, ACSSU189

City spiders are fatter than country spiders

Biology, Earth Science

Did you know that golden orb spiders in cities are bigger and healthier than country spiders?

Researchers from the University of NSW compared city versus country spiders to determine the effect that urbanisation has on them.

Spiders from Sydney were larger and had better reproductive health than rural spiders.

In fact, the more densely populated the site, the bigger and healthier they were.

Wealthier suburbs have larger and healthier spiders, although it is not clear why (possibly associated with better park/garden management).

Big and healthy spiders are good for urban food chains/ecosystems because they control pest insects and are good food for birds.

This is an example of how human urbanisation of natural landscapes is good for some species (although it’s usually bad for most others).

 

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Background

Human overpopulation and urbanisation alters natural landscapes and ecosystems.

Many plant and animal species suffer, while others thrive.

What happens to the golden orb spider?

This species is relatively large, common in Australia and builds semi-permanent webs that they remain in for their whole life.

They have an important position in the food chain, since they control pest insects and are themselves food for many bird species.

Researchers from the University of NSW compared city versus country spiders to determine the effect that urbanisation has on them.

Materials and Methods

Golden orb spiders were collected from sites in Sydney and rural NSW (average 11 spiders per site, total of 222). Size was inferred from the length of the tibia (leg bone), while health was inferred from the ratio of weight to size (fatness). Reproductive health was inferred from the weight of ovaries (indicates bigger eggs and more of them). NOTE that ovaries were analysed in only 29 female spiders (small number), so conclusions on reproductive health should be taken with caution.

Results

Spiders from Sydney were larger and had better reproductive health than rural spiders.

The more densely populated the site, the bigger and healthier they were.

The spiders preferred concrete and metal environments over vegetation because of the ‘heat island effect’ (they heat up and increase the ambient temperature – the spiders prefer warm climates). Also, there is an abundance of insects in the city for them to eat, partly due to food waste from humans and artificial street lighting at nights.

Wealthier suburbs have larger and healthier spiders, although it is not clear why (possibly associated with better park/garden management).

Discussion

Big and healthy spiders are good for urban food chains/ecosystems because they control pest insects and are food for birds.

Article

Urbanisation at multiple scales is associated with larger size and higher fecundity of an orb-weaving spider

Lowe et al., 2014 PLoS One 9:e105480

Keywords

Food chain, food web, ecosystem, environment, urban, rural, Sydney, NSW, Australia, spider

Subject

Science, Biology, Zoology, ST1-10LW, ACSSU017, ACSSU030, ST1-11LW, ACSSU211, ST2-11LW, ACSSU073, ST3-11LW, ACSSU094, SC4-15LW, ACSSU112, SC5-14LW, ACSSU176

Life below a kilometre of Antarctic ice

Biology, Earth Science, Geology

Did you know life forms have been discovered in a lake nearly a kilometre below Antarctica?

American scientists drilled down to Lake Whillans to retrieve subglacial water samples and detected life forms using RNA sequencing.

Despite temperatures of -0.5°C, oxygen levels 1/7th of surface water and complete darkness, they detected ~4,000 species of bacteria.

They get their energy from chemicals such as iron (FeII) and sulphides.

This further supports the idea that life is extremely tough and can survive virtually anywhere on Earth.

Similar conditions are predicted in the liquid oceans below the ice crusts of Europa and Enceladus, the moons of Jupiter and Saturn, respectively. Therefore, it is possible that life could exist elsewhere in the solar system.

 

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Background

Life appears in many unlikely and inhospitable environments on Earth.

Could it possibly exist in the extremely harsh environment below a kilometre of ice in Antarctica?

There are ~400 lakes below ~55% of Antarctica.

Lake Whillans is 800m below the ice, ~12 x 7 km in size, but only ~2.2m deep.

Materials and Methods

A team of American scientists used a hot water drilling system to bore through 800m of ice to retrieve water samples from Lake Whillans.

They detected life forms in the water using gene sequencing (of small subunit ribosomal RNA).

Results

The water temperature was -0.5°C, pH 8.1, oxygen levels 1/7th of surface water and completely dark (no sunlight).

The source of the water was found to be melting glaciers (heated by geothermal heating and the friction of glaciers grinding over the bedrock), with only a very small amount of sea water.

Incredibly, the water contained ~4,000 species of bacteria (prokaryotes).

No eukaryotes (e.g. worms) were found, although it remains possible they are down there.

The bacteria get their energy from chemical sources. The crushing of rocks by the glaciers releases chemicals such as iron (FeII) and sulphides that react with oxygen in the water to provide the bacteria with energy.

