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Why Are Marsupials Found Only In Australia?

Take a look at global animal distribution and you’ll notice how each country in the world has a specific type or species of animal, that isn’t found anywhere else.

One such group of animals is the Marsupials – animals that possess a pouch which they use to raise their young in. Some of the best examples of Marsupials are kangaroos, koalas, possums and wombats.

When we think about marsupials, we always associate them with the Land Down Under. Why is it that marsupials are found only in Australia?

Okay, let’s take a moment to set the record straight. Marsupials aren’t found only in Australia. They are also found in South America, Central America and certain parts of North America & Southern Canada. The best example of an American marsupial is the Opossum

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An opossum

Scientists believe that the first marsupials were actually born in South America and they crossed Antarctica to finally land on and inhabit Australia. This was 180 million years ago, when Australia, Antarctica and South America were a single super-continent called Gondwana. A common marsupial ancestor born in South America branched into two distinct species, with one residing in the Americas and the other migrating to Australia. Today, over 200 species of marsupials are found in Australia, 100 in South America and 13 in Central America – all descendants of the single American ancestor. 

Gondwana
A representative image of the ancient super-continent of Gondwana (image source)

So, the question we should be asking now is – “Why are a majority of the animals that are found in Australia, marsupial?” Or, a better question would be, “Why are so many marsupials still alive in Australia, when most of their American counterparts are extinct?” What makes Australia such a fertile ground for the birth (& survival) of so many marsupial species?. 

The answer can be two-pronged. One line of thinking states that the geography of the country-continent is the reason for a high percentage of marsupials in Australia.

Australia has been a landmass that has remained largely separate from other continents for millions of years. This meant, it was subject to weather and soil conditions that was completely different from what was found on other continents. In turn, this affected the type of plants that grew on the continent, which changed the diet of the Australian marsupials significantly from their American counterparts. The researchers who support this theory believe that the diet offered by Australia was more conducive to the development of the marsupial species as a whole, compared to the diet elsewhere.

The second theory is that, since Australia was largely and for a very long time secluded and protected from the invasion of foreign species, the marsupials of yore didn’t have much competition to face for shelter, food and water. Additionally, the predominantly marsupial population ensured the birth of more marsupials and over time, the continent was soon overrun by marsupials. 

On the other hand, the Americas blossomed with many distinct species of animals, leading to intense competition for resources and as a result, the extinction of many marsupial species. We need to remember here that marsupial babies are born underdeveloped due to the lack of a placenta. They need additional time compared to their placental or egg-born cousins to grow into strong & mature creatures. With so many threats lurking around and such few resources to be shared by thousands of animals, it was just a matter of time before the genetically-weaker marsupial species in the Americas went extinct. 

Placenta vs marsupial
A short list of placental mammals and marsupials commonly found in the wild (image source)

The future of Australia’s marsupials

So, what’s next for our pouched friends?

Species around the world are experiencing the brunt of habitat loss and governments are implementing conservation projects to keep them safe. In Australia, the kangaroo is given protected status – with criminals found injuring or killing them, getting a one-way ticket to prison. But not all marsupials have been afforded this luxury, making conservation a challenging endeavour.

Additionally, some species like the antechinus, are going extinct for another (never-anticipated) reason – their suicidal mating tendencies – and have stumped scientists. Experts are now scrambling to save these almost-extinct species, but it may already be too late. 

In terms of whether we’ll see any new marsupial species being discovered anytime soon; only time will tell. For now, the focus is on preserving the population that is present in the Land Down Under.

 

-NISHA PRAKASH 

P.S: Featured image: Pixabay
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5 Fun Facts About Dugongs

Dugongs are marine animals which belong to the family Dugongidae. They are part of the order called Sirenia aka sea cows, which also includes the manatees. They can be found dispersed across the Indian ocean, Pacific ocean and the region between East Africa & Australia. 

