 |
| Cicada |
Violins With Wings
Cicadas are essentially violins with wings. A significantly large portion of their body is empty, which serve as amplifiers to the sound produced by specialized membranes called ‘Tymbals’. The sound is produced by the males of the species to attract females for mating. Each species has a unique song that attracts the females of the same species only, which is an intriguing fact, considering there are more than 3000 species of cicadas. Cicadas are of the super-family Cicadoidea and are physically distinguished by their stout bodies, broad heads, clear-membrane wings and large compound eyes.
Cicadas can be roughly classified into two types, Perennial and Periodical cicadas. Periodical cicadas are mysteriously fascinating as they spend most of their lifetime underground, somewhere between 13 and 17 years, feeding on plant sap from the roots of the forests and emerge only once from the soil mainly to mate. Once out of the soil their life span is rather short, around 4 to 6 weeks. The emergence is considered a unique natural phenomenon and this year 2020 is expected to witness one such emergence since the last one, recorded at 2003.
Perennial cicadas contrary to their name live from 3 to 5 years. Like their periodical counterparts, these cicadas spend their juvenile phase underground coming to moult into adults and to mate. But their arrival is not synchronized, making their arrival less notable than that of periodical cicadas.
While perennial cicadas can be found throughout the world, periodical cicadas are limited to parts of North America. Periodical cicadas are often mistaken for locusts because of their swarming nature, and are considered pests. But they are not as destructive as locusts, although large swarms of up to 15 lakh individuals can overwhelm young trees, they don’t feed on them, just lay eggs on tree barks. A single female can lay up to 400 eggs. They use a sharp appendage to slit a small portion off of the stem of young branches, and lay eggs in them. This causes the branch to wither and brown, a process known as flagging. So older trees are left with little damage only.
As for their environmental benefits, cicadas serve as a permanent food source for many of their predators, and the nymphs help aerate the soil. They play a vital role in returning nutrients to the soil. A cicada’s primary source of nutrition is plant sap, or in other words xylem fluid, which has a very low concentration of minerals. Since attracting the females by “singing” is very exhausting, cicadas have developed a specialized digestive that enables them to take in large quantities of cell sap and excrete it quickly through external ducts. This helps reduce the temperature of the surrounding atmosphere, also in keeping their body temperature down. So the next time you take a stroll into the woods and you feel raindrops falling on a sunny day, you know who to thank.
Vocal mimicry in song birds
Mimicry is a very common aspect among birds. The internet is filled with videos of parakeets and macaws imitating human speech and other man-made sounds that they have been accustomed to in captivity. The very famous Australian lyrebird can imitate plenty of song birds and can reproduce numerous sounds, including a chainsaw and a burglar alarm. Even though this may be considered as a remarkable aspect in avian behavior, this is not natural or normal in any sense. This is because the birds were never exposed to other species, or members of their own in the wild. But of-course there are birds which practice mimicry in the wild too. One classic example for visual mimicry is of the Indian cuckoo, a brood parasite, whose eggs look very similar to the foster parents’. The Greater Racket Tailed Drongo is perhaps one of the most interesting “ artists “ when it comes to vocal mimicry in the jungle. It is a very common passerine, found in most forests in southeast Asia. These birds can be easily identified by their glossy black plumage and two elongated racket like tail feathers and a significant crust. Acoustic landscaping studies have shown that these birds can mimic 40 species of birds, a dozen mammals, a few insects and even two species of frogs! Now that it is known what they mimic, lets try and understand why they mimic. The first and the most obvious one is to attract mates. A male which can mimic a larger number of birds, and in turn a display a better variety in performance has a better chance of wooing a female. The second explanation and perhaps the most intriguing one is how these birds use mimicry to aid in foraging. They mimic the alarm calls of giant squirrels and macaques to alert herds of deer. The frightened deer flee, causing a disturbance in the leaf bed which in turn exposes grubs and insects. The Drongo perches on a high branch, from where it can easily overwatch a flock of Babblers. Once the babblers catch a worm, the drongo falsely alerts them of an eagle’s presence nearby. The poor babblers leave the prey and fly for dear life, and thats exactly when the drongo swoops in to have an easy meal. When a Greater racket tailed drongo feels left out or lonely, it will mimic other birds to blend in with their flocks to form what is called a mixed species flock. Apart from these Drongos have their own calls too. Mimicry is a really vast topic and it is the most fascinating part of the jungle’s intricate weaving. These birds are magnificent, lazy but still smart, have knowledge about the hierarchy in the foodweb and even give false alarms to watch deer flee (few naturalist even call them the bully of the jungle), are smart enough to use vocal mimicry in different social situations to their aid. When considering all these facts, one will use the phrase “bird brain” rarely as an insult.
Flehmen's response
Described in 1813 by Ludwig Jacobson, the Flehmen's response is a behavioral aspect observed in numerous mammals. This response is signified by the animal curling its upper lips, exposing its gums and teeth while holding this position to sniff, with its nostrils usually closed. By doing so the animals transfer pheromones and other scents towards the Vomeronasal or the Jacobson's organ. Pheromones are chemical compounds that perform functions similar to those of hormones, only outside of the organism's body. The Vomeronasal organ is found at the base of the nasal cavity close to the vomer and nasal bones, thus the name. This organ is a paired auxiliary olfactory sense organ which has specialized receptor cells. When the particles from the air sniffed in reach the receptors, they send specific signals to the animal's brain which interprets the sensory information as a particular smell, such as the presence of a potential mate, territorial threat etc. A similar mechanism involving Jacobson's organ is observed in reptiles too. Instead of sniffing, reptiles slither their forked tongues in and out. The two pointed ends of the tongue collect chemical particles on their moist surface and fit perfectly into the Vomeronasal organ when pulled back in. This behavior is in most cases associated with a sexual reason or to detect territorial threats. In the first case female mammals release pheromones that can be read by males of the same species and understood that the individual is ready to mate. The second case is observed mostly in territorial felines like tigers. Tigers mark their territories by spraying urine on tree barks. Urine is packed with pheromones. Any new tiger in the region will know that its trespassing. If it wants to challenge the resident tiger to claim the territory, it will spray its urine on trees of that territory. It will later be detected by the resident tiger and they will battle till one of them gives up and flees. To make sure the smell is strong enough to warn off intruders, tigers urinate on trees regularly and sometimes repeatedly on the same tree. Sometimes a grin, or expression of pain are mistaken for the Flehmen's response. Their faces looks as if they are flinching upon smelling a very uncomfortable scent, hence the Flehmen's response is also called as "The Stinkface
Feral dogs
It’s almost impossible to be gloomy around a puppy or an affectionate dog. They’re practically fluffy balls of dopamine-inducing cuteness. Other than serving emotional support to humans and being one of the most favoured pets in the world, dogs are also useful in the army, the forensics field, in aiding handicapped people, and they’re also used as house guards (for obvious reasons). Despite being such versatile and resourceful animals, well above half of India’s population of dogs are feral(stray) dogs. That’s on the huge pet-breeding business mafia. While that is an issue that needs to be addressed as well, this article shall wholly focus only on an entirely different aspect of Man’s Best Friend. India has about 6 crore floofs and of them, 350,00,000 are stray dogs. Most of them are simply dependent upon urban waste or kind humans for their survival, both of which are currently abundant resources for the doggos (considering their rocketing populations). The rest, which is an alarmingly large number, seem to have tapped into their ancient predatory instincts. Feral dogs that live in rural or protected forest areas have resorted to preying on wildlife. Dogs are extremely agile and ferocious pack hunters. They are remarkable swimmers and that allows them to hunt down prey both in land and water. They prey upon and interact with several vulnerable species, ranging from Olive Ridley Turtles to Himalayan Brown Bears with deer and antelopes filling the large gap in between This is a problem because: A. It drastically reduces the prey base for wild predators such as tigers and leopards; B. Poses a serious threat to conservation of endangered and vulnerable species population and C. Increases chances of wild canids (wolves, foxes and dholes)contracting infectious diseases such as the Canine Distemper Virus. The Neanderthal who got a bit too friendly with a wolf surely did not see this coming 30,000 years ago. This is an unfair disruption of nature’s intricate ecological balance. To solve this issue, mass sheltering and euthanasia are labeled ethically and statistically wrong, looking at the birth rates of feral dogs. Animal birth control, re-sheltering and relocating of feral dogs away from land inhabited by wild animals are some solutions that will not stir a protest among the public and are currently being debated upon in the Supreme Court. Presently we are left with no efficient measure to tackle this increasingly severe threat to Indian wildlife. This article was in no way intended to show dogs in a bad light. If it is any consolation to dog-people, cats are an equally intimidating threat to rural wildlife, especially birds.
Consequences of lack of awareness
Despite the impressive variety, benefits, spiritual and cultural references related to snakes, we Indians have never had a pleasant relationship with them. Snakes are mysterious creatures, often misunderstood because of the unnecessary fear associated with them. There are approximately 350 species of snakes in our country, with only 60 being venomous, and only 4 responsible for most snake bite cases. More than 80% are harmless snakes just playing their role in the food chain in keeping a check on the rodent populations. Even among the venomous ones, most snakes are shy and prefer to avoid interactions with humans. But sadly, the general population of snakes has been plummeting for a long time and it still is. Most snakes are killed consciously by people, owing to the extreme fear that has always been among us. Habitat loss and road-kills appear too trivial a reason for their deaths in comparison. This is the consequence of lack of awareness.
In rural India, it is considered an act of heroism when someone kills a snake. This culture is nowhere conducive to the rise in snake population. Macho men, women who are fearless and over excited preteens compete among themselves to kill a snake in case one is spotted. It actually is an act of pure stupidity born out of fear and lack of awareness. Snakes help farmers by eating rats, they play a vital role in the food chain, and above all are beautiful creatures which have a right to exist too. Children must be taught to respect all kinds of lives, and must be familiarized with creatures like snakes, so that when they see one, they admire it and not panic and run away. Once a kid is taught to admire them he/she can never harm a snake ever again, even by will.
There are several videos available online which spread awareness about the importance of snakes, how to handle them, snake rescue teams and how to contact them etc. People must take time to learn more about these magnificent creatures so that they can prevent any accidents lead to human or snake deaths. We have already pushed several species of snakes to the very verge of extinction. We have caused the same fate for other creatures like scorpions, spiders and so on. It takes a little effort to learn to love these serpents. It is our duty to stop the unnecessary killing of snakes. We must take it upon ourselves to spread awareness and help bring back the snake population to what it once was. Although snakes are to be admired and saved, do not engage on your own to handle them. If you want to rescue snakes and help in this sensation, make sure you have been properly trained by a professional. The lack of proper knowledge not only costs your life, but of an innocent snake’s too. That is the sole reason for the whole situation we find ourselves in now. And it is high time we realize the consequences of our ignorance.
STOP KILLING SNAKES
Article and Photos by A.Rahul Tharun (B.Sc Forestry - Honors)
----------------------------------------------
 |
| A.Rahul Tharun |
A.Rahul Tharun - Wildlife photographer, Snake rescuer Traveler. Studied B.Sc Forestry - Honors. Now doing MBA Christ University, Bangalore.
