My Science School

Every year at a particular time, a wide variety of animals, including mammals, birds, reptiles, amphibians, fish, and even insects undertake migration - they move in large numbers from one place to another in search of food and water or suitable breeding ground.

Some habitats may have unfavourable climate such as extreme heat, or cold or wet conditions, which the animals may want to escape from. On the other hand, some habitats may offer easy access to food and water or better shelter, beckoning animals to move there so that they could flourish. But migration is temporary; it always includes a return journey.

Why is animal migration important?

Migration of animals plays a very important role in the Earth's ecosystem. Migratory animals help in pollination and seed dispersal. They provide food for other animals and also control the population of species in various ecosystems. For example, migratory birds reproduce and their young ones eat insects that may destroy crops. Locust attack is a major disaster that arises from the absence of birds.

Climate change

Several animal species have changed their migration routes in response to the changing climate. The rising temperatures on land and sea are forcing more and more animals to migrate to cooler climates. The moose, found in the northern U.S. and Canada, is a cold-weather animal. But milder winters have led to an increase in the population of winter ticks. These blood-sucking parasites are killing dozens of moose every year, forcing them to move farther north.

Habitat destruction

Habitat destruction is mostly a result of human activities. These include farming, cutting down trees for construction activities. filling wetlands, building dams, digging for oil and gas exploration, amongst others.

Habitat destruction makes it difficult for migrating animals to find places to rest and get food on their migratory paths. Several fish species migrate from open waters to headwaters to breed or spawn. But dams, which are constructed for water retention or hydroelectric power generation, can completely disrupt migratory pathways for fish.

In China, thousands of Siberian cranes spend the winter at the Poyang Lake. However, drought and water management in the region have destroyed the cranes habitat, forcing them to travel to suboptimal areas. Now, a proposed dam at the outlet of the lake is a new threat that will reduce the quality of the restricted area these birds rely on.

Human behaviour

Migratory animals also face a unique threat of obstruction along their migratory routes. Roads, fences, dams, wind farms, and buildings extending into forests can create huge obstacles. Here are a few examples.

Every year, thousands of wildebeest and zebras in the savannah grasslands of Africa undertake an arduous migration over the vast expanse of land in search of food and water. In the last decade, however, several small enclosed plots have disrupted free movement of animals on their migratory path.

Tens of millions of red crabs cover roads on Christmas Island and Cuba as they undertake their annual migration, travelling from the forest to the coast to spawn. Millions die each season on the road as they get crushed by passing vehicles.

Poorly located windmills too can result in the death of migratory birds. The Wolfe Island Wind Farm, located in North America, is one of the deadliest barriers to migratory birds.

Picture Credit : Google 

Love the thrill of watching a butterfly flutter by? The excitement of discovering the name of a tree species? Understanding how living beings evolve? If you're a wildlife lover, here are four career options you can explore.

Marine biologist

What to study: BSc in marine biology or a related field such as oceanography, marine science, or earth science, followed by a Masters.

What the job entails: Marine biologists study animal, plant, and microscopic life in oceans. But this does not mean they're always into deep-sea diving! They work with samples in research laboratories for any discoveries, and also prepare reports worthy of publication.

Benefits: In addition to closely observing all kinds of marine creatures, they could be a changemaker. Apparently, a little more than three-fourth of all life on our planet is found under the ocean surface. And since they are also indicators of the changes around us - such as pollution and climate change - marine biologists could be the one to announce this to the world, nudging citizens to be responsible and protect our world.

Challenges: While not always, field work - in oceans - can be physically demanding, due to being in water for a long while, lugging heavy equipment, etc. The location could be remote, affecting one's social life for long periods of time.

Wildlife photographer/ filmmaker

What to study: For both photography and filmmaking, there are degree and short-term courses offered both in India and abroad.

What the job entails: As is evident from the job title, one photographs or shoots films about wildlife. It also involves team work, constant learning, being aware, fit, resilient, quick to adapt, among others.

Benefits: Watching wildlife, learning about them, and enlightening the layperson. Though it is not a 9-to-5 job, it has the potential to be lucrative. Professionals can even be part of wildlife magazines or television channels. And, there is recognition. going by the growing number of awards presented to wildlife photographers and filmmakers globally. But, do they match the reward of watching Nature up-close?

Challenges: While the technicalities of shooting a picture or film/ documentary can be learnt through professional courses offered across the globe, certain aspects are learnt on the job. For instance, patience and acceptance. Nature is what it is one has no control over timing the blooming of a flower or a tiger snagging its prey. Sometimes no matter how much one is prepared, the result may not be what one wants.

Wildlife rehabilitator

What to study: While a degree in biology or ecology is seen as necessary, the subjects covered could include ornithology, mammalogy, animal behaviour, etc.

