My Science School

Porcupine is a large rodent that lives in Africa Europe, Americas and Asia. It is known for the sharp quills that cover its body. There are over two dozen porcupine species and all of them have these quills. Some porcupines have up to 30,000 quills on their body.

It uses the quills as a defence. These quills typically lie flat until it is threatened. They rise up and deter predators. The quills are easily released when predators get in touch with it. Lost quills are replaced with new quills.

 It is a nocturnal animal, eating leaves, stem, bark and fruit. It lives in tree branches or tangles of roots, and rock crevices. Its home is called a den.

The largest porcupine is the North African crested porcupine. It grows up to 36 inches (90 centimeters) long. The smallest is the Bahia hairy dwarf porcupine. It grows up to 15 inches (38 cm) long. Porcupines weigh 2.5 to 77 lbs. (1.2 to 35 kilograms), depending on species, and their tails can grow up to 8 to 12 inches (20 to 30 cm), according to the San Diego Zoo. The length of quills varies by type. New World porcupines have small quills that are around 4 inches (10 cm) long, while Old World porcupines have quills that can grow up to 20 inches (51 cm) long, though there are some exceptions.

A typical mating ritual consists of two males fighting over a single female. The males are careful not to injure themselves during the fight, and the winner territorially urinates on the female so that she knows to move her tail aside for safe, quill-free mating.

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Octopus is a soft-bodied, eight-limbed molluscs of the order Octopoda. It lives in all the world's oceans. It has a bulbous head, eight arms with suction cups on the bottom and three hearts. The colour of its blood is blue because of the copper-based protein called hemocyanin in the blood.

 It squirts an ink-like liquid to deter predators. This will temporarily blind and confuse a potential attacker, giving him the time to swim away.

It can squeeze into (or out of) tight spaces in search of food and shelter. It diet includes clams, shrimps, lobsters, fish, and even sharks.

Females usually lay 200,000 to 400.000 eggs. They guard the eggs even without eating. Once the eggs hatch, the female octopus dies and so does male octopus within a few months.

Octopuses live in oceans all over the world. Most are pelagic, meaning they live near the water's surface in shells, reefs and crevices. Some species live on the floor of the ocean, making their homes out of caves. Octopuses tend to be solitary, though they do interact with other octopuses at times. Some species of octopuses hunt at night, while others only hunt at dusk and dawn. 

When scared, octopuses will shoot a dark liquid, sometimes called ink, at the thing that scared them. This will temporarily blind and confuse a potential attacker, giving the octopus time to swim away. The ink can also dull the attacker’s smelling and tasting abilities, according to the Smithsonian article.  

Octopuses can also change color to hide and match their surroundings. They can turn blue, gray, pink, brown or green. The mimic octopus can also flex its body to resemble more dangerous animals, such as eels and lionfish, according to the World Animal Foundation.

If an octopus does get caught — no problem. They can lose arms and regrow them, according to National Geographic. 

Octopuses are fast swimmers but they prefer to slowly crawl along the sea bottom. To swim, octopuses suck water into their bodies and shoot it out a tube called a siphon, according to the World Animal Foundation. This lets the octopus blast off, away from attackers. 

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The Democratic Republic of Congo officially declared on December 16, 2021 the end of the 13th outbreak of Ebola Virus Disease which had resurfaced on October 8, 2021, in Beni in North Kivu province. What is Ebola Virus Disease? What causes it? Let's find out.

Deadly viral fever

Ebola is a life-threatening disease caused by a virus belonging to the family Filoviridae The viral haemorrhagic fever was first identified in central Africa in 1976. The 2014-2016 outbreak in West Africa was the largest Ebola outbreak ever since the virus was discovered, leading to over 11,000 deaths. The disease was named after the Ebola River in Congo, formerly Zaire, where it was originally identified.

Ebola is a zoonotic disease, meaning it spreads from animals to humans. The virus which badly affects the immune system as it spreads through the body is transmitted to people from animals such as chimpanzees, gorillas, and monkeys. It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts. It spreads among humans through contact with the bodily fluids (blood, faeces, urine, vomit, or semen) of infected people. Ebola is called a haemorrhagic fever virus as it causes problems with how our blood dots leading to internal bleeding.

What are the symptoms?

The main symptoms of Ebola Viral Disease include fever fatigue, sore throat severe headache, muscle and joint pain loss of appetite, vomiting, bleeding and diarrhoea. The virus can be detected in blood within a few days of the manifestation of symptoms. Immediate medical attention, early intervention with rehydration, and symptomatic treatment are said to improve chances of survival.

