WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity Environmental Crisis and Conservation of Endangered Animals Long Answer Type Questions

Chapter 10 Biodiversity, Environmental Animals Long Answer Type Questions


Question 1. Forests can grow and regenerate on their own-explain for reasons. Mention the anthropogenic factors that are threatening wildlife.

Forests can grow and regenerate on their own:-

The dead part of trees, dead animals, and animal wastes keep on collecting on the forest floor. The decomposers act on the dead plant and animal matter and animal wastes and convert them into humus.

  1. The hummus mixes with the forest soil and makes it fertile. The animals and birds of the forest, wind, and water disperse the seeds of trees on the forest soil.
  2. The seeds obtain nutrients and water from the forest soil and germinate to form seedlings. The seedlings grow to form trees.
  3. The growing of new trees regenerates the forest naturally. The animals help the forests to grow and regenerate in two ways:
  4. The dead animals and animal wastes decay to provide nutrients to the forest soil and make it fertile.
  5. The animals carry out pollination and dispersal of seeds throughout the forest. Thus the forest can grow and regenerate on its own.
  6. The anthropogenic factors responsible for threatening wildlife are-
  7. indiscriminate use of natural resources belonging to forests.
  8. Mass-scale deforestation for urbanization, road expansion, expansion of cultivable land, etc.
  9. Habitat destruction of wildlife.
  10. Pollution, global warming, and climate change
  11. Introduction of exotic species
  12. Poaching and overhunting to fuel the illegal trade of animal parts

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Question 2. Write about the vertical stratification of forests. Mention some importance of forests.

The Vertical stratification of a forest:-

Evergreen forests, such as the Amazon Rainforest and the tropical rain forests have a peculiar structure, in terms of the layers in which the trees are organized.

This organization is shaped mainly by abiotic factors such as humidity, sunlight, wind, etc. There are six basic layers namely the emergent, canopy, understory, shrub layer, herb layer, and forest floor.

The Emergent layer: The Emergent layer is made up of the tallest trees, spaced out, usually with straight branch-free trunks (large trees are about 16ft in diameter), with a crown on the tops.

They are about 100 ft – 200 ft tall with supporting buttress roots spreading up to about 20-30ft. The trees have small pointed leaves, which are adapted to withstand wind action over tree tops.

Trees here are in constant sunlight. Birds such as hummingbirds and parrots are common. Animals here tend to be lightweight and include the Sloth and the Spider, Monkey. The Brazil Nut tree and Kapok Tree are common trees in this emergent layer.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals The vertical stratification of a forest


The Canopy: The Canopy is the layer that stops sunlight and rainwater from getting to the layers below it.

The trees grow up to about 130 ft and have broader leaves and drip spouts. This leaf feature makes rainwater drip down quickly rather than staying on the leaves.

There are millions of insects and animals in this layer as they have enough food to keep them there. Common animals include squirrels, monkeys, reptiles, bats, and a variety of birds.

Visibility is low from the thickness of leaves and the network of branches. As a result, animal sounds are loudest in this layer because they communicate with sounds.

The Understory: The Understory has fewer trees, but lots of shrubs and small trees growing up to about 12 ft high – The area is made up of carnivores, many of which have climbing abilities.

Animals are also larger in size and heavier than animals in the other layers. They include scorpions, armadillos, wild cats, mongooses, lizards, snakes, and a variety of insects.

The Shrub layer: The shrub layer consists of mature shrubs and bushes and lies just below the understory. It has a smaller vegetation which is between 3 ft to 6 ft in height from the forest floor.

The animals such as deer and bears obtain a lot of food from the shrub layer of vegetation. Many of the shrubs depend on animals for the dispersal of their seeds. There is not much sunlight in the shrub layer.

The Herb layer: The herb layer is the lowest layer of vegetation in the forest having leafy plants belonging to herbs, ferns, and grasses.

This layer ranges from the forest floor to about 3ft in height. Very little sunlight remains for the plants in the herb layer.

The plants grow and flower early in the season so as to get sufficient sunlight before the canopy leaves open and obstructs sunlight. Most of the plants in the herb layer have short life cycles.

The Forest Floor: The forest floor is the ground level of the structure. It has shallow soils of poor quality, with microorganisms and life- forms feeding on decaying matter on the floor.