What the job entails: Wildlife rehabilitators care for and treat injured, orphaned, or displaced wildlife. Their aim is to ensure that the animals are healthy and prepared appropriately to finally return to the wild.

Benefits: In addition to saving and protecting wildlife, they play a huge role in rescuing animals during natural disasters and also educating people about wildlife. Their role helps reduce human-wildlife conflicts, and create a sense of responsibility among people towards wildlife.

Challenges: In this line of work, it is not possible to save every animal one rescues. It is important to understand that sometimes, an animal's life is beyond one's control.

(Natural History) Museum curator

What to study: Masters in biology, ecology, museum studies, etc. Some museums may require doctoral studies in related fields, in addition to work experience.

What the job entails: As with most other jobs, this one too spans a wide range of responsibilities. However, what is particularly vital is that the curator possesses the wisdom and necessary skills to gather, understand, and put together a dynamic collection of relevant specimens that can be viewed on a regular basis or specifically presented in highly stimulating and themed exhibitions.

Benefits: The greatest take away from the job could be the pleasure of learning. and working with a rare and an incredible variety of specimens, some of which could go back even centuries. And, of course, the opportunities to interact with curious visitors who may share the curators joy in natural history.

Challenges: If the museums are small, one is likely to take on several responsibilities, as mentioned earlier. This, of course may mean longer working hours but a richer learning experience too. Since many of the specimens will be very old and fragile, extra care is required in handling them.

Picture Credit : Google 

In protecting and preserving rainforests, we are merely preserving our future.  The year is 2070. Kids are on an expedition to a part of the Amazon rainforest and are clueless when their teachers throw around words such as "Spider monkey" and "Harpy eagle". What else could they be, for, they have never heard about these erstwhile creatures that became extinct well before their time? Back to the present. Today, in 2022, did you know that about 17 % of the Amazon rainforest, the largest in the world, has been destroyed over the last five decades? It is time to wake up and smell the forest fire.

Rainforests are home to some of the most biologically diverse and important ecosystems in the world more than half of Earth's plants and animals are found in them. June 22 was World Rainforests Day, and doesn't it make sense that one of our most important natural resources has a day dedicated to it? In a bid to raise awareness and encourage action to protect the world's rainforests, the first World Rainforest Day was celebrated on June 22, 2017, by the Rainforest Partnership, an international non-profit.

Fear factor

 So, how serious is the threat to rainforests? In an interview, Gabriel Labbate, head, United Nations Environment Programme's (UNEPS) Climate Mitigation Unit, shed some light on the issue. "There are worrying signs that some of these systems may be close to tipping points. For example, an article I read in the last six months documented clear signs that the Amazon was losing resilience. The Amazon is like a gigantic recycler, a water pump. Water may be recycled up to five times as it travels from the southeast to the northwest of the Amazon. When rain falls on trees and vegetation, part of it is absorbed, and part of it goes back up into the air following evapotranspiration. You stop this water pump and the whole system may transform into a savannah because there is not enough water left to sustain a tropical forest. There will be a cascade of impacts following the disappearance of an ecosystem like that."

While Labbate has spoken specifically about the Amazon Rainforest, the danger to other rainforests is just as real. Many of them have suffered from heavy logging for their hardwoods, slash-and-burn cultivation, and forest fires, throughout the 20th century. Consequently, the area covered by rainforests around the world is shrinking, and large numbers of multiple species are being driven to extinction

Almost 90% of West Africa's rainforests have been ravaged, as have two-thirds of Madagascars. In fact, the situation turned so dire that several countries, most specifically Brazil, declared deforestation a national emergency, and it was instrumental in slowing down the damage from 2004 to 2012. deforestation reduced by about 80 % in the country.

While it is arduous to completely reverse the effects of rainforest destruction, here are a few steps you can take to tackle the problem:

• Start by reading more about it and teach others about the importance of the environment and how they can help save rainforests.
• Try and restore damaged ecosystems by planting trees on land where forests have been cut down.
• Encourage people to live in a sustainable manner, one that won't harm the environment.
• While not all of us have the resources financial or otherwise to protect) rainforests and wildlife on a large scale, it is possible to support organisations that help minimise damage to the environment. The time is ripe. Spread the word.

Picture Credit : Google 

An unplanned, uncontrolled fire that burns in a natural area such as a forest, grassland, or prairie, wildfires can happen anywhere at any time. Likely caused by human activity or natural phenomenon like lightning, it is not known as to how over half of the recorded wildfires began. Even though wildfires keep the ecosystem healthy and are even essential for the continued survival of certain plant species, they also simultaneously impact weather and climate by releasing large amounts of carbon dioxide, carbon monoxide, and fine particulate matter into the atmosphere.