Here are five facts about them: 

  1. Apart from manatees, dugongs are the only marine animals that are strictly herbivorous, eating sea grass, weeds and aquatic plants. All other marine animals are omnivorous. 
  2. The closest relative of dugongs is the Steller’s Sea Cow, which was driven to extinction in the mid-1700s.
  3. A dugong’s gestation period lasts one year and females give birth once every 3-7 years. 
  4. Although they resemble seals and walruses in appearance, dugongs are actually more genetically similar to elephants. That’s because these animals evolved from the same ancestor. 
  5. According to the IUCN Red List, dugongs have a “Vulnerable” classification; meaning they are very vulnerable to becoming extinct if conservation efforts aren’t set in place. As of today, less than 7500 dugongs are alive in the world.  

 

Bonus

The name “dugong” comes from the Malay word “duyung“, which means “Lady of the Sea“. Before scientists officially documented this species, sailors & fishermen out at sea assumed dugongs (and their cousins, the manatees) to be mermaids, sirens and other mystical creatures. This was predominantly because of the way these animals swam.

Dugongs and manatees rise out from the underneath the water and perform tail-stands (where they stand & balance on the tip of their tails) when coming up for air. This prompted sailors & fishermen to assume they were the mythical sea-dwelling creatures they grew up hearing about. 

 

 

Steller's Sea Cow
A representative image of a Steller’s Sea Cow – the extinct relative of the dugong (image source)

 

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Some more facts about dugongs (image source: pinterest)

 

Video: Now let’s see a dugong in action

 

 

-NISHA PRAKASH 

P.S: Featured image: National Geographic; Dugong vs Manatee: Indigoscuba
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5 Fun Facts About Africa’s Great Migration

You may have seen it on television – it’s an event that National Geographic has always loved to film. A grand spectacle and a treat for the senses, the Great Migration in Africa is the annual movement of the world’s largest (non-human) land animal group from one part of Africa to the other, in search of food and safer breeding grounds*.

Wildebeests, antelope, zebra and big cats congregate for five months of rigorous walking, eating, birthing and killing. Here are 5 amazing facts about it:

  1. The Great Migration starts in Tanzania at the Serengeti and Ngorongoro Conservation areas and ends at the Maasai Mara National Reserve in Kenya. The migration starts in the month of November and the animals reach their destination in March.
  2. A recorded 1.5 million wildebeest, 200,000 zebra and thousands of antelope make the migration each year. The animals travel a staggering 2900 kilometres (1800 miles) in total, from Tanzania to Kenya and back during this journey.
  3. The Great Migration follows one of the most dangerous routes in Africa. Animals making the journey have to deal with hungry predators (lions, cheetahs & crocodiles), treacherous floods, the uncaring African sun, mean-spirited tsetse flies and physical tiredness. More than 250,000 wildebeests and thousands of zebras and antelopes die each year on the journey. This is excluding the thousands of calves who are left orphaned and vulnerable to predators after their mothers die. A recorded 3000 lions follow the herds on their journey, picking off the weak and the injured.
  4. More than a foraging mission, the Great Migration is a breeding expedition. Pregnant wildebeests move from Tanzania to Kenya for better environmental conditions for calving. An estimated half a million baby wildebeests are born annually during the migration. In the peak of the calving season (February), more than 8000 wildebeest calves are born in a single day!
  5. Although they look like they’re confused and panicked all the time, the massive herds of wildebeests, zebras and antelopes actually function together as one cohesive unit. They display a tactic researchers call “swarm intelligence”, where they carefully analyse, strategise and implement a  plan of action to get safely past any threat together. There’s no “I” in this family.

 

Bonus

There is still no established and accepted explanation for the occurrence of the Great Migration.

Some scientists believe the changing chemistry of the grass could be the reason for the movement. When levels of phosphorous and nitrogen in the Serengeti grassland reduces, the wildebeests may be encouraged to move elsewhere for more nutritious meals, acting as the catalyst for the Great Migration. Others believe that the migration may be the result of a co-ordinated effort helmed by a leader. But so far there has been no evidence of there ever being an alpha-wildebeest in any herd. Then there are those scientists who believe that the Great Migration is the consequence of instinct and DNA – a purely biological process that has no other reason.

