Category Wildlife

Found in India, which dolphin lives only in freshwater?

Ganges river dolphins once lived in the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh. But the species is extinct from most of its early distribution ranges.

The Ganges river dolphin can only live in freshwater and is essentially blind.

Once present in tens of thousands of numbers, the Ganges river dolphin has dwindled abysmally to less than 2000 during the last century owing to direct killing, habitat fragmentation by dams and barrages and indiscriminate fishing. It is for these reasons that despite high level of protection, its numbers continue to decline. The absence of a coordinated conservation plan, lack of awareness and continuing anthropogenic pressure, are posing incessant threats to the existing dolphin population.

The Ganges river dolphin inhabit freshwater river systems, mostly in plains with slow-flowing rivers. They have a preference for deep waters, where prey availability is high. They mainly feed on fish and invertebrates, using echolocation to detect their prey.

 

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Which sea turtle gets its name from the shape of its bill?

Hawksbill – named for its narrow head and hawk-like beak. The hawksbill is one of the smaller sea turtles. Head is narrow and has 2 pairs of prefrontal scales (scales in front of its eyes). Jaw is not serrated. Carapace is bony without ridges and has large, over-lapping scutes (scales) present and has 4 lateral scutes. Carapace is elliptical in shape. Flippers have 2 claws. The carapace is orange, brown or yellow and hatchlings are mostly brown with pale blotches on scutes.

Hawksbill turtles are found throughout the tropical waters of the Atlantic, Pacific, and Indian Oceans. They avoid deep waters, preferring coastlines where the sponges they like to feed on are abundant, and sandy nesting sites are within reach. These highly migratory reptiles help maintain a healthy coral reef ecosystem.

Hawksbills are omnivorous and will also eat mollusks, marine algae, crustaceans, sea urchins, fish, and jellyfish. Their hard shells protect them from many predators, but they still fall prey to large fish, sharks, crocodiles, octopuses, and humans.

 

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Which is the only penguin species found north of the equator?

The Galápagos penguin (Spheniscus mendiculus) is a penguin endemic to the Galápagos Islands. It is the only penguin found north of the equator.

The average Galápagos penguin is 49–50 centimetres (19–20 in) tall and weighs around 2.5–4.5 kilograms (5.5–9.9 lb). It is the second smallest species of penguin, after the little penguin. Females are usually smaller than males. Galápagos penguins have a black head with a white border running from behind the eye, around the black ear coverts and chin, to join on the throat. The top of the beaks are black and fade into pink on the bottom. They have two black bands across the breast that connect to the back, the lower band extending down the flanks to the thigh. Juveniles differ in having a wholly dark head, grayer on side and chin, and no breast band.

The penguins are confined to the archipelago, foraging in the cool Cromwell Current during the day and returning to the land at night. They eat small schooling fish, mainly mullet and sardines, and sometimes crustaceans. They normally range only a few kilometers from their breeding sites, depending on the cold, nutrient-rich currents to bring them food.

 

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Will endangered species become extinct?

One of the most fascinating aspects about our planet is its biodiversity. We do not know for certain how many species call Earth home. Millions of species have been discovered so far, and the number of undiscovered species is perhaps just as much. But what we do know for certain is that many species have gone extinct and many are on the verge of going the same way. Throughout history, a whole range of species has gone extinct and that’s how Nature works. But now we’re losing and endangering a whole lot of species at an alarming rate because of our indiscriminate behaviour. This includes everything from habitat destruction to excessive hunting and poaching. Though measures are in place to conserve many species, many are critically endangered today. So endangered that the population of some of these animals remains in one or two digits.

Vaquita: A recent study conducted by the International Committee for the Recovery of the Vaquita (a rare marine mammal), suggests only about 10 individuals remain

Javan rhinoceros: Despite an increasing number and the unexpected pleasure of discovering two newbonis, the population of the Javan rhinoceros is said to be a dismal 70-odd today

Amur leopards: The number of Amur leopards (found at the Russia-China intersection) in the wild is believed to be 80-plus.

