My Science School

Avocet is a medium-sized wading bird found in Europe, Asia, Australia and North America. It inhabits wetlands, marshes and swamps.

Its body is covered with black and white feathers. It has long, slender legs and webbed feet. Its long, upward curled beak is most distinctive feature.

Its diet includes insects, worms, crustaceans, molluscs, fish and amphibians. It is a social bird that lives in large flocks. It is highly territorial and it aggressively protects its territory.

Their nests are little more than depressions in the sand or platforms of grass on mudflats. If the water rises, the breeding pair raises the nest a foot or more with sticks, weeds, bones, and feathers to keep the eggs above water.
After hatching, the young not only feed themselves, but they can also swim.
Avocets will defend themselves using distraction tactics such as loud screeching, a "crippled bird" act, and even a "dive bomb" display where the bird will swoop down on the predator and narrowly miss it until the intruder turns away.

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Cockroaches can live without their heads for weeks. If they lose their head, their neck will seal off by clotting. As a result, there is no uncontrolled bleeding. Besides, roaches continue to breathe through spiracles, which are tiny holes in their bodies. However, they could die of starvation as they won’t be able to eat without their heads.

Besides their ability to live without a head, cockroaches have even more interesting survival tactics. For example, cockroaches can hold their breath for forty minutes! They can even survive being submerged underwater for up to thirty minutes.

Cockroaches are also very fast. They can run up to three miles per hour—about as fast as a person can walk. Even a one-day-old baby cockroach can run nearly as fast as its parents! Unfortunately for us humans, this also means that they can spread germs and bacteria throughout our homes very quickly. This can make us very sick and trigger asthma symptoms.

Because cockroaches are some of the most adaptable creatures in the world, dealing with a cockroach infestation at home can be very difficult. To avoid having these pesky insects come over uninvited, there are a few steps that you and your family can take.

Credit :  Pest World 

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The Galapagos penguin is the only penguin species found in the north of the equator. Native to the Galapagos Islands, it is believed to survive the warmer environment because of the Humboldt Current that brings cold waters to the islands. One of the smaller penguins, it has bare patches of skin around its eyes and at the base of its beak.

Based on their small geographic distribution, their already naturally low numbers, and their decreasing population size, Galapagos penguins are considered endangered (highly vulnerable to extinction). Some individuals are accidentally caught by fishers targeting other species, but the two biggest issues for Galapagos penguin populations are climate variability and invasive species. The cyclical, large-scale climate phenomenon known as El Niño significantly reduces the amount of food available to Galapagos penguins, causing them to skip nesting. In severe cases, these events can lead to starvation of the adults. While El Nino is a natural phenomenon, there is some growing evidence that human activities acting on the climate system as a whole may increase the severity or frequency of El Nino events. Perhaps a greater risk to this species is the introduction of two very different species, both of which threaten adult and juvenile Galapagos penguins. Introduced cats attack and eat these penguins and have contributed to a direct reduction in population size. Introduced mosquitoes carry avian flu, a virus that is particularly deadly to Galapagos penguins and its close relatives. An outbreak of this flu could easily spread through large swaths of the remaining Galapagos penguin population. Finally, as Galapagos penguins (like all penguins) are air breathers that regularly come to the sea surface, an oil spill in the Galapagos Islands could be a major threat to this rare, coastal species. Scientists estimate that there are fewer than 600 breeding pairs of Galapagos penguins alive today, so without continuing conservation measures, the species could be at risk of being lost.

Credit : Oceana 

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The hummingbird has a long tail to probe into flowers for nectar. In fact, the bill acts like a covering to protect its forked tongue which is what the bird uses to get its fill of nectar. Did you know a hummingbird’s tongue is lightning fast, going in and out of a flower 18 to 20 times per second?

What makes them so intriguing to us is the result of this simple dietary choice: they drink nectar. Each flower doesn't offer a lot, so to make a living off tiny amounts of nectar spread throughout the forest, hummingbirds are tiny, fast and feisty.

Feeding on nectar is hummingbirds' defining characteristic, but until now scientists didn't know the exact mechanics of how they do it. In our new study, we were able to slow them down on video to see how they really drink nectar. And what we found was quite different from the conventional wisdom since the 1800s.

