My Science School

Researchers at a Florida university say a species of shark with the ability to walk on land is evolving to survive warming seas and the climate crisis.

The epaulette shark, found on shallow reefs of Australia and New Guinea, can walk for upto 90 feet on dry land using its paddle-shaped fins, and survive hypoxia (deficiency of oxygen) for up to two hours. The 3 foot long sharks are able to slow and fast walk, as well as swim, giving them an exceptional ability to cross land to reach more favourable environments.

Tide pools and coral reef environments are subjected to warm temperatures when the tide is out. These sharks can move from tide pool to tide pool, allowing them to access new pools to forage for food or tide pools with better oxygenated water.

What sets epaulette sharks apart from other shark species with these abilities, is their tolerance of hypoxia for a prolonged period, and ability to not only survive being on land but walk distances up to 30 times its body length. This gives them better agility to evade predators, reach areas with more plentiful food and less competition for it.

Picture Credit : Google 

In the world of animals, speed defines everything. You need to run faster than your predator to survive. Here we take a look at some of the fastest animals in the wild.

BLACK MARLIN - THE FASTEST FISH

It is estimated that the black marlin can go to a top speed of up to 80 miles per hour. It is also one of the top predators of the seas and uses its speed for hunting and evasion. They are seen to inhabit the shallow waters, close to shores, and are seen in the Indian, and Pacific Oceans.

CHEETAH-FASTEST LAND ANIMAL –

This cat can sprint faster than 70 miles per hour. A cheetah can go from 0 to 60 miles per hour in less than three seconds! However, this mammal can maintain this speed only for short distances. Cheetahs live in the wild in scattered parts of central, eastern, and southern Africa. A small number of wild cheetahs live in Iran. India was once home to a thriving cheetah population which went extinct duelto hunting and habitat loss, Recently efforts were taken to reintroduce the cheetah to India with eight cheetahs being brought in from Namibia in southern Africa. The ambitious cheetah reintroduction project is being carried out in the Kuno National Park in Madhya Pradesh.

PRONGHORN-FASTEST LAND ANIMAL (LONG DISTANCES)

 The cheetah may be the fastest sprinter but the pronghom is the fastest "long-distance runner as it can maintain a speed of nearly 35 miles per hour over long distances. Also called American antelope, the pronghom is distinct in being the only animal that has branching horns that it sheds annually. It lives in open plains and semi-deserts. It has remarkable vision and can identify predators at distances of up to 0.6 miles.

PEREGRINE FALCON –

The fastest flying animal A bird of prey, the fastest bird is the Peregrine falcon. It is seen on every continent except Antarctica. It is known for its diving speed during flight. It can attempt a mid-air dive at speeds of even 200 miles an hour. This is also how they hunt, by flying high and diving at their prey.

HORSE FLY-FASTEST INSECT

Large and agile, these flies can attain a speed of 90 miles per hour. It is considered the fastest insect in the animal kingdom. They can be as tiny as a housefly or as large as a bumble bee. Considered pests to both humans and animals, they are usually found around streams, marshes, and wooded areas. They are carriers of various diseases.

Picture Credit : Google 

As their name suggests, giant anteaters are large. Like so many large mammals the world over, these creatures too are facing rising extinction risk, especially in Brazil. What are the reasons for this? Come, let's find out.

Giant anteaters are native to Central and South America. In 2020, the Pantanal region of South America witnessed fires that destroyed about a third of the area. It proved to be injurious or fatal for wildlife such as jaguars inhabiting the region. According to a report, the fires killed "an estimated 17 million animals". The numbers are not available for those injured or displaced. But among those that suffered are giant anteaters. Apparently, "more than 50 giant anteaters injured or displaced by the Pantanal fires were taken in by state rescue projects - a leap from 13 the previous year". In 2021, Pantanal witnessed fires again, though on a scale smaller than the previous year. However, reports suggest that a few areas from 2020 suffered in 2021 too - this could spell disaster for the species there since they'd be denied time for recovery. Several animals are also indirectly affected by such fires. For instance, young animals could be orphaned and ones trying to escape such fires could get involved in accidents or end up in the hands of poachers. As for giant anteaters, some tried to escape the fire in 2021 and got hit by cars; they were rescued.