India update: The scene is no different in India. From snow leopards and sangai (a deer species) to bird species such as the Bengal florican, many are endangered, crying for our immediate attention.

 

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How owls twist their heads almost 360 degrees?

Many species of birds have flexible necks, but owls rank among some of the most impressive when it comes to rotating their heads. While it’s a common misconception that owls can turn their heads 360 degrees, they still can perform some pretty dramatic feats when it comes to checking out their environment.

Many owl species are capable of turning their heads 270 degrees in either direction. That means “they can look to the left by rotating all the way to the right, or vice versa,” LiveScience.com reports. They can also position their necks so that their heads are almost upside down while their bodies are still facing forward, states The Owl Pages.

So why do owls need to turn their heads as far as they do? Unlike humans and animal species that have spherical-shaped eyes, owl’s eyes are elongated tubes that are fixed in their eye sockets by bone. While this tubular shape comes in handy for an owl’s amazing binocular eyesight, an owl cannot turn or roll its eyes. They can only look straight ahead. So having the flexibility to turn their heads allows them to get a good look around.

Equally as amazing as the head-turning habits of owls is how they can rotate their necks as far as they do without cutting off blood flow to their brains. Research conducted in 2013 at John Hopkins University School of Medicine tried to explain just that. If humans attempted to turn their heads as quickly or as far as owls do, artery linings would tear, causing blood clots to form and potentially leading to a stroke not to mention broken necks, explained study author Dr. Philippe Gailloud in a statement.

 

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Why does the color red trigger Bulls?

The color red does not make bulls angry. In fact, bulls are partially color blind compared to healthy humans, so that they cannot see red. According to the book “Improving Animal Welfare” by Temple Grandin, cattle lack the red retina receptor and can only see yellow, green, blue, and violet colors. Color vision in mammals is accomplished by a collection of cone cells on the back of the eye (the retina). There are three kinds of cone cells: one kind that detects predominantly red colors, another kind that detects mainly green, and the last kind that detects mainly blue. Although cone cells respond most strongly to their main color, they can still respond to other close colors. This color overlap of the cones’ sensitivity is what allows us to see so many colors. For instance, a pure yellow color stimulates both the red cone and the green cone, and we experience the combination as yellow. If instead of looking at a pure yellow dot of light, you looked instead at a red dot very close to a green dot with the right balance, you would still experience yellow because the red cones and green cones are being stimulated in the same way. This fact makes the manufacture of computer screens very practical. Instead of implanting a million pixels into a computer screen at every point, each with a different color, the manufacturer only has to construct a grid of red, green, and blue pixels. Humans are actually looking at an array of red, green, and blue dots on a screen but perceive millions of colors. Most mammals, including bulls, are dichromats. This means that they only have two different kinds of cones, as opposed to the three in humans. Bulls lack the red cones, but still have the green and blue cones. A bull’s vision is very similar to the vision of a human with red-cone color blindness, known as protanopia. To them, a red cape looks yellowish-gray. It is perhaps the threatening, waving motion of the matador’s red cape that enrages a bull, and not the color.

 

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Do elephants have a good memory?

Elephants are incredible creatures. The largest land mammals on earth, they show a wide range of behavioral and emotional patterns in their up-to-60-year lifespans. They grieve over the bodies of dead herd members, and can even recognize their own reflections in a mirror. And, of course, there’s that old saying: “Elephants never forget.” While it may be an exaggeration, there’s more truth to the adage than you might realize. 