Well, whatever the rationale, fossil records show that the Great Migration has been in occurrence in East Africa for over one million years.

 

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The Great Migration – Route Map (image source)

 

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A sea of wildebeests, zebras and antelopes greet the eyes during the Great Migration. Often, these herds extend all the way to the horizon; but they don’t stop there. They go on & on. (image source)

 

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Wildebeests crossing the Mara river – this is where they are most vulnerable to attack from crocodiles. (image source)

 

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A wildebeest mother with her newborn calf. (image source)

 

Video: Watch the culmination of the Great Migration – wildebeest giving birth & a newborn’s first, wobbly steps. 

 

-NISHA PRAKASH

P.S: Featured image
*Humans take the crown for the farthest migrations in search of food and shelter. 
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Deceptive Sizing: 3 Newborn Animals Who Are Ridiculously Smaller Than Their Parents

Ah baby animals…these bundles of joy have been lighting up the wild for millennia. While everyone has been raving about their cuteness, not a lot of people have spoken about their size. Let’s face it, when it comes to size, some animals are impressive…impressively small. 

Here are 3 animals whose babies are way smaller than you thought they would be: 

 

Kangaroos

Kangaroo adults can reach heights of 5.25 feet (1.6 meters) and can weigh 90 kilograms (200lbs). But their newborn joeys are smaller than gummy bears, often smaller than 25 millimeters. 

 

 

Watch the incredible journey this little joey makes to reach the safety of its mother’s pouch:

 

 

Pandas

At their heaviest, adult pandas can weigh 160 kilograms (350 lbs). But their tiny cubs weigh only 1/900th of their mother’s weight! Now that’s really tiny. 

 

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A panda mom with her newborn cub

See that little pink floppy thing on the left side? yup, that little nugget is the cub.

Here’s a fun question; what do you call a group of pandas? An embarrassment! Ha ha, all jokes aside, a group of pandas is called “an embarrassment” because of the boisterous way in which panda cubs play when they’re together. It could embarrass any mum. 

Now indulge in some cub time by watching twin panda cubs embark on their first 100 days of life. 

 

 

Elephants

One of the most intelligent animals on the planet, elephants have longest gestation period in the wild. It takes their bodies 22 months to fully develop the calf (imagine being pregnant for almost two years!). But surprisingly, baby elephants when born are only 90 kilograms (200 lbs), while their heavy-weight mothers, aunts and sisters (and not to forget, their brothers and fathers) can reach ridiculously high weights of 3600 kilograms (4 tonnes)! 

 

 

Watch as this newborn calf, just hours old, meets his herd-mates, learns how slopes are not a baby’s friend and discovers the forest he is to grow up in. 

 

 

 

-NISHA PRAKASH 

 

 

 

 

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5 Fun Facts About Crabs

Crabs are crustaceans, marine animals which have a thick exoskeleton made of a chemical called chitin (which is chemically derived from glucose). Crabs belong to the class Malacostraca, which means “soft shelled animal” and to the order Decapoda, which mostly includes marine crustaceans (like lobster, shrimp and prawn) that scavenge for food, as opposed to hunting them. This makes crabs soft-shelled scavengers.

Here are five fun facts about them: 