The crushed rocks also release phosphorous, however another essential nutrient for life, nitrogen, is harder to come by. This is mostly supplied by a few species of nitrifying bacteria and recycling from dead bacteria.

Discussion

Bacteria are able to survive in the extremely harsh environment of Lake Whillans in Antarctica below nearly a kilometre of ice in freezing conditions without any sunlight.

Further supports the idea that life is extremely tough and can survive virtually anywhere on Earth.

Similar conditions are predicted in the liquid oceans below the ice crusts of Europa and Enceladus, the moons of Jupiter and Saturn, respectively. Therefore, it is possible that life could exist elsewhere in the solar system.

Article

A microbial ecosystem beneath the West Antarctic ice sheet

Christner et al., 2014 Nature 512:310-3

Keywords

Life, bacteria, prokaryote, eukaryote, survive, microbiology, Antarctica, ice, lake, Lake Whillans, RNA, ribosome, sequencing

Subject

Science, Biology, Earth Science, Geology, ST1-9ES, ST1-11LW, ACSSU211, ST2-8ES, ACSSU075, ST2-11LW, ACSSU073, ST3-11LW, ACSSU094, SC4-15LW, ACSSU112, SC5-14LW, ACSSU176

Rock snot invades the Earth

Earth Science

Did you know that many rivers in America, Europe, Asia and New Zealand have been invaded by ‘rock snot’ in the past 20 years?

It’s a type of algae that forms long white mucus-like strands that clog up rivers and are harmful to fish.

Scientists don’t know what has caused the recent explosion in rock snot.

It’s not new, since fossil records have shown it’s been around for at least 10,000 years.

Rather, the recent massive blooms are caused by low phosphorous levels in rivers. This is surprising, since algal growth is normally caused by excess phosphorous (e.g. from farm fertilisers).

More research is needed to understand how this algae grows and to identify best ways to control it.

 

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Background

Since the 1990s, many rivers in North America, South America, Europe, Asia and New Zealand have been invaded by ‘rock snot’.

‘Rock snot’ is produced by an algae called Didymosphenia geminata, or Didymo for short.

It is microscopic and normally quite rare.

But when it blooms, it grows stalks that are 5-8 cm long with white mucus-like blobs at the end. They clump together to form ‘rock snot’ that dominates a river.

It is not toxic to humans, but it can trap insects that fish like to eat, depriving them of food.

What has caused the recent explosion in rock snot around the world?

Materials and Methods

This study determined if Didymo is native or introduced (an invader) to these continents using fossil and historical data. They also identified nutrients in water that might cause the blooms.

Results

Didymo was detected in fossils at least 10,000 years old, so it is not a recent invader to these continents.

The blooms are caused by reduced phosphorous levels in the rivers.

It produces the long stalks in an attempt to trap more phosphorous from the water.

This is opposite to most other algae that thrive on higher than normal phosphorous levels due to overuse of fertilisers on farms. Some of these algae can be toxic to animals and humans.

Therefore, increasing phosphorous levels to reduce ‘rock snot’ levels is not advisable, since it will promote the growth of algal species.

More research is needed to understand how Didymo grows and to identify best ways to control it.

Article

The origin of invasive microorganisms matters for science, policy and management: The case of Didymosphenia geminata

Taylor and Bothwwell, 2014 BioScience 64:531-8

Keywords

Algae, river, plants, bloom, ecosystem, environment, fish, water, phosphorous, fossil, stalk, growth, microorganism, snot, mucus, lake, farm, fertiliser

Subject

Science, Biology, Botany, Environment, ST1-8ES, ACSSU019, SC4-13ES, ACSSU222, SC4-15LW, ACSSU112, SC5-13ES, ACSSU189

Where has the ocean plastic pollution gone?

Earth Science

Did you know that a huge amount of waste plastic in the ocean has gone missing?

The world produces 265 million tons of plastic each year.

Some of it ends up in the oceans and is harmful for marine life and the environment.

This paper found there is ~7,000-35,000 tons of ocean plastic waste.

This is actually far less than expected.

So where has most of it gone?

The answer is, we don’t know.

However, it is important to work out where it has gone to better protect the environment and animal species.

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Background

Plastic was introduced in the 1950s and is an amazingly useful material.

The world currently produces 265 million tons of plastic each year.

It is very durable and doesn’t easily degrade (lasts a long time).

Therefore, a lot of waste plastic accumulates as rubbish.

A proportion (0.1%) of plastic waste is washed via storm water drains out to sea, polluting the oceans where it is harmful to marine species.

