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Migratory Birds in Chandigarh – Why fewer birds are migrating to Chandigarh? Bird Census Key Points

Migratory Birds in Chandigarh – Why fewer birds are migrating to Chandigarh? Bird Census Key Points

Relevance:

  • GS 3|| Environment || Biodiversity || Animal Diversity

Why in the news?

“Increasing human footprints, disturbance, especially around the specific habitats for the migratory birds like regulatory ends of Sukhna Lake, along with increasing water level of water bodies are among major reasons for this trend

What are Migratory Birds?

  • Migratory species are those animals that move from one habitat to another during different times of the year, due to various factors such as food, sunlight, temperature, climate, etc.
  • The movement between habitats, can sometimes exceed thousands of miles/kilometres for some migratory birds and mammals.
  • A migratory route can involve nesting and also requires the availability of habitats before and after each migration.

What happened now?

  • With the change in weather, migratory birds start arriving in Chandigarh.
  • A variety of winged visitors can be spotted at water bodies in and around the City Beautiful between November and March.
  • Every year Sukhna Lake acts as a home for numerous migratory birds from the Himalayas and far-off places, such as Europe, Japan, China and Central Asia
  • The common species that can beseen here during the season are Common Pochards,Tufted Ducks and Greylag

Why Do Birds Migrate?

  • Birds migrate to move from areas of low or decreasing resources to areas of high or increasing resources.
  • The two primary resources being sought are food and nesting locations.
  • Birds that nest in the Northern Hemisphere tend to migrate northward in the spring to take advantage of burgeoning insect populations, budding plants and an abundance of nesting locations.
  • As winter approaches and the availability of insects and other food drops, the birds move south again.
  • Escaping the cold is a motivating factor but many species, including hummingbirds, can withstand freezing temperatures as long as an adequate supply of food is available.

Types of Bird Migration:

  • Latitudinal migration: The latitudinal migration usually means the movement from north to south, and vice versa. Most birds live in the land masses of the northern temperate and subarctic zones where they get facilities for nesting and feeding during summer. They move towards south during winter.
  • Longitudinal migration: The longitudinal migration occurs when the birds migrate from east to west and vice- versa. Starlings (Sturnus vulgaris), a resident of east Europe and west Asia migrate towards the Atlantic coast. California gulls, a resident and breed in Utah, migrate westward to winter in the Pacific coast.
  • Altitudinal migration: The altitudinal migration occurs in moun­tainous regions. Many birds inhabiting the mountain peaks migrate to low lands during winter. Birds migrate either in flocks or in pairs.
  • Partial migration: All the members of a group of birds do not take part in migration. Only several members of a group take part in migration. Blue Jays of Canada and northern part of United States travel southwards to blend with the sedentary populations of the Southern States of U.S.A. Coots and spoon bills (Platalea) of our country may be example of partial migration.
  • Total migration: When all the members of a species take part in the migration, it is called total migration.
  • Vagrant or irregular migration: When some of the birds disperse to a short or long distance for safety and food, it is called vagrant or irregular migration. Herons may be the example of vagrant or irregular migration. Other examples are black stork (Ciconia nigra), Glossy ibis (Plegadis falcinellus), spotted eagle (Aquila clanga), and bee eater (Merops apiaster).
  • Daily migration: Some birds make daily journey from their nests by the influence of environmental factors such as temperature, light, and humidity also. Examples are crows, herons and starlings.
  • Seasonal migration: Some birds migrates at different seasons of the year for food or breeding, called seasonal migration, e.g., cuckoos, swifts, swallows etc. They migrate from the south to the north during summer. These birds are called summer visitors. Again there are some birds like snow bunting, red wing, shore lark, grey plover etc. which migrate from north to south during winter. They are called winter visitors.