The moist, dark conditions aid decomposition of organic matter, and nutrients are quickly absorbed by the trees and other plants on them. There is very little light here. Animals that are found here are herbivores and

Importance of Forests

Forests and biodiversity are key to all life forms. Forests have always had great importance to people. Prehistoric people got their food mainly by hunting and gathering wild plants.

Many of these people lived in the forest and were a natural part of it. With the development of civilization, people settled in cities. But they still went to the forest to get timber and hunt. Below is some more importance of forests:

Watershed: Forests serve as a watershed. This is because almost all water ultimately comes from rivers and lakes and from forest-derived water tables. Some rivers running through forests are also kept cool and prevented from drying out.

Habitat and Ecosystems: Forests serve as a home (habitat) to millions of animals. Think . of the many types of reptiles (snakes and lizards) wild animals, butterflies and insects, birds, and tree-top animals as well as all those that live in the forest streams and rivers.

Animals form part of the food chain in the forests. All these different animals and plants are called biodiversity, and the interaction with one another and with their physical environment is what we call an ecosystem.

Healthy ecosystems can better withstand and recover from a variety of disasters such as floods and wildfires.

Economic benefits: Forests are of immense economic importance to us. For example, plantation forests provide humans with timber and wood, which are exported and used in all parts of the world.

They also provide tourism income to inhabitants (people living in or close to forests) when people visit to see the best of nature.

Climate control: Climate control and atmosphere purification are key for human existence. Trees and soils help regulate atmospheric temperatures through a process called evapotranspiration. This helps to stabilize and cool the climate.

Additionally, they enrich the atmosphere by absorbing bad gases (for example C02 and .other greenhouse gases) and producing oxygen. Trees also help to remove air pollutants.

Control of soil erosion and flood: The roots of trees and plants growing in the forest bind the topsoil particles and hold the soil together. Due to this, strong winds and flowing rainwater are not able to carry away the topsoil. Hence soil erosion is prevented.

The cover of trees and many layers of vegetation in the forest softens the effect of heavy rain on the soil due to which the soil does not become loose. Thus, forest help in the conservation of soil.

The forest floor is covered with a lot of decaying material and small vegetation which absorbs most of the rainwater which falls down during heavy rain.

The roots of trees help the rainwater to seep into the forest ground and raise the water table. The forest releases this absorbed water slowly and steadily into rivers through the soil.

By holding back rainwater and then releasing it slowly into rivers, the forests prevent the occurrence of floods in the rivers.

Question 3. what is a forest fire? Write about its causes and effects.

Forest fires

Forest fire causes imbalances in nature and endangers biodiversity by reducing faunal and floral wealth.

Causes of a forest fire: Traditionally Indian forests have been affected by fires. The menace has been aggravated by the rising human and cattle populations and the consequent increase in demand for forest products by individuals and communities.

Causes of forest fires can be divided into two broad categories: environmental (which is beyond control) and human-related (which is controllable).

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals Forest fires


1. Environmental causes

These are largely related to climatic conditions such as temperature, wind speed, and direction, level of moisture in soil and atmosphere, and duration of dry spells.

Other natural causes are the friction of bamboo swaying due to high wind velocity, rolling stones that result in sparks setting off fires in highly inflammable leaf litter on the forest floor, volcanic eruption, lightning, etc.

2. Human-related cause

These result from human activity as well as methods of forest management. These can be intentional or unintentional, for example-

fire set by grazers and gatherers of various forest products to facilitate the gathering of minor forest produce like flowers of Madhuca indica and leaves of Diospyros melanoxylon.

  1. The centuries-old practice of shifting cultivated land by firing forest.
  2. The use of fires by villagers to ward off wild animals.

Question 4. How do mangroves excrete excess salt from their body? Mention the names of two endangered animals present in the mangrove forest. Do desert travelers take the help of which is plants to quench their thirst?

Terrestrial mangrove vegetation cannot tolerate salts measuring more than 33-38g in one thousand grams of marine water. Excess salt causes toxicity in the plant tissues.

They eliminate the excess salt partially through the glands present in their roots and leaves. Besides these, the plants also eliminate salt by shedding off leaves.

Estuarine crocodiles and River Terrapin (River turtles) are some of the endangered animals of mangrove forest.
The desert travelers quench their thirst with the help of Saguaro cactus. They collect water by cutting their expanded trunk.

Question 5. What is the full form of IUCN? What is Red Data Book? What do you mean by ex-situ conservation?


