Thinning of vulture populations in the Indian subcontinent

Thinning of vulture populations in the Indian subcontinent

March 31, 2015 by  
Filed under Features

Vultures constitute an important component of the ecosystem. Being carrion feeders, they perform an important task as finishers in the ecosystem in returning human and animal corpses into their elemental forms back into the system and thus play a significant role as cleaners or disposers in the nature. They are capable of stripping carcasses free of all flesh, soft and hard tissues such as tendons, cartilages, softer bones, skins, hairs and keratins with their sharp claws and beaks; and due to special enzymes in their stomach are capable of digesting them. Different species of vultures are reported from the Indian subcontinent and unfortunately the populations of most of these ecologically important species are showing serious signs of decline across most of their natural ranges. Some of the factors that have contributed towards the rapid decline of the populations of different species of vultures across the subcontinent include: loss of habitats and habitat fragmentations; removal of old and big trees in and around city fringes, city parks and city gardens causing loss of suitable nesting sites; rapid and unplanned urbanization drive to cater to the growing human populations in the cities and towns; unprecedented boom of real estate business and infrastructural developments causing the loss of green spaces within and around the major city areas, the added areas and their subsequent extensions and in the greater metropolitan areas including district towns and municipalities; rapid, unrestricted, unplanned and unmonitored growth of both legal as well as illegal industrial units within city limits and adjacent areas causing pollution of the local environment; severe anthropogenic pressures in the remaining open spaces at the city fringes due to human encroachments and establishments of slums and shanties; communicable diseases among vulture populations; and last but not the least, poisoning of the animal carcasses on which these birds feed as their primary food sources both intentionally as well as accidentally. Furthermore, pesticide poisoning of the birds have also been reported from several parts of the subcontinent.

Subsequent scientific studies established that diclofenac, an anti-inflammatory drug commonly administered to the Indian livestock for the treatment of wounds and inflammations, as one of the potent chemicals that have been killing and decimating the vulture populations in India through the process of biomagnification. The leading cause of death through poisoning by the drug among vultures is through drastic renal failures. The species that have been worst impacted are the Indian vulture (Gyps indicus Scopoli), the white-rumped vulture (Gyps bengalensis Gmelin) and the slender-billed vulture (Gyps tenuirostris Hodgson (in Gray)); that were reduced from stable populations of several millions to just a few thousands over the span of two-three decades.

In several parts of their former ranges a decline between >70-85% to < 97-99% in their wild populations have been reported raising an important concern for their threats to extinction in the next 20-25 years.  Unfortunately, the Indian vulture, the slender-billed vulture and the white-rumped vultures are all now placed under the category of critically endangered by the IUCN; while the Egyptian vulture (Neophron percnopterus Linnaeus) is currently considered to be endangered. The only species that is evaluated to be near threatened in the wild is the famous