Great Barrier Reef Under Threat

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The Great Barrier Reef off the coast of Queensland, Australia, is under threat due to global warming-induced rises in sea surface temperatures. Photo source: NASA (public domain)

Two-thirds of the Great Barrier Reef is now under threat due to global warming-induced rising sea surface temperatures, a recent new aerial survey has found.

Sadly, mass bleaching events have occurred twice in quick succession – once in 2016 and now again this year – which means that the largest coral reef system on Earth might not have a chance to recover. This is particularly concerning given that even fast-growing corals can take up to 10 years to recover from bleaching, especially as bleaching can make coral more vulnerable to disease.

The survey, conducted by scientists at the Australian Research Council’s Centre of Excellence for Coral Reef Studies, found that only the southern part of the UNESCO World Heritage Site has been unaffected so far. All other regions off the coast of Queensland are experiencing an alarmingly high frequency of bleaching events.

While it is still unclear how much of the reef will be affected, it is estimated that the death toll will extend about 500 kilometres (about 300 miles) south of last year’s bleaching event. That’s bigger than the width of Switzerland.

Combating sea surface warming is clearly a pertinent problem that we need to solve if we are to save one of the most impressive and important natural phenomena on Earth. Hopefully, as word currently spreads through news outlets and on social media, the world can unite to come up with an effective and lasting solution.

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The Wonders of Planet Earth Captured on Camera

Last night I watched the latest episode in the BBC’s second series of Planet Earth (aptly named Planet Earth II). Coming ten years after the first series, it uses the latest technologies to capture breath-taking, never before seen footage in ultra-high definition (4K UHD). The animals featured in it appear so real you could almost reach out and touch them. The programme is set to awe and inspire you more than ever, as it did me.

You would think that it would be difficult to top the racer snake vs. marine iguana stand-off and komodo dragon wars in the first episode. But the second episode, while maybe not so dramatic, was just as stunning. Showcasing life in the planet’s mountains, I actually held my breath for several moments during scenes featuring the snow leopard, Panthera uncia. As the programme’s narrator, Sir David Attenborough, points out, these animals are extremely rare. In their lonely habitats of the vast mountain peaks of the Himalayas in Central and Southern Asia, there are estimated to be only about 2,500 individuals reproducing in the wild.

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The snow leopard, Panthera uncia, is listed as Endangered by the IUCN.

So it was with extreme awe that I was able to watch these rare leopards on my television last night. Not only had the programme captured these magnificent big cats on camera – using the latest remote-sensing video cameras – but they had filmed it close-up performing several behaviours that we have never been able to see before.

Like other leopard species, these cats rarely come into contact with one another, instead living a lonely life padding around their large territories communicating remotely with various rituals. For the first time, we were able to witness these communication rituals: a female leopard wiping her cheek pads and spraying urine on particular rocks to mark her presence, and roaring on a snowy peak, the grating calls echoing eerily among those vast lonely mountains.

Given the rarity of these beautiful creatures and their lonesome habits, it is amazing that we were able to see not just one leopard, but four, at one time. The scenes that followed were more exhilarating than you could imagine. My heart was in my mouth. The female leopard, with her almost-grown cub in tow, was in heat. Her scent and roars had attracted two huge males that threatened to kill her cub. She mated with both of them after some ferocious fights. The cub managed to get away and, despite an injury to the mother, they were both seen again a month later. The cub had finally been weaned and was making her own plea for survival among those harsh snowy peaks.

You might think that that this would be the one stand-out highlight of the episode, but still, the wild golden eagles (Aquila chrysaetos) fighting over the carcass of a fox was another remarkable feature (it also reminded me of one of my previous posts).

Accompanying footage of a ‘bird’s eye view’ of a golden eagle in flight – actually the footage from a tandem-paragliding cameraman  – may have caused some controversy, but in my opinion, it only added to the drama and was testament to the extraordinary efforts of the show’s producers to entertain and delight us.

The Leafy Sea Dragon – Did You Know?

In my Did You Know series, learn some fun facts about an animal in 5 minutes. I’ll tell you stuff you didn’t already know (hopefully). Let me know if I surprised you!

Today I’ll tantalise your curiosity taste buds with a master of masquerade: the leafy sea dragon.

