My Science School

The first thing you will notice when comparing an alpaca and a llama is their size difference. Llamas are significantly bigger than alpacas. 

In regards to their height, llamas are taller, reaching 42 to 46 inches (106 to 117 cm) on average. Alpacas measure between 34 to 36 inches (86 to 92 cm) on average.

However, the weight difference between these two animals is even more significant. On average, llamas weigh between 280 and 450 pounds (127 to 204 kg). That is quite a lot compared to the 106 to 185-pound (48 to 84 kg) average weight range for alpacas.

Llamas have a longer face with a larger muzzle. Alpacas, on the other hand, have round, smooshed faces. They also have fluffy fur on their face, especially on their foreheads. Llamas tend to have short and thin fur around their face. 

Alpacas have softer facial features than llamas. Because of this, many people believe alpacas are the cuter of the two.

Llama ears are tall and long. They stand up in a shape that looks like a banana. Alpacas have shorter, pointy ears. Their fuzziness continues onto their ears, whereas llamas tend to have smoother and straighter fur around their ears. 

Credit : Peru For Less

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Llamas are hardy, smart animals that are easy to train. Native to Central and South America, they are used as pack animals as they can carry a generous load of weight. However, when they are overloaded, they simply lie down and refuse to move. Did you know llamas spit and kick when provoked or threatened?

Llamas, guanacos, vicuñas (Vicugna vicugna), and alpacas (V. pacos) are known collectively as lamoids. Unlike camels, llamas and other lamoids do not have the characteristic camel humps; they are slender-bodied animals and have long legs and long necks, short tails, small heads, and large pointed ears. Gregarious animals, they graze on grass and other plants. When annoyed, they spit. Lamoids are able to interbreed with one another and produce fertile offspring.

The llama is the largest of the four lamoid species. It averages 120 cm (47 inches) at the shoulder, with most males weighing between 136 and 181.4 kg (300 and 400 pounds) and most females weighing between 104.3 and 158.7 kg (230 and 350 pounds). A 113-kg (250-pound) llama can carry a load of 45–60 kg and average 25 to 30 km (15 to 20 miles) travel a day. The llama’s high thirst tolerance, endurance, and ability to subsist on a wide variety of forage makes it an important transport animal on the bleak Andean plateaus and mountains.

Credit : Britannica

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You may have come across news stories about captive-breeding programmes being successful or failures. What is captive breeding?

Captive breeding is a programme where usually animals, birds, reptiles, etc. that are extinct or nearly extinct in the wild, or those that are endangered, are bred in a controlled facility under human supervision. It is seen as a conservation effort because it strives to ensure that a species does not go extinct, and as a result, also protects the animal's habitat. Captive breeding is also viewed as part of species-survival plans that help create "large, healthy, and genetically diverse populations", thus leading to biodiversity too. There are many instances of captive breeding leading to newer populations of animals. For instance, the Arabian oryx that went extinct in the wild in the 1960s was captive bred and reintroduced into the wild in the mid-1980s.

However, the process is not without concern.

Normally, the creatures are bred in an environment different from their natural habitat. They are also in a safe environment, and are fed, which means they lack opportunities for their natural instincts to kick in or to learn survival skills. This could prove problematic or even fatal when such animals are released into the wild. Also, since only a small population is used for breeding, it can lead to in-breeding. In-breeding happens when closely related animals breed. If there are genetic problems or infections in the breeding population, this is likely to continue over generations.

Captive breeding may not always be taken up for conservation. Animals could be bred this way for zoos where they are primarily used for exhibition, often in cages under unhygenic conditions. Exotic animals can be bred to be pets or for the pet trade, or for illegal trade where they are killed for their skin, meat, etc.

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A chameleon is a very unique lizard that inhabits warm locations such as rainforests and deserts. They are known for their colour-changing abilities, long tongues, and unusual eye movements. The word chameleon comes from the Latin word chamaeleon, derived from Greek words chamai and leon, meaning ground and lion respectively. So, chameleon means lion on the ground. It is thought that the name refers to the ornate mane-shaped crests around the heads of some species.

The longest chameleon in the world is Parson’s chameleon (Calumma parsonii), which may grow up to 69.5 cm (about 27 inches) long. On the other hand, the world’s shortest chameleon, the male nano-chameleon (Brookesia nana), can be as small as 21.6 mm (about 0.9 inch) long. Most chameleons, however, are 17–25 cm (7–10 inches) long. The body is laterally compressed, the tail is sometimes curled, and the bulged eyes move independently of one another. Also, some chameleons possess helmet-shaped heads.