The world’s most comprehensive inventory of the global conservation status of biological status is published by IUCN as the Red Data Book.

Species are classified by IUCN Red Book into nine groups, specified through criteria such as rate of decline, population size, geographic distribution, and distribution fragmentation. The IUCN aims to re-evaluate the data of species every five years if possible or at least every ten years.

Question 6. What is Agenda 21? Mention the crisis factors that the Gangetic dolphins are facing due to human activities. Name the world’s first Dolphin sanctuary.

Agenda 21:-

The Earth Summit 1992 produced the Rio Declaration on Environment and Development and Agenda 21. Agenda 21 is a comprehensive plan to work together to protect the environment through sustainable development.

Crisis of Gangetic dolphins:

Excessive water pollution is a serious threat to the lives of dolphins. The number of fish is dwindling due to water pollution. Hence the dolphins are endangered due to lack of food.

The depth of water in the river is decreasing due to the construction of dams and silting. The emergence of sandbars are dividing the river into small parts.

This is hindering the movement of the dolphins. As a result, the communication between the different groups of dolphins is lost. The small and segregated dolphins are facing breeding problems.

Dolphins are sometimes dead due to entrapment in fishing nets. The world’s first dolphin sanctuary, Vikramshila Gangetic Dolphin Sanctuary has been set up in 1991 between Sultanganj and Kahalgao of Bihar.

Question 7. When do Arctic animals lay eggs? Briefly describe some adaptive features of penguins.

Most Arctic animals avoid giving birth to their young ones in the intense cold period.

  1. The scarcity of food compels them to adopt such behavior. Animals start establishing their territory at the end of spring.
  2. They lay eggs or give birth to young ones during the short summer days. However, female Polar bears give birth in winter.
  3. Some of the adaptive features of penguins are:
  4. Penguin is black and white in color but still, it merges well with the white background of ice and snow.
  5. They have thick skin and a layer of fat below the skin to protect them from excessive cold.
  6. They live together in large numbers. Penguins huddle together to keep themselves warm.
  7. Penguins have streamlined bodies, flipper-like wings, and webbed feet which make them good swimmers.

Question 8. How many types of camels are there? Describe the lifestyles of people living in the desert.

The camels are of two types: 1. humped (Arabian camel) and 2. two-humped (Bactrian Camel).

Though life in the desert is hard, people have been living in the desert since prehistoric days.

1. People living in the Namib desert are known as Bushmen. They dig holes in the sand and live there. They hunt animals using bow and arrow. They eat the animals by roasting them.

2. San Bushman are the people living in the Kalahari desert. They make holes in wet sand and then suck the water by inserting a strong hollow grass stem.

They use empty Ostrich eggs as water pots. They can easily understand that water is present in the sand by seeing the texture of the sand.

3. Tuareg, the tribes living in the Sahara desert, make huts with grasses found in the desert. They also make sand tunnels and live within them.

4. The Red Indians of the American desert live together. Every house has quite a number of rooms. These stone-made houses are called Pueblo.

5. The nomadic people who live in the Thar desert are Wardha, Bhil, Gadi-Lohar, etc.

6. The Beduins of the Sahara and Arabian desert wear long loose dresses which cover their whole body. They travel miles together at a stretch on camels and take rest in tents for a few intermediate days.

Question 9. What are the functions of the rhino horn? What role does a rhino play in the grassland ecosystem?

Functions of the rhino horn:-

Name two vulture rehabilitation centers in India. The rhinoceros uses its horn to search for food by digging in the soil to find out roots of trees. It also uses the horn to fight other male rhinos in the breeding season.

The one-horned rhino exerts various influences on the grassland ecosystem:

1. It digs up the soil with the horn. This opens up the possibility of new seed germination. This in turn enriches and expands the grassland. As a result, the prey population of the predators, ie. the number of herbivores, increases.

2. The rhino defecates in the same place. When the dunghill rises to a certain height, the rhino levels it with its horn.

The excreta contains nutrients in high proportion. When seeds are egested out after 3-7 days of ingestion and they fall on the excreta, germination occurs.

Thus dispersal of seeds takes place. Sometimes birds also take away some of these seeds to other places to carry out the dispersal.

Two significant vulture rehabilitation centers are Pinjar of Haryana and Rajabhatkhawa of North Bengal.

Question 10. Describe the methods of biodiversity conservation using a line diagram. Name three endangered animals of India. How is the conservation of fishing cats being carried out?