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The leafy seadragon or Glauert’s seadragon, Phycodurus eques. Photo credit: James Rosindell

Did You Know?

  • It is a species of fish named after the dragons described in Chinese mythology and folklore (and more recently in George R. R Martin’s Game of Thrones)
  • It is the only member of the Phycodurus genus in the Syngnathidae family of fishes.
  • Its resemblance to a piece of drifting seaweed may help to protect it from predators. Its seaweed-like appearance not only allows it to match the background of seaweed and kelp it lives amongst (making it very hard for predators to spot), but it may also serve as a type of camouflage called ‘masquerade’. This is when an animal tricks its predator into thinking it’s an inedible object that isn’t dinner, similarly to that seen in leaf and stick insects. If you’re interested, you can read more about masquerade here and here.
  • Another aspect of this ‘floating seaweed’ trick seems to be the sea dragon’s sedate movement through the water. It moves at a slow rate of about 150m per hour propelled by fins along the side of its head but often stays in the same place for long periods of time.

 

 

  • Unusually in the animal kingdom, the male is the sole responsible parent. The female deposits 150-250 bright pink eggs onto the male’s tail, and then leaves him to it. He carries them in a honeycomb-like structure called the brood patch for 8 weeks where they are supplied with oxygen until the young emerge (like its relatives: seahorses, pipefish and other sea dragons). Only about 5% of the eggs survive and the young are completely independent at birth.
  • It feeds exclusively on small crustaceans like mysid shrimp.
  • Their natural habitat is calm, cold water (10-12 degrees Celsius) in the southern coasts of Australia, where they are known locally as ‘leafies’.
  • It is classified as Near Threatened by the IUCN Red List 2006, and may even be reclassified as Endangered, mainly due to habitat loss and pollution through human activity.
  • It has been protected by the Australian government since 1982 and is the marine emblem for the state of South Australia.

Thanks for reading and look out for other posts in my Did You Know? series!

Choosing the best of the nests makes sage grouse good mothers

Recent research published in  The Condor: Ornithological Applications has shown that greater sage grouse mothers (Centrocercus urophasianus) can choose nesting habitats that better ensure the survival of their chicks after they fledge.

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Female greater sage-grouse (Centrocercus urophasianus) [front of image] can select nesting habitats that ensure their offspring survive. Photo credit: Jeannie Stafford/USFWS.
Evolution not only drives animals to act to benefit their own survival (direct fitness) but also that of their own offspring (indirect fitness). Maximising such lifetime reproductive success is probably what drives us to protect our own children.

But can animals actually make active decisions that benefit their reproductive success? This is the question that Dr Daniel Gibson and his colleagues set out to answer in their study of the greater sage grouse.

These birds are the largest grouse in North America, inhabiting open grassland habitats that make them particularly vulnerable to predators. The species is classified as Near Threatened by the IUCN Red List. They have a complex mating system, whereby males gather in groups (leks) to perform lively, colourful mating displays to attract females [see picture]. This means that females get to be extremely picky about who they mate with.

Dr Gibson and his team found that females are not only choosy about their sexual partners but also are picky about where they nest. They tend to choose nesting habitats with characteristics that ensure reproductive success: specifically, greater shrub cover and forb (flowering plant) diversity. By observing over 200 mothers over a period of 8 years, they found that these habitat features predicted the survival of chicks after fledging.

This means that even our feathery friends can make active choices that determine the survival of their offspring, which is pretty impressive. What isn’t so clear is whether the mothers themselves were more likely to survive – were they also acting to protect themselves as they sat helpless on their nests? Or is their behaviour purely selfless?

Whatever the answer, it is likely that many other animals are able to protect their young by making these real-time decisions – what can be termed ‘behavioural plasticity’ – something that evolution is likely to promote in order to maximise indirect fitness and pass on genes to future generations.

Knowing this will also help conservation efforts because land managers now have clues about where these birds are most likely to nest, and hence which habitats they should protect the most.

 

 

The language of wolves and dogs is probably more complex than you thought

If like me you tend to struggle with speaking a foreign language, then you’ve probably also experienced that ‘lost in translation’ feeling. During my PhD research studying Aegean wall lizards in Greece I learned various Greek phrases to get by, but the language baffled me all the same. Yes, I’ve said it many times before – it’s all Greek to me.