There are vaccines for protection against Ebola. These anti-Ebola jabs have been administered to help control the spread of Ebola outbreaks in Congo.

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Bongo is the largest and the heaviest African forest antelope. It has a chestnut coat with distinctive vertical whitish-yellow stripes running down its sides. Both males and females have spiral, lyre-shaped horns.

It is herbivorous and nocturnal. Its predators are lions, hyenas, leopards and pythons. It wallows in the mud to decrease its body temperature during the warmer periods of the year.

Bongos produce snorts, grunts and bleating noise when they are distressed. Females produce mooing calls for communication with their offspring. Mating season of bongos takes place between October and January.

Pregnancy in females lasts 9 months and ends with one baby. Female leaves the herd to give birth in secluded area. Baby remains hidden in dense vegetation during the first week of its life, before it becomes ready to join the herd with its mother. Young bongos grow quickly. Their horns start to develop at the age of 3 to 4 months. Bongos reach sexual maturity at the age of 2 to 2.5 years. Bongo can survive 10 to 18 years in the wild and up to 19 years in the captivity.

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Elephant shrew is a small insectivorous mammal native to Africa. It belongs to the group of animals called sengis.

It has an elongated, pointed head and a long, trunk-like nose (hence the name "elephant shrew"), large ears and eyes, long hind legs and a long, scaly tail. Though it resembles a shrew, it is not one. It can jump like a rabbit. Hence, it is also called a jumping shrew.

It is active during the day, but it is rarely spotted. It is good at camouflaging and dashing away from threats. It creates a series of pathways underground, which it uses to hunt its prey and also to escapes from predators. Its diet includes ants, termites, worms, grubs and spiders.

Elephant shrews live in pairs (that mate for a lifetime). They occupy territory of few acres, but spend most of the time alone (they gather only to mate).

Elephant shrews use scent glands under the tail to mark their trails and point out toward direction of food. They aggressively defend their territory against other elephant shrews (both males and females scream and fight with intruders).

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Birds-of-paradise found in New Guinea and surrounding islands are the most attractive birds in the world. They stand out for their striking colours and bright plumage in shades of scarlet, blue, yellow and green. Males have vibrant ruffs of long, pointed feathers known as wires. Their dances are a treat to the eye.

Consider the efforts of the male Superb bird-of-paradise. He totally changes his appearance to get the attention of a female. He fans out his black feathers with a few electric-blue feathers sticking out. It makes him look a crazed smiley face. Then he hops around excitedly, making sure the female always gets his best angle. He whirs and clicks and snaps his tail in rhythm, flashing a breastplate of shimmery feathers. The female watches, showing no emotion.

His dance moves may appear unpredictable, but they are carefully planned. He is trying to convince a female that he is the best mate. The male works hard to impress, tirelessly refining his moves until the female is won over. After all, she is the one in control. She ultimately decides who her mate will be.

Stunning as it is, the male's beauty is impractical. For example, take the ribbon-tailed Astrapia. It boasts bright white tail feathers that stretch one meter (three feet) long. Such long tail feathers might help it attract mates, but they aren't exactly useful for survival.

So how did long feathers and other features evolve? Famous naturalist Charles Darwin proposed his theory of natural selection to answer the question of how certain animals end up with certain features. Natural selection is sometimes called "survival of the fittest." It means that animals with traits that help them survive will live on. A trait might be its color. It might be what they eat or how they hunt. If an animal lives long enough, its children can also have traits that help them survive. Animals without these traits might get eaten or die out.

Yet the Astrapia's trait of bright long tail feathers does not seem to offer any survival advantage. They actually might put the bird at risk. A predator could spot it easier.

Credit : National Geographic Society

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The cassowary is considered the most dangerous bird in the world. The large, flightless bird, native to Australia and south-east Asia, has 4-inch long, dagger-like claws. It can inflict injuries with slashing blows of its feet. Besides, it has a reputation for aggressively defending itself when threatened.

Cassowaries are certainly striking to look at, with a vivid blue face, two red wattles (flaps of skin) hanging from their neck and a hollow "helmet", known as a casque, atop their heads. 

The anatomy that makes them so dangerous lies lower down. Muscular legs that can pack a powerful kick terminate with three claw-tipped toes. The claw on the inner toe is particularly formidable, reaching lengths of 12 cm (5 in)! If a cassowary feels threatened, it will leap up and strike out with these dagger-like weapons, inflicting potentially lethal wounds to internal organs and causing severe bleeding. 