But, fires are not the only reason for falling giant anteater populations. A report says "Brazil's anteater populations have fallen 30% over 26 years". As solitary creatures, they require a large range for habitation. But this is becoming more and more difficult due to land seizures, expansion of farming, ranching, and mining "in the Amazon and the Brazilian savanna". Further, the animal also has "a low population growth rate due to its life history of long gestation periods and single offspring".

The giant anteater plays a significant role as both predator and prey. While it is consumed by jaguars and pumas, the mammal consumes large quantities of insects, especially ants and termites. Given this interconnectedness, the extinction of this insectivore can have unimaginable impacts on its ecological range.

Fires are not the only reason for falling giant anteater populations. As solitary creatures, they require a large range for habitation. But this is becoming more and more difficult due to land seizures, expansion of farming, ranching, and mining "in the Amazon and the Brazilian savanna". Further, the animal also has "a low population growth rate due to its life history of long gestation periods and single offspring".

Picture Credit : Google 

Have you ever wondered about the vibrant colours of some frogs? Did you know that their colouring is a warning to predators that they are foul-tasting and poisonous? Read on to know more fascinating facts about these amphibians.

It is small enough to fit into the palm of one's hand, but it packs a powerful punch. A single golden poison dart frog, measuring just 6 on long, contains sufficient poison to kill 10 grown humans! The frog species derives its name from the centuries-old practice of the Emberá and Chocó, indigenous peoples of Colombia and Panama, who tipped their blowgun darts with its poison while hunting.

The poison is called a batrachotoxin (some beetles and birds also have it). The word batrachos is Greek for frog'. Even minute amounts lead to paralysis and death.

Poisonous species

There are only four species of frogs that are so poisonous that even a tiny drop is enough to kill small mammals (monkeys, for example) and birds. Most of them produce poison only potent enough to kill insects-flies, crickets, ants, termites. and beetles which are their main prey.

The frogs average around 2.5 cm in length. They are found in the wild only in the tropical rainforests of South and Central America.

The frogs sport gaudy colours and patterns, usually in combination with black-orange, red, blue, yellow, purple, pink, green, and even silver! Their colouring is a warning to predators that they are foul-tasting and poisonous. Once a predator has tried eating one and survived, it avoids similar-looking frogs.

The fire-bellied snake of the Amazon forests is resistant to golden poison frog toxin and is its only predator.

The little frogs usually live in the leaf litter on the forest floor, near streams and ponds, but a few species also live high up in the canopy and may never come down. Unlike most frog species that are nocturnal, poison frogs are active during the day when their colours can be best seen.

Caring for the young

Females lay from one to 30 eggs at a time in a dark, moist place such as the base of a big leaf, the hollow of a tree trunk or crook of a branch. Both parents are involved in the care of the eggs. When the eggs hatch, the parents carry the tadpoles on their backs and deposit them in water. Blue poison frog tadpoles eat their own siblings, so the parents must find a different water body for each individual hatchling!

The female feeds the tadpoles with unfertilized eggs that contain small amounts of poison, so that even the tadpoles are protected from predation.

Researchers are studying poison frogs to see if their toxins can be used in medicines, mainly painkillers. The poison from the phantasmal poison frog has been found to be 200 times more effective than morphine and without its side-effects!

Fact File

• Wild poison frogs ingest the poison from the different bugs they eat and store it in their skin. Frogs bred in captivity lose their toxicity.
• In the past decade, hundreds of frogs have died of a fungus that grows on their skin, preventing them from absorbing oxygen and water.
• The population of the more brilliantly coloured poison frogs has plummeted because they are popular as pets.