The origins of human language, and how it has diverged into a massive 6,500 different languages around the world, is an intriguing and complex question that remains largely unsolved, attracting a long history of debate and potential explanations, such as its importance in developing tools.

But we can also gain a lot of insight by studying the early evolution of vocal communication in other animals, particularly in those that are socially and behaviourally similar to us.

Animals in the Canidae family – wolves, domestic dogs, jackals and coyotes – are extremely sociable like us, often hunting and living in large packs and ranging over wide distances. Howling vocalisations help them to communicate over these great distances and are thought to play a role in important social interactions like maintaining group cohesion as well as in territorial advertising. Previous experiments using playbacks have shown that wolves better recognise the “voice” of familiar than unfamiliar individuals, (even if elements of their howls are artificially changed) and howling between individuals depends on how well the two get along.

New research published this week in Behavioural Processes has revealed that canids use different types of howls that are specific to their own species, and even subspecies, revealing new insights about the diversity and specialisation of their vocal communication.

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The grey wolf (Canis lupus) and other canids use howling to communicate over long distances. Wikipedia Commons.

The study, led by Dr Arik Kershenbaum at the University of Cambridge, is the largest of its kind so far. Initially, the researchers diligently gathered 6,000 recordings from captive and wild howling canids from all over the globe, ranging from India to Australia, to Europe and the United States. This included downloading recordings of domestic dog howls from YouTube. Maybe this beauty was part of the sample?

The 6,000 recordings were whittled down to 2,000 from a total of 13 species and subspecies of canids for the final study.  These were fed into a machine learning computer algorithm, which eventually classified them into 21 discrete (distinguishable) types.

I particularly like this computer algorithm method because it avoids previously used human-based classification of howls. In particular, this new computer analysis is more likely to identify subtle similarities and differences between the vocalisations that human assessments could miss.

The study found that the vocalisations were usually very distinct among the 13 different species/subspecies, revealing typical vocal dialects or “vocal signatures” for each group.

But, some bore quite striking similarities, the consequences of which could be drastic. Specifically, similar vocalisations between different species could lead to interbreeding and the resulting hybrids could decrease genetic diversity, outcompete indigenous pure species, and even cause sterility. In one case, it could even threaten the survival of one species – the red wolf (Canis rufus).

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The critically endangered red wolf (Canis rufus). Success of reintroductions in the U.S. has been threatened by hybridisation with coyotes. The similar vocalisations of coyotes and red wolves may be one reason why hybridisation frequently occurs. Wikipedia Commons.

Red wolves, which had been hunted almost to extinction in the U.S. by the middle of the 20th century, have been reintroduced into the wild but their success has been threatened by hybridisation with coyotes. This may be in part because the two species were found to use very similar vocalisations: modulated, whining howls. The researchers suggest that these new insights into howling behaviour could help keep the red wolf and coyote populations apart and so prevent the red wolf from disappearing altogether.

I think the next step is to develop ways of measuring how these vocal signals are transmitted to the actual ear of intended, natural receivers – that is, conspecifics – in natural environments, and their ensuing behavioural responses to them. This way we can understand how the howls have evolved to become tuned to effectively transmit to the ear of conspecifics in a given environment, as well as what type of information they are actually communicating.

For now, though, we are getting closer to realising the sheer complexity and specialisation of vocal communication in animals, which can have important consequences on species conservation.

Perhaps this type of research can also tell us something about how our own language skills and diverse dialects have arisen.  We know that primitive humans started talking to each other at some point between 50,000 to 100,000 years ago, after which complex language quickly developed, with languages being universally connected by syntax.

 

 

Penguin Jumpers

Here’s a throwback post to celebrate the wonderful lengths us humans go to in order to protect our planet’s wildlife. I love penguins and I love the fact that thousands of volunteers have kindly knitted jumpers* to help oiled penguins recover. Aren’t they just the best? It makes me want to take up knitting.

*Brit word for sweaters. My dear Australian friend assures me it’s odd but adorable.

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Volunteers have hand-knitted thousands of woolly jumpers to help with the rehabilitation of oiled little penguins (Eudyptula minor).