The amount of ocean plastic pollution in the 1970s was ~45,000 tons/year (when total plastic production was a fifth of what it is now). Therefore, now predicted to be ~225,000 tons.

40 years later, has the amount of waste plastic increased or decreased?

Materials and Methods

The authors were passengers on cruise ships and dropped a net out the back of the boat at 141 sites around the world to collect samples of floating plastic waste.

Results

Most of the floating plastic waste was in the convergence zones of each of the 5 large subtropical gyres (where the big ocean currents meet).

The greatest amount was in the North Pacific Ocean, which corresponds with the high population densities of China, Asia and the USA West Coast.

The total amount of floating plastic in the world’s oceans is ~7,000-35,000 tons.

This is far less than expected/predicted from the 1970s (~225,000 tons).

There are many pieces of plastic ~2mm in size, but very few <1mm.

So where has the missing plastic gone?

Discussion

The answer is not yet known, although the 4 most likely explanations are:

1) Washed up on shore.

2) Broken up into smaller pieces (nano-fragmentation).

3) Biofouling (mixed with seawater or sea floor).

4) Eaten by animals (up to a third of fish contain plastic in their tummies).

The authors suggest it is probably a combination of these options. A contributing factor may also be human efforts to reduce the amount of plastic being washed into the oceans.

Article

Plastic debris in the open ocean

Cozar et al., 2014 Proc. Natl. Acad. Sci. USA 111:10239-44

Keywords

Environment, ecology, ecosystem, pollution, rubbish, waste, plastic, ocean, animal

Subject

Science, Environment, Earth Sciences, Chemistry, Materials, ST1-9ES, ACSSU032, SC4-13ES, ACSSU116, ACSSU222, SC5-13ES, ACSSU189, SC5-17CW, ACSSU187

Climate change causes war

Earth Science, Psychology

Did you know that climate change is likely to increase the chance of war? Even violence between individual people?

Scientists performed a meta-analysis (pooled data from 60 different studies) to show that dramatic changes in climate increased the frequency of wars and interpersonal violence throughout the last 12,000 years.

This occurred all over the world, in rich and poor communities.

According to this pattern, future global warming is predicted to increased the risk of war by >28%. Risk of interpersonal violence increases ~5%.

The major contributing factors are increased temperature and extreme rainfall.

There are probably multiple causes for climate’s effect on aggression, including competition for scare resources. People have gotta eat!

 

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Article

Quantifying the influence of climate on human conflict

Hsiang et al., 2013 Science 341:1212

Keywords

Climate, greenhouse, global, warming, environment, temperature, rain, rainfall, aggression, war, violence, human, population

Subject

Science, Earth and Space, psychology, ST1-9ES, ACSSU032, ST1-14BE, ST2-11LW, ACSSU073, SC4-13ES, ACSSU116, SC5-13ES, ACSSU189

Superfast enzyme captures greenhouse gas

Chemistry, Earth Science

Did you know an enzyme from a super-tough bacterium could dramatically reduce greenhouse gas emissions by coal and gas power stations?

Release of CO2 from coal and gas power stations is the largest human source of greenhouse gases.

Currently, the most viable form of CO2-capture from these power stations is amine solvents (scrubbing).

However, it is currently inefficient and not economically viable.

Here, scientists mutated an enzyme called carbonic anhydrase to withstand the high temperatures and pH of amine scrubber solvents.

Inclusion of the enzyme in the solvent improved CO2-capture 25-fold.

If successfully scaled up, it could significantly reduce greenhouse gas production by coal and gas power stations.

 

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Background

Release of CO2 from coal and gas power stations is the largest human source of greenhouse gases contributing to global warming.

It accumulates in the atmosphere and reduces heat being reflected from the Earth’s surface back out to space (i.e. retains heat like a blanket).

Over 9 billion tons of CO2 are released each year from global coal-fired power plants.

Australia is one of the largest coal exporters and also one of the largest producers of CO2 (per capita) in the world.

Currently, the most viable form of CO2-capture from flue gases at coal/gas-fired power stations is amine solvent (scrubbing).

The CO2 binds to amine molecules and is retained in the solvent.

However, this is currently inefficient and not economically viable.

An enzyme called carbonic anhydrase, present in almost all living organisms, converts CO2 to bicarbonate and water almost a million times per second. One of the fastest enzymes on the planet.

Inclusion of this enzyme could improve the efficiency of CO2-capture by the amine scrubber solvent, but the enzyme is unstable in this solvent.