  1. There are two types of crabs in the world – true crabs and false crabs – classified so because of their differing physiology. True crabs have the traditional body structure of a crab – a short and shallow abdomen curled underneath the shell and 4 pairs of legs excluding the pincers. False crabs on the other hand, look a little like crabs, but not completely. They have longer abdomens and less than 4 pairs of legs. True crabs include spider crab, blue crab and ghost crab. False crabs include king crab, hermit crab and porcelain crab. There are a total of 5000 crabs in the world – 4500 true crabs and 500 false crabs. 
  2. The largest crab in the world is the Japanese Spider Crab, which measures 13 feet or almost 4 meters from one end of the body to another. In comparison are the Coral Gall crab, Pea crab, Marsh Fiddler crab and Flattop crab – all of which measure in at a teeny-tiny half an inch at adulthood. If you kept 4.5 standard sized mail boxes one-on-top-of-the-other on one side and a small pea on the other side…well, that’s how the size difference would look between these crabs.  
  3. A small species of crab called Lybia or boxer crab, carry stinging anemones in their pincers anywhere they go. Why?  Lybia are very small in size and they don’t have venom to protect themselves from predators. They use the anemones in a mutually-beneficial partnership where the anemone acts as their defensive, venom-filled gloves. If an animal were to attack the Lybia, the anemone would sting the predator, protecting the crab. In return, the crab takes the anemone to different water bodies, allowing it to feed-off various sources and gaining valuable nutrients not found in its native environment. 
  4. If a crab loses its limbs in a fight, it can grow them back in a matter of months. This is a feature that is also found in starfish and lizards. 
  5. Crabs walk sideways because their legs are positioned to the sides of their body and their joints bend outwards and sideways. The reason for this type of evolution traces back to the crabs’ feeding behaviour. As sand-digging scavengers, crabs never needed to move forwards or move fast. This meant they didn’t need forward bending legs (which are one of the reasons animals can walk or run fast) and could make-do with sideways legs and sideways walking. However, not all crabs walk sideways. Frog crabs and spider crabs belong to the handful of crab species that walk forwards. 

 

 

Bonus

There is a type of parasitic barnacle called the Sacculina, which injects itself into the crab’s body, takes control of the crab’s will and makes it do its bidding. Crabs infected by Sacculina can’t control their own body mechanisms and are forced to become walking, breathing incubators of Sacculina eggs. Read this highly-informative article to learn all about the relationship between the Sacculina and its crab host. 

Here’s what a crab infected by Sacculina look like: 

 

 

Video: Coconut tree crabs are the only type of crabs that can climb trees. Watch this monster of a crab climb a tree, bend coke bottle caps and more. 

 

 

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A Lybia with anemone in its pincers (image source)

 

 

 

 

-NISHA PRAKASH 

P.S: Featured image – The Sally Lightfoot crab from the Galapagos Islands. Sacculina – Mental Floss & Wikipedia.

 

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5 Fun Facts About Possums

Posssums are marsupials (pouched mammals) that are found in North America. They are the only marsupial species found outside Australia and New Guinea. They belong to the order Didelphimorphia, to which belong 95 species of possums. 

 

Here are 5 fun facts about them: 

  1. Possums are renowned for their ability to “play dead”. In reality, possums don’t actually “play” dead. Their paralysis and almost-dead like state is an involuntary physiological reaction where their nerves and muscles literally freeze and stop working for hours due to stress. This in-built defense mechanism has allowed the possum to survive from pre-historic times. 
  2. Lyme disease is a tick-bite induced disease that results in terribly itchy and inflamed rashes, joint pain and fatigue. Possums in your backyard is a great defense against Lyme disease. It’s been found that possums prey on over 5000 of the ticks and fleas that spread the bacterium Borrelia burgdorferi, which causes Lyme disease. 
  3. Apart from the venom of the Coral Rattlesnake, possums are immune to all other snake venom. That’s why they regularly prey on snakes in the wild. A few years ago researchers created an anti-venom using possum peptides (short chain amino acids linked by peptide bonds), which they injected into mice. They then injected snake venom into the mice only to find the venom absolutely useless. 
  4. Rabies virus require very hot temperatures to develop and spread. But possums have very low body temperatures compared to other mammals and this makes them invulnerable to rabies. You can almost never find a possum with rabies. 
  5. Primates aren’t the only species to be gifted with opposable thumbs. Possums have opposable thumbs called “halux” on their feet and they use them to climb atop the steepest trees and into the deepest sewers in search of food. 

 

Bonus

Contrary to popular belief, possums and opposums aren’t the same animal. They also don’t belong to the same species. For one, possums belong to the Didelphimorphia order in North America, while opossums belong to the order Phalangeridae in Australia. Both animals look similar, but behave completely differently. It was because of this similarity in physical features that led scientists to confuse the opposum for a possum. 

