"Canopy Bridges Help India's Wildlife Cross Fragmented Habitats"
Habitat fragmentation
splitting of a continuous habitat into isolated patches by roads, railways or other barriers
Brachiation
specialised arm-over-arm swinging movement used by apes like gibbons to move through tree canopies
India's wildlife protection law, the Wildlife (Protection) Act, 1972, banned hunting and gave legal protection to the habitats of endangered species. However, a protected area on paper does not stop roads and railway lines from cutting through it. Habitat fragmentation is the splitting of a continuous habitat into isolated patches by linear infrastructure like roads or rail lines. This is a major threat to species that need large connected ranges. Many people do not notice this problem.
The Hoolock gibbon is found mainly south of the Brahmaputra river in Northeast India. It is India's only ape species besides humans and is listed as Endangered by the IUCN. Gibbons use a specialised form of movement called brachiation (meaning: swinging arm-over-arm between tree branches). This makes them fast and graceful in trees. On the ground, they are awkward and vulnerable. Predators like wild dogs and leopards can easily catch them there. When a railway line cut through Eastern Assam's forests in the late 19th century, it split gibbon habitat into fragments. One such fragment later became the Hoollongapar Gibbon Sanctuary. It is now home to only about 130 western hoolock gibbons. The total population in Northeast India is 3,000-5,000.
Fragmentation affects other arboreal (tree-dwelling) species too. The lion-tailed macaque's natural range lies in the rainforests of the Western Ghats. This range spreads across Tamil Nadu, Kerala and Karnataka. Around the town of Valparai in Tamil Nadu, coffee and tea estates and connecting roads have broken this habitat into isolated patches. Similar problems affect the slow loris in Indonesia and the three-toed sloth in Central America. Both are slow-moving animals that depend on continuous canopy cover.
Western hoolock gibbons have a lightweight, slender build adapted for arboreal life. Gorillas have a heavy, powerful build. Among primates like lion-tailed macaque, malabar civet, and sambar deer, only the malabar civet is generally nocturnal or most active after sunset.
The core mechanism of fragmentation-driven decline is simple but serious. Smaller, isolated territories support fewer individuals. Over time, this leads to genetic isolation, inbreeding and population decline. Species that mate for life and defend fixed territories, like gibbons, are especially affected. A severed canopy stops pairs from finding new mates or expanding their range. Small groups become trapped in shrinking pockets.
Conservation responses have focused on physically restoring connectivity. They have not removed the infrastructure itself. At Hoollongapar, local organisations such as Aranyak first installed gantry bridges (artificial crossing structures). …
With respect to the Western Hoolock Gibbons, which of the following statements is/are correct?
1.A Sanctuary in North-east India is home to this ape species listed as Endangered in the International Union for Conservation of Nature (IUCN) Red List.
2.They have specialized brachiation and can easily swing between trees.
3.They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers.
Select the answer using the code given below:
In which of the following States is lion-tailed macaque found in its natural habitat?
1.Tamil Nadu
2.Kerala
3.Karnataka
4.Andhra Pradesh
Select the correct answer using the codes given below.
Consider the following statements about the Hoolock gibbon:
1.It is India's only ape species apart from humans.
2.It is found mainly to the north of the Brahmaputra river.
3.It is listed as Endangered on the IUCN Red List.
How many of the above statements are correct?
The lion-tailed macaque is found in its natural habitat in which of the following States?
1.Tamil Nadu
2.Kerala
3.Karnataka
4.Odisha
Select the correct answer using the code given below:
The Wildlife (Protection) Act, 1972 primarily provides for which of the following?
Match the following arboreal species with the connectivity structure used to help them cross fragmented habitats:
Species:
1.Western hoolock gibbon
2.Giant Indian squirrel
3.Ground-dwelling wildlife in the Netherlands
Structure:
A.Rope bridge
B.Animal overpass
C.Canopy bridge
Select the correct match:
Want the full note, Prelims Facts & MCQ answers?
Create a free account — takes less than a minute.
Create free account