My Science School

Reptiles are scaly-skinned creatures such as crocodiles, lizards and snakes. They are cold-blooded, which means they depend on the Sun for warmth and have to move back and forth between warm and cold places to maintain the right temperature in their bodies. They may spend hours basking in the sun to gain enough energy to hunt for food. Reptiles can survive on limited food, but they cannot live in cold places.

Here are a few things you may not know about them:

1. Lizards can’t feel warm or cold the way we can. But their movements and speed are affected by the outside temperature. So for instance, while they can’t feel cold, cold will make them slow. Imagine instead of saying “I feel cold” you would simply not be able to move as quickly.
2. Green iguanas become immobile when the temperature drops below 40 degrees. Since they often like to sit in trees, when the weather in places where they live, like South Florida, gets very cold they have been known to drop out of trees. While these iguanas may appear to be dead, they are often simply cold and will thaw out in the sun. However, you should never move a frozen iguana as they often become frightened as they thaw. When they become frightened, they become unpredictable. Experts would rather you leave them where they are or notify a professional to have them moved.
3. As prevalent as the Green Iguana is in Southern Florida, it is not indigenous. They were originally brought to the area as pets and were later released into the wild where they thrived. We also see this in pythons and lionfish. Never release an animal into the wild. It will affect the local ecosystem and can, in some cases, mar it for decades.
4. Evidence of the earliest reptiles dates back to 312 million years ago.
5. Although reptiles are often found in warm areas, they actually inhabit every continent but Antarctica.
6. Reptiles come in a broad range of sizes. Of the living versions, not including anything that’s extinct, The tiniest is the gecko at under an inch and the largest on record is the saltwater crocodile, which can reach about 20 feet long.
7. A crocodile needs a tenth of the food a lion does for survival. That’s why the crocodile can go up to half a year without eating, if necessary. Because of this, crocodiles can survive temporary food shortages that might kill off or cause other animals to leave an area for food. A crocodile will stay in an area long after its main food source is gone or it may look for another one. That’s the reason why when new developments are built around water, these animals may stay long after others have left due to human invasion.
8. All reptiles use lungs to breathe.
9. Most reptilians must hold their breath while swallowing. This is not the case for crocodilians, who have a secondary palate that allows them to continue breathing even while their mouth is full of struggling prey.
10. The turtles’ lungs are attached to the inside of the top of their shells.
11. On land, female green sea turtles do not breathe while they’re walking. They either rest and take a breath or wait until they are in the nest they’ve created.
12. Reptiles’ skin is watertight, meaning they do not get soggy and water does not penetrate their scales.
13. Reptiles shed their skin periodically. The younger they are, the more often they shed.
14. Snakes shed from head to tail in one whole section, which you know if you ever come across a snakeskin. Some snakeskins, at first glance, almost look like the snake they came from. On the other hand, lizards shed their skin in patchy sections.
15. Some tortoises have disproportionately large bladders. Charles Darwin noted that the Galapagos turtle can store 20% of its body weight in its bladder.
16. Some reptiles that live in desert climates have secondary bladders that allow them to store water for several months.
17. Reptiles digest food slower than mammals do. This is due to a slower metabolism but also the fact that many reptiles do not masticate (or chew) on their prey. Many just swallow it whole.
18. Large reptiles, like crocodiles and constrictors, can live several months on a single meal.
19. Some reptiles that eat plants and lack the teeth to chew them actually swallow rocks to aid in the digestion of this plant matter.
20. Reptiles are considered less intelligent than mammals because the size of their brain relative to their body is smaller. However, larger reptiles have been known to play (the Komodo dragon) and show cooperation (monitors), so this may be a slightly unfair assumption.
21. Most reptiles can see colors better than most mammals can.

Credit : Alligator wildlife discovery centre 

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Bees are flying insects found in every continent of the earth (except Antarctica), and in every habitat where there are insect-pollinated flowering plants. There are over 16,000 species of bees! Bees like honeybees and bumblebees live in colonies, in hives or nests. Many fruits and vegetables that humans eat are pollinated by bees. Even food eaten by cattle and other farm animals needs bees for pollination. So, when we are eating plants directly or meat from an animal that has had a diet of plants, we depend on bees for our food.

Why are bees important?

Health products

Not all bees produce honey, but it is one of the main reasons people value them. The substance is a natural sweetener with many potential health qualities.

People have used bees and bee-related products for medicinal purposes for thousands of years. ResearchersTrusted Source have noted claims that it has antioxidant, antimicrobial, anti-inflammatory, and anticancer properties.

Pollination

In recent years, it has become clear that honey may not be the most important reason to protect bees. This is because bees play a crucial role in pollination, where they use the hairs on their bodies to carry large grains of pollen between plants.

