̽��ֱ�� of Cambridge - ̽��ֱ�� of Cape Town

Birds and honey badgers could be cooperating to steal from bees in parts of Africa

jg533 — Thu, 29 Jun 2023 11:27:19 +0000

̽��ֱ��tale of two charismatic species cooperating for mutual benefit has captivated naturalists for centuries – but evidence has been patchy. Researchers have now carried out the first large-scale search for evidence.

Seawater could have provided phosphorous required for emerging life

cmm201 — Tue, 27 Sep 2022 13:40:56 +0000

Their results, published in the journal Nature Communications, show that seawater might be the missing source of phosphate, meaning that it could have been available on a large enough scale for life without requiring special environmental conditions.

“This could really change how we think about the environments in which life first originated,” said co-author Professor Nick Tosca from Cambridge's Department of Earth Sciences.

̽��ֱ��study, which was led by Matthew Brady, a PhD student from Cambridge's Department of Earth Sciences, shows that early seawater could have held one thousand to ten thousand times more phosphate than previously estimated — as long as the water contained a lot of iron.

Phosphate is an essential ingredient in creating life’s building blocks — forming a key component of DNA and RNA — but it is one of the least abundant elements in the cosmos in relation to its biological importance. When in its mineral form, phosphate is also relatively inaccessible — it can be hard to dissolve in water so that life can use it.

Scientists have long suspected that phosphorus became part of biology early on, but they have only recently begun to recognize the role of phosphate in directing the synthesis of molecules required by life on Earth. “Experiments show it makes amazing things happen – chemists can synthesize crucial biomolecules if there is a lot of phosphate in solution,” said Tosca.

But the exact environment needed to produce phosphate has been a topic of discussion. Some studies have suggested that when iron is abundant then phosphate should actually be even less accessible to life. This is, however, controversial because early Earth would have had an oxygen-poor atmosphere where iron would have been widespread.

To understand how life came to depend on phosphate, and the sort of environment that this element would have formed in, they carried out geochemical modelling to recreate early conditions on Earth.

“It’s exciting to see how simple experiments in a bottle can overturn our thinking about the conditions that were present on the early Earth,” said Brady.

In the lab, they made up seawater with the same chemistry thought to have existed in Earth’s early history. They also ran their experiments in an atmosphere starved of oxygen, just like on ancient Earth.

̽��ֱ��team’s results suggest that seawater itself could have been a major source of this essential element.

“This doesn’t necessarily mean that life on Earth started in seawater,” said Tosca, “It opens up a lot of possibilities for how seawater could have supplied phosphate to different environments— for instance, lakes, lagoons, or shorelines where sea spray could have carried the phosphate onto land.”

Previously scientists had come up with a range of ways of generating phosphate, some theories involving special environments such as acidic volcanic springs or alkaline lakes, and rare minerals found only in meteorites.

“We had a hunch that iron was key to phosphate solubility, but there just wasn’t enough data,” said Tosca. ̽��ֱ��idea for the team’s experiments came when they looked at waters that bathe sediments deposited in the modern Baltic Sea. “It is unusual because it's high in both phosphate and iron — we started to wonder what was so different about those particular waters.”

In their experiments, the researchers added different amounts of iron to a range of synthetic seawater samples and tested how much phosphorous it could hold before crystals formed and minerals separated from the liquid. They then built these data points into a model that could predict how much phosphate ancient seawater could hold.

̽��ֱ��Baltic Sea pore waters provided one set of modern samples they used to test their model. “We could reproduce that unusual water chemistry perfectly,” said Tosca. From there they went on to explore the chemistry of seawater before any biology was around.

̽��ֱ��results also have implications for scientists trying to understand the possibilities for life beyond Earth. “If iron helps put more phosphate in solution, then this could have relevance to early Mars,” said Tosca.

Evidence for water on ancient Mars is abundant, including old river beds and flood deposits, and we also know that there was a lot of iron at the surface and the atmosphere was at times oxygen-poor, said Tosca.