Although this avian family are widely considered the most dangerous birds, this is the first confirmed human death attributed to a cassowary in 93 years. The last-known victim was 16-year-old hunter Phillip McClean, who tripped while fleeing from a bird in Australia in April 1926. It was when McClean was on the ground that he received a fatal blow to the neck. 

Credit : Guinness World Records

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A snake's fangs last for just 10 weeks. But new ones start growing right away. These long, sharp teeth are connected to poison sacs located behind a snake's eyes. It is these sacs that produce venom.

Snakes replace all their teeth -- including their fangs -- often. Teeth regularly break, wear out or become stuck in prey. Some snakes, for example puff adders (Bitis arietans), have up to 6 replacement fangs, in various states of development, embedded in the gum tissue behind each of the active fangs. Occasionally a replacement fang pops into place before the old fang falls out, so a snake can temporarily have three fangs -- one on one side and two on the other. This is no problem for the snake; they can still bite and inject venom very efficiently.

Herpetologists classify snakes in four primary groups according to the type of fangs they possess. Snakes without venom-injecting teeth of any kind are called aglyphous; they have varying amounts of teeth, but none modified for envenomation. Opisthoglyphous snakes are often colloquially called “rear-fanged” snakes, as their fangs reside at the rear of the maxilla, right below the eyes. Most opisthoglyphous snake fangs have a groove or channel down which venom flows into a wound. Proteroglyphous snakes have relatively small, hollow fangs at the very front of their mouths, which transmit venom directly into the body of their prey. Finally, solenoglyphous snakes have hollow fangs that are so large they must fold flat against the roof of the snakes’ mouths to allow the snakes to close their mouths properly.

Sometimes keepers find shed teeth or fangs in their snake’s waste. This happens because teeth and fangs can become stuck in their prey. While the prey is largely digested, the teeth pass through the digestive system relatively unharmed. Because small snakes have very small teeth, you are more likely to find teeth in the feces of large snakes.

Credit : Pets On Mom.com

Avocados do not ripen on the tree unlike many other fruits. So farmers will allow them to remain attached to the tree until they can pluck and sell them. The fruits remain fresh on the tree for over two months. They soften only after they have been harvested.

While avocados are grown in California and Florida, the majority sold in grocery stores come from south central Mexico. The main reason for the abundance of “south of the border” avocados is that Mexico is blessed with a year-round growing climate. The avocado is believed to have originated in the state of Puebla, Mexico, as far back as 10,000 B.C. Avocados’ taste and texture depend on the region they’re from. Florida-grown avocados are lower in fat and firmer, while Hass avocados, from Mexico, are perfect for mashing and whipping.

It wasn’t until the 1950s when Americans turned to avocados. This makes it a relatively new food in our country. As with most imported trends, avocados were made popular in the coastal states-Florida and California-and Hawaii, too, before evolving into mainstream culinary culture.

Hard to believe, but it’s true: Avocados have higher levels of potassium than bananas. In fact, the levels are almost double-a single avocado contains 975 milligrams of potassium, compared to 487 milligrams in a banana. 

Credit : Taste of Home

Both frogs and toads are amphibians, come in different sizes and colours, and are similar in many ways. They usually do not have tails, scales, or claws on their feet. And technically speaking, toads are a type of frog, meaning all toads are frogs, but not all frogs are toads. Frogs and toads are also different in a few aspects. What are they?

One of the easy-to-spot differences between the two is the skin. Frogs normally have smooth or slimy skin that is moist, while toads have uneven, thicker, drier skin, sometimes with warts. Further, frogs are said to have big, bulging eyes, whereas toads eyes are not as prominent. Also, frogs normally seem to come in brighter colours as against the duller colours of toads. Frogs have long and slim bodies with a pointed nose, and toads have a broader body and nose. Frog legs are longer (sometimes longer than the frog's body) than the toad's, and help the former jump and swim well.

Where you spot them is a good clue too-frogs live in or near water, but toads "live on land and return to water to breed". Speaking of breeding, both frogs and toads lay their eggs in water, but "the egg arrangement is different. Frog eggs are laid in clumps or clusters, while toad eggs are laid like a chain or a ribbon. Even the tadpoles (the larva) are different-"frog tadpoles are longer and skinnier than toad tadpoles, which tend to be short and fat".

But always do remember that there are exceptions, meaning there are bright-coloured toads, dry-skinned frogs, etc.