Picture Credit : Google 

Often, conservation stories underline the importance of the role of all creatures-big and small-for balance in ecosystem. For instance, krill crustaceans barely two inches long are a huge link in the global food chain. If such a small organism can have a telling impact on the food chain, one can only imagine the kind of effect larger animals have in an ecosystem. So, when the population of a large animal plunges, it is always a cause for concern.

Grey whales are among the largest animals on Earth- nearly 50 feet long and weighing over 40 tonnes. These giants are known for their long annual migration of more than 15,000 km "between feeding grounds in the Arctic and breeding grounds in Baja Mexico" Recent research has revealed that the number of these fascinating creatures is witnessing a worrying slump- by nearly 40% in just six years. From 27,000 whales in 2016, the number stands at a concerning 16,650 today. Several factors are attributed to this decrease. One of them is the increase in strandings in 2019, when about 600 of these creatures washed up dead along the west coast of North America Though boat collisions and killer whale attacks caused a few of these deaths most of the dead whales were malnourished which takes us to n crucial of interconnectedness in an ecosystem. It is believed that the malnourishment could be the result of "the whales’ food sources of tiny crustaceans and other invertebrates they prey on in the Arctic shifting due to environmental changes. Further, the overall population among West Coast grey whales "coincides with diminished reproduction" While there were 383 baby whales during the calf production season last year, there have been a mere 217 newborns this year - "the lowest number since such counts began in 1994"

Grey whales were close to extinction several decades ago due to commercial whaling before their population improved due to timely conservation efforts. Even then, the 80s and 90s saw a plunge of about 40%, and eventually they rebounded. It is important for this whale population to recover too because they keep the population of certain other creatures in the food chain in check. Even in death-as carcasses- these large marine mammals help feed several other organisms.

Often, grey whales are washed up dead along the U.S. west coasts. Though boat collisions and killer whale attacks cause some deaths, researchers say malnourishment is a major reason. With tiny crustaceans and other invertebrates shifting due to environmental changes, the grey whales are left without food.

Picture Credit : Google 

Scorpionfish

Scorpionfish, one of the most venomous fish in the world, are found across the world in warm waters. They are most common in the Indian and Pacific Oceans. They are also known as rockfish and stonefish as they commonly live among rocks. They are perch-like fish with large, spiny heads and strong, sometimes venomous. fin spines. While their spines protect them from predators, it is their colouring that helps them in hiding. They are carnivorous and generally sedentary. The fin spines, even ones without venom, can inflict deep, painful wounds. While some are dull in colour, others are brighter, often some shade of red. The largest members of the family grow about 39 inches long.

Walkingstick

Suddenly seeing a twig crawling down a tree trunk? It isn't a twig but a walkingstick, also called stick insect. The stick-like trickster uses its appearance to save itself from enemies. They are commonly found in tropical and temperate (or mild) forests across the world. Though related to grasshoppers, crickets, and mantises, these crawlies are either brown, green, or black. They're also the world's longest insects. The largest one found was 22 inches long with its legs extended. They spend most of their time on trees, munching on leaves. When predators like birds approach, the bug tries to remain still to blend with the branches. However, if the predator manages to catch the bug by its legs, the insect can detach the leg and scuttle away. The leg will later regenerate, or grow back.

Camouflage

Also known as cryptic colouration, is a defence mechanism used by organisms to disguise their appearence, usually to blend/ in with their surroundings. This tactic is used to mask their location, identity and even movement. This helps the prey to protect themselves from predators.

Chameleon

Chameleons have the ability to change their colour and pattern. They are found in warm climates and in parts of the Middle East, southwestern Asia, and southern Europe, Madagascar nearly all of Africa, and parts of India and Sri Lanka. There are more than 200 species of chameleons, of which 76 are found on the island of Madagascar. Their diet consists of insects and plants, though some may eat rodents or small birds. They live in a range of habitats, including deserts, rainforests, and savannahs. The word chameleon comes from the Greek 'khamai' meaning on the ground, earth and leon' meaning 'lion'. probably because the head of some species resembles a lion's mane. The distinctive features of these lizards are their telescopic eyes, grasping tail, colour-changing skin, and projectile tongue.