Their simulations of surface waters filtering through rocks on the Martian surface suggest that iron-rich water might have supplied phosphates in this environment too.

“It’s going to be fascinating to see how the community uses our results to explore new, alternative pathways for the evolution of life on our planet and beyond,” said Brady.

Reference:
Matthew P Brady et al. 'Marine phosphate availability and the chemical origins of life on Earth.' Nature Communications (2022). DOI: 10.1038/s41467-022-32815-x

̽��ֱ��problem of how phosphorus became a universal ingredient for life on Earth may have been solved by researchers from the ̽��ֱ�� of Cambridge and the ̽��ֱ�� of Cape Town, who have recreated primordial seawater containing the element in the lab.

This could really change how we think about the environments in which life first originated

Nick Tosca

NASA

Artist Concept of an Early Earth

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Licence type:

Public Domain

Scientists crack egg forging evolutionary puzzle

ta385 — Tue, 12 Apr 2022 06:00:00 +0000

A genetic study of Zambian cuckoo finches has solved one of nature’s biggest criminal cases, an egg forgery scandal two million years in the making. Its findings suggest that the victims of this fraud may now be gaining the upper hand.

Cheating birds mimic host nestlings to deceive foster parents

jg533 — Fri, 02 Oct 2020 13:23:30 +0000

Working in the savannahs of Zambia, a team of international researchers collected images, sounds and videos over four years to reveal a striking and highly specialised form of mimicry. They focused on a group of finches occurring across much of Africa called the indigobirds and whydahs, of the genus Vidua.

Like cuckoos, the 19 different species within this group of finches forego their parental duties and instead lay their eggs in the nests of other birds. Each species of indigobird and whydah chooses to lay its eggs in the nests of a particular species of grassfinch. Their hosts then incubate the foreign eggs, and feed the young alongside their own when they hatch.

Grassfinches are unusual in having brightly coloured and distinctively patterned nestlings, and nestlings of different grassfinch species have their own unique appearance, begging calls and begging movements. Vidua finches are extremely specialised parasites, with each species mostly exploiting a single host species.

Nestlings of these ‘brood-parasitic’ Vidua finches were found to mimic the appearance, sounds and movements of their grassfinch host’s chicks, right down to the same elaborately colourful patterns on the inside of their mouths. ̽��ֱ��study is published in the journal Evolution.

“ ̽��ֱ��mimicry is astounding in its intricacy and is highly species-specific,” said Dr Gabriel Jamie, lead author on the paper and a research scientist in the ̽��ֱ�� of Cambridge’s Department of Zoology, and at the FitzPatrick Institute of African Ornithology, ̽��ֱ�� of Cape Town.

He added: “We were able to test for mimicry using statistical models that approximate the vision of birds. Birds process colour and pattern differently to humans so it is important to analyse the mimicry from their perspective rather than just relying on human assessments.”

While the mimicry is very precise, the researchers did find some minor imperfections. These may exist due to insufficient time for more precise mimicry to evolve, or because current levels of mimicry are already good enough to fool the host parents. ̽��ֱ��researchers think that some imperfections might actually be enhanced versions of the hosts’ signal, forcing it to feed the parasite chick even more than it would its own.

̽��ֱ��mimetic adaptations to different hosts identified in the study may also be critical in the formation of new species, and in preventing species collapse through hybridisation.

“ ̽��ֱ��mimicry is not only amazing in its own right but may also have important implications for how new species of parasitic finches evolve,” added Professor Claire Spottiswoode, an author of the paper and a research scientist at both the ̽��ֱ�� of Cambridge and Cape Town.

Vidua nestlings imprint on their hosts, altering their mating and host preferences based on early life experiences. These preferences strongly influence the host environment in which their offspring grow up, and therefore the evolutionary selection pressures they experience from foster parents. When maintained over multiple generations, these selection pressures generate the astounding host-specific mimetic adaptations observed in the study.