When little penguins (Eudyptula minor) are unlucky enough to get oiled during an illegal fuel dump/accidental oil spill, the Penguin Foundation wildlife clinic at St Philip Island Nature Parks, near Melbourne, Australia, leap to the rescue. Since 1998, they have been using woolly jumpers to help oil-affected little penguins recover, and in 2012 recruited thousands of volunteers to donate hand-knitted woolly jumpers in the “Knits for Nature” programme. Although the programme is now closed (they’ve got enough jumpers for now, thanks), the clinic have a huge stockpile of jumpers in case another oil spill occurs.

Oil spills have historically affected the waters surrounding St Philip Island and the little penguins that live there. Oil can threaten the lives of penguins and other birds. It makes them heavy and, because the matted oil prevents their feathers from performing their natural thermoregulatory function, they become very cold very quickly. So, oiled birds have problems hunting successfully and can quickly die of starvation and exposure.

The theory is that the jumpers help oiled birds recover because, as soon as they are rescued, the garments to stop them preening and thus ingesting the poisonous oil. The jumpers are made of 100% wool to keep the birds warm while allowing air to circulate so they don’t overheat. It also absorbs some of the oil (so jumpers aren’t re-used). The jumpers have allowed 96% of all rescued little penguins on St Philip Island to be released back into the wild.

However, there has been some concern that the jumpers may be more of a hindrance than a help.

Even if the jumpers don’t have any direct practical benefit, they are surely better than nothing. Especially as the charity has been improving the jumper design for almost 20 years to minimise any risk they impose on the birds, like flippers/beaks getting caught in the wool or damage to feathers. And jumpers that were sent in by helpful volunteers that weren’t quite the right size or material can also benefit the birds. In September 2015, an Ebay store was launched where you could buy these jumpers from the exclusive “Pinguini” collection, with the proceeds going to the Penguin Foundation.

Thank you, kind humans. Give yourselves a massive pat on the back. You are wonderful. Keep up the good work. Perhaps you could also knit us an alternative, renewable energy source to replace oil? Just an idea.

Fox vs. Eagle

Think of the last time you saw two different animal species meet. Perhaps it was the classic stand-off: dog chasing cat down road, cat scratching dog on nose.

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Stand off between cat (Felis catus) and dog (Canis familiaris). Wikipedia Commons.

Whatever your experiences, I bet you’ve never seen this one before. And if you have, I’ll eat my hat.

New video footage from the currently airing BBC 2 Winterwatch in the remote, mountainous Trossachs National Park in Scotland has captured a fascinating, rarely-seen interaction between a red fox (Vulpes vulpes) and a golden eagle (Aquila chrysaetos). The interaction could have been due to the harsh, snowy conditions with both animals hungry and vying over a tasty treat: a carcass to scavenge.

Given the golden eagle’s hunting prowess, including its large size and razor-sharp talons, (and the fact that they are known to attack and kill foxes; see e.g. Kazakhs hunting with eagles), you might think that the outcome of the interaction would be an obvious one, but you might be surprised…

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A golden eagle (Aquila chrysaetos). A very large bird, its wingspan can be longer than Michael Jordan is tall, ranging from 5 ft 11 inches to 7 ft 8 inches. It builds its nests on cliff edges.

What a brave fox! Perhaps this was a particularly hungry or aggressive individual. Or maybe the eagle was young and inexperienced, or not so hungry as to risk the wrath of the fox. Whatever the reason, it is amazing to see. This footage is made all the more impressive given that there are only about 400 breeding pairs of golden eagles in Scotland, all living in highly remote, mountainous areas. So, to catch one on camera, let alone record one fighting with a red fox, is sensational.

These beautiful eagles have no natural predators but have been historically persecuted by humans, either by shooting or poisoning, due to the perception that they take game and lambs. They have been extinct in England and Wales since 1850, except for one breeding pair near Haweswater in the Lake District, which is now under threat. The remaining small numbers in Scotland have only recently started to make a comeback, particularly in the Western Isles, although for unknown reasons they have failed to re-colonise apparently suitable areas. They are still under threat from illegal persecution and low food availability and are afforded the highest degree of protection under the Wildlife and Countryside Act 1981.

Serious kudos to the fox, though. I don’t think I’d take on a golden eagle over lunch, even if it were lobster thermidor.