Conservations of Biodiversity

Conservation is the protection, preservation, management, or restoration of wildlife and natural resources such as forests and water.

Through the conservation of biodiversity and the survival of many species and habitats which are threatened due to human activities can be ensured. There is an urgent need, not only to manage and conserve biotic wealth but also to restore degraded ecosystems.

Types of Conservation

Conservation can broadly be divided into two types: In-situ conservation and Ex-situ conservation. Biodiversity Conservation

in-situ Conservation: In-situ conservation is on-site conservation or the conservation of genetic resources in natural populations of plant or animal species, such as forest genetic resources in natural populations of tree species.

It is the process of protecting an endangered plant or animal species in its natural habitat, either by protecting or cleaning up the habitat itself or by defending the species from predators.

It is applied to the conservation of agricultural biodiversity in agro-forestry by farmers, especially those using unconventional farming practices.

In-situ conservation is being done by declaring the area as a protected area. In India following types of natural habitats are being maintained:

  1. National parks
  2. Wildlife sanctuaries
  3. Biosphere reserves

India has over 600 protected areas, which include over 90 national parks, over 500 animal sanctuaries, and 15 biosphere reserves.

Ex-Situ Conservation; Ex-situ conservation is the preservation of components of biological diversity outside their natural habitats.

This involves the conservation of genetic resources, as well as wild and cultivated species, and draws on a diverse body of techniques and facilities.

Such strategies include the establishment of botanical gardens, zoos, conservation strands and genes, pollen seeds, seedlings, tissue cultures, and DNA banks.

Some endangered animals in India

The world is filled with endangered species of animals, many of which can be found in India. While some of these species are critically endangered, some are near threatened and some are even extinct.

There are some species that are left in such few numbers that the next generation may not be able to ever see them if nothing is done for their conservation.

While we hope that more efforts are taken to conserve these species, here’s a list of some endangered animals that you can find in different parts of India.

1. Bengal Tiger

The Bengal Tiger is the national animal of both, India and Bangladesh. The tiger’s coat is yellow to light orange, with stripes ranging from dark brown to black. The number of tigers has reduced dramatically in the past few years, due to poaching and human-tiger conflict.

Can be spotted at Tadoba National Park, Ranthambore National Park, Sundarbans National Park, Sariska Tiger Reserve, Jim Corbett National Park, and Bandhavgarh National Park. [Snow Leopard The snow leopard is a large cat native to the mountain ranges in Central and South Asia.

Snow leopards have long, thick fur, and their base color varies from smoky gray to yellowish tan, with whitish underparts.

Can be spotted: at Hemis National Park, Ladakh, Nanda Devi National Park, Uttarakhand, Dibang Wildlife Sanctuary, Arunachal Pradesh,]

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals Bengal tiger

2. Asiatic Lion

Asiatic Lion aka the Indian Lion or Persian Lion is a lion subspecies that is endangered. It differs from the African lion by less inflated auditory bullae, a larger tail tuft, and a less developed mane.

Can be spotted: at Gir Forest National Park, Gujarat.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals Asiatic lion


3. Snow Leopard

The snow leopard is a large cat native to the mountain ranges in Central and South Asia. Snow leopards have long, thick fur, and their base color varies from smoky gray to yellowish tan, with whitish underparts.

Can be spotted at: Hemis National Park, Ladakh, Nanda Devi National Park, Uttarakhand, Dibang Wildlife Sanctuary, Arunachal Pradesh, Kibber Wildlife Sanctuary, Lahaul Spiti, Himachal Pradesh, Pin Valley National Park, Great Himalayan National Park, Kullu, Himachal Pradesh.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals Snow leopeard

4. Blackbuck

The Blackbuck is an ungulate species of antelope and it is near threatened. The main threat to this species is poaching, predation, habitat destruction, overgrazing, inbreeding, and sanctuary visitors.

Can be spotted: at Guindy National park, Tamil Nadu, Rollapadu, Andhra Pradesh, Chilka, Odisha.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals black buck

5. Red Panda

Red Panda is also known as a lesser panda or red cat-bear. It is an arboreal mammal native to the eastern Himalayas. Red Panda’s population is on a decrease given to habitat loss and fragmentation, poaching, and inbreeding depression.