Reference
Jamie, G. A, et al: ‘Multimodal mimicry of hosts in a radiation of parasitic finches.’ Evolution, July 2020. DOI:10.1111/evo.14057

̽��ֱ��common cuckoo is known for its deceitful nesting behaviour – by laying eggs in the nests of other bird species, it fools host parents into rearing cuckoo chicks alongside their own. While cuckoos mimic their host’s eggs, new research has revealed that a group of parasitic finch species in Africa have evolved to mimic their host’s chicks - and with astonishing accuracy.

̽��ֱ��mimicry is astounding in its intricacy and is highly species-specific.

Gabriel Jamie

Cheating birds mimic host nestlings to deceive foster parents

Yes

Cambridge attends U7+ Alliance global summit of Universities

plc32 — Fri, 12 Jul 2019 10:37:35 +0000

̽��ֱ��U7+ summit brought together 47 universities from G7 countries and beyond, who are committed to academic freedom and scholarly values and convinced of the key role of universities as global actors, to engage in discussions leading to concrete action to address pressing global challenges.

Professor Ferran was invited by U7+ Alliance organisers Sciences Po to be one of five ̽��ֱ�� presidents and representatives to carry conclusions from their discussion groups to a meeting with French President Emmanuel Macron, who sponsored the summit as part of his preparations for the G7 summit in Paris later this year.

"It was a great honour for Cambridge to be invited to summarise some very stimulating discussions on how universities can help to confront the global challenges facing us all for a leader with an important voice at the G7," Ferran said.

̽��ֱ��summit provided a unique opportunity to discuss a common agenda and establish a framework for action in today’s global landscape, resulting in a 2019 Presidential Declaration, which included a mission statement and the adoption of six agreed principles.

̽��ֱ��principles included commitments to pursue joint action through the U7+, recognition of the responsibility to train and nurture responsible and active citizens, to address environmental challenges, to combat polarisation in society, to promote interdisciplinary research, and to consolidate and share best practices worldwide.

"It was inspiring to hear from so many other ̽��ֱ�� leaders who share Cambridge's determination to tackle the great challenges that lie before us in the 21st century," Ferran said. "We can all clearly see that collaboration is vital if we are to mitigate threats to humanity such as climate change and to ensure that rapid technological change works for the benefit of society."

̽��ֱ�� of Cambridge Pro-Vice-Chancellor for International Relations Eilis Ferran attended the inaugural two-day Paris summit of the U7+ Alliance of universities from 18 countries across the globe this week.

It was inspiring to hear from so many other ̽��ֱ�� leaders who share Cambridge's determination to tackle the great challenges that lie before us in the 21st century

Pro-Vice-Chancellor Eilis Ferran

U7+ Alliance of world universities

Yes

How humans and wild birds collaborate to get precious resources of honey and wax

amb206 — Fri, 22 Jul 2016 08:17:43 +0000

Humans have trained a range of species to help them find food: examples are dogs, falcons and cormorants. These animals are domesticated or taught to cooperate by their owners. Human-animal collaboration in the wild is much rarer. But it has long been known that, in many parts of Africa, people and a species of wax-eating bird called the greater honeyguide work together to find wild bees’ nests which provide a valuable resource to them both.

Honeyguides give a special call to attract people’s attention, then fly from tree to tree to indicate the direction of a bees’ nest. We humans are useful collaborators to honeyguides because of our ability to subdue stinging bees with smoke and chop open their nest, providing wax for the honeyguide and honey for ourselves.

Experiments carried out in the Mozambican bush now show that this unique human-animal relationship has an extra dimension: not only do honeyguides use calls to solicit human partners, but humans use specialised calls to recruit birds’ assistance. Research in the Niassa National Reserve reveals that by using specialised calls to communicate and cooperate with each other, people and wild birds can significantly increase their chances of locating vital sources of calorie-laden food.