Great Potoo

The Great Potoo is a nocturnal bird of the American tropics. Its name is similar to its wailing cry, "po-TOO," made by some species. Their patterns of grey, black, and brown plumage resemble tree bark. Their camouflage helps them to even sleep while perched out in the open during daylight During the day, the birds sleep, vertically perched and virtually indistinguishable from the dead branches they roost on They wake up at dusk with their huge, wide-open eyes capable of spotting moths and other flying insects in the dark. They are mainly solitary creatures and highly restricted nesters. Instead of building a nest, they choose a branch or stub with a crevice just enough to accommodate the single egg they lay.

Nightjar

Nightjar is a medium-sized bird that are mostly active at night feeding on flying insects. They have a protective colouring of grey, brown, or reddish brown. There are about 60 to 70 species of nightjars. They are found almost worldwide in temperate to tropical regions, except for New Zealand and some islands of Oceania. They do not make nests, instead deposit their eggs on the ground or on the leaf-covered floor of the woodland. Some of the species, mainly the North American nighthawks, have adapted to urban life and nest on flat gravel-covered rooftops. The nightjar’s soft plumage and variegated colouring help it blend in with its surroundings. Despite their skill at camouflage, some nightjar species are endangered.

Picture Credit : Google 

Every year, certain animals stay in a comatose state, sending themselves into a sleepy stupor. They hibernate to conserve energy. They cool their bodies by 5° to 10°C and slow down their metabolism. For instance, the Arctic ground squirrels cool themselves to subfreezing temperatures! They do wake up and warm up intermittently. Some animals even hibernate as a response to the shortage of food. Here we take a look at some of the animals that go into hibernation.

SNAKES

In the case of snakes, they experience brumation, where they remain dormant. is technically different from hibernation, but they prepare for the winter by going into a state of partial sleep. This helps them conserve energy for breeding. The length of the dormancy varies according to the location of the snakes. While some may go into brumation for weeks, others might for months. There are also occasions when they venture out of their resting spot for hydration. While some snakes brumate alone, some such as the garter snakes brumate together, more like a communal brumation.

BEARS

Think hibernation and the first animal that comes to your mind is the bear. Of course, when the winter sets in, they go into hibernation and survive the winter thus. But with climate change and changes in the temperature, bears have been seen to come out of their hibernation a bit earlier than usual. According to wildlife experts, this early emergence from hibernation isn't good for the animal.

COMMON POORWILLL

 You wouldn't have heard about birds going into hibernation. Yet there is one bird that does the unthinkable. The Common poorwill is the only bind that hibernates, the sole reason being that the bird's insect food isn't available during the winter season! So instead of migrating, like other birds do, they pull through the winter by huddling inside a hollow log, lowering their metabolism and hibernating.

MARMOTS

With the onset of fall, marmots use dirt and plants to cover their tunnel entrances. They are preparing for the annual ritual of hibernation to hide from predators. For about 8 months of a year, the marmots go into hibernation. During this inactive state, they burn the fat that they stored and slow down their vitals. They even reduce their heart rate. And once spring sets in, they emerge from the hibernation.

SNAILS

Did you know that snails also hibernate? Well, some snails hibernate during the colder months. They cover their bodies in a layer of mucus. They crawl into their shell and seal the entrance with mucus. This thin mucus layer prevents them from drying out. The same  activity is carried out by some snails during the summer and this is called aestivation, a prolonged period of inactivity to survive the dry periods.

BUMBLEBEES

While not all bees go into hibernation, bumblebees do. In fact, they hibernate for a longer period of their lives. Some queen bees even hibernate for nine months. That is like three-fourths of their entire life span!

Picture Credit : Google