Scientific American video about my research on lizard camouflage

Scientific American have produced a great video about my PhD research on lizard camouflage in Greece. I found that lizards are able to pick certain rock backgrounds to sit on that make them most camouflaged to a predatory bird’s eye. Intriguingly, this means that somehow they know the colour of their own backs and how well it will match a given rock – a puzzle I haven’t quite worked out yet. You can watch the video here.

 

40 Words For Emotions You’ve Felt, But Couldn’t Explain | Thought Catalog

Have you ever felt an emotion but had no word to describe it? Then consult this post by Brianna West on thoughtcatalog.com. It helpfully lists 40 words that will perfectly cure that lost-for-words, tip-of-the-tongue feeling.

So next time you have a hanker sore, you can relieve it with a bit of ambedo. I dare you to start using them in your everyday conversations and writings. It’s time for some liberosis, people. 

Underwater shipwrecks hold secrets to life as well as pots of gold

The tragic event of losing a ship at sea is one that has occurred far too often in history. The sad remnants of sea-ravaged ships lying forgotten underwater for hundreds of years not only tell us secrets about the disastrous events themselves but also hold valuable physical clues to past times we know little about, including actual treasure troves of gold and jewels. Not surprisingly then, shipwrecks have long intrigued painters, writers, scientists, filmmakers, historians and even professional treasure hunters alike.

We only need to think of the (arguably) hit film The Titanic, in which Kate Winslet and Leonardo DiCaprio are immortalised as tragic lovers on a ship bound for the bottom of the Atlantic. The poem The Wreck of the Hesperus by Henry W. Longfellow even inspired a song by The Beatles’ George Harrison, and is a term my mum uses to describe me when I’m looking particularly unkempt. So it seems that shipwrecks have had such an impact on us that they have even infiltrated the English language.

800px-The_Wreck,_by_Knud-Andreassen_Baade_c.1835
The Wreck by Knud-Andreasson Baade c.1835. Wikipedia Commons.

Shipwrecks also have remarkable stories to tell us about the past. With rapid advances in technology, we now have sophisticated remote-sensing and remotely operated diving equipment, allowing diving archeologists to find and reach much deeper underwater sites, meaning that no site is beyond the reach of our research into the past. We only have to think of the 2003 discovery of the shipwreck of The Santa Maria off the coast of Haiti – one of the ships now thought to have carried Christopher Columbus over the Atlantic to America – and the excavation of the 2,000 year-old Antikythera shipwreck to uncover ancient treasures including the world’s first known computer.

Now, scientists have uncovered other secrets related to the rich and deep ecosystems that shipwrecks support in the Gulf of Mexico. Here, over 2,000 shipwrecks languish on the bottom of the sea spanning over 500 years of maritime history from the time of the 16th century Spanish explorers to the American Civil War and through the World War II era. A team of scientists have dived down to discover exactly what kind of life these ships support and how it has been affected by a huge and devastating oil spill in this area (the Deepwater Horizon oil spill in 2010).

In the first ever study of its kind plunging into deep-sea shipwreck ecosystems, the team discovered that the presence of shipwrecks on the seafloor alters what kind of microorganisms are found there. They also revealed that the chemicals used to clean up the oil spill has changed this microbial community, even after four years, thus having knock-on effects on other animals that depend on them like crabs, fish and coral.

The team also found that the oil spill could degrade not only the surrounding ecosystems but also the ships themselves, as the oil seems to increase metal corrosion on the ships’  surfaces. The researchers plan to use innovative 3D-laser and sonar technology to produce high-resolution images of the vessels to document how the oil spill affects their future state of preservation.

What I found most exciting about this study is that it shows how investigating deep-sea shipwrecks can help us monitor the rich ecosystems they support, as well as helping to preserve the precious historic value of the ships themselves. It could also help scientists studying other aspects of the deep sea – a huge part of our planet that still remains mostly a mystery to us.

One thing I am sure about is that the enigma that lies beneath the surface of our oceans  – the secrets of its dark history and ecological treasures – will continue to intrigue and inspire us for a long time to come.

A video about the research can be found here and was presented at the 2016 Ocean Sciences Meeting in New Orleans, U.S.A. yesterday.

Co-authors of the study:

Jennifer Salerno: George Mason University, Fairfax, VA, USA;

Brenda Little, Jason Lee, Ricky Ray: Naval Research Laboratory, Stennis Space Center, MS, USA;

Leila Hamdan: George Mason University, Fairfax, VA, USA.

The Platypus – Did You Know?

In my new Did You Know blog series, learn 10 facts about one animal in 5 minutes. In the series, I’ll tell you stuff you didn’t already know (hopefully). Let me know how many surprised you!

Today I’m going to blow your mind about an ancient mammal: the duck-billed platypus.

Did You Know that platypuses…

1. …Are one of only five mammal species that lay eggs instead of giving birth to live young (Monotremes). The other four are species of echidna. The eggs develop internally for 28 days and are incubated externally for 10 days. The platypus genome has both reptilian and mammalian genes associated with egg fertilisation.

2. …Are one of very few venomous mammals. The male has a spur on the hind leg that can cause severe pain in humans.

3. …Is a recognisable and iconic symbol of Australia. It is endemic to eastern Australia, including Tasmania, and appears on the reverse side of the Australian 20-cent coin.