 

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Possums are excellent climbers and use their tails as rudders and as a fifth limb to improve their dexterity. (image source)

 

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A possum with her young (image source- pixabay)

 

-NISHA PRAKASH

 

P.S: Featured image – Wikipedia 
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5 Fun Facts About Dung Beetles

Dung Beetles are members of the order Coleoptera, which include insects that have hardened wing cases and not papery wings like other insects. As members of coleoptera, they belong to the super-order Endopterygota, which constitutes insects whose bodies undergo a drastic transformation from how they are in the larval stage to how they are in the adult stage. Other insects that share their super-order are bees, butterflies, flies and ants. 

Here are 5 fun facts about dung beetles: 

  1. We all know that dung beetles love to eat poop. But research shows that dung beetles have a blatant preference for herbivore poop, given the high nutritional value it has from the undigested plant matter. Carnivore and omnivore droppings which contain much less nutrition than what beetles require, are only consumed occasionally.
  2. Did you know that dung beetles have been around from the past 30 million years? Fossil records in South America show prehistoric dung balls, similar to the dung balls today’s dung beetles make, around sites where herbivorous dinosaurs were found. Looks like someone was a good samaritan, keeping dino poop off the streets. 
  3. Although the quintessential image of a dung beetle is that of a beetle pushing around a ball of poop, most dung beetles actually don’t indulge in this behavior. Many dung beetles either live within piles of animal poop or burrow holes into the ground below the poop, as these help the beetles gain quick access to the poop when they’re hungry. Dung beetles only roll their dung when they need to carry food to their nests, which may be far away from the pile of fresh poop. 
  4. One type of dung beetle from Africa, the Scarabaeus satyrus, uses the Milky Way Galaxy to navigate and travel. When this beetle needs to transport its ball of poop, it waits for it to get dark, gets on top of the poop ball, looks towards the sky, finds the milky way and uses the stars to make its way home. If anything blocks their view of the stars (like scientists did when they placed tiny hats on these dung beetles to check their navigation reflexes when blind), these beetles will wander aimlessly like lost puppies. Talk about requiring celestial guidance.  
  5. If you thought a tiny hat didn’t complete its trousseau, don’t worry. There’s more to come. To test whether dung beetle poop-ball-rolling efficiency was affected by the heat of the midday sun, scientists put selected dung beetles in tiny silicon booties. They noticed that the beetles wearing the booties took lesser breaks and were faster in their walk & poop-rolling. 

Bonus

With all this talk of poop-rolling, don’t you want to know what weight a dung beetle can pull during each poop-rolling session? A dung beetle can pull as high as 1,141 times its own body weight! That’s the equivalent of a 70 kilograms human being pulling six double decker buses filled with people!

Here is what we do in the name of scientific inquiry: 

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(image source – pixabay)

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(image source)

-NISHA PRAKASH 

P.S: Featured image – Pixabay; Dung beetle wearing a hat – Nat Geo; Dun beetle wearing shoes – Scientific American
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5 Differences Between Turtles & Tortoises

Turtles & Tortoises must have been the source of the “Find the difference” game, because they are two animals that most people can’t distinguish between. 

Turtles & tortoises are both reptiles which belong to the Testudines family of animals – animals which developed a bony/cartilaginous layer on their backs, which cover their bodies as a shield. They belong to the same group as crocodiles and snakes. 

A lot of times, many aspiring pet owners don’t know how to differentiate between a turtle and a tortoise and end up caring for them the wrong way. They give them the wrong food and expose them to the wrong living conditions. This results in many animal deaths. Those owners who try to do right by their pets by releasing them back into the wild, release turtles & tortoises in environments they actually aren’t supposed to, leading to more deaths. 

