The State of the World’s Birds, an annual review of environmental resources published recently by nine natural sciences and avian specialists across the globe, has revealed that the population of 48% of the 10,994 surviving species of birds is declining.
GS III- Environment and Ecology ( Conservation, Environmental Pollution & Degradation)
Dimensions of the Article:
- About State of the World’s Birds
- Key findings of the study:
- Importance of birds to ecosystems and culture
- Threats contributing to avian biodiversity loss
About State of the World’s Birds
- Manchester Metropolitan University is the publisher of the report.
- It presents an overview of how our understanding of bird biodiversity has evolved and how threatened it is.
- The research is based on BirdLife International’s most recent evaluation of all birds for the Red List of the International Union for Conservation of Nature.
Key findings of the study:
- The study found that 5,245 or about 48% of the existing bird species worldwide are known or suspected to be undergoing population declines.
- While 4,295 or 39% of the species have stable trends, about 7% or 778 species have increasing population trends.
- The trend of 37 species was unknown.
- The study draws from BirdLife International’s latest assessment of all birds for the International Union for Conservation of Nature’s Red List that shows 1,481 or 13.5% species are currently threatened with global extinction.
- These include 798 species classified as vulnerable, 460 as endangered and 223 as critically endangered while 52 species were considered to be data deficient.
- About 73% species are estimated to have fewer than 10,000 mature individuals, 40% have fewer than 2,500 mature individuals, and almost 5% have fewer than 50 mature individuals.
- The bird species are non-randomly threatened across the avian tree of life, with richness of threatened species disproportionately high among families such as parrots, pheasants and allies, albatrosses and allies, rails, cranes, cracids, grebes, megapodes, and pigeons.
- The more threatened bird species (86.4%) are found in tropical than in temperate latitudes (31.7%), with hotspots for threatened species concentrated in the tropical Andes, southeast Brazil, eastern Himalayas, eastern Madagascar, and Southeast Asian islands.
Importance of birds to ecosystems and culture
- Birds contribute toward many ecosystem services that either directly or indirectly benefit humanity.
- These include provisioning, regulating, cultural, and supporting services.
- The functional role of birds within ecosystems as pollinators, seed-dispersers, ecosystem engineers, scavengers and predators not only facilitate accrual and maintenance of biodiversity but also support human endeavours such as sustainable agriculture via pest control besides aiding other animals to multiply.
- For instance, coral reef fish productivity has been shown to increase as seabird colonies recovered following rat eradication in the Chagos archipelago.
- Wild birds and products derived from them are also economically important as food (meat, eggs).
- Approximately 45% of all extant bird species are used in some way by people, primarily as pets (37%) and for food (14%).
- Beyond its symbolic and artistic values, birdwatching is a global pastime practised by millions of people. Garden bird-feeding is valued at $5-6 billion per year and growing by four per cent annually.
Threats contributing to avian biodiversity loss
- The study lists eight factors, topped by land cover and land-use change.
- The continued growth of human populations and of per capita rates of consumption lead directly to conversion and degradation of primary natural habitats.
- Deforestation has been driven by afforestation with plantations (often of non-native species) plus land abandonment in parts of the global North, with net loss in the tropics.
- The other factors are habitat fragmentation, degradation, hunting and trapping.
-Source: The Hindu