My Science School

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

Picture Credit : Google 

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

Picture Credit :Google 

'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 

Picture Credit : Google 

Definition of living fossil: An organism that has remained essentially unchanged from earlier geologic times and whose close relatives are usually extinct. For example :Ginkgo biloba, Syntexis libocedrii.

Did you know that the horseshoe crab has been around for 450 million years, quietly watching dinosaurs go extinct and early fish slowly evolve into land-dwelling creatures? Despite having been around for so long, today it is "listed as vulnerable in America and endangered in Asia". Sadly, one of the reasons for this is the crab being deeply linked to the safety of human life. How so? Come, let's find out.

There's one kind of bacteria that can infect medications, needles, and even certain types of medical devices. And the horseshoe crab helps detect the presence of this bacteria - its bright blue blood clots in the presence of harmful bacterial components called endotoxins. This has helped test the safety of biomedical products for nearly 50 years now. However, the pharmaceutical industry is one of the reasons that the species is endangered. The other suspects are the usuals habitat loss and overharvesting for food. The crabs are also vulnerable during the breeding season. They come to the beach for breeding and during the tide some of them end up on their backs. The unlucky among them that cannot turn back are likely to be exposed to the sun for a long time, which can prove to be fatal.

In fact, over 20 years ago, the Just flip 'em' campaign came to be, "encouraging members of the public to do their part by gently picking up upturned crabs that are still alive". While this literally saves the lives of crabs, the larger aim is that such public engagement helps them care more for and seek protection for these creatures.

Did you know?

• Calling them crabs could be a bit of a misnomer because they are more closely related to spiders and scorpions.
• Horseshoe crabs have five pairs of legs that are connected to their mouth. They crush their food, such as worms and clams, between their legs and passing it to their mouths. They also have 10 eyes.

Picture Credit : Google