Materials and Methods

Scientists in California obtained carbonic anhydrase from a bacterium and mutated it (changed its amino acids) to make it more stable at high temperatures and high pH.

Results

Scientists used carbonic anhydrase from a bacterium called Desulfovibrio vulgaris as a starting point. This was chosen because it has naturally high activity in the amine scrubber solution (high temp/pH).

They mutated its amino acids to improve its stability in the solvent.

In total, they tested over 27,000 mutant forms of carbonic anhydrase.

Eventually, they developed a form of the enzyme that could tolerate temperatures up to 107°C and pH>10.

It can also be re-used for several days/weeks.

When added to the scrubber solvent, it increased CO2-capture 25-fold.

Discussion

Inclusion of this new heat/pH-resistant form of carbonic anhydrase improves the CO2-capture rate of amine scrubber solvents 25-fold.

If successfully scaled up, it could significantly reduce greenhouse gas production by coal and gas power stations.

Article

Directed evolution of an ultrastable carbonic anhydrase for highly efficient carbon capture from flue gas

Alvizo et al., 2014 Proc. Nat. Acad. Sci. USA 111:16436-41

Keywords

Greenhouse, gas, climate, global, warming, coal, power, station, electricity, emissions, capture, carbon, dioxide, CO2, flue, temperature, pH, catalyst, enzyme, reaction, solvent, molecule, amine, mutation

Subject

Science, chemistry, ST1-8ES, ACSSU019, ST1-9ES, ACSSU032, SC4-13ES, ACSSU116, SC4-17CW, ACSSU113, ACSSU225, SC5-13ES, ACSSU189, SC5-15LW, ACSSU184, SC5-17CW, ACSSU187

Correlation between belief in gods and poorer habitats

Earth Science, Psychology

Did you know that communities that believe in gods are more likely to live in harsh environments?

Religion has played a major role in human history (and still does).

Here, computer and mathematical modelling was used to investigate a potential relationship between belief in gods and various ecological and social factors.

It found that communities that believe in gods are more likely to live in harsh habitats (e.g. poor agriculture, scare resources, natural disasters).

It is suggested that belief in gods might improve a community’s ability to cope with environmental challenges.

 

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Background

Anthropology is the scientific study of humans, past and present.

It combines many types of disciplines, including life sciences, social sciences, archaeology, geography, history and others (interdisciplinary).

Religion has played a major role in human history (and still does).

Here, the authors compared the potential relationship between a community’s local environment/habitat and their belief in a moralising high god (defined as a supernatural being that created reality and governs human affairs).

Materials and Methods

The authors used computer and mathematical modelling to analyse global distribution of 583 human societies and their relationship to local environment/habitat, practice of agriculture, belief in god, political complexity and recognition of movable property (i.e. buying and selling).

Results

This study found that communities that believe in gods tend to live in harsh habitats (e.g. poor agriculture, scare resources, natural disasters).

Discussion

The authors suggest that belief in moralising high gods might improve a community’s ability to cope with environmental pressures (e.g. droughts, cyclones, etc).

This might have been especially important and influential prior to modern times, before science began to provide alternative explanations and solutions to environmental events.

Article

The ecology of religious beliefs

Botero et al., 2014 Proc. Nat. Acad. Sci. USA 111:16784-9

Keywords

Anthropology, human, society, community, population, history, environment, ecology, habitat, agriculture, farming, religion, god

Subject

Science, Earth sciences, ST1-9ES, ACSSU032, ST1-11LW, ACSSU211, ST1-14BE, ST2-11LW, ACSSU073, ST3-9ES, ACSSU096, ST3-14BE, SC4-15LW, ACSSU112, SC5-13ES, ACSSU189

Low oxygen delayed emergence of animals on Earth

Biology, Earth Science, Geology

Bacteria took ~1 billion years to emerge on Earth, but why did it take another ~3 billion years for animals to appear?

Scientists analysed isotopes of Chromium in rocks as a measure O2 levels in the atmosphere of the early Earth.

Reduced-Cr(III) indicates low O2 levels, oxidised-Cr(IV) indicates high O2 levels.

Atmospheric O2 levels dramatically increased ~700-800 million years ago, just before the emergence of animals in the Cambrian explosion.

The rise in O2 levels (and decrease in CO2) was mostly caused by photosynthesis in cyanobacteria (and later algae).

This was a crucial factor for helping animal life emerge on Earth.

 

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Background

The Earth is ~4.54 billion years old.

The first life forms were bacteria, then cyanobacteria (photosynthesising microorganisms), emerging around ~3-3.6 billion years ago.