Can be spotted: at Sikkim, Arunachal Pradesh, and West Bengal’s Khangchendzonga and Namdapha National Park.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals red panda

6. The Nilgiri Tahr:

The Nilgiri Tahr is an ungulate, endemic to the Nilgiri Hills. Nilgiri tahrs are stocky goats with short, coarse fur and a bristly mane.

Can be spotted: at Eravikulam National Park, Nilgiri Hills, Anaimalai Hills, Periyar National Park, and Palni Hills.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals the nilgiri tahr


7. Kashmir Red Stag (Hangul)

The Kashmir stag also known as Hangul is a critically endangered species. This deer has a light rump patch without including the tail. Each of its antlers consists of 5 tines.

Wildlife Sanctuary, OveraAru, Sind Valley, and in the forests of Kishtwar and Bhaderwah, all of which are a part of Jammu and Kashmir.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals Kashmir red stag

8. Lion-Tailed Macaque

The Lion-tailed macaque is an Old World Monkey, endemic to the Western Ghats of South India. Its outstanding characteristic is the silver-white mane that surrounds the head from the cheeks down to the chin.

Can be spotted: at Silent Valley National Park, Kerala, Papanasam part of the KalakkadMundanthurai Tiger Reserve, Tamil Nadu, and Sirsi-Honnavara rainforests of NorthWestern Ghats in Karnataka.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals lion tailed macaque

9. Indian Bison (Gaur)

Indian Bison is the largest extant bovine, native to South Asia and South-East Asia. The bison are highly threatened by poaching for trade to supply international markets.

Can be spotted: at Arignar Anna Zoological Park, Chennai, and Chinnar Wildlife Sanctuary, Kerala.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals indian bison gaur

10. Vultures

Vultures were once the most abundant large birds of prey and nature’s scavengers across the world, including the Indian subcontinent.

But today they are one of the most endangered bird species. This has not only resulted in the near-total disappearance of a magnificent bird from our skies but also jeopardized health and cleanliness in the countryside and caused unnatural changes in the natural food chain.

The species breeds mainly on cliffs but is known to use trees to nest in Rajasthan. Like other vultures it is a scavenger, feeding mostly on carcasses of dead animals which it finds by soaring over the savannah and around human habitation.

They often move in flocks. For centuries, vultures have been silently performing a very important task in the cycle of nature.  They are Nature’s Custodians of Cleanliness. They have been revered in most ancient cultures for the role they play in the ecosystem.

For instance, in India, they appear as Jatayu and Sampati in the great epic Ramayan. They have been playing a lion’s share in disposing of the carcasses of dead animals, both wild and domestic, along with other lesser scavengers such as jackals, hyenas, dogs, crows, and kites.

Between 2000-2007 annual decline rates of this species and the slender-billed vulture averaged over sixteen percent. The cause of this has been identified as poisoning caused by the veterinary drug diclofenac.

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) and when given to working animals it can reduce joint pain and so keep them working for longer.

The drug is believed to be swallowed by vultures with the flesh of dead cattle who were given diclofenac in the last days of life.

Diclofenac causes kidney failure in several species of vultures. In March 2006 the Indian Government announced its support for a ban on the veterinary use of diclofenac.

Another NSAID, meloxicam, has been found to be harmless to vultures and should prove to be an acceptable substitute for diclofenac.

When meloxicam production is increased it is hoped that it will be as cheap as diclofenac. As of August 2011, the ban for veterinary use for approximately a year did not prevent diclofenac use across India.

Small numbers of birds have bred across peninsular India, in Karnataka and Tamil Nadu. Captive breeding programs for several species of Indian vulture have been started.

The vultures are long-lived and slow in breeding, so the programs are expected to take decades. Vultures reach breeding age at about five years old.

It is hoped that captive-bred birds will be released to the wild when the environment is clear of diclofenac.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals vulture


11. Gangetic Dolphins

The Ganges River dolphin (or susu, blind dolphin, Gangetic dolphin, South Asian River Dolphin) inhabits the Ganges-Brahmaputra- Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh.

This vast area has been altered by the construction of more than 50 dams and other irrigation-related projects, with dire consequences for the river dolphins. The scientific name is – Platanista gangetica.

Physical Description: A long thin snout, rounded belly, stocky body, and large flippers are characteristics of the Ganges River dolphin.

Although its eye lacks a lens (this species is also referred to as the “blind dolphin”), the dolphin still uses its eye to locate itself.

The species has a slit similar to a blowhole on the top of the head, which acts as a nostril. The dolphin has the peculiarity of swimming on one side so that its flipper trails the muddy bottom.