Credit : Phys.org 

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Pigeon poop was popular as a natural fertilizer, and highly prized in countries like Persia (now Iran) and France. Remember the dovecotes? It is said that in the 18th Century, King George I of England declared all pigeon droppings to be the property of the Crown as the manure was used in making gunpowder. Saltpetre (potassium nitrate), an important ingredient in gunpowder, was extracted from pigeon poop.

The use of pigeon guano as fertilizer continued throughout history up until the development of agribusiness that resulted in cheaper more efficient means of fertilizer. In early history however, it’s plausible to suggest that the domestication of pigeons led to advances in the ability to grow the best possible crops. There is also evidence that pigeon poop is a better fertilizer than other farm animal manure, which ultimately could have led to the development of more efficient agrarian societies. The importance of the discovery of pigeon poop as a fertilizer certainly had a great influence on the history of human agriculture.

Today of course saltpeter can be synthesized with modern chemistry however in a historical context pigeon guano would have been a valuable commodity in earlier history when other sources were not as abundant or still largely undiscovered. In 16th century England, the humble pigeon was the only source of saltpeter, giving pigeons a huge role in the combative effectiveness of the English during this period.  Perhaps pigeon poop was an important factor in the outcomes of some of the first wars involving guns, potentially changing the flow of history. 

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The narwhal is the unicorn of the sea, a pale-colored porpoise found in Arctic coastal waters and rivers. These legendary animals have two teeth. In males, the more prominent tooth grows into a swordlike, spiral tusk up to 10 feet long. The ivory tusk tooth grows right through the narwhal's upper lip. Scientists are not certain of the tusk's purpose, but some believe it is prominent in mating rituals, perhaps used to impress females or to battle rival suitors. Females sometimes grow a small tusk of their own, but it does not become as prominent as the male's.

Narwhals are related to bottlenose dolphins, belugas, harbor porpoises, and orcas. Like some other porpoises, they travel in groups and feed on fish, shrimp, squid, and other aquatic fare. They are often sighted swimming in groups of 15 to 20, but gatherings of hundreds—or even several thousands—of narwhals have been reported. Sometimes these groups become trapped by shifting pack ice and fall victim to Inuit hunters, polar bears, or walruses.

Inuit people hunt the narwhal for their long tusks and their skin, an important source of vitamin C in the traditional Arctic diet.

Credit : National Geographic 

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Humpback whales are found in every ocean in the world. Their Latin name, Megaptera novaeangliae, means "big wing of New England." It refers to their giant pectoral fins, which can grow up to 16 feet long, and their appearance off the coast of New England, where European whalers first encountered them. They have dark backs, light bellies, pleats on their throats, and a small hump in front of their dorsal fins, leading to the common name of "humpback."

Humpback whales are known for their magical songs, which travel for great distances through the world's oceans. These sequences of moans, howls, cries, and other noises are quite complex and often continue for hours on end. Scientists are studying these sounds to decipher their meaning. It is most likely that humpbacks sing to communicate with others and to attract potential mates. Humpback calves are known to "whisper" to their mothers.

These baleen whales are found near coastlines, feeding on tiny shrimp-like krill, plankton, and small fish. Humpbacks migrate annually from summer feeding grounds near the poles to warmer winter breeding waters closer to the Equator. Mothers and their young swim close together, often touching one another with their flippers with what appear to be gestures of affection. Females nurse their calves for almost a year, though it takes far longer than that for a humpback whale to reach full adulthood. Calves do not stop growing until they are 10 years old.

Humpbacks are powerful swimmers, and they use their massive tail fins, called flukes, to propel themselves through the water and sometimes completely out of it. These whales, like others, regularly leap from the water, landing with a tremendous splash. Scientists aren't sure if this breaching behavior serves some purpose, such as cleaning pests from the whale's skin, or whether whales simply do it for fun.

Credit : National Geographic 

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Gray whales have a hump and a ridge of sharp bumps along their backs, instead of a dorsal fin. They are a type of baleen whale, which means they filter food from the water through special bristly structures in their mouths. Gray whales stay close to shore and feed in shallow water. Their well-known migrations take them between feeding and breeding areas, swimming as much as 12,000 miles round trip.