Around 75% of crops produce better yields if animals help them pollinate. Of all animals, bees are the most dominant pollinators of wild and crop plants. They visit over 90% of the world’s top 107 crops.

Historical importance

People have been working with bees around the world for millennia. The significance comes from the direct harvesting of honey and beeswax and cultural beliefs.

For example, the Ancient Greeks thought of bees as a symbol of immortality. In the 19th century, beekeepers in New England would inform their bees of any major events in human society. Meanwhile, native northern Australians used beeswax when producing rock art.

Society and the environment

Bees are very intelligent, and people have applied knowledge of their mannerisms and social interactions when creating human initiatives.

For example, researchers have suggested that studying the actions of bees could help experts develop emergency plans to evacuate people from an overcrowded environment.

How does this affect humans?

Farming practices, global warming, and disease are just a few reasons why bee numbers are declining. Experts are concerned about the impact on world food supplies, especially fruits, nuts, and vegetables.

They say that without bees, there will be no more nuts, coffee, cocoa, tomatoes, apples, or almonds, to name a few crops. This could lead to nutritional deficiencies in the human diet, as these products are essential sources of vital nutrients.

Additionally, the emergingTrusted Source medicinal properties of bee venom and other bee products may never be accessible without bees to provide them.

Credit : Medical news today 

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Insects are small animals with no bones. An insect's body is protected by a hard outer covering called an exoskeleton. The body has three segments: head, thorax and abdomen. The head has eyes - which can have six to 30,000 lenses - and a pair of antennae to feel, taste and smell things. The thorax has wings and legs. The abdomen includes systems for digesting food.

The insects have proved to be the most successful arthropods. There are far more species in the class Insecta than in any other group of animals. These amazingly diverse animals have conquered all the environments on earth except for the frozen polar environments at the highest altitudes and in the immediate vicinity of active volcanoes.

Insects are the only invertebrates (animals without backbones) with wings. Much of their success results from their ability to fly and colonise new habitats. The study of insects is called entomology and entomologists are scientists who study insects.

Insects play a very important role in the web of life, in every environment. Some of their jobs include pollinating flowering plants, being a source of food for insectivorous animals and assisting in the decomposition of plants and animals.

Insect classification

Modern insect classification divides the Insecta into 29 orders, many of which have common names. Some of the more common orders are:

Mantodea - praying mantids
Blattodea - cockroaches
Isoptera - termites
Siphonaptera - fleas
Odonata - dragonflies and damselflies
Dermaptera - earwigs
Diptera - flies
Lepidoptera - butterflies and moths
Orthoptera - grasshoppers, katydids, crickets
Coleoptera - beetles
Hymenoptera - wasps, bees, ants, sawflies

Insect features

The insect body is divided into three main parts, the head, thorax and abdomen.
Insects have no internal skeleton, instead they are covered in an external shell (exoskeleton) that protects their soft internal organs.
No insect has more than three pairs of legs, except for some immature forms such as caterpillars that have prolegs. These are appendages that serve the purpose of legs.
The typical insect mouth has a pair of lower jaws (maxillae) and upper jaws (mandibles) which are designed to bite. There are many variations to this structure, as many moths and butterflies have tubular sucking mouthparts, many bugs and other blood-sucking insects have sucking stabbing mouthparts and some adult insects simply don't have functional mouthparts.
Insects have one pair of antennae located on the head
Most insects have one or two pairs of wings although some insects such as lice, fleas, bristletails and silverfish are completely wingless.

Credit : Australian.museum

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Animals kept by humans to help them in farm work, carrying loads, travelling from one place to another, and producing goods for everyday needs, like milk, fur, wool and leather are livestock animals. Cattle, sheep, pigs, goats, horses, donkeys, mules, buffaloes, camels and llamas are livestock. Farmed birds like chicken, turkeys and geese are poultry, not livestock.

An efficient and prosperous animal agriculture historically has been the mark of a strong, well-developed nation. Such an agriculture permits a nation to store large quantities of grains and other foodstuffs in concentrated form to be utilized to raise animals for human consumption during such emergencies as war or natural calamity. Furthermore, meat has long been known for its high nutritive value, producing stronger, healthier people.

Ruminant (cud-chewing) animals such as cattle, sheep, and goats convert large quantities of pasture forage, harvested roughage, or by-product feeds, as well as nonprotein nitrogen such as urea, into meat, milk, and wool. Ruminants are therefore extremely important; more than 60 percent of the world’s farmland is in meadows and pasture. Poultry also convert feed efficiently into protein; chickens, especially, are unexcelled in meat and egg production. Milk is one of the most complete and oldest known animal foods. Cows were milked as early as 9000 BCE. Hippocrates, the Greek physician, recommended milk as a medicine in the 5th century BCE. Sanskrit writings from ancient India refer to milk as one of the most essential human foods.