Females are larger than males and attain a maximum size of 2.67 m. Males are about 2.12 m. The color of the dolphin is grayish brown. The calves and young ones are dark in color but as the animal grows in size, the color lightens.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals gaint dolphin

Ecology and Habitat:

The species is found exclusively in freshwater habitats. In Nepal, it inhabits Clearwater and rapids. In Bangladesh and India, individuals live in rivers that flow slowly through the plains.

The Ganges River dolphin favors deep pools, eddy counter-currents located downstream of the convergence of rivers and of sharp meanders, and upstream and downstream of mid-channel islands/

Susu shares its habitat with crocodiles, freshwater turtles, and wetland birds, many of which are fish eaters and potential competitors. with dolphins.

Why is this species important? The presence of dolphins in a river system signals a healthy ecosystem. Since the river dolphin is at the apex of the aquatic food chain,

Its presence in adequate numbers symbolizes greater biodiversity in the river system and helps keep the ecosystem in balance.

What are the main threats to the Ganges River dolphin? Dolphins are in danger because of less habitat area due to the construction of dams, fishing, and pesticide.

They are also killed for meat and oil. Dolphins in India come under extinct animals due to polluted rivers and poaching.

Every year nearly 100 Dolphins are getting killed by humans. If anyone kills the Dolphin, or if anyone has the body parts of the Dolphin, will be treated as a crime they will be punished.

Conservation: India has declared Ganga Dolphin as the National Aquatic Animal of India. The Ganges River Dolphin is a rare species of dolphin found only in India and neighboring countries.

There are various conservation works going on in the Sanctuary Areas to protect the National Aquatic Animal of India. Vikramshila Gangetic dolphin sanctuary is the only protected area for the endangered Gangetic dolphins in Asia.

It is located in the Bhagalpur District of Bihar, India. Only a few hundred dolphins remain in India, of which half are found here.

WWF-India and Aaranyak an NGO have been working closely with various government departments to protect these blind river Dolphins of India.

One horned rhinoceros

The Indian rhinoceros (Rhinoceros unicornis), also called the greater one-horned rhinoceros and Indian one-horned rhinoceros.

Listed as a vulnerable species, the large mammal is primarily found in India’s Assam, West Bengal, and in protected areas in the Terai of Nepal, where populations are confined to the riverine grasslands in the foothills of the Himalayas.

The Indian rhinoceros once ranged throughout the entire stretch of the Indo-Gangetic Plain, but excessive hunting reduced their range drastically. Today, more than 3,000 rhinos live in the wild.

WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals one horned rhinoceros.jpg


Physical description: The Indian rhinoceros has thick grey-brown skin with pinkish skin folds and a black horn. Its upper legs and shoulders are covered in wart-like bumps.

It has very little body hair, aside from eyelashes, ear fringes, and tail brushes. Males have huge neck folds. Its skull is heavy with a basal length above 60 cm (24 in) and an occiput above 19 cm (7.5 in).

Its nasal horn is slightly back-curved with a base of about 18.5 cm (7.3 in) by 12 cm (4.7 in) that rapidly narrows until a smooth, even stem part begins about 55 mm (2.2 in) above the base. In captive animals, the horn is frequently worn down to a thick knob.

The rhino’s single horn is present in both males and females but not in newborns young. The black horn is our keratin, like human fingernails, and starts to show after about six years.

In most adults, the caches have a length of about 25 cm (9.8 in), but has been recorded up to 57.2 cm (22.5 in) in length.

Distribution and habitat: One-homed rhinos once ranged across the entire northern part of the infant Subcontinent along the Indus, Ganges, and Brahmaputra River basins, from Pakistan to the Indian-Burmese border, including Bangladesh and the southern parts of Nepal and Bhutan.

They may have also occurred in Myanmar, southern China, and Indochina. Today, their range has further shrunk to a few pockets in southern Nepal, northern Bengal, and the Brahmaputra Valley.

Ecology and behavior: Rhinos are mostly solitary creatures, with the exception of mothers and calves and breeding pairs, although they sometimes congregate in bathing areas.

Dominant males tolerate males passing through their territories except when they are in mating season when dangerous fights break out. They are active at night and early morning.

They are very good swimmers. Indian rhinos bathe -regularly. The folds in their skin trap water and hold it even when they come back on land.