4. …Completely stunned European naturalists when it was first discovered in 1798. The specimen of a bizarre duck-billed, beaver-tailed, egg-laying mammal was first thought a hoax.

5. …Is the only type of mammal (except some dolphins) to use electroreception. Monotremes (platypuses and the four echidna species) can locate their crustacean prey by sensing the electric fields caused by their muscle movements. A sheet of electroreceptors is found on the bill. By shaking its head from side-to-side while swimming it can detect differences in signal strength to sense the direction of the electrical source.

800px-Platypus-sketch
The platypus (Ornithorhynchus anatinus) is one of the world’s most primitive mammals. John Gould print image: Wikipedia Commons.

6. …Closes its eyes, ears and nose when it hunts underwater. Solely relying on electroreception and sense of touch (mechanoreceptors) on the bill, prey are found by detecting both the electrical fields and mechanical pressure pulses they emit. The different arrival times of these two signals to the bill signify the distance to the prey.

7. …Have unusual eyes among mammals. Their poor vision is more similar to Pacific hagfish than to other tetrapods (vertebrates higher than fishes) and the eyes contain double cones involved in luminance (brightness) perception, which most mammals do not have. Although vision may have been important for hunting in distant ancestors, this may have been sacrificed for the electrosensory system that is better suited to an aquatic and nocturnal lifestyle.

8. …Have a unique swimming motion among mammals. Webbed feet propel them through the water, although only the front feet are used for power in an alternate rowing motion; the hind feet and tail are used for steering.

9. …Feed their young with milk released through pores in the skin. Although platypuses have mammary glands – one of the defining features of a mammal – they lack teats. Instead the blind, helpless and naked young drink milk that pools in grooves on the mother’s abdomen.

10. …Are descended from the extinct monotreme Steropodon.  The fossilised specimen is thought to be about 110 million years old, making it the oldest mammal fossil to be found in Australia. Another fossil relative, Monotrematum sudamericanum, can be placed in the supercontinent Gondwana (when Antarctica joined Australia and South America) up to about 167 million years ago.

Feel free to make suggestions about other animals you want to see featured in the series!

In the click of a camera button

In the millisecond it took to click the button of my camera, I caught this ethereal little egret taking off in a shower of water droplets and elegance. I love that a scene of beauty like this can be captured in the time it takes to blink. I love that the wings blur to show the flurry of motion in just one tiny point in time, yet the image is one of peace and stillness that will last forever. This is my image of time.

Kyoto heron_B&W.JPG
A little egret taking off from the Kamo river, Kyoto, Japan. Photo credit: Kate Marshall.

 

Great White Sharks – Did You Know?

In my new Did You Know blog series, learn 10 fun facts about one animal in 5 minutes. In the series, I’ll tell you stuff you didn’t already know (hopefully). Let me know how many surprised you!

Today I’m focusing on one deadly predator: the great white shark.

Did You Know that great white sharks…

1. …Have serrated teeth. When feeding, they shake their head from side to side so the teeth can tear off large hunks of flesh.

2. …Are known to attack and kill people. This may not come as much of a surprise, given Peter Benchley’s best-selling novel “Jaws” and the popular gory 1975 film adaptation by Steven Spielberg. Most shark attacks on humans appear to come from great whites. But despite its deadly reputation, shark researchers say out of all the prey great whites attack they rarely attack and kill humans.

3. …Have an extra sense organ. Ampullae of Lorenzini in sharks’ skin allow them to detect the electromagnetic field emitted by the movement of living animals. This has led to the development of electric-emitting deterrents to prevent attacks on people.

800px-White_shark.jpg
The great white shark (Carcharodon carcharias). Wikipedia Commons.

4. …Can change their core body temperature. Cooler blood in the arteries is heated up by warmer blood in the veins to heat core temperature, helping them to chase agile and fast prey like sea lions. Core temperature can also be reduced to conserve energy.

5. …Rely on their liver for long-distance migrations. Fat and oil stores in their livers help provide energy during long migrations through nutrient-poor waters.

6. …Are pretty huge. Females can reach a length of 16 feet (almost 5 metres). That’s two and a half Michael Jordans laid end-to-end. Some 20 ft monsters have been recorded.

 

508px-Great_white_shark_size_comparison.svg
Size comparison between a human and a typical great white. Wikipedia Commons.

7. …Have a massive bite force of 669 pounds per square inch (18,000 newtons) revealed by computer models. But, relative to other animals like polar bears, snapping turtles, and killer whales, this is actually rather wimpy. Perhaps this is because they can rely on their serrated teeth as predatory weapons, rather than just on the power of their jaws.

8. …Are one of few sharks known to use ‘spy-hopping’. This involves poking their head above the sea surface to look at other objects in the water, such as prey.

9. …Are highly opportunistic ambush predators likened to human serial killers. When hunting seals, great whites breach the water surface due to the momentum of their high speed pursuit (see the breathtaking slow-motion video of this happening in BBC Planet Earth).

10. …Can be killed and eaten by killer whales (orcas). When the two competing species meet, orcas have been known to suffocate sharks by pinning them upside-down to then eat their liver.

Feel free to make suggestions about other animals you want to see featured in the series!