In a paper (Reciprocal signaling in honeyguide-human mutualism) published in Science today (22 July 2016), evolutionary biologist Dr Claire Spottiswoode ( ̽��ֱ�� of Cambridge and ̽��ֱ�� of Cape Town) and co-authors (conservationists Keith Begg and Dr Colleen Begg of the Niassa Carnivore Project) reveal that honeyguides are able to respond adaptively to specialised signals given by people seeking their collaboration, resulting in two-way communication between humans and wild birds.

This reciprocal relationship plays out in the wild and occurs without any conventional kind of ‘training’ or coercion. “What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years,” says Spottiswoode, a specialist in bird behavioural ecology in Africa.

“Thanks to the work in Kenya of Hussein Isack, who electrified me as an 11-year-old when I heard him speak in Cape Town, we’ve long known that people can increase their rate of finding bees’ nests by collaborating with honeyguides, sometimes following them for over a kilometre. Keith and Colleen Begg, who do wonderful conservation work in northern Mozambique, alerted me to the Yao people’s traditional practice of using a distinctive call which they believe helps them to recruit honeyguides. This was instantly intriguing – could these calls really be a mode of communication between humans and a wild animal?”

With the help of honey-hunters from the local Yao community, Spottiswoode carried out controlled experiments in Mozambique’s Niassa National Reserve to test whether the birds were able to distinguish the call from other human sounds, and so to respond to it appropriately. ̽��ֱ��‘honey-hunting call’ made by honey-hunters, and passed from generation to generation, is a loud trill followed by a short grunt: ‘brrr-hm’.

To discover whether honeyguides associate ‘brrr-hm’ with a specific meaning , Spottiswoode made recordings of this call and two kinds of ‘control’ sounds : arbitrary words called out by the honey-hunters and the calls of another bird species. When these sounds were played back in the wild during experimental honey-hunting trips, birds were much more likely respond to the ‘brrr-hm’ call made to attract them than they were to either of the other sounds.

“ ̽��ֱ��traditional ‘brrr-hm’ call increased the probability of being guided by a honeyguide from 33% to 66%, and the overall probability of being shown a bees’ nest from 16% to 54% compared to the control sounds. In other words, the ‘brrr-hm’ call more than tripled the chances of a successful interaction, yielding honey for the humans and wax for the bird,” says Spottiswoode.

“Intriguingly, people in other parts of Africa use very different sounds for the same purpose – for example, our colleague Brian Wood’s work has shown that Hadza honey-hunters in Tanzania make a melodious whistling sound to recruit honeyguides. We’d love to know whether honeyguides have learnt this language-like variation in human signals across Africa, allowing them to recognise good collaborators among the local people living alongside them.”

̽��ֱ��greater honeyguide is widely found in sub-Saharan Africa, where its unassuming brown plumage belies its complex interactions with other species. Its interactions with humans to obtain food are mutually beneficial, but to obtain care for its young it is a brutal exploiter of other birds.

“Like a cuckoo, it lays its eggs in the nests of other birds, and its chick hatches equipped with sharp hooks at the tips of its beak. Only a few days old, the young honeyguide uses these built-in weapons to kill its foster siblings as soon as they hatch,” says Spottiswoode. “So the greater honeyguide is a master of deception and exploitation as well as cooperation – a proper Jekyll and Hyde of the bird world.”

Human cooperation is crucial to honeyguides because bees’ nests are often hidden in inaccessible crevices high up in trees – and honeybees sting ferociously. Therefore the honeyguide waits while an expert human undertakes the dangerous tasks of subduing the bees (by smoking them out using a flaming bundle of twigs and leaves hoisted high into the tree) and extracting the honey from within, usually by felling the entire tree. There is no competition for the prize: the honey-hunters harvest the honey and honeyguides devour the wax combs left behind.

