14 Extinction of Species with Special Reference to India

Saleha Jamal

Structure

1.1 Introduction

1.2 Types of Extinction Processes

1.3 Causes of Extinction

1.4 Extinction of Species in India

1.5 Extinct and Endangered Species of Animals and Birds in India

1.6 Can Extinction be stopped?

Objectives:

At the end of this module the student should be able to:

• Explain the types of extinction processes
• Recognize the causes of extinction
• Explain the status of extinction of species in India
• Have clear understanding about the conservation and management of threatened species

1.1 Introduction

A species becomes extinct when the last existing member of that species dies. Extinction therefore becomes a certainty when there are no surviving individuals that are able to reproduce and create a new generation. A species may become functionally extinct when only a handful of individuals survive, which are unable to reproduce due to poor health, age, sparse distribution over a large range, a lack of individuals of both sexes (in sexually reproducing species), or other reasons. Speciation (evolution of new species) and species extinction (complete elimination of species) are the natural processes which follow the evolution of animal. Just to illustrate the degree of biodiversity loss we’re facing, let’s take you through one scientific analysis (Singh, 2010). The rapid loss of species we are seeing today is estimated by experts to be between 1,000 and 10,000 times higher than the natural extinction rate. These experts calculate that between 0.01 and 0.1 per cent of all species will become extinct each year. If the low estimate of the number of species out there is true – i.e. that there are around 2 million different species on our planet then that means between 200 and 2000 extinctions occur every year. But if the upper estimate of species numbers is true – that there are 100 million different species co-existing with us on our planet – then between 10000 and 100000 species are becoming extinct each year (World Wildlife Fund, 2017).

1.2 Types of Extinction Processes

Extinction is a natural process. Species have disappeared and new ones have evolved to take their place over the long geological history of the earth. During the past 3.5 billion years, 4 billion species are estimated to have evolved, of which 99 per cent have gone extinct. It is useful to distinguish three types of extinction processes which are as follows:

Natural extinction: as the environmental condition changes with time some species disappear and some are ready to take the place of disappeared ones which are more adapted to changed conditions. This loss of species which occurred in the geological past at a very slow rate is called natural or background extinction.

Mass Extinction: Mass extinctions are periodic rises in the extinction rate above the background level. They are events which are not caused by changes in habitat or competition but catastrophes. These are the mass extinctions, they cause a dramatic decrease in the earth’s biodiversity, and punctuate the earth’s history, and are used by Geologists to break up geological time. Recent thinking has however been to class events by their ecological impacts, rather than by the number of species lost. Scientist has identified five main extinction events in earth’s history with some so severe that more than 90 per cent of all life forms were killed off. These five extinction events are famous by the name of BIG-5 which are as follows (Myers 1997; Erwin 1998):

The late Ordovician event 438 million years ago, when 100 families went extinct. Late Devonian 360 million years ago, when 30% of families went extinct.

End Permian 245 million years ago, the biggest extinction of all time when over 50% of all families were lost.

Late Triassic 35% of families died out.

                     Fig. 1 (Extinction of Species over time)

Source: Benton, 1995 

The Cretaceous -Tertiary (K-T) 65 Million years ago, this ended the reign of the dinosaurs. According to a report by The Guardian after the BIG-5 the modern world is experiencing a ‘sixth great extinction’ of animal species even when the lowest estimates of extinction rates are considered, scientist have warned. The rate of extinction for species in the 20th century was up to 100 times higher than it (Refer fig. 1). would have been without man’s impact (Vaughan, 2015).Today we are in the middle of a sixth extinction event that began about 50,000 years ago but is now accelerating in an alarming speed! This extinction event is not a natural event, but is caused directly or indirectly by humans. Most recent extinctions have been associated with European expansion in the 15th and 16th century

Anthropogenic Extinction: An increasing number of species is disappearing from the face of the earth due to human activities. Each of the past mass extinctions was spread over million years or less, compared to only 200 years of the anticipated extinction due to human interference. Thus in comparison to mass extinctions of geological pasts, the manmade mass extinction represents a very severe depletion of biodiversity. As many as 733 animals (mostly vertebrates and molluscs) and 110 plant species (flowering plants and lower groups of plants) and one red algae have been extinct or extinct in the wild since 1500 AD.