Science has also proven that elephants have great memories. In 2007, researchers at the University of Saint Andrews in Scotland placed urine samples in front of female elephants at the Amboseli National Park in Kenya; according to Scientific American, the elephants “acted up” when they smelled urine that didn’t come from an elephant in their herd. The researchers concluded that elephants can recognize and track as many as 30 of their companions. “Imagine taking your family to a crowded department store and the Christmas sales are on,” said psychologist Richard Byrne, one of the scientists who participated in the study. “What a job to keep track of where four or five family members are. These elephants are doing it with 30 traveling-mates.” Elephants “almost certainly know every [member] in their group,” Byrne said, and exhibit cognitive abilities “far in advance of anything other animals have been shown to have.” 

 

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Why do crocodiles shed tears?

The term crocodile tears refers to feigned or insincere sadness.  This term has an etymology dating back several centuries.  As early as the fourth century, crocodile tears are referenced in the literature as a metaphor for fake sorrow.  Apparently, the fable goes that crocodile’s weep while eating their prey because they are sad; however, this sadness is fake.

The term crocodile tears became widely popular after it was documented in a fifteenth-century book titled, The Voyage and Travel of Sir John Mandeville, Knight.  A passage from the book reads: “In that country be a general plenty of crocodiles …These serpents slay men and they eat them weeping.”

As you may already know, crocodilians likely feel bad about little–especially feeding.  However, the premise of the crocodile-tears metaphor may be true.  In other words, the observation that alligators, crocodiles and other crocodilians cry is apparently true.  

In humans, crocodile tears (paradoxical lacrimation) is a medical condition that causes a person to tear up while eating.  Crocodile tears typically occur as a complication of Bell’s palsy; Bell’s palsy is a temporary facial paralysis due to damage of the facial nerve.  Specifically, when the facial nerve regenerates in the wake of Bell’s palsy, it does so incorrectly thus resulting in tears during mastication. Crocodile tears are treated using a shot of botulinum toxin administered to the lacrimal gland.

 

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Do Snakes have ears?

In the past, it was a common belief that snakes couldn’t hear much if anything since they have no external ears and don’t seem to respond to noises. However, scientific research refutes this common misconception.

As previously mentioned, snakes do not have external ears (pinnae) or eardrums like we do but they do have fully formed inner ear structures. In addition to their inner ear structures, they have a bone called the quadrate bone in their jaws. This bone moves slightly in response to vibrations while they slither on the ground.

For many years it was undetermined whether or not snakes could hear noises that were not ground vibrations. Research has since shown that this quadrate bone does, in fact, respond to airborne vibrations as well as ground vibrations1? (thought to be due to spinal nerves that have conducted the vibrations from the skin recognizing them and causing the quadrate bone to vibrate, referred to as somatic hearing). As with other animal ears, this movement is transferred (via bones) to the inner ear and then signals are sent to the brain and interpreted as sound.

 

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Are bats blind?

“Blind as a bat.- Ouch that must hurt. Especially if you’re a bat! Because bats are NOT blind. And they can see better at night than in daylight. The myth about their blindness could have come about because we all learn that they use echolocation – using echoes of self produced sounds bouncing off objects – to navigate. Research says that some bats do not echolocate and have sharp vision instead to help them. In fact, studies say that occasionally some bats use their eyes even for hunting. Reports suggest that there are more than 1,000 species of bats and they have evolved different visual abilities. For instance, there are species with visual receptors that help them see better in daylight and a few colours too. Apparently, some species can even see ultraviolet light, which humans can’t!

There are at least 1,300 species of bat, according to the advocacy group Bat Conservation International, and those species are a diverse bunch: Some feed off flowers; others eat insects; and three (all Latin American species) feed off blood.

So different species have evolved different visual abilities. Researchers reporting in a 2009 study in the journal PLOS ONE, for example, found that Pallas’s long-tongued bat (Glossophaga soricina) and Seba’s short-tailed bat (Carollia perspicillata), two small bats from South and Central America, have visual receptors enabling them to see in daylight and to see some colors. In fact, some of the receptors may enable these bat species to see ultraviolet light, wavelengths of color that are outside of the human visual spectrum. 

 

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