Wildfires can burn in vegetation located both in and above the soil. Ground fires typically ignite in soil thick with organic matter that can feed the flames, like plant roots. Ground fires can smolder for a long time—even an entire season—until conditions are right for them to grow to a surface or crown fire. Surface fires, on the other hand, burn in dead or dry vegetation that is lying or growing just above the ground. Parched grass or fallen leaves often fuel surface fires. Crown fires burn in the leaves and canopies of trees and shrubs.

Some regions, like the mixed conifer forests of California’s Sierra Nevada mountain range, can be affected by different types of wildfires. Sierra Nevada forest fires often include both crown and surface spots.

Wildfires can start with a natural occurrence—such as a lightning strike—or a human-made spark. However, it is often the weather conditions that determine how much a wildfire grows. Wind, high temperatures, and little rainfall can all leave trees, shrubs, fallen leaves, and limbs dried out and primed to fuel a fire. Topography plays a big part too: flames burn uphill faster than they burn downhill.

Wildfires that burn near communities can become dangerous and even deadly if they grow out of control. For example, the 2018 Camp Fire in Butte County, California destroyed almost the entire town of Paradise; in total, 86 people died.

Still, wildfires are essential to the continued survival of some plant species. For example, some tree cones need to be heated before they open and release their seeds; chaparral plants, which include manzanita, chamise (Adenostoma fasciculatum), and scrub oak (Quercus berberidifolia), require fire before seeds will germinate. The leaves of these plants include a flammable resin that feeds fire, helping the plants to propagate. Plants such as these depend on wildfires in order to pass through a regular life cycle. Some plants require fire every few years, while others require fire just a few times a century for the species to continue.

Wildfires also help keep ecosystems healthy. They can kill insects and diseases that harm trees. By clearing scrub and underbrush, fires can make way for new grasses, herbs, and shrubs that provide food and habitat for animals and birds. At a low intensity, flames can clean up debris and underbrush on the forest floor, add nutrients to the soil, and open up space to let sunlight through to the ground. That sunlight can nourish smaller plants and give larger trees room to grow and flourish.

While many plants and animals need and benefit from wildfires, climate change has left some ecosystems more susceptible to flames, especially in the southwest United States. Warmer temperatures have intensified drought and dried out forests. The historic practice of putting out all fires also has caused an unnatural buildup of shrubs and debris, which can fuel larger and more intense blazes.

Credit : National geographic 

Picture Credit : Google 

 

Rainforests are regions that consist of several tall trees, most of which are evergreen ones, and receive a large quantity of rainfall. They play an important role in taking in carbon dioxide from the atmosphere, and so, are often referred to as the lungs of the planet. They host an impressive variety of wildlife, and also influence weather patterns elsewhere in the world. All continents except Antartica house rainforests. The Amazon in South America is the world's largest rainforest.

Tropical rainforests are home to 80 percent of the world’s terrestrial biodiversity, all squeezed into a narrow strip of equatorial land. They are also home to millions of human beings that have been a part of forest ecosystem for thousands of years. While tropical rainforests are perhaps the most iconic, temperate rainforests are equally diverse and beautiful. Together, rainforests offer a gallery of the most beautiful, awe-inspiring places and creatures on Earth.

Since the beginning of history, humans have relied on rainforests, finding in them a steady supply of wood, plants, and animals, as well as fruits, fibers, grains, medicines, cloths, resins, pigments, and other materials. As millennia passed and many human communities moved farther away from the forest, our reliance on the forests did not weaken. Major trade routes, and even empires, developed to control the flow of the rainforest’s treasures.

Today, most of the industrialized world senses little connection to the rainforest, living in large, busy cities far away from these fertile ecological powerhouses. We forget that the forest regularly saves our global food supply by offering new, disease-resistant crops. We forget about the hundreds of billions of dollars worth of trade in timber, non-timber forest products and forest-derived pharmaceuticals. We forget about things that are ultimately beyond value: the livelihoods of millions of forest communities, a stable and livable climate for us all, the existence of most of our fellow species, and simple things we take for granted, like regular rain and clean air.

In tropical nations, many developing and debt-ridden, the forest is cleared in the hope of securing an economic future. Huge industrial interests—such as timber, agriculture, and mining—see an endless, profitable supply of cheap resources just waiting to be taken. Meanwhile, family farmers and loggers feel they have no option but to deforest in order to feed their families. However, innumerable studies and recent history show that little security can be found in tropical deforestation.

Thus far, our human family has erased half of our original endowment of rainforests. Our world is now facing a sixth mass extinction—the greatest extinction crisis since the fall of the dinosaurs 65 million years ago. The future of over half of Earth’s plants and animals—and hundreds of human cultures—will be determined within the next few decades. Since our lives are so dependent on the forest’s bounty, our future is at stake as well.

