World’s Migratory Species & Threats

Category
Ecology and Environment
Published
23rd Mar, 2024

Context

The flocks of birds are dwindling in numbers as they navigate through regions that are becoming ‘increasingly uninhabitable’ for them. Nearly half of all migratory species are in decline.

1: Dimension-Factors responsible for decline

Loss of natural habitat and overexploitation: These species face shifting landscapes due to urbanisation, farming and climate change among several other challenges.
Habitat loss happens when land becomes urbanised, transformed for human use or degraded through pollution. Farming is a primary driver of this sort of fragmentation.
- Migratory birds have experienced significant declines across certain regions, particularly those using the Afro-Palearctic migratory route. These birds typically travel southwards across Africa from Europe and Asia.
Agricultural and industrial activity also release dangerous chemicals into habitats.

2: Dimension-Role of climate change in affecting migratory species

Decline: Climate change is the second most significant factor contributing to the decline of migratory species.
Changes to natural landscape: The changes in temperature, precipitation and weather patterns can affect the suitability of breeding and stopover sites along migration routes.
Direct mortality of species or less breeding: Species may no longer be able to follow their usual migratory patterns.

3: Dimension-Impact of this decline on human and environment

Ecological, economic and cultural importance: They help keep ecosystems from degradation and collapse. This can especially support carbon sequestration, the removal of carbon dioxide from the atmosphere, which mitigates climate change. This occurs through thicker vegetation or healthier coral reefs, for instance.
Strong coastal ecosystems: They can also hold back floods and storm surges.
Other “ecosystem services”: Pollination, seed dispersal, and pest-control.

DATA BOX

IUCN Report

Migratory Birds: About 14 percent of migratory birds around the world are threatened, which amounts to 134 of the 960 species listed by the UN.
Fish species: Ninety-seven percent of the 58 fish species (monitored by UN) are threatened with extinction. They include several species of sturgeon, shark, ray and sawfish.
An additional 399 species that are not currently listed in the CMS are also threatened or are at risk of coming under threat, which means they could also benefit from protective measures.
Examples: Indus River dolphin and albatross.
About 44 percent of migratory species across the world are in decline while one in five faces the threat of all-out extinction.
Some of the most critically endangered migratory birds include the Amsterdam Island albatross and Balearic shearwater

Migratory Flyways

Migratory birds use flyways, a term for their established routes across geographical regions. There are five flyways covering Asia:
The Asian–East African Flyway starts from the northern breeding grounds of waterbirds in Siberia and leads across Asia to East Africa.
The Central Asian Flyway starts from the northern breeding grounds of water birds in Siberia and leads across Asia to the Indian subcontinent.
The East Asian–Australasian Flyway starts at the Taymyr Peninsula in Russia and Alaska and extends southwards to southeastern Asia, Australia and New Zealand. About 60 species of shorebird use this route.
The West Pacific Flyway links New Zealand and the east coast of Australia, through the central Pacific Ocean and the east coast of northern Asia, including Japan and the Korean Peninsula, ending up in eastern Siberia, including the Chukchi and Kamchatka Peninsulas, and Alaska. This flyway overlaps with the East Asian–Australasian Flyway.
The African-Eurasian Flyway covers the whole of Europe, Africa and the Middle East as well as the Canadian Archipelago and parts of Central Asia.

Mains Practice Question

Q: Migratory species globally are facing critical challenges, with nearly half in decline. Analyse the impact of climate change as an “amplifier” of other such threats as overexploitation and habitat loss along the Central Asian Flyway, citing specific examples.