The chameleon’s specialized vision and a specialized tongue-projection system permit the capture of insects and even birds from a distance. The chameleon’s eyes are very good at detecting and regulating light. The lens of a chameleon’s eye is capable of focusing extremely rapidly, and it can enlarge visual images much like a telephoto lens. Although many other lizards also use the tongue to capture prey, most can expel it only a short distance. 

Credit : Britannica

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Cobra is a species of highly venomous snakes, which expand the neck ribs to form a hood. These snakes are prevalent in India. It is believed that the Portuguese colonists in India gave the snakes their name. Cobra de capello is Portuguese for serpent of the hood or hooded serpent. Its genus name Naja has Indian origins, and may have derived from the Sanskrit word for snake Naga.

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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Hippopotamuses are large, round, water-loving animals that are native to Africa. Greek writer Herodotus is credited with naming this unusual creature. In Greek, the word hippo means horse and potamos means river. But hippos are not related to horses, they are in fact related to pigs, whales, and dolphins!

Hippo is often attributed to terms related to horse. For instance, hippodrome is a stadium for racing horses (and not hippos). Seahorses belong to a genus called hippocampus

(Hippocampus is Greek for seamonster, and it originally referred to a mythological creature that resembled a horse with wings).

Do you know why our brain area hippocampus is called so? Because the part resembles a seahorse.

Hippos live in sub-Saharan Africa. They live in areas with abundant water, as they spend most of their time submerged to keep their skin cool and moist. Considered amphibious animals, hippos spend up to 16 hours per day in the water, according to National Geographic.

Hippos are social beasts, hanging out in groups called schools, bloats, pods or sieges. Schools of hippos usually consist of 10 to 30 members, including both females and males, although some groups have as many as 200 individuals. No matter the size, the school is usually led by a dominant male.

According to the International Union for Conservation of Nature (IUCN), the common hippo isn't endangered, but it is vulnerable to extinction. The IUCN estimates that between 125,000 and 148,000 hippos remain in the wild. Poaching and habitat loss reduced the hippo's global numbers during the late 1990s and early 2000s, but the population has since plateaued thanks to stricter law enforcement, according to the IUCN.

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Rhinoceros is a giant horn-bearing herbivore that's among the largest living land mammals. It derives its names from its most pronounced feature: the horn. The term stems from the Latin word rhinoceros and Greek word rhinokeros, both of which take root in rhinos, which means nose, and keras, meaning horn. (Keras is also the origin of keratin, the protein that is the main substance of hair, nails, horns, and feathers).

Rhinoceroses are characterized by the possession of one or two horns on the upper surface of the snout; these horns are not true horns but are composed of keratin, a fibrous protein found in hair. Modern rhinoceroses are large animals, ranging from 2.5 metres (8 feet) long and 1.5 metres (5 feet) high at the shoulder in the Sumatran rhinoceros to about 4 metres (13 feet) long and nearly 2 metres (7 feet) high in the white rhinoceros. Adults of larger species weigh 3–5 tons. Rhinoceroses are noted for their thick skin, which forms platelike folds, especially at the shoulders and thighs. All rhinos are gray or brown in colour, including the white rhinoceros, which tends to be paler than the others. Aside from the Sumatran rhinoceros, they are nearly or completely hairless, except for the tail tip and ear fringes, but some fossil species were covered with dense fur. The feet of the modern species have three short toes, tipped with broad, blunt nails.

In rhinoceroses, females do not conceive until about six years of age; gestation is long (16 months in most species), and they give birth to only one calf at a time. The period of birth between calves can range from 2 to 4.5 years. Thus, the loss of a number of breeding-age females to poachers can greatly slow the recovery of rhinoceros populations.

Credit : Britannica

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Orangutans are great apes native to the rainforests of Indonesia and Malaysia. The name orangutan is derived from two Malay words - orang, meaning person and hutan meaning forest. So orangutan means person of the forest. Humans and orangutans share approximately 97% of the DNA and 28 physical traits. Orangutans laugh, recognise faces, 'talk about the past learn from each other, and pass on the knowledge to the next generation. Hence, it is only fitting that we call the animal the 'person of the forest.

