Category Animal World

Should our focus be only on species teetering on the edge of extinction and whose numbers are plummeting? Come, let’s find out.

Do the names Sudan, Martha, and George ring a bell? And, what is common to them? Sudan, a male northern white rhinoceros; Martha, a passenger pigeon and George, a Hawaiian tree snail were all the last of their kind (none of them is alive today). Thankfully, the world has been alive to the concerns of extinction for a while now. Which explains concerted conservation efforts globally to ensure we do not forever lose species as an unfair consequence of our own actions. Population decline in several species has been reversed, while some have been stopped from going extinct. But should our focus be only on species teetering on the edge of extinction and whose numbers are plummeting? Come, let’s find out.

Nature is limitless. Or, is it? Even as recently as the 19th Century, extinction at sea was deemed impossible. “given the reproductive capacity of marine organisms and the impracticality of overfishing”. Species such as the passenger pigeon, the northern cod (a type of fish), the plains bison, the American chestnut (a deciduous tree), and the eastern white pine were once considered super-abundant, and their decline/disappearance, inconceivable. But the reality in all these cases has been different. And points to the fact that common species face decline and extinction too.

It’s wise to remember that several species on the brink of extinction started off as abundant or common. Abundance offers only a “partial buffer” against extinction, and the focus should be on the rate of decline because abundant species “are not immune to decimation”. For instance, a study of North American birds uncovered that “three billion birds on this continent within the past two generations” were lost. The focus on common species is as important as on rare ones because “the shifts in abundance of common species can translate into sizeable shifts in ecosystem functioning”.

 Take the case of birds. Given the amount of “insects they eat, the flowers they pollinate and the seeds they disperse”, a sudden and drastic decrease in the population of a common species can spell disaster in an ecosystem. Apart from this, studies show that encounters in the natural world-even a butterfly in a garden- improve the mental health of humans. When common species go, so will our chance of such encounters.

While rare species do require the attention they get,” the extinction of Commonness” should be prevented. And this can be done when we “monitor nature closely, guard against complacency and invest for the long term.”

Picture Credit: Google 

The science behind pronghorn’s speed

When we think of very fast land animals, the first one that comes to our mind is perhaps the cheetah. Why not? It is the fastest land animal! Do you know which one is the second fastest? The pronghorn. And, the theory behind how it developed such. speed is fascinating. Let's find out more about the animal and its sprinting capacity.

A hoofed mammal, the pronghorn is native to North America, and does not have any close relative anywhere in the world. Healthy populations of the animals exist in their range and are listed under 'Least Concern' in the International Union for Conservation of Nature Red List of Threatened Species. Though it looks a lot like an antelope, the herbivore belongs to its own taxonomic family called Antilocapridae. Pronghorns get their name from the forward-facing projection – the prong on their horns. Interestingly, their ‘horns’ exhibit characteristics of both a horn and an antler. The sheath of its horn is made of keratin, the substance horns are made of. But, these horns are forked and shed every year-just like antlers are! While much can be written about what else is unusual about the pronghorn, its most unique characteristic is its speed.

Running at more than 80 kmph, the pronghorn is the fastest land mammal in its entire natural range- from Canada through the US to Mexico in one aspect, it even gets better than the African cheetah-it can maintain a fast speed for a longer period of time than those carnivores. But the pronghom has no natural predator to match this speed, and so scientists had been stumped by the need for this speed. This is where the science of evolution comes in.

According to a study published recently, during the Ice Age, North America was home to several mammals that no longer exist today. Some of them are well-known today – woolly mammoths, giant sloths, and saber-toothed cats. There were lesser-known ones too, such as ‘Miracinongs’ a cheetah-like cat. The skeletal remains of ‘Miracinonyx’ show that “this now-extinct cat shares the morphological characteristics that indicate high speed capabilities with its African counterpart, the cheetah (Acinony)”. It is a close relative of the puma and the African cheetah. Both puma and ‘Miracinonyx’ are native to North America. Results provide support to "the hypothesis that ‘Miracinonyx’ preyed upon Antilocapra, but not exclusively”. Though it is not seen as conclusive evidence and more study is required, scientists say this "may provide an explanation for why pronghorns are so fast. Maybe they were chased by cheetahs after all".

Picture Crdit : Google 

What are some interesting facts about jaguars?

Did you know that the jaguar is the third-largest cat species in the world after the tiger and the lion? Read on to know fascinating facts about the big cat species.

WHAT DOES IT LOOK LIKE?