Credit : Rainforest aligns 

Picture Credit : Google 

Mangroves are bushes or trees that grow in thick clusters along sea coasts and riverbanks.

Their roots stick out of the mud in thick tangles and prevent the waves from washing away the sand (or dirt) from the coastline Sundarbans in Bangladesh and India is the world's largest single tract of mangroves.

Where Are Mangroves Found?

Mangroves grow in sheltered tropical and subtropical coastal areas across the globe. In general, this is an area between latitudes of 25 degrees north and 25 degrees south, however, geographical limits are highly variable depending upon the area of the world and local climates. In Eastern Australia, the mangrove Avicennia marina can grow as far south as 38 degrees and Avicennia germinans can grow as far north as 32 degrees in the Atlantic. A major restriction for where mangroves can live is temperature. The cooler temperatures of northern temperate regions prove too much for the mangroves. A fluctuation of ten degrees in a short period of time is enough stress to damage the plant and freezing temperatures for even a few hours can kill some mangrove species. However, rising temperatures and sea level due to climate change are allowing mangroves to expand their ranges farther away from the equator and encroach on temperate wetlands, like salt marshes. Also, on some isolated tropical islands, such as Hawaii and Tahiti, mangroves are not native and are sometimes considered invasive species.

Growth and Reproduction

Life by the ocean has its perks—for mangroves, proximity to the waves and tides helps with reproduction. 

For most plants, the seeds remain dormant until after they are dispersed to a favorable environment. Not mangroves. Mangrove offspring begin to grow while still attached to their parent. This type of plant reproduction is called vivipary. After mangrove flowers are pollinated the plants produce seeds that immediately begin to germinate into seedlings. The little seedlings, called propagules, then fall off the tree, and can be swept away by the ocean current. Depending upon the species, propagules will float for a number of days before becoming waterlogged and sinking to the muddy bottom, where they lodge in the soil. Propagules of Rhizophora are able to grow over a year after they are released from their parent tree, while the white mangrove, Laguncularia racemosa, floats for up to 24 days, though it starts losing its ability to take root after eight. The flotation time allows for the propagules to vacate the area where their parent grows and avoid competition with an already established mangrove.

Mangroves as Ecosystems

Mangroves are among the most productive and biologically complex ecosystems on Earth. They cover between roughly 53,000 and 77,000 square miles (138,000 and 200,000 square km) globally, acting as a bridge connecting the land and sea. Though most will be less than a couple miles thick along the coastline, in some areas of the world they are massive aquatic forests. The Sundarbans Forest, a UNESCO World Heritage site at the mouth of the Ganges, Brahmaputra, and Megha Rivers in the Bay of Bengal fronting India and Bangladesh, is a network of muddy islands and waterways that extends roughly 3,860 square miles (10,000 square km), two times the size of the state of Delaware. 

Credit : Ocean find your blues

Picture Credit : Google

Keystone species play a unique and crucial role in the functioning of an ecosystem. The animals and organisms that come under this category help to maintain biodiversity within their community either by controlling populations of other species that would otherwise dominate the community or by providing critical resources for the survival of a wide range of organisms.

These species act as the glue that holds the system together. The term was coined by Dr Robert Paine in 1969, to describe the power a single species exerts on an ecosystem. Examples of keystone species include starfish, sea otters, beavers, wolves, elephants, prairiedogs and bees.

Keystone Species Examples

Sea Otter

The sea otter (shown below) is considered a keystone species as their consumption of sea urchins, preventing the destruction of kelp forests caused by the sea urchin population. Kelp forests are a critical habitat for many species in nearshore ecosystems. In the absence of sea otters, sea urchins feed on the nearshore kelp forests, thereby disrupting these nearshore ecosystems. However, when sea otters are present, their consumption of sea urchins restricts the sea urchin population to smaller organisms confined to protective crevices. Thus, the sea otter protects the kelp forests by reducing the local sea urchin population.

Large Mammalian Predators

While small predators are important keystone species in many ecosystems, as mentioned above, large mammalian predators are also considered keystone species in larger ecosystems. For example, the lion, jaguar (shown below), and gray wolf are considered keystone species as they help balance large ecosystems (e.g., Central and South American rainforests) by consuming a wide variety of prey species.

Sea Star

Sea stars (shown below) are another commonly recognized keystone species as they consume mussels in areas without natural predators. In many cases, when the sea star is removed from an ecosystem, the population of mussels proliferates uncontrollably, and negatively effects the resources available to other species within the ecosystem.

Credit :  Biology dictionary  

Picture Credit : Google