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Cobra, any of various species of highly venomous snakes, most of which expand the neck ribs to form a hood. While the hood is characteristic of cobras, not all of them are closely related. Cobras are found from southern Africa through southern Asia to islands of Southeast Asia. Throughout their range, different species are favourites of snake charmers, who frighten them into assuming the upreared defense posture. The snake sways in response to the movement and perhaps also to the music of the charmer, who knows how to avoid the relatively slow strike and who may have removed the snake’s fangs. The short fangs at the front of the mouth have an enclosed groove, which delivers the venom. Cobra venom generally contains neurotoxins active against the nervous system of prey—primarily small vertebrates and other snakes. Bites, particularly from larger species, can be fatal depending on the amount of venom injected. Neurotoxins affect breathing, and although antivenin is effective, it must be administered soon after the bite. Thousands of deaths occur each year in South and Southeast Asia.

The world’s largest venomous snake is the king cobra, or hamadryad (Ophiophagus hannah). Found predominantly in forests from India through Southeast Asia to the Philippines and Indonesia, it preys chiefly on other snakes. Maximum confirmed length is 5.6 metres (18 feet), but most do not exceed 3.6 metres (12 feet). King cobras guard a nest of 20 to 40 eggs, which are laid in a mound of leaves gathered by the female. The guarding parent will strike if a predator or a person approaches too closely. Not all cobras are egg layers.

The Indian cobra (or Indian spectacled cobra, Naja naja) was formerly considered a single species with much the same distribution as the king cobra. Recently, however, biologists have discovered that nearly a dozen species exist in Asia, some being venom spitters and others not. They vary both in size (most ranging between 1.25 and 1.75 metres) and in the toxicity of their venom. Spitters propel venom through the fangs by muscular contraction of the venom ducts and by forcing air out of the single lung.

Credit : Britannica

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Pythons are nonvenomous snakes found in Asia, Africa and Australia. Because they are not native to North or South America, they are considered Old World snakes. The word python can refer to both the family Pythonidae or the genus Python, found within Pythonidae.

There are 41 species of python found within the family Pythonidae, according to the Reptile Database. Though both pythons and boas are large constrictors, they are separate families.

The family Pythonidae contains some of the largest snakes snakes in the world, according to Sara Viernum, Wisconsin-based founder of The Wandering Herpetologist. “Most pythons are large snakes … such as the reticulated python (Python reticulatus), which can grow over 30 feet [9 meters] in length,” she said. “There are also small species of pythons such as the anthill python (Antaresia perthensis), which only grows up to 24 inches [61 centimeters] in length and is considered the smallest python species in the world.”

The coloration and size of different species of python vary widely. Depending on their local habitats and need for camouflage, coloring can range from elaborately patterned scales (such as those on the Burmese python, the ball python and many other species) to solid brown (leiopythons) to bright green (the green tree python), but scientists note some more subtle physical commonalities.

Within Asia, Africa, Oceania and Australia, pythons stay in relatively warm, wet climates. Many species thrive in rain forests, though pythons also live in grasslands, woodlands, swamps, rocky outcrops, dunes and shrubs, according to the San Diego Zoo. Pythons shelter in hollows, under rocks, in abandoned mammal burrows and tree branches, depending on the species. As humans have developed python habitats, pythons have become accustomed to sheltering in urban debris and farms.

Though native to the Old World, one species of python has made its home in the Western Hemisphere. “The Burmese python is an invasive species that has been discovered living and successfully breeding in the Florida Everglades,” Viernum said. The climate of the Everglades allows it to live much as it would in a Southeast Asian swamp.

Credit : Live Science 

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Anacondas are semiaquatic snakes found in tropical South America. They are some of the largest snakes in the world and are known for their swimming ability. “Anaconda” is the common name for the genus Eunectes, a genus of boa. Eunectes means “good swimmer” in Greek.

There are four recognized species of anaconda, according to Bill Heyborne, a herpetologist and professor of biology at Southern Utah University. They are the green anaconda, the yellow or Paraguayan anaconda, the dark-spotted anaconda and the Beni or Bolivian anaconda. “They can be differentiated from one another genetically, but also based on their size and geographic range,” Heyborne said. 

Heyborne said that when most people say “anaconda,” they are actually referring to the green anaconda, the largest of the four species. The green anaconda is the heaviest snake in the world and one of the longest. 

Anacondas are stocky, muscular snakes that are thicker than other boas. They have thick necks and narrow but large heads. All anacondas have nostrils and eyes on the tops of their heads, which allow them to see above the water while remaining mostly submerged. They have a thick black stripe that runs from the eye to the jaw.