*A jaguar has an attractive, tawny coat with black rosettes. The jaguar rosettes have a spot in the middle and they are irregularly shaped.

* A jaguar is stockier and more heavily muscled, with a larger head and wider shoulders.

*It has the shortest tail among the big cats from 45 to 75 cm in length.

 *From tip to tail, it measures 1.5 m to 2.5 m and weighs between 68 and 136 kg.

*The legs are short, but thick and powerful with broad paws.

Found in the Amazon basin

The only big cat species in the New World, jaguars are today found mostly in the Amazon basin of South and Central America and southern Mexico, though they once ranged as far north as southern USA. They are the third-largest cat species in the world after the tiger and the lion.

To the indigenous Americans, particularly the Maya, the Aztec and the Olmec, the jaguar was a god of both night and light, and was revered and feared in equal measure for his strength, fertility, agility and beauty. The native chiefs sat on jaguar thrones and wore jaguar pelts. A Mayan tribe named itself Jaguar’s Paw.

Jaguars vs. leopards

Like leopards, which belong to the Old World and whom they most resemble, jaguars have an attractive tawny or orange coat with black rosettes. However, jaguar rosettes have a spot in the middle and they are irregularly shaped. Leopard rosettes are complete and the spots are absent.

Though both live in similar habitats and have similar habits, the physical resemblance ends there. A jaguar is stockier and more heavily muscled, with a larger head and wider shoulders. It has the shortest tail among the big cats from 45 to 75 cm in length. From tip to tail, it measures 1.5 m to 2.5 m and weighs between 68 and 136 kilos. The legs are short, but thick and powerful with broad paws.

Lethal bite

Jaguars are most at home in the tropical rainforest, though they are adaptable to grasslands, woodlands and even deserts. Their build and coloration are ideal for stalking prey stealthily on the ground or ambushing them from the top of trees, and for swimming. The jaguar is the only big cat that grasps the prey's head in its powerful jaws and kills with a lethal bite by piercing the prey's skull with its sharp teeth, rather than by breaking its neck. It is very comfortable eating the spectacled caiman (a kind of small alligator) and hard-shelled turtles and tortoises. It also devours capybaras, the world's biggest rodents. It goes fishing too, slapping the water with its tail, and spearing the fish thus lured with its sharp claws!

Solitary and nocturnal

These elusive cats are nocturnal, solitary and extremely territorial, coming together only to mate. A male jaguar’s roar is more like a loud bark that ends in a deep growl. The female makes a coughing sound.

The female raises her one to four cubs alone, and is so protective she will bristle with rage even if the father approaches! The cubs stay with the mother till they are two years old.

Picture Credit : Google 

 

What is the importance of elephants in the natural ecosystem?

Elephants are the largest land mammals, and also a keystone species, meaning they play a crucial role in keeping the natural ecosystem balanced. Despite such a significant function, the numbers of Aafrican elephants dwindled over the last few centuries due to European colonisation, poaching, and habitat loss. Now the species faces an additional challenge – drought. This climate change-induced drought in Africa can also affect more than one generation of these gentle giants. How? Come, let’s find out.

Droughts in most African regions have become longer and more acute. Some have lasted for over two decades. And this can affect elephant populations in more ways than one. “Heat accumulates through an elephant’s natural metabolism and physical activity, as well as being absorbed from the environment.” But they cannot sweat it off the way humans do because they lack sweat glands. Further, their thick skin slows loss of heat. This is where water comes in; it helps regulate the animal’s body temperature and keep it cool. Not just drinking, even swimming and spraying their skin with mud and water cools them down.

Without water, elephants can experience high internal temperatures, which “can disrupt the function of cells, tissues and organs such as the liver and cause them to become sick and die”.

Importantly, drought “can also reduce the availability of food, causing elephants to starve. It can also mean young elephants die or don’t develop properly, because their parched mothers produce less milk”. This is to say, longer-lasting droughts can affect the next generation or even prevent the very existence of that generation.

The creation of artificial water sources for elephants could lead to denial of water to humans and also ecosystem damage due to animal congregation at a specific spot. So, the answer to saving the elephants could be in creating or restoring wildlife corridors.

Traditionally, these animals moved to other places in search of water during droughts. But this has been affected due to fences, fragmented habitats, etc.

Conservationists stress the need for finding such solutions. Because, if we don’t find solutions, and quickly, at that, we risk losing not just this majestic beast but also so many other species that depend on it for their survival.