Orangutans are not as powerfully built as the gorilla but are larger than the chimpanzee. The adult male is typically twice the size of the female and may attain a height of 1.3 metres (4.3 feet) and a weight of 130 kg (285 pounds) in the wild; females weigh 37 kg (82 pounds) or less. Older males develop wide cheek pads, a unique feature among primates. The typically dark tan or brownish skin is covered with relatively coarse and usually sparse red hair. Adult males and some older adult females may have partially or entirely bare backs, but the hair on a male can be so long as to look like a cape when he moves his arms.

Orangutans are predominantly ripe-fruit eaters, although they consume more than 400 different types of food, including invertebrates and, on rare and opportunistic occasions, meat. Almost every night orangutans construct a sleeping platform in the trees by bending and breaking branches, leaves, and twigs. Unlike the African apes, orangutans frequently use vegetation to protect themselves from the rain.

Credit : Britannica

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Lemurs are 100 or so species of primates in Madagascar. The name lemur derives from the Latin word lemures, which some dictionaries translate as ghosts. In Ancient Rome, lemures were believed to be a kind of eerie-looking malignant dead that wandered the earth at night, causing hurt and injury to the living. It is believed that the name got attached to the primates because of their reflective eyes and their silent nocturnal wanderings.

A number of lemurs are rare or endangered. Several either were not discovered until the late 20th century or were rediscovered after having been thought extinct. Remains exist of species larger than any of today’s lemurs. Some of these may have survived until only 500 years ago. They were probably exterminated by overhunting or habitat modification by the Malagasy people, who arrived on the island less than 2,000 years ago.

Lemurs are less intelligent than monkeys. Their sense of smell is more acute but their vision less so. Although some species are at times active during the day, their eyes seem to be adapted for nocturnal life, trading acuity for increased sensitivity in low light conditions. All lemurs are characterized by a reflective layer (tapetum) behind the retina in the eye, but no fovea or macula lutea; a hairless, moist tip to the muzzle; a noninvasive (epitheliochorial) placenta; comblike forward-directed lower front teeth (with the exception of the aye-aye); and a claw (“toilet claw”) on the second toe of the foot.

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The Tripod fish or the 'stilt walker' has modified pelvic and caudal fins that are elongated at the tips, called rays or elements. It uses these rays to perch on the deep sea floor. Scientists suspect that fluid is: pumped through the extremely long rays, making them rigid and allowing the fish to balance while "standing". As a result of living in virtually complete darkness, these eyeless fish have developed long pectoral fins that extend upward like antennae, and serve as tactile organs or hands, when it searches for food.

Tripod fish positions its body upstream, toward the water current and waits for the prey to come. Main purpose of elongated structures is to lift the fish from the ocean floor where water current doesn't exist. This tactic ensures preservation of energy (tripod fish doesn't move when hunts) and continual supplying with the prey (which ocean current brings).

Tripod fish possesses long, feathery pectoral fins that are used as tactile organ. They float in front of the fish and detect movement of the water and potential prey. When edible prey is detected, tripod fish catches it and transports it directly into the mouth (these fins are also used as hands).

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Gastrodia agnicellus is the 'ugliest orchid in the world' according to the Royal Botanical Gardens, Kew (U.K.). Native to Madagascar, it grows underground in decaying leaf litter for most of its life cycle. The fleshy brown flowers, which are probably pollinated by flies, measure less than half an inch and have a musk rose-like scent. The orchid depends on fungi for nutrition and has no leaves or any other photosynthetic tissue.

Orchids are fascinating and there are so many variants of the flower species. The latest discovery challenges the usual approach of orchids being a delicate flower species. The blooms are often colourful and fragrant, but the latest one is described ugliest because of its appearance and flesh nature. Although assessed as a threatened species, the plants have some protection because they are located in a national park. The flowers, too, are small—just 11 millimetres in length, ranging from brown to white in colour. No one realised the significance until recently.

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Monarch butterflies embark on a marvelous migratory phenomenon. They travel between 1,200 and 2,800 miles or more from the United States and Canada to central Mexican forests. There the butterflies hibernate in the mountain forests, where a less extreme climate provides them a better chance to survive. 