Multi-cellular animals (metazoans) took much longer to appear, sometime around ~540 million years ago. This period is called the Cambrian explosion (lasting ~25 million years), when many new animal species emerged (e.g. sponges, molluscs, crustaceans, worms).

If unicellular life took ~1 billion years to emerge, why did it take another ~3 billion years for animals to appear?

Materials and Methods

A team of scientists (including Peter McGoldrick from the University of Tasmania) measured oxygen levels in the early Earth’s atmosphere by analysing isotopes of Chromium found in rocks of different ages from Australia, China and North America. High levels of reduced Cr(III) indicate low atmospheric oxygen levels, while higher levels of oxidised Cr(IV) indicates high atmospheric oxygen levels.

Results

Early Earth atmosphere had very low O2 levels (high CO2 levels).

Atmospheric O2 levels dramatically increased ~700-800 million years ago, just before the emergence of animals in the Cambrian explosion.

Discussion

The rise in atmospheric O2 levels was a crucial factor for helping animal life emerge on Earth.

The rise in O2 levels (and decrease in CO2) was mostly caused by photosynthesis in cyanobacteria (and algae).

Genetic and developmental innovations almost certainly contributed to emergence of animals as well.

Article

Low mid-proterozoic atmospheric oxygen levels and the delayed rise of animals

Planavsky et al., 2014 Science 346:635-8

Keywords

Life, Earth, bacteria, cyanobacteria, photosynthesis, oxygen, O2, CO2, carbon dioxide, atmosphere, Cambrian, animal, chromium, isotope, reduced, oxidised, rocks

Subject

Science, chemistry, ST1-11LW, ACSSU211, ST2-10LW, ACSSU044, ST3-11LW, ACSSU094, SC4-12ES, ACSSU153, ACSSU115, SC4-14LW, ACSSU111, ACSSU149, ACSSU150, SC5-13ES, ACSSU189, SC5-14LW, ACSSU175, SC5-15LW, ACSSU185, SC5-17CW, ACSSU178, ACSSU179

Dung beetles have stars in their eyes

Astronomy, Biology, Earth Science

Did you know that dung beetles use the stars as a satnav?

Many dung beetles are nocturnal and roll their balls of dung around at night.

They use the moon for direction.

However, when the moon isn’t out (around half of the nights in a month), how do they know where to go?

This paper put dung beetles inside a planetarium in South Africa and showed them the moon, individual stars and the milky way to see which they used for direction on moon-less nights.

They found that the beetles can use the white band of the milky way to orientate themselves.

This is the first example of any animal using the milky way for orientation.

 

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Background

Many animals use the night sky for orientation/direction at night, especially the moon.

Only birds, seals and humans are known to use stars.

Dung beetles lay eggs in large balls of dung, roll it to a suitable position and bury it. The dung feeds their offspring when they hatch.

Many dung beetles are nocturnal, and they are known to use the moon for direction.

They have relatively primitive compound eyes that can detect the moon, but not individual stars.

So when the moon is not in the sky (~half of all nights), how do they orientate themselves on the other nights?

Materials and Methods

The authors went to South Africa to study the dung beetles.

They recorded the movements and direction of the dung beetles rolling their dung balls using cameras.

They measured the distance and direction of travel when the beetles had a transparent v cardboard helmet on (only the latter blocked) out the night sky.

To distinguish between the effect of the moon and stars, they took the beetles and their dung balls to the Johannesburg planetarium and exposed them to the full night sky, moon, stars, etc.

Results

When the dung beetles couldn’t see the night sky due to the cardboard helmet blocking their vision, their direction was impaired, indicating they used the night sky for orientation.

At the planetarium, it was discovered that beetles could use the moon or the band/streak of the milky way for orientation, although they couldn’t use individual stars.

Discussion

On nights when there is no moon, the dung beetles can use the longitudinal white band of the milky way to orientate themselves while they are rolling around their dung balls.

Their primitive compound eyes don’t allow them to distinguish individual stars, but instead they use the longitudinal white band of the milky way to orientate themselves.

These are the first insects shown to use stars for orientation, and the first use of the milky way for the whole animal kingdom.

Article

Dung beetles us the milky way for orientation

Dacke et al., 2013 Current Biology 23:298-300.

Keywords

Insect, beetle, direction, orientation, environment, moon, stars, milky way, night, sky, dung, planetarium, South Africa, compound, eye

Subject

Science, biology, ST1-8ES, ACSSU019, ST2-11LW, ACSSU073, ST3-11LW, ACSSU094, SC4-15LW, ACSSU112, SC5-14LW, ACSSU176