Picture Credit : Google 

Unique defence mechanisms in animals

Our planet is indeed a wonderland with zillions of creatures inhabiting it, each having its own unique way of adapting to its habitat. Among these, there are some creatures that have developed some bizarre defence mechanisms. Let’s read up on some of these animal species.

IBERIAN RIBBED NEWT

Imagine ribs that you can use as poisonous spikes. The iberian ribbed newt is capable of pushing its ribs outside its skin when attacked. These form spikes which the newt uses to defend itself. The animal does this by moving its ribs away from the spine and increasing their angle by 50 degrees. The tips of the ribs then stick outside the animal’s body, like a set of spines. At the same time, the newt is capable of producing a poisonous milky substance on its body surface. This coupled with its protruding ribs acts as its stinging tool.

GOLDEN POISON FROG

The golden poison frog is one of the most toxic animals on Earth. It is known for its vibrant colours and the potent poison produced by its skin. While its bright colour is itself a warning sign to predators, the frog takes its defence one notch higher by producing toxins such as steroidal alkaloids batrachotoxin, homobatrachotoxin, and batrachotoxin A. These compounds can cause arrhythmias, fibrillation, and cardiac failure in humans.

TEXAS HORNED LIZARD

Here is a lizard that shoots blood from its eyes. When under threat, the Texas horned lizard sprays out pressurised blood from the corners of its eyes at its attacker. In biology, this is called autohaemorrhaging or reflex bleeding. The animal resorts to this when all its other defences such as camouflage fail. This is carried out by the lizard by rupturing its own sinus membranes.

MOTYXIA MILLIPEDE

While the most common defence mechanism is to display vibrant colours to ward off predators, there are some animals that use their bioluminescence as a warning. A genus of millipedes that is endemic to California called the Motyxia uses its bioluminescence to warn off predators. But the most unusual ability this creature possesses is that it can produce and ooze cyanide from the pores on its body. The cyanide is toxic for the predators of this species such as rodents, centipedes, and beetles.

MALAYSIAN ANT

Imagine a defence strategy that kills your predator but you end up getting the raw deal as well. These are the ants that will destroy themselves to defend their colony when under attack. These exploding ants are called the Malaysian ants. Whenever their nest is invaded, they will “blow” up (rupture) their abdomens. The ants have poison glands that get burst when they flex their body, releasing the poisonous substance onto their predator. This can either kill the enemy or incapacitate it.

HAIRY FROG

Meet the “Wolverine” in the wild. When threatened, this frog can crack its own finger bones and pierce them through its skin. These are then used as claws. On one end of the bone, there is a muscle that the frog can use to contract and thereby break a fragment of bone and push it outwards.

Picture Credit : Google 

Our connection to other mammals

What makes us humans different from our ape cousins? Well, our brain power. And, that came about through tweaks in the genes, according to an ambitious project, whose results were published recently. Come, let’s find out more about this, and also how we are similar to and different from other mammals.

The Zoonomia Project compared the genomes (the genetic material that makes up a living organism) of 240 mammal species, including humans, to trace evolutionary changes over 100 million years. It studied a wide variety of mammals-from the huge North Pacific right whale (59 feet long) to the tiny bumblebee bat, just 3 cm long. It also included our closest evolutionary relatives – chimpanzees and bonobos. Do you know what startling result the study threw up? “The researchers identified genomic elements- 4,552 in all – that were pretty much the same across all mammals and were identical in at least 235 of the 240 species, including people.” It means that certain parts of genomes have remained unchanged across all mammal species, humans included, over millions of years of evolution.

As for how humans are different from other mammals, the study points to areas “associated with developmental and neurological genes”. It suggests that when Homo sapiens evolved, it involved changes in how the nervous system genes were “regulated”. And these were just tweaks rather than any dramatic and major changes to the genes themselves. This explains why we still share a large part of our genetic makeup with our ape cousins.

And, genes are also responsible for traits unique to some mammals. For instance, hibernation and the sense of smell. While some mammals have a keen sense of smell, others have almost none. Humans are “somewhat average”. The study also saw changes in genetic sequences in some species “in relatively short periods of time”, indicating how they are adapting to their environments.

While the findings are fascinating by themselves. scientists believe they “could inform human therapeutics, critical care and long-distance space flight”, and “also can help identify genetic mutations that lead to disease”.

In a study, researchers identified genomic elements – 4,552 in all-that were pretty much the same across all mammals and were identical in at least 235 of the 240 species, including people. It means that certain parts of genomes have remained unchanged across all mammal species, humans included, over millions of years of evolution.

Picture Credit : Google