So, how can we stop this vicious cycle? By learning more about them of course. Here are the top 5 differences between turtles & tortoises

  1. Turtles can swim, tortoises can’t. That’s why turtles have webbed feet (sea turtles have full-fledged flippers) and tortoises have feet that have toes (like that of an elephant) which they use to walk & climb. 
  2. With the exception of the Sonoran mud turtles and Box turtles, all other turtle species have a streamlined and flat shell. All tortoises have deep, domed shells. The streamlined shells of turtles are highly-aerodynamic and reduce drag in the water. Tortoises never needed to evolve a flat shell because they never needed to swim. 
  3. Turtles live on an average for 80 years. Tortoises for 150 years. There have been instances where turtles and tortoises in healthy captive conditions lived well beyond their natural lifespans, some reaching an estimated 250 years of age. 
  4. Turtles are omnivores and like to eat a mix of plants and meat like larvae, insects, small fish and jellyfish. Tortoises are mostly herbivores and love their green leaves, with only a handful of species choosing to eat meat. 
  5. Female turtles come on shore only to lay eggs and will return to the water immediately after. Female tortoises on the other hand, often stay a few days protecting the nest and will return to their territories much later. If you’ve seen a turtle/tortoise lay her eggs near your property and you want to do your bit to give these eggs a chance to hatch (and not get eaten by predators), read this really-informative article by the Tortoise Protection Group here

Bonus

Okay, here’s a fun fact that can turn everything you’ve just learnt on its head. 

Scientifically speaking, there’s no distinct species called “tortoise”!

Okay, before you drop your device in shock, let me just clarify that there’s more to it.

So, according to taxonomy (the science of classification), all animals that have shells which cover their body completely are called “turtles”. What this means is that all tortoises are in reality a type of turtle

Let’s break it down further. The species called “turtles” includes – tortoises, terrapins (yep, that’s a new one) and turtles.

  • Tortoises are turtles which live exclusively on land.
  • Terrapins are turtles whose shells resemble those of sea turtles (only smaller), but whose legs look like those on tortoises and they swim in freshwater.
  • Turtles are actually sea-turtles which live in the ocean and do not remain long on land. 

Basically, all tortoises and terrapins are turtles, but all turtles are not tortoises and terrapins. 

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An Australian sea turtle (image source)
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A Galapagos giant tortoise (image source)
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A Terrapin – see how they look like a cross between a turtle and a tortoise. Their shells are flat and streamlined, but their feet are only slightly-webbed with long claws attached, making them perfect for both land and water-based living.  (image source)
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Turtles & tortoises have different types of feet. (image source)

-NISHA PRAKASH 

P.S: Featured Image
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5 Fun Facts About Uguisu

(Hear the pronunciation of “Uguisu” here)

Uguisu, called the Japanese Bush Warbler in English, is a small bird that is predominantly found on the island nation of Japan and in certain places of Korea, China and Russia. A very shy bird, very little is known about it. 

Here are fun five fun facts about Uguisu:

  1. Uguisu have a very melodious chirp, one of the most refreshing in the bird world. In fact, when people actually see the pale, olive-coloured Uguisu, they are surprised that something so drab-looking can produce such a beautiful sound. 
  2. Speaking of their song, Uguisu songs are thought to fulfill multiple purposes. Apart from functioning as mating calls, Uguisu are also thought to use songs to wage wars, claim territories, convey danger and indicate the presence of food. Each song is slightly distinct from the other. 
  3. During breeding season, it is the Uguisu female that builds the nest, incubates the eggs, feeds the newborn chicks and teaches them to fly. The males’ only role is to fertilise the eggs. 
  4. Uguisu droppings are one of the most sought-after natural items in Japan. They are used to make skin lightening & brightening creams. It is believed that Geisha and Kabuki actors in the Edo period routinely applied it to their faces in preparation for their performances. Uguisu-feaces inclusive cosmetic – “Uguisu-no-Fun” – was sold extensively in Japan for quite a long time, with companies often illegally capturing and caging Uguisu birds in captivity. This was the case until authorities set in place stringent measures to prevent this illegal kidnapping. It was reported that the secret to Victoria Beckham’s beauty was Uguisu-droppings cream. 
  5. Uguisu resemble Bushtits and Nightingales in appearance. That’s why the discoverer of the Uguisu – Heinrich von Kittlitz – confused them for nightingales. That’s why even today, the Uguisu  are called Japanese Nightingales outside Japan. 