Anacondas have small, smooth scales that grow larger toward the posterior of their bodies. They have loose, soft skin that can handle a great deal of water absorption, according to the University of Michigan’s Animal Diversity Web (ADW). 

Near their cloacal region, anacondas have spurs on their scales. Males have larger spurs than females, though females are overall larger and longer snakes. In fact, anacondas exhibit the largest sexual dimorphism (with the female being larger) of any tetrapod species, according to Jesus Rivas, a herpetologist and founder of the Anaconda Project.

Anacondas’ coloring and size depends on the species. Their spotted, green, yellow and brown color palettes allow them to blend in with tropical rivers and rainforests. 

Credit : Live Science             

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Vipers are a large family of snakes; the scientific name is Viperidae. They are found all over the world, with the exceptions of Antarctica, Australia, New Zealand, Madagascar, north of the Arctic Circle and island clusters such as Hawaii. 

The family Viperidae includes adders, pit vipers (like rattlesnakes, cottonmouths and copperheads), the Gaboon viper, green vipers and horned vipers. 

All vipers are venomous and have long, hinged fangs. "Generally more venomous vipers are in tropical areas, particularly South America and Africa," said Alan Savitzky, a professor of biological sciences at Utah State University specializing in the biology of snakes. Vipers found in colder, northern climates, such as the black or European adder have more moderate venom. 

Vipers range widely in size, though are generally stocky with short tails. One of the world’s smallest vipers is the Mao-Lan pit viper (Protobothrops maolanensis), which was discovered in China in 2011. They are less than 2 feet (61 centimeters) long, according to National Geographic. The longest viper — and the longest venomous snake in the Americas — is the South American Bushmaster (Lachesis muta), which grows to more than 11 feet (335 cm), according to the University of Michigan’s Animal Diversity Web (ADW). 

Almost all vipers have a distinctive triangular head, according to Discover magazine. This head shape is due to the placement of their large venom glands in the mouth. Some nonvenomous species have evolved a similarly shaped head in order to potentially trick predators into thinking they are vipers. Additionally, most vipers have keeled scales, vertically elliptical pupils and coloring and patterns that serve as camouflage. 

Vipers are known for their extreme fangs, which are long, hollow, hinged and rotatable, according to an article in the journal Physiological and Biochemical Zoology. These fangs connect to venom glands located behind the eyes at the back upper part of the jaw. Venom travels down through the follow teeth to be injected into prey as the viper bites. 

Vipers can rotate their fangs together or independently, which allows them to wait until the last second to erect their fangs. Their mouths can open nearly 180 degrees so the ability to rotate their fangs within that space is an advantage. When not in use, vipers’ hinged fangs fold up and lie against the roof of the snake’s mouth. This allows their fangs to grow relatively long, according to Andrew Solway, author of "Deadly Snakes" (Heinemann-Raintree, 2005).

Vipers can extend their fangs and bite without injecting venom. This is known as a dry bite and is common in human snakebites. Dry bites enable vipers to conserve their previous venom, which can run out and takes a while to replenish, according to an article in the journal Tropical and Geographical Medicine. 

Credit : Live Science 

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Black mamba is species of mamba snake known for its large size, quickness, and extremely potent venom. It lives in sub-Saharan Africa and is one of the continent’s most dangerous snakes.

The average black mamba is 2–2.5 metres (6.6–8.2 feet) long, with a maximum length of 4.3 metres (14 feet). Despite its name, the snake is not black. Instead, it ranges in colour from gray to dark brown, with a lighter underside. The black actually refers to the colour of the inside of its mouth; green mambas and other snakes have white mouths. The black mamba is found in rocky savannas and lowland forests. Unlike the other mamba species, the black mamba is not primarily arboreal, preferring the ground, where it often sleeps in termite mounds or tree hollows. One of the fastest snakes, it is capable of speeds of more than 12 miles (19 km) per hour. The black mamba typically lays 6 to 20 eggs. Prey consists primarily of small mammals and birds.

Although it has an aggressive reputation, the black mamba is generally shy and nervous, and it will use its incredible speed to escape threats. However, if disturbed or cornered, the snake may rear up and threaten with an open mouth and a slightly expanded or flattened neck (or hood) before striking; once a black mamba attacks, it will bite its victim repeatedly. Its extremely toxic venom—two drops of which will reportedly kill most humans—attacks both the nervous system and the heart. Even though most bites are fatal, it is responsible for only a small number of deaths annually, and unprovoked attacks on humans have not been proved. In the wild, black mambas will typically live at least 11 years, while those in captivity have life spans of more than 20 years.

Credit : Britannica 

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