1.3 Causes of Extinction

When one talk about the extinction then it becomes necessary to understand that it is not just about the disappearance of single specie but also the effects of its disappearance to the environment that it interacts with. It’s a broad topic. Concerned groups and governments are trying to save these endangered species through breeding and preserving their habitat – but these are all temporary solutions. What we need to do is to address the root causes of extinction of species. Extinctions have happened several times in our geological history and they were mostly caused by natural events such as comets and volcanic eruption and some causes remain unknown. Though there are several natural causes of species extinction but the modern man has accelerated the pace of extinction. It is believed that about 200 species of mammals and birds have become extinct during the last 2000 years. During the contemporary time the situation is that a few numbers of species of plants and animals have come down to such a small size that if they are not provided immediate protection they will soon become extinct. Some of the main causes of extinction are discussed below.

Over hunting, unregulated or illegal killings or poaching: over hunting is one of the main cause of extinction by the human beings because human beings kill animals for getting some precious things such as the ivory of elephants, the fur and organs of tigers, the deliciousness of tuna fish, and supposedly medicinal effect of shark’s fin are some of the examples that man has hunted these animals to the point of extinction. Illegal killings and poaching of rare plants and animals is a human cause of extinction and unfortunately across the world various socio-economic factors drive hunting and poaching of endangered plant and animal species and where this occur at unregulated, unsustainable levels, vulnerable species may be pushed towards extinction.

Destruction of Habitat: presently this is one of the biggest causes of animal extinction. The main habitat where most of the animals live is the forest and the process of deforestation has killed off more species than we can count. The whole of the ecosystems lives in the forest and it is believed that all of our rainforest can disappear in the next 100 years the process of deforestation will be left unchecked. Other anthropogenic factors are construction of highways, expressways, urban encroachment on agricultural land, artificial land drainage etc. Some natural phenomena too become the cause of species extinction such as floods, volcanoes, hurricanes etc. When a plant or animal does not have a habitat and cannot adapt to a different environment it will become extinct.

Pollution: apart from forest the next main habitat of the animals and plant is the water such as oceans, rivers, ponds and lakes. Man because of unchecked industrial development is introducing unnatural chemicals into the water bodies. These chemicals enter into the body of animals living in water and affecting their metabolic activities. Threats in marine and fresh water systems are poorly understood but it appears that over-exploitation is presently the greatest threat to marine species, followed by habitat loss. Incidentals death in fisheries affects seabirds, marine mammals and others. Man is also polluting the air which is a home of thousands of birds and animals. Air pollutants such as carbon monoxide, sulphur dioxide and nitrogen oxides are very harmful for the animal and plant species.

Introduction to Foreign Species: The introduction of foreign or alien species into new territories can often lead to ecological and economic disaster. An introduced species’ niche may overlap that of a native species, the newcomer may out-complete the native species, resulting in its extinction. Through, species are often intentionally introduced to improve fishing and hunting, it can lead to problems also.

Invasive alien species were historically the greatest threat to birds, followed by over-exploitation and habitat loss. Today, habitat loss has emerged as the dominant threat to birds, followed by invasive species and overexploitation.

    Competition: Ongoing evolutionary processes are driven by competition, and over (usually) long periods of time, plant and animal taxa that are unable to adapt may be out competed and naturally displaced from their habitat, and pushed towards extinction.

Diseases: the sudden outbreak of diseases and pest infections caused by changed environmental conditions of the region concerned causes species extinctions.

Sudden Events: some sudden events like forest fires, volcanic eruptions etc causes species extinction.

National and International Wildlife Trade: poaching and (legal and illegal) wildlife trades are another common threat to animals. Some examples of trade are pet trade, fur trade, bush-meat trade, body parts trade and trade for biomedical research.

1.4 Extinction of Species in India

When one looks at north-eastern region of India it looks lush green and Andaman pristine but somewhere deep in the wilderness of India’s biodiversity hotspots everything is not fine because loss of habitat is on its way due to deforestation and human encroachment is silently pushing hundreds of trees and plant species to the brink. The World Conservation Union (IUCN) has put 45 tree species across India on its “Red List of Threatened Plant Species 2007” as being “critically endangered”. It has flagged 247 tree species from the country as “threatened”. The ilex khasiana, a high-altitude tree found only in Meghalaya, has run into its last generation. There are just four left in a small area, mostly confined to Shillong Peak, the list says. The IUCN’s critically endangered list is for species facing an “extremely high risk of extinction in the immediate future”. It says trees like ilex khasiana may vanish because of “poor regeneration and habitat decline”. About 247 species of plants faced grave threat and were being overused for medicinal and religious purposes without adequate conservation. In the Nilgiri Hills, there’s a tree that goes by the name of Actinodaphnelanata. The Red List says there is just one of it left. In 2006 the Botanical Survey of India (BSI) recollected an extremely rare species after a gap of 65 years from Arunachal Pradesh. One species in the Northeast, Bogania, had become extinct when large scale felling took place to create space for tea gardens. There are no records for many species feared extinct since 2000 (Haq, 2007).