Animal products like milk, meat and eggs have long been part of the human diet. They provide us with caloric energy and many essential nutrients. For example:

A 250ml serving of milk provides 150% of the reference nutrient intake (RNI) for vitamin B12.
A 200g serving of lean beef provides 36% and 62% of the RNI for iron for female and male adults respectively .

Many farmers all over the world specialise in producing livestock which are of central economic importance to their farming businesses. Some farmers keep livestock and grow crops as a mixed farming enterprise where the livestock are an integral part of the farm’s system – providing manure to support arable crop growth.

Credit : Brittannica 

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Although natural disasters and sudden changes on Earth's surface, such as earthquakes, volcanoes and wildfires, can hurt the animal kingdom, human-led changes, such as the cutting down of forests, deliberate forest fires, water and air pollution, have also severely affected wild animal habitats across the world.

Earthquakes and tsunamis

According to United States Geological Survey (USGS), each year there are 15-20 major earthquakes worldwide with a magnitude of over 7.0 and over a thousand that measure above 5.0.5 Unlike hurricanes and volcanoes, earthquakes hit without warning.6 In addition to shaking land, they can shake and displace the seabed. Islands and beaches can disappear from subsiding land or double in size because the land surrounding it is uplifted.7 When the ocean floor is displaced, it can create a tsunami, which is a series of high, fast waves that begin quickly, can cross oceans, and can last for days.8 They may be followed by landslides that bury animals alive and destroy their homes9 or floods that can sweep them away.

Volcanoes

There are at least 20 volcanoes erupting around the world at any time, not including volcanoes erupting underwater, which are much greater in number.13 Eruptions can last for months or years, spewing abrasive and toxic lava and ash, causing explosions, and heating nearby water that can boil marine animals alive.

Storms

The wind, rain, and debris from storms injure and kill animals and cause a lot of damage to their habitats, including destroying shelters and contaminating food and water sources. During Hurricane Dorian in 2019, winds reached 295 km per hour. Strong winds and rain can cause broken limbs, head trauma, as well as breathing problems and infections from getting water in the lungs. Animals are displaced and orphaned. Most of these problems would not be fatal if the animals were able to receive care, but in most cases they do not. A few lucky mammals and birds get care if they are blown into urban areas and are found disoriented on someone’s lawn.

Floods

Smaller animals are more vulnerable to drowning or dying in resulting floods and mudslides. Burrowing animals may be safe from smaller disturbances, but torrential rains can collapse their burrows or block the entrances, trapping them or leaving them without shelter. Burrow entrances can be blocked by branches, leaves, stones and other debris moved around by water or wind.

Fires

A single wildfire can kill millions of animals. The flames and smoke of forest fires kill most animals in their path, including many burrowing animals who are too near the surface, and animals who live in rivers and streams as the flames pass over. Even if they survive the fires, the aftermath can leave animals with burns, blindness, and respiratory problems that can be fatal or permanently debilitating. Hurricane force winds can carry embers and ash from a fire up to a mile away, which can trigger new fires. Strong fires generate so much energy that they change the local weather by modifying wind and temperature. The moisture coming off a fire can generate clouds that cause rain.

Credit : Animal ethics

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When one animal kills another for food, it is called predation. The animal which kills is called a predator, and the animal which gets killed is known as prey. Predators often have special skills for hunting, with highly tuned vision, hearing and sense of smell. Many have sharp claws and jaws to grab hold of and tear the body of the prey. Predators can act in a group or can kill alone. At times they hide and wait to catch their prey off-guard in an ambush killing.

Predator and prey evolve together. The prey is part of the predator's environment, and the predator dies if it does not get food, so it evolves whatever is necessary in order to eat the prey: speed, stealth, camouflage (to hide while approaching the prey), a good sense of smell, sight, or hearing (to find the prey), immunity to the prey's poison, poison (to kill the prey) the right kind of mouth parts or digestive system, etc. Likewise, the predator is part of the prey's environment, and the prey dies if it is eaten by the predator, so it evolves whatever is necessary to avoid being eaten: speed, camouflage (to hide from the predator), a good sense of smell, sight, or hearing (to detect the predator), thorns, poison (to spray when approached or bitten), etc.

In this snowy environment, the polar bear is white to avoid being noticed as it approaches the seal, and the seal pup is white to avoid being noticed by the bear.

The fastest lions are able to catch food and eat, so they survive and reproduce, and gradually, faster lions make up more and more of the population. The fastest zebras are able to escape the lions, so they survive and reproduce, and gradually, faster zebras make up more and more of the population. An important thing to realize is that as both organisms become faster to adapt to their environments, their relationship remains the same: because they are both getting faster, neither gets faster in relation to the other. This is true in all predator-prey relationships.