Monarch caterpillars are striped with yellow, black, and white bands, and reach lengths of two inches (five centimeters) before metamorphosis. They have a set of antennae-like tentacles at each end of their body. The monarch chrysalis, where the caterpillar undergoes metamorphosis into the winged adult butterfly, is a beautiful seafoam green with tiny yellow spots along its edge.

Whether monarchs are present in a given area within their range depends on the time of year. They are one of the few migratory insects, traveling great distances between summer breeding habitat and winter habitat where they spend several months inactive. In the summer they range as far north as southern Canada. In the fall the eastern population migrates to the cool, high mountains of central Mexico and the western population migrates to coastal California, where they spend the entire winter.

The monarch population has declined by approximately 90 percent since the 1990s. Monarchs face habitat loss and fragmentation in the United States and Mexico. For example, over 90 percent of the grassland ecosystems along the eastern monarch’s central migratory flyway corridor have been lost, converted to intensive agriculture or urban development. Pesticides are also a danger. Herbicides kill both native nectar plants where adult monarchs feed, as well as the milkweed their caterpillars need as host plants. Insecticides kill the monarchs themselves. Climate change alters the timing of migration as well as weather patterns, posing a risk to monarchs during migration and while overwintering. The U.S. Fish & Wildlife Service is currently reviewing the species’ status.

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Whether delicately perched on a cattail or hovering over a pond, dragonflies are a sure sign of summer.

Living on every continent but Antarctica, these insects are instantly recognizable by their large bodies; four long, horizontal wings; and the way they hover and zip around. Dragonflies can reach speeds of up to 35 miles an hour and fly just as gracefully backward by lifting off vertically, helicopter style.

Dragonflies are important to their environments both as predators (particularly of mosquitos) and as prey to birds and fish. Because these insects require stable oxygen levels and clean water, scientists consider them reliable bioindicators of the health of an ecosystem.

In 2009, the first comprehensive assessment of insect species showed that 10 percent of dragonfly species were under threat of extinction. The animals are imperiled by destruction of freshwater habitats—particularly ponds, bogs, and fens—by pollution, and non-native vegetation.

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Sea turtles are reptiles remarkably suited to life in the sea. Their hydrodynamic shape, large size, and powerful front flippers allow them to dive to great depths and swim long distances. These front flippers are long, narrow, and winglike, while their hind flippers are shorter. Although sea turtles can remain submerged for hours at a time while resting or sleeping, they typically surface several times each hour to breathe.

Sea turtles are among the oldest creatures on Earth and have remained essentially unchanged for 110 million years. In most sea turtles, the top shell—or carapace—is composed of many bones covered with horny scales, or scutes. Unlike their terrestrial relatives, they cannot retract their heads into their shells. The smallest of the sea turtles are the two species of ridleys, weighing in at 85 to 100 pounds (38 to 45 kilograms) as adults. Leatherbacks are the biggest and can grow to 2,000 pounds (900 kilograms). Most sea turtles grow slowly and have a lifespan of many decades.

All sea turtles are threatened or endangered. They face an uncertain future due to threats of many kinds, including pollution and the encroachment of coastal development on their nesting beaches. They are also susceptible to accidental drowning in fishing gear and are at risk from the international trade in turtle meat and shell products.

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The crabs' breeding timetable is fixed around the phases of the moon. Spawning (the dropping of their eggs into the sea) must occur before sunrise on spring tides during the last quarter of the moon, regardless of any other factor. The timing of spawning is the only certain and predictable part of the whole migration; all other stages of the migration will vary with the prevailing weather.

The crabs will start their migration if there is enough time for them to complete their downward migration, mate and develop eggs before the next suitable spawning date.

The red crab breeding migration comprises a series of separate actions on the crabs' part that follow on from one to the other in a programmed sequence. These separate actions in combination make up the breeding migration and one action will not occur unless the preceding action is accomplished. If there isn't enough time for them to be able to do all of these things before the next spawning opportunity, they will delay the start of their migration and attempt to meet the following month's spawning date.

The red crab migration is Christmas Island’s biggest tourist attraction, drawing nature-lovers from all over the world.

The easiest places to watch the migration and spawning are Drumsite, Flying Fish Cove, Ethel Beach and Greta Beach.

To protect our red crabs, some sections of roads may close for part or all of the day during the peak migration time, often at short notice. But you can park your car and carefully walk among the sea of moving crabs as they make their way to and from the beach.

You will also see crab bridges built over the roads. These are great places to stand and watch the flow of crabs.

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