Change in migration pattern:

  • Biodiversity loss: Overexploitation, unsustainable natural resource use, population explosion, increased weather variability, and climate change have all contributed to biodiversity loss. Eg. parrots, pigeons, and pheasants
  • Depleting water sources: excessive water use and changes in rainfall patterns have resulted in a decrease in groundwater levels. E Pin-tailed ducks (come from Central Siberia and Central Asia)
  • Illegal hunting: Certain migratory bird species are threatened by illegal hunting along migration routes. Eg. Quail
  • Loss of stopover habitat: During their migration, migratory birds use stopover sites to feed, rest, and re energize. However, due to increased urbanization and overexploitation, many stopover sites are in jeopardy.
  • Collision: Migratory birds have been harmed by structures such as power lines, windmills, and offshore oil rigs.
  • Pesticide poisoning: Pesticides have a negative impact on migratory birds because they can destroy them directly.
  • Increasing illumination: Artificial light at night confuses birds, which has a negative impact on migration.
  • Encroachment and human interference: As a result of increasing encroachment and human interference, a shortage of food has become a problem, and birds have died as a result of starvation. Eg, greater flamingo

Importance of migration of birds:

  • Migratory birds help to keep the ecosystem in balance by bringing in new species. They aid in the pollination of plants, the dispersal of seeds, the control of pests, and the consumption of insects and small mammals.
  • When these birds are absent from a region, disasters such as a Locust attack may occur.
  • Ducks aid in the transfer of fish eggs from their guts to other bodies of water. Bird droppings are an excellent source of nitrogen as well as organic fertilizers.
  • Migratory birds form both prey and predator bases in ecosystems seasonally and can, therefore, have an ecological impact. Prevalence of migratory birds helps analyse the state of environment in an area.

Example of migration of birds:

  • Birds often migrate to and from specific sites and hence, certain regions become identified with certain species. Pallikaranai in Chennai attracts a large number of flamingoes, ducks and waders.
  • Pulicat Lake on the Tamil Nadu-Andhra border hosts flamingoes; ducks and waders can be seen in Chilika lagoon in Odisha. Other notable sites to see migratory birds are the Keoladeo National Park in Bharatpur in Rajasthan and Khijadia Bird Sanctuary in Jamnagar in Gujarat.
  • In the past years we have seen decline in migratory bird.

Reasons behind decline

  • Chandigarh hosts a large number of latitudinal migrants in the winter from Siberia. Some of the common species are Graylag Goose, Bar-headed Goose, Northern Shoveller, common Pochard, Tufted Duck, Black-tailed Godwit Ruddy Shell Ducks etc.
  • Sadly, count of these birds decreasing.
  • Migratory birds can be divided in two categories- Ducks and Waders (shorebirds).
  • A majority of migratory birds prefer to stay around shallow water bodies for easy availability of food. Though this time we included waterbodies situated in Mohali assuming that birds can be shifted from Sukhna Lake to these bodies, the findings were not encouraging. Number of waders is decreasing largely,
  • Increasing human footprints, disturbance, especially around the specific habitats for the migratory birds like regulatory ends of Sukhna Lake, along with increasing water level of water bodies are among major reasons for this trend

CMS:

  • In order to protect the migratory species throughout their range countries, a Convention on Conservation of Migratory Species (CMS), has been in force, under the aegis of United Nations Environment Programme.
  • Also referred to as the Bonn Convention, it provides a global platform for the conservation and sustainable use of migratory animals and their habitats and brings together the States through which migratory animals pass, the Range States, and lays the legal foundation for internationally coordinated conservation measures throughout a migratory range.
  • India and the CMS:
    • India has been a party to the Convention since 1983.
    • India has signed a non-legally binding Memorandum of Understanding (MoU) with CMS on conservation and management of Siberian Cranes (1998), Marine Turtles (2007), Dugongs (2008), and Raptors (2016).
    • With 2.4% of the world’s land area, India contributes to around 8% of the known global biodiversity.
    • Indian subcontinent is a part of a significant bird flyway network, i.e, Central Asian Flyway that covers areas between the Arctic and Indian Oceans with at least 279 populations of 182 migratory waterbird species (including 29 globally threatened species).

Conclusion:

Migratory behavior has and is being intensely studied for over a century, by an ever growing group of scientist and researchers. The amount of literature on migration, in the broadest sentence, is almost limitless. Although the efforts made, there still is mystery in migration, how it originated and how it evolved.

Mains oriented question:

In the past years we have seen major decline in migratory birds, what are the possible reason for the decline, how it can affect the ecosystem?