My Science School

The largest brackish winter lagoon in Asia, the Chiluka Lake in Odisha spreads across more than 1,000 sq km comprises wide areas of manhes, lowlands and plenty of islands The fresh water from inland rivers and saline water from Bay of Bengal mix together to result in a unique ecosystem that supports rich biodiversity One of the largest wintering grounds in the country for migratory birds Chilika attracts tens of thousands of winged visitors even from as far as Mongolia and remote parts of Russia. The binds are ably supported by marine life marked by a variety of small fishes. The Chilika Lake comprises the chilika Bird Sanctuary and Nalbana Island also a bird sanctuary.

Wildlife

The birds one can spot in the region include ducks, geese, shelducks, pochards, flamingoes, grebes, doves, swifts, cuckoos, rails, crakes, storks, pelicans, bitterns, herons, egrets, ibises. cormorants, plovers, lapwings, jacanas, godwits, sandpipers, stints, snipes, redshanks, gulls, terms, vultures, kites, buzzards, eagles, owls. barbets, bee eaters, kingfishers, falcons, weavers. pipits, wagtails, larks, warblers, swallows. bulbuls, babblers, starlings and mynas, The area nurtures not just birds but also mammal species such as cheetal blackbuck mongoose and porcupines, and reptiles such as snakes, turtles and lizards. Some of the marine creatures found here are sharks, dolphins, stingrays, eels, herrings, anchovies, carbs. catfish, seahorses, mackerels, tunas and barracudas.

A million splendid birds!

The annual bird count held by the Chilika Wildlife Division early this year brought ecstatic news to bird lovers and conservationists. More than 11 lakh birds spanning as many as 184 species had arrived in Chilika. This is an increase from the previous years 10-lakh-odd birds from 183 species. Reports said that five rare great knot (a small wader) were sighted after a gap of five years in the region. The birds found hearty meals such as fish, prawns, frogs, snakes and molluscs in the open wetlands. The increase in bird numbers is said to be a reflection of a certain change in the lake. Previously, illegal prawn cultivation had taken up a part of the waterbody. This is believed to have ended after a high court order, resulting in more space for the birds.

The dolphin story

The Irrawaddy dolphin is an endangered species. And according to the report of a monitoring survey 2018, the Chilika lake emerged as the "single largest habitat of Irrawaddy dolphins in the world. The number of the dolphin population was estimated to be 155. Meanwhile, in May this year, media reports indicated that a research project undertaken the Indian Institute of Technology Madras helped in "tripling the population of the Irrawaddy dolphins". in addition to a seven-fold increase in the fish population at Chilika. The sand bars were widening and the position of the sea mouth was changing, leading to the gradual degradation of the lake and calling for an urgent need to save its ecosystem. The researchers developed a dredging methodology and performed it with minimum impact on the ecosystem", to successful and happy results.

 

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In the avian world colour is one of the aspects that differentiates one species from another. But did you know that in many species, there are colour differences between male and female birds? Invariably, the males are brighter and more colourful than the females. Why is this so? Come, let's find out Naturalist Charles Darwin attributed this difference to the theory of sexual selection. After extensive research he arrived at the conclusion that female birds of certain species usually chose to mate with males that were brighter in colour, which led to males gradually evolving to be more and more colourful For long scientists have gone with this explanation. However. more recent studies point to a few other reasons for the muted colours of the females. According to a study published a few years ago, in many species of birds both males and females started out looking similar - bright and colourful. However, female started losing colour faster than the males gained it The study says this evolution is because of natural selection. The drab colour of the females is said to have emerged to help them escape predation by blending in with their surroundings. This comes in handy also during nesting, which helps keep their lineage alive.

 

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Minks are small mammals, native to the Northern Hemisphere. They belong to the weasel family. Both the European minks and the American minks are valued for their luxurious fur.

Why is coronavirus in minks a concern?

Scientists say minks may be more susceptible to the coronavirus than other animals due to a combination of genetic and environmental factors. In mink farms, where thousands of animals are kept in close proximity, COVID-19 can spread rapidly from animal to animal.

Unlike dogs, cats and some other animals, which show only mild symptoms, minks can get very sick and even die from the infection. So far, minks are the only animals known to both catch the virus from people and transmit it to them.

Which are the other places where minks have contracted COVID-19?

Coronavirus cases have also been detected in farmed minks in four other European countries: the Netherlands, Spain, Sweden and Italy. Millions of animals have been culled in these places too. In the U.S., more than 15,000 minks have died of the coronavirus since August, and authorities are keeping about a dozen farms under quarantine while they investigate the cases.

 

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Denmark's decision to cull millions of minks over coronavirus fear has shocked animal lovers around the world. While the scientific community is divided over the validity of the concern, we will take a look at what is culling and why it is carried out in the first place.

Denmark began culling millions of minks over coronavirus fear last month. A mutated form of coronavirus that can spread to humans was found among minks in hundreds of fur farms in the country. More than a dozen people were found to have caught the infection from the animals. However, there is no evidence that the mutations that originated in minks pose an increased threat to humans.

Denmark is the world's biggest producer of mink fur and its main export markets are China and Hong Kong. Mink farms have been found to be reservoirs of the coronavirus with over 200 of the 1,200 farms affected. Danish scientists are worried that genetic changes in mink-related form of the virus have the potential to render future vaccines less effective. Global health officials are now considering minks a potential risk, particularly in the midst of a resurgence of the virus in the human population. Denmark decided to cull all the minks in the country (instead of just the ones in the affected farms) as a precautionary step to protect people from contracting the virus. But later rolled back the order as it did not have the legal basis to kill all the animals.

While some scientists feel the concerns over mutated strain are exaggerated, others think the virus could jump from minks to other animals. Let's take a look at what culling is and why is it being done...

What is culling?

Culling is the organised and systematic elimination of sick or surplus farm or wild animals and birds, Culling or the selective slaughtering is carried out by authorised wildlife officials with proper permits and approvals.

Why are they culled?

• Mass killing of birds and animals are carried out when they are infected with a contagious disease. It is done to avoid the spread of the disease to other animals and humans. For instance, in the United Kingdom badger culling has been carried out for years to control the spread of bovine tuberculosis (bTB). Badger is a carrier of bTB.

• Aggressive invaders, such as invasive birds that take over nesting sites or attack native birds, are culled to save the local ecological balance.

• Culling is carried out to keep certain animal and bird populations in check. Unusual population growth may cause an imbalance in local ecology, disrupting food sources and other essential resources. In certain parts of Australia, kangaroos are considered vermins (pests), because they damage crops and compete with livestock for scarce resources. Kangaroos are involved in more than 80% of vehicle animal collisions there. In some places of the country, kangaroos are said to outnumber humans.

How is culling perceived by experts?

Culling has always been controversial. On one side, conservationists support it for the common good of all the species in an ecosystem. They perceive culling as a necessary means to protect native biodiversity. But on the other side, animal activists protest over the effectiveness and humaneness of different methods of culling. They oppose when governments resort to culling as a short-term measure Opposition also comes from the perception that every animal should have the right to live.

 

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Balloons, glitters and confetti add colour to our celebrations. But did you know while we treat ourselves to these small pleasures, we inadvertently pollute Earth? After all, what goes up must come down. Free-flying balloons and confetti ultimately become litter and put animals and birds at risk.

Balloons

Balloons are of two types - latex and mylar. Although latex balloons are promoted as biodegradable, they take anywhere between six months and four years to decompose. Mylar balloons are composed of synthetic nylon with a metallic coating. They are non biodegradable.

Balloons (when released into the sky, say as part of events or campaigns) travel thousands of miles, capable of polluting the most remote and pristine places. Deflated balloons that settle on land and sea surface are mistaken for food and eaten by animals and birds. They get lodged in their digestive tract, causing obstruction, loss of nutrition, internal injury, starvation, and death. String or ribbon often found attached to balloons can cause entanglement in animals, again leading to their death. Animals such as sea turtles are at special risk because the balloons resemble their favourite food - jellyfish. Seabirds are not safe either. According to a study released in 2019, if a seabird swallows a balloon, it's 32 times more likely to die than if it had gulped down a piece of hard plastic.

Glitter and confetti

Confetti has been used for thousands of years. The tradition can be traced back to the pagan times when people tossed grains and sweets during weddings and festivals. It has been adopted by many cultures around the world. But in recent years, it has taken a different form. We toss confetti and glitter at weddings and stage performances today, which simply disperse microplastics everywhere. Because confetti and glitter are made of plastic - polyvinyl chloride (PVC) and polyethylene terephthalate (PET), respectively.

Microplastics are plastic particles that are less than 5mm in diameter and are an emerging environmental issue. Glitter is usually less than 1mm in diameter and is used in a wide array of products, including cosmetics. It leads into the environment and often ends up in the oceans. It can be accidentally consumed by plankton, fish, shellfish, seabirds, and other marine life. When microplastic builds up in their systems, it can lead to death.

Further, PET, the plastic most glitter is made from, can break down and release chemicals that can disrupt human and animal hormones.

 

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The crows in your neighborhood know who you are by sight: they’re judging you, and they’re discussing you with their friends. Upset a crow enough and you may find yourself being harassed by entire flocks... for years.

How do we know this?

Researchers at the University of Washington captured and tagged crows while wearing different masks with distinct faces (everybody knows crows consider capturing and tagging an egregious insult). We don’t know exactly how, but the word spread through the entire local crow population. Before long, and even years later, any researcher wearing the “bad face” mask was harassed by scores of crows not just all over campus, but throughout the entire metro area of Seattle. Even the crows who had never before seen those faces somehow knew too loudly hate on anyone wearing it.

Crows are freakily brilliant. They solve problems requiring multiple solutions and integrated steps. They build tools from scratch. They learn from watching humans and innovate on what they’ve seen.

On the positive side, crows are known to reward kind behavior from humans. If you’re consistently nice to them, they may even start bringing you presents.

 

Credit : Quora

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