Co-author Dr Colleen Begg adds: “ ̽��ֱ��Niassa National Reserve is as much about people as it is about wildlife, and this is really exemplified by these human-honeyguide interactions that have been forged over thousands of years of coexistence. While many people consider wilderness not to have people in it, at Niassa people are an essential part of the landscape.”

This foraging partnership was recorded in print as early as 1588, when a Portuguese missionary in what is now Mozambique observed a small brown bird slipping into his church to nibble his wax candles. He described how this bird had another remarkable habit: it led men to bees’ nests by calling and flying from tree to tree. Once the nest was located, he wrote in his account of life on the eastern African coast in the 17^th century, Ethiopia Oriental, the men harvested the honey and the bird fed on the wax.

“What João dos Santos described was what we now call a mutualism between species. Mutualisms are crucial everywhere in nature, but to our knowledge, the only comparable foraging partnership between wild animals and our own species involves free-living dolphins who chase schools of mullet into fishermen’s nets and in so doing manage to catch more for themselves. It would be fascinating to know whether dolphins respond to special calls made by fishermen, as Pliny the Elder asserted nearly two thousand years ago,” says Spottiswoode.

“Back in Africa, we’re fascinated by the evolution of the honeyguide-human mutualism and, as a next step, we want to test whether young honeyguides learn to recognise local human signals, creating a mosaic of honeyguide cultural variation that reflects that of their human partners. Sadly, the mutualism has already vanished from many parts of Africa. ̽��ֱ��world is a richer place for wildernesses like Niassa where this astonishing example of human-animal cooperation still thrives.”

̽��ֱ��project was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) in the UK and the DST-NRF Centre of Excellence at the FitzPatrick Institute in South Africa.

For further information on this and other projects go to www.africancuckoos.com and www.niassalion.org

Inset images: Yao honey-hunter Orlando Yassene harvests honeycombs from a wild bees’ nest in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene holds a female greater honeyguide temporarily captured for research in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene chops open a bees’ nest in a felled tree in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene holds a wax comb (honeyguide food) from a wild bees’ nest harvested in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Claire Spottiswoode interviewing honey-hunter Issufo "Kambunga" Jaime (Mbumba Marufo).

By following honeyguides, a species of bird, people in Africa are able to locate bees’ nests to harvest honey. Research now reveals that humans use special calls to solicit the help of honeyguides and that honeyguides actively recruit appropriate human partners. This relationship is a rare example of cooperation between humans and free-living animals.

What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years.

Claire Spottiswoode

How honeyguide birds talk to people

Claire Spottiswoode

Yao honey-hunter Orlando Yassene holds a male greater honeyguide temporarily captured for research in the Niassa National Reserve, Mozambique.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Low-impact hub generates electrical current from pure plant power

lw355 — Fri, 06 Mar 2015 09:00:52 +0000

A prototype “green bus shelter” that could eventually generate enough electricity to light itself, has been built by a collaboration of ̽��ֱ�� of Cambridge researchers and eco-companies.

̽��ֱ��ongoing living experiment, hosted by the Cambridge ̽��ֱ�� Botanic Garden and open to the visiting public, is incorporated in a distinct wooden hub, designed by architects MCMM to resemble a structure like a bus shelter. Eight vertical green wall units – created by green wall specialists, Scotscape – are housed along with four semi-transparent solar panels and two flexible solar panels provided by Polysolar.

̽��ֱ��hub has specially adapted vertical green walls that harvest electrons naturally produced as a by-product of photosynthesis and metabolic activity, and convert them into electrical current. It is the brainchild of Professor Christopher Howe and Dr Paolo Bombelli of the Department of Biochemistry. Their previous experiments resulted in a device able to power a radio using the current generated by moss.

̽��ֱ��thin-film solar panels turn light into electricity by using mainly the blue and green radiation of the solar spectrum. Plants grow behind the solar glass, ‘sharing the light’ by utilising the red spectrum radiation needed for photosynthesis, while avoiding the scorching effect of UV light. ̽��ֱ��plants generate electrical currents as a consequence of photosynthesis and metabolic activity during the day and night.