1.5 Extinct and Endangered Species of Animals and Birds in India

Extinction is an accepted phenomena and anything created on this earth destined to come into extinction at some period of time which is true in several cases discussed in detail in the later part of this article. As we all know that we have come to the verge of sixth extinction event that has already began some 50000 years ago and now accelerating. India is among those countries which are encountering wildlife extinction day by day and from the last 90 years and this rate is accelerating at a great pace.There was a time when India was home for some of the most beautiful wild animals, Due to excessive hunting and poaching for sport and body parts by man, these wild animals have become extinction. India has numerous varieties of wild species as their natural habitat due to tropical environment. Along with 17 mega diverse countries, India is home to about 60-70% of the world’s biodiversity. With European expansion and urbanization, most of the extinction in India has been witnessed. Apart from that brutal human behaviours to fulfil their greed and their unauthorized hobbies including shooting and hunting have also led to the loss of the count of these species. India alone is the major cause of loss of number of species of the wild organisms including the Bengal Tiger which is ironically our national animal. Some of the wild species are on the brink of extinction and some of them are already extinct such as:

Indian Cheetah (Acinonyx jubatus venaticus): Indian Cheetah also known as Asiatic Cheetah has been known to exist in India for a very long time ago. Due to access hunting, Deforestation and habitat loss, the fastest land animal on earth become extinct in India. Today, this species only survive in some parts of Iran. The government is planning to introduce this species in India with the help of international organizations.

Indian Aurochs (Bos primigenius namadicus): The Indian Aurochs once lived in the hot and dry areas of India. The huge wild cattle were larger than most modern domestic cattle with height of 6.6 feet and weight of 1000 kilograms.

Sivatherium (Shiva’s beast): Sivatherium was a very large approximately 7ft tall extinct animal found in India. The giant beast was first discovered in India, where it was called as “Sivatherium” due to the Hindu God Lord Shiva. The Sivatherium were the tallest and fastest monsters found in India ever.

Sumatran Rhinoceros (Dicerorhinus Sumatrensis): The Sumatran Rhinoceros has been declared as one of the extinct animal in India. The Sumatran rhinoceros is the smallest  rhinoceros  with  two  horns  and  only  extant  species  of  the  genus Dicerorhinus.  The  extinct  Sumatran  rhinoceros  once  roamed  and  inhabited rainforests of India and neighbor North- East Asian countries. They are now critically endangered species and estimated to number fewer than 275 only and found in neighboring countries of India.

Snow Leopard (Panthera Uncial): It is one of the most secretive cats and not many people in the world have had the privilege to see them in the wild in India. The wild cat loves to roam in the rocky mountain ranges of high altitude and it is estimated that in India there are about 200-600 snow leopards found in Hemis National Park, in east Ladakh, Nanda Devi National Park and Valley of Flowers National Park, in the state of Uttarakand a UNESCO Natural World Heritage Site, and Dibang Wildlife Sanctuary, near Anini.

Pink-Headed Duck (Rhodonessa Caryophyllacea): Pink-headed Duck was a large diving blackish-brown duck; it was one of the most beautiful birds in India. The long-necked duck once found in throughout India, but its beautiful appearance made it most hunted birds in India. Due to access of hunting this beautiful bird is fall in the category of extinct birds in India. This bird was also found in Bangladesh and northern Myanmar. They became extinct during 1960s.

Seychelles Parakeet (Psittaculawardi): Seychelles Parakeet a bird similar in appearance to a parrot used to be found in the Indian Ocean islands of the Seychelles group. Main reason for their extinction was intense persecution by farmers and coconut plantation owners. The species was extinct by 1906.