Indian rhinos have few natural enemies, except for tigers, which sometimes kill unguarded calves, but adult rhinos are less vulnerable due to their size.

They have excellent senses of hearing and smell, but relatively poor eyesight. The Indian rhinoceros makes a wide variety of vocalizations.

Diet: Indian rhinoceros are grazers. Their diets consist almost entirely of grasses, but they also eat leaves, branches of shrubs and trees, fruits, and submerged and floating aquatic plants. They feed in the mornings and evenings.

Reproduction: Captive males breed at five years of age, but wild males attain dominance much later when they are larger.

In one five-year field study, only one rhino estimated to be younger than 15 years mated successfully. Captive females breed as young as four years of age but in the wild,

They usually start breeding only when six years old, which likely indicates they need to be large enough to avoid being killed by aggressive males. Their gestation period is around 15.7 months, and their birth interval ranges from 3451 months.

Threats: Sport hunting became common in the late 1800s and early 1900s. Indian rhinos were hunted relentlessly and persistently.

Poaching for rhinoceros horn became the single most important reason for the decline of the Indian rhino after conservation measures were put in place from the beginning of the 20th century when legal hunting ended. From 1980 to 1993,692 rhinos were poached in India.

Poaching, mainly for the use of the horn in traditional Chinese medicine, has remained a constant and has led to decreases in several important populations.

The enormous reduction in the range of rhinos was mainly caused by the disappearance of alluvial plain grasslands. Today, the need for land by the growing human population is a threat to the species.

Many of the protected areas with rhinos have now reached the limit of the number of individuals they can support. This leads to human-rhino conflict as rhinos leave the boundaries of the protected areas to forage in the surrounding villages.

Conservation: The Indian and Nepalese governments have taken major steps towards Indian rhinoceros conservation, especially with the help of the World Wide Fund for Nature (WWF) and other non-governmental organizations. In 1910, all rhino hunting in India became prohibited.

In 1984, five rhinos were relocated to Dudhwa National Park — four from the fields outside the Pabitora Wildlife Sanctuary and one from Goalpara.

Thanks to rigorous conservation efforts, their numbers have increased dramatically since 1975. By 2012, conservation efforts saw the population grow to over 3,000 in the Terai Arc Landscape of India and Nepal and the grasslands of Assam and north Bengal in northeast India.

Fishing Cat

Larger than a domestic cat, the Fishing Cat Prionailurus vibe minus is well adapted to catching fish, its primary prey.
One remarkable feature is the layered structure of their fur, a crucial adaptation to life in the water. Next to the skin lies a layer of short hair so dense that water cannot penetrate it.

  1. Like snug-fitting thermal underwear, this coat helps keep the animal warm and dry even during chilly fishing expeditions.
  2. Sprouting up through the first coat is another layer of long guard hairs which gives the cat its pattern and glossy sheen.

Distribution: Fishing Cats have a discontinuous distribution in South East Asia, northern India, and Sri Lanka. On the island of Java, it has become scarce and apparently restricted to a few coastal wetlands.

Threats: Expansion of roads, housing, shopping malls, and human habitation is reducing bushy jungles or wetlands. Factories and brick kilns are also being constructed here and there. As a result, the habitat and source of natural food for fishing cats are decreasing day by day.

They are also being killed by humans when they are compelled to intrude upon human habitat in search of ducks and hens. Hence their number is endangered.

Conservation: Locally common in some areas of eastern India and Bangladesh, they have become increasingly difficult to locate throughout the remainder of their range.

The scarcity of recent records suggests that over the past decade, they have undergone a serious and significant population decline.

Even in protected wetlands and former Fishing Cat study areas, researchers have been unable to document their presence. Fishing cats are listed as endangered on the lUCN’s Red List of Threatened Species.

They are threatened by habitat loss and hunting for food and fur. People have drained many wetland areas to make room for farmland and roads.

Pollution from industries has poisoned rivers and streams where fishing cats once fed. However, fishing cats appear to do well in suburban habitats, so they may prove more adaptable to human activities than some other species.

The fishing cat is the state animal of West Bengal. In the Bengali language, the fishing cat is known as ‘mach-baghrol’.’ mach means fish, and ‘bagha’ means tiger. The name is due to their tiger-like appearance and fish-eating habit.


WBBSE Solutions For Class 8 School Science Chapter 10 Biodiversity, Environmental Crisis and Conservation of Endangered Animals fishing cat


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