Bonus

There is a type of wooden floorboard used in traditional Japanese construction, which when stepped on creates a creaking sound that is eerily similar to the call of the Uguisu  bird. This type of floorboard is called – Uguisubari – in Japan. The purpose of these floorboards is to announce to the home owner, the presence of other people (often unwelcome & uninvited) in the house.

Video: Listen to a Uguisu  tease us with his/her beautiful voice. Notice how he/she isn’t visible at all. These birds are masters of camouflage. 

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An Uguisu in the wild. (image source)
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A bottle of Uguisu-no-Fun face cream made from Uguisu droppings. (image source)

-NISHA PRAKASH 

P.S: Featured image
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5 Fun Facts About Sea Sponge

Sea Sponges are multi-cellular creatures that do not have a brain and organ systems and depend on the constant flow of water through their porous bodies to get the oxygen and food they need to survive. There are over 9000 recorded varieties of sea sponges in the world today and they can be found at various depths right from the seashore to the abyssal zone, which is the deepest part of the ocean. 

Here are 5 fun facts about them: 

  1. Fossil records of sea sponges indicate that sponges first made an appearance on the Earth 650 million years ago. This makes them one of the earliest life forms on the planet.
  2. There are currently 480,931 marine species known and on record and an estimated 2 million that are as yet unrecorded and unknown (i.e. there is not enough evidence – be it visual proof or physical proof – to classify any unknown animal as a distinct species) in all the lakes, seas and oceans of the world. It’s believed that 75% of the world’s entire marine population (480K + 2 Million) accounts for sponges.
  3. Since they don’t have any age-rings (like in trees), it can be hard to accurately estimate the age of a sea sponge. But analysis of growth rates indicates that some sea sponges grow 0.2 mm (0.000656168 feet) per year. Based on this, sponges as small as 1 meter (3.2 feet) wide may be over 4500 years old!
  4. A sea sponge in the Caribbean – Tectitethya crypta – produces two chemical compounds which can treat certain types of cancer and HIV. The chemicals – spongothymidine and spongouridine – have been used to develop the HIV drug Azidothymidine (AZT) which can be used to prevent mother-to-child and needle-to-skin AIDS/HIV transmission. The same chemicals have also helped create medication for leukemia and herpes. 
  5. The biggest debate since the time of Aristotle has been – “Are sea sponges plants or animals?” Although they resemble plants in appearance and remain permanently fixed to the spot they grow on like plants, sea sponges are not plants. Why? 

– Sea sponges can’t produce their own food like plants and rely on stray organic matter to float into their pores via the flowing water.

– Sea sponges have an immune system like other animals which reject dissimilar cells if transplanted into them. Scientists need to use immunosuppressants to successfully transplant dissimilar cells into their bodies. 

– Finally, some sea sponges produce and release sperm to indulge in sexual reproduction. 

These characteristics makes sea sponges inherently animal-like.

 

Bonus

Today, you can find a feminine hygiene product called “Menstrual Sponges” on the market. Basically, these are sea sponges that are used as re-usable tampons. In many parts of the world (especially in developed, first-world countries), sea sponges are a favoured alternative to toxic, non-biodegradable and expensive sanitary pads and tampons. Here is a link to the Top 5 most preferred sea sponge tampons

Would you use them?

 

Tidal zones
Various tidal zones in the ocean – sea sponges are found at each level, right from the seabed to the Abyssal zone.

 

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Sponges grow in large clusters across the ocean bed. (image source)

 

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A female sea sponge that’s spawning .i.e. releasing fertilised eggs into the ocean. Most sponges are hermaphrodites – both male and female – and can produce sperm and eggs simultaneously.  (image source)

 

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Different types of sea sponges in the world. (image source)

 

 

-NISHA PRAKASH 

P.S: Featured image source