Another example of predator-prey evolution is that of the Galapagos tortoise. Galapagos tortoises eat the branches of the cactus plants that grow on the Galapagos islands. On one of the islands, where long-necked tortoises live, the branches are higher off the ground. On another island, where short-necked tortoises live, the branches are lower down. The cactuses, the prey, may have evolved high branches so that the tortoises, the predators, can't reach them.

Credit : New England complex system institute

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'Fauna' is a word for all the animal life within a region or period of time. The word comes from Greek mythology and roughly means 'creatures of the wild'. The naturalist Carl Linnaeus was the first to use this term in 1974 in the title of his book Fauna Svecica, which means the 'wildlife of Sweden'.

History of Fauna

Fauna was first used as a biological term by naturalist Carl Linnaeus, as a term which described the animals of a region, as opposed to the plants. Plant life was dubbed flora. Thus, the flora and fauna of a region or time describe all of the life within. Linnaeus seems to have borrowed the term from Greek and Roman mythology.

In Greek mythology, the god Pan is the goat-legged offspring of a more powerful god and a wood nymph. This leads him to become the representative god of the wild. Roman mythology adopted this persona in the gods Faunus and Fauna, which gave rise to a number of man-creatures which populated the mythology. Linnaeus adopted the word for his formal work on the animals of Sweden Fauna Suecica, in 1745. Roughly translated, this means the “wildlife of Sweden”.

Following his lead, naturalists began to use the terms flora and fauna to identify the various living organisms in a taxonomic hierarchy. Flora included everything in the kingdom Plantae, while fauna included the kingdom Animalia. The definition of fauna has expanded and changed over the years. For instance, when genotyping became a reality and it was understood that there are actually 3 domains of life, the Archaea, Bacteria, and the Eukarya.

With this change came the formal phasing out of the word fauna, scientifically. While the word flora had maintained its definition as “any organism within the kingdom Plantae”, fauna had changed drastically. Fauna, as used currently, typically describes any organisms in the domains Archaea and Bacteria, plus the kingdom Animalia. This is not a monophyletic grouping, and as such does not accurately describe anything for scientists trying to organize the forms of life in a place or time. Further, flora and fauna tend to exclude the kingdom Fungi, which was once recognized as a plant but is now recognized as its own kingdom.

Examples of Fauna

Fauna of the Great Plains, 2018

If you were to conduct a survey, today, of all the fauna in the Great Plains of the United States, you would find a great many species. You would find many species of birds, from pheasants to eagles. You would find mammals, from the tiny field mouse to the mighty bison. Most other groups, from the reptiles to the worms, would also be represented. You would surely find an abundance of insects. On the microscopic level, the soil and waters are teeming with fauna. Even waters too acidic or hot for the normal fauna can host thermophilic or acidophilic bacteria and other organisms, evolved to deal with the harsh conditions. In essence, if you take the entirety of life on the Great Plains today, subtract all the plants, you have a representation of the fauna. This is obviously a large and intangible collection of many different inter-related species.

Fauna of the Great Plains, 100 Million Years Ago

If we could take ourselves back in time, the fauna of the Great Plains would look much different. Although we would remain in the same place, the environment would be very different. At that time, glaciers had melted to a low, and a vast inland sea had spread across the continental United States.

In this inland sea would have existed a variety of monsters, from the first modern sharks, to giant marine reptiles like Ichthyosaur and Plesiosaur. Modern bony fishes were evolving, as well as a variety of other marine organism. In this vast sea, you could have found everything from early starfish, to horseshoe crabs, to all sorts of evolving arthropods. Other fauna of the historical Great Plains would include the microscopic diatoms and zooplankton and algae, which would have been the base of the food-chain at the time. As the glaciers reformed, the land was colonized by the terrestrial organisms we know today. You can see how the fauna of a region can easily change over time.

Gut Fauna

A popular term these days is “gut fauna”, or in other words, the creatures living inside of your digestive tract. Humans, like almost all other animals, have a complex symbiotic relationship with the organism harbored within them. While there are barriers in place to keep these organisms from infecting the body, they are essential to digesting many types of food. Technically speaking, the fauna in the gut is referred to as the microbiome, because it is its own unique ecosystem. There are many species of bacteria and eukaryotes which take part in digestion, and each fills a unique niche in the ecosystem. While scientists have yet to fully understand the microbiome of the digestive system, there are many diets and probiotics on the market which claim to positively affect the fauna of the microbiome. These claims have yet to be confirmed by mainstream science.

Credit : Biology dictionary 

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