Aquilariamalaccensis (Thymelacaceae): is an economically important tree species known for its precious resin impregnated ‘agarwood’. Variously known as ‘eaglewood’, ‘aloeswood’, ‘gaharu’. This tree is a rich and sacred source of oleoresin since ancient period of time. It has been utilized in Egypt, Arabia and throughout the Far East from time immemorial in incense, perfume, medicinal, writing material and ceremonial uses. Assam region of Northeast India is believed to be the origin of agarwood and spread throughout Southeast Asia. Because of its multifarious uses and high market demand, mature agarwood trees have been harvested indiscriminately from wild resulting in rapid decline of the species in natural habitat.

Gleditsiaassamica and  Gymnocladusassamica: these two are the endemic tree species of northeast India. Both the sister genera have typical distribution pattern and a few species are available in North and South America, Egypt and Vietnam. Clear felling along with habitat degradation severely affected the natural population of these trees and these species is also listed as Vulnerable in the IUCN red list of threatened species (IUCN 2009).

G. Assamicus: locally known as ‘Menangmanba-shi’ by the Monpa tribe is a medium size (15 to 17 meter in height) deciduous tree. Highly saponaceous mature pods are popularly used in cleansing and religious activities. Natural population of this variety is extremely small having very few reproducing individuals. Though the species is not included in IUCN red list of threatened species but it has been designated as critically endangered regionally and also included in the priority list for national recovery programme in India (Choudhury and Khan, 2010).

1.6 Can Extinction be stopped?

The threats which has been discussed in the present article above is threatening our wildlife whether it to be to animal or plants is increasing and will continue to rage out of control until we have eventually nothing left remaining within the wild. Though extinction of any species whether plant or animal takes much time to extinct but once they are gone they are gone forever. Thus those species that are under threatened category requires a combination of conservation response to save them. From mega-fauna to plants and reptiles to birds everything living and breeding is in dire need of protection. Human overpopulation will most certainly be the biggest threat to wildlife. Overpopulation is not going to decrease anytime soon and sadly planet earth does not grow any larger. Something eventually has to give. There is no easy answer to stem the vast wildlife hemorrhaging. But one cannot simply wait and watch these wildlife species dying and getting extinct. Something has to be done in order to save them because they are assets and once loosed they will never returned back. If proper steps had taken in the past so the species of plants and animals that has been extinct might have been present amongst us today. These responses with respect to the conservation and management of species extinction includes research, species specific actions, sites and habitat based interventions, policy responses and communication and education. The tools and techniques required for stopping the extinction are effective management and restoration of habitats and ecosystem that are destroyed by natural phenomenon and human beings. Judicious use of pesticides, herbicides and other chemical inputs which are greatly used in agricultural can be helpful to reduce extinction of species. The conservation and management requires capital thus, creation of incentives and finance for conservation is necessary.

References

• Benton, MJ (1995): Diversification and Extinction in the History of Life, Science, 268 (5207), pp.52-58.
• Chauhan C (2016): Half of India’s wildlife in danger of extinction: Living Planet Report 2016, Hindustan Times, October 27, 2016.
• Choudhury B and Khan ML (2010): Conservation and Management of Endangered Plant Species: A Case Study from Northeast India. Bioremediation Biodiversity and Bioavailability, Vol. 4, No. 1, pp. 47-53.
• Erwin DH (1998): The end and beginning: recoveries from mass extinctions, Trends in Ecology and Evolution 13, pp.344-349.
• Haq Z (2007): Forty five tree species in India almost extinct. The Hindustan Times online. December 15, 2007.
• Myers N (1997): Mass extinction and evolution, Science, 278: pp.597-598.
• Sarkar D and Ghosh R (2013): Environmental Governance in India, Global Vision Publishing House, New Delhi, pp. 252-313.
• Saxena HM (2004): Environmental Geography, Rawat Publications, Jaipur, pp.58-69.
• Singh JS, Singh SP and Gupta SR (2015): Ecology Environmental Science and Conservation, S. Chand and Company Pvt Ltd. New Delhi, pp.664-714.
• Singh S (2010): Biogeography. Prayag Pustak Bhawan, Allahabad. pp. 163-188.
•  Vaughan A (2015): Human creating sixth great extinction of animal species say scientist. The Guardian Online. Friday19th June, 2015.
• Walk through India (2010): The 5 Extinction Wild Animals in India, [Online] Available at: http://www.walkthroughindia.com/wildlife/the-5-extinction-wild-animals-in-india, [Accessed – 18 August 201].

• World Wildlife Fund (2017): Conservation Issues, WWF, India.