“Ideally you can have the solar panels generating during the day, and the biological system at night. To address the world’s energy needs, we need a portfolio of many different technologies, and it’s even better if these technologies can operate in synergy,” said Bombelli.

̽��ֱ��structure of the hub allows different combinations of the photovoltaic and biological systems to be tested. On the north east aspect of the hub, plants receive light directly, without being exposed to too much direct sun. On the south west orientation, a green wall panel is housed behind a semi-transparent solar panel so that the effect on the plants and their ability to generate current can be monitored. Next to that, in the same orientation, a single solar panel stands alone, and two further panels are also mounted on the roof.

“ ̽��ֱ��combination of horticulture with renewable energy production constitutes a powerful solution to food and resource shortages on an increasingly populated planet,” explained Joanna Slota-Newson from Polysolar. “We build our semi-transparent solar panels into greenhouses, producing electrical energy from the sun which can in turn be used to power irrigation pumps or artificial lighting, while offering a controlled environment to improve agricultural yields. In this collaboration with Cambridge ̽��ֱ��, the public can experience the plants’ healthy growth behind Polysolar panels.”

̽��ֱ��green wall panels in the hub are made from a synthetic material containing pockets, each holding a litre of soil and several plants. ̽��ֱ��pockets are fitted with a lining of carbon fibre on the back, which acts as an anode to receive electrons from the metabolism of plants and bacteria in the soil, and a carbon/catalyst plate on the front which acts as a cathode.

When a plant photosynthesises, energy from the sun is used to convert carbon dioxide into organic compounds that the plant needs to grow. Some of the compounds – such as carbohydrates, proteins and lipids – are leached into the soil where they are broken down by bacteria, which in turn release by-products, including electrons, as part of the process.

Electrons have a negative charge so, when they are generated, protons (with a positive charge) are also created. When the anode and cathode are connected to each other by a wire acting as an external circuit, the negative charges migrate between those two electrodes. Simultaneously, the positive charges migrate from the anodic region to the cathode through a wet system, in this case the soil. ̽��ֱ��cathode contains a catalyst that enables the electrons, protons and atmospheric oxygen to recombine to form water, thus completing the circuit and permitting an electrical current to be generated in the external circuit.

̽��ֱ��P2P hub therefore generates electrical current from the combination of biological and physical elements. Each element of the hub is monitored separately, and members of the public can track the findings in real time, at a dedicated website and on a computer embedded in the hub itself.

Margherita Cesca, Senior Architect and Director of MCMM Architettura, the hub’s designer, is pleased that it has garnered so much interest. “This prototype is intended to inspire the imagination, and encourage people to consider what could be achieved with these pioneering technologies. ̽��ֱ��challenging design incorporates and showcases green wall and solar panels as well as glass, creating an interesting element which sits beautifully within Cambridge ̽��ֱ�� Botanic Garden,” she said.

Bombelli added: “ ̽��ֱ��long-term aim of the P2P solar hub research is to develop a range of self-powered sustainable buildings for multi-purpose use all over the world, from bus stops to refugee shelters.”

̽��ֱ��P2P project was supported by a Partnership Development Award grant from the ̽��ֱ��’s EPSRC Impact Acceleration Account.

P2P is an outreach activity developed under the umbrella of the BPV (BioPhotoVoltaic) project working in collaboration with green technology companies including MCMM, Polysolar and Scotscape. ̽��ֱ��BPV project includes scientists from the Departments of Biochemistry, Plant Sciences, Physics and Chemistry at the ̽��ֱ�� of Cambridge, together with the ̽��ֱ�� of Edinburgh, Imperial College London and the ̽��ֱ�� of Cape Town.

Green wall technology and semi-transparent solar panels have been combined to generate electrical current from a renewable source of energy both day and night.

This prototype is intended to inspire the imagination, and encourage people to consider what could be achieved with these pioneering technologies

Margherita Cesca, MCMM Architettura

̽��ֱ��text in this work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page. For image rights, please see the credits associated with each individual image.

Yes

Black hole trio holds promise for gravity wave hunt

jfp40 — Wed, 25 Jun 2014 17:05:48 +0000

An international team, including ̽��ֱ�� of Cambridge scientists, led by Dr Roger Deane from the ̽��ֱ�� of Cape Town, examined six systems thought to contain two supermassive black holes. ̽��ֱ��team found that one of these contained three supermassive black holes – the tightest trio of black holes detected at such a large distance – with two of them orbiting each other rather like binary stars. ̽��ֱ��finding suggests that these closely-packed supermassive black holes are far more common than previously thought.

A report of the research is published in this week’s Nature.

Dr Roger Deane from the ̽��ֱ�� of Cape Town said: ‘What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein’s Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth. Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe. It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometre Array (SKA).’

̽��ֱ��team used a technique called Very Long Baseline Interferometry (VLBI) to discover the inner two black holes of the triple system. This technique combines the signals from large radio antennas separated by up to 10,000 kilometres to see detail 50 times finer than that possible with the Hubble Space Telescope. ̽��ֱ��discovery was made with the European VLBI Network, an array of European, Chinese, Russian and South African antennas, as well as the 305 metre Arecibo Observatory in Puerto Rico. Future radio telescopes such as the SKA will be able to measure the gravitational waves from such black hole systems as their orbits decrease.

At this point, very little is actually known about black hole systems that are so close to one another that they emit detectable gravitational waves. According to Prof Matt Jarvis from the Universities of Oxford and the Western Cape, ‘This discovery not only suggests that close-pair black hole systems emitting at radio wavelengths are much more common than previously expected, but also predicts that radio telescopes such as MeerKAT and the African VLBI Network (AVN, a network of antennas across the continent) will directly assist in the detection and understanding of the gravitational wave signal. Further in the future the SKA will allow us to find and study these systems in exquisite detail, and really allow us gain a much better understanding of how black holes shape galaxies over the history of the Universe.’

Dr Keith Grainge of the ̽��ֱ�� of Manchester, an author of the paper, said: ‘This exciting discovery perfectly illustrates the power of the VLBI technique, whose exquisite sharpness of view allows us to see deep into the hearts of distant galaxies. ̽��ֱ��next generation radio observatory, the SKA, is being designed with VLBI capabilities very much in mind.’

While the VLBI technique was essential to discover the inner two black, the team has also shown that the binary black hole presence can be revealed by much larger scale features. ̽��ֱ��orbital motion of the black hole is imprinted onto its large jets, twisting them into a helical or corkscrew-like shape. So even though black holes may be so close together that our telescopes cannot tell them apart, their twisted jets may provide easy-to-find pointers to them, much like using a flare to mark your location at sea. Indeed, the high radio frequency Arcminute Microkelvin Imager (AMI) telescope at Cambridge, used in the paper, shows emission from this black-hole system that increases at high frequency, a phenomenon directly due to extremely compact jets yet with relativistic speeds. This may provide sensitive future telescopes like MeerKAT and the SKA a way to find binary black holes with much greater efficiency.

̽��ֱ��discovery of three closely orbiting supermassive black holes in a galaxy more than four billion light years away could help astronomers in the search for gravitational waves: the ‘ripples in spacetime’ predicted by Einstein.

This exciting discovery perfectly illustrates the power of the VLBI technique, whose exquisite sharpness of view allows us to see deep into the hearts of distant galaxies.

Dr Keith Grainge

Roger Deane (large image); NASA Goddard (inset bottom left; modified from original)

Helical jets from one supermassive black hole caused by a very closely orbiting companion (see blue dots). ̽��ֱ��third black hole is part of the system, but farther away and therefore emits relatively straight jets.

Yes