Critically endangered western gray whales migrate into their summer feeding grounds near Sahkalin Island, Russia in late May or early June and return to their winter feeding grounds in the South China Sea in late autumn. Summer feeding grounds for the eastern population lie in the Bering and Chukchi Seas between Alaska and Russia. In the winter, these eastern gray whales migrate south along the west coast of the US to Mexico to breed and have their calves.

The calm, warm waters of the lagoons are a safe place for young whales, free from predators like killer whales. Locals here affectionately call gray whales "friendly ones" as they have an unusual tendency to approach whale-watching boats and check out the occupants.

Credit : WWF

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The blue whale is the largest animal on the planet, weighing as much as 200 tons (approximately 33 elephants). The blue whale has a heart the size of a Volkswagen Beetle. Its stomach can hold one ton of krill and it needs to eat about four tons of krill each day. They are the loudest animals on Earth and are even louder than a jet engine. Their calls reach 188 decibels, while a jet reaches 140 decibels. Their low frequency whistle can be heard for hundreds of miles and is probably used to attract other blue whales.

Whales are at the top of the food chain and have an important role in the overall health of the marine environment. During the 20th century, the blue whale was an important whaling target and even after it was protected and commercial whaling stopped in 1966, exploitation efforts by the former Soviet Union persisted.

Blue whales live in all the world's oceans, except the Arctic, occasionally swimming in small groups but usually alone or in pairs. They often spend summers feeding in polar waters and undertake lengthy migrations towards the Equator as winter arrives.

These graceful swimmers cruise the ocean at more than five miles an hour, but accelerate to more than 20 miles an hour when they are agitated. Blue whales are among the loudest animals on the planet. They emit a series of pulses, groans, and moans, and it’s thought that, in good conditions, blue whales can hear each other up to 1,000 miles away. Scientists think they use these vocalizations not only to communicate, but, along with their excellent hearing, to sonar-navigate the lightless ocean depths.

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Nile crocodile is a large crocodile native to freshwater habitats in Africa.

Its body has dark bronze colouration, with faded blackish spots and stripes variably appearing across the back. It has a huge, teeth-filled mouth. It can reach a maximum size of about 20 feet.

Its diet includes mainly fish, but it does not mind eating other animals such as zebras, small hippos, porcupines, birds and even other crocodiles.

The females keep constant guard over the nest during the three-month incubation period. Just before hatching, the young crocs send out high-pitched sounds a signal for help. The female digs up the nest for young ones to emerge from the eggs.

Nile crocodiles have a dark bronze colouration above, with black spots on the back and a dirty purple on the belly. The flanks, which are yellowish-green in colour, have dark patches arranged in oblique stripes. There is some variation relative to environment; specimens from swift-flowing waters tend to be lighter in colour than those dwelling in lakes or swamps. They have green eyes.

Like all crocodiles, the Nile crocodile is a quadruped with four short, splayed legs, a long, powerful tail, a scaly hide with rows of ossified scutes running down its back and tail, and powerful jaws. It has nictitating membranes to protect the eyes and lachrymal glands to cleanse its eyes with tears. The nostrils, eyes, and ears are situated on the top of the head, so the rest of the body can remain concealed underwater. The coloration also helps to camouflage it; juveniles are grey, multicoloured, or brown, with dark cross-bands on the tail and body. As it matures, it becomes darker and the cross-bands fade, especially those on the body. The underbelly is yellowish green.

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Olive ridley turtle is a species of turtle that live globally in the coastal waters of at least 80 countries. It is named for the generally greenish colour of its skin and shell, or carapace.

It is among the smallest of the sea turtles, reaching only about 2 feet in shell length. It feeds on jellyfish, snails, crabs, and shrimp and occasionally algae and seaweed.

Females migrate hundreds or even thousands of miles every year to lay eggs on tropical and subtropical beaches. They lay about a hundred eggs, but may nest up to three times a year.

These turtles are solitary, preferring the open ocean. They migrate hundreds or even thousands of miles every year, and come together as a group only once a year for the arribada, when females return to the beaches where they hatched and lumber onshore, sometimes in the thousands, to nest.

Olive ridleys have nesting sites all over the world, on tropical and subtropical beaches. During nesting, they use the wind and the tide to help them reach the beach. Females lay about a hundred eggs, but may nest up to three times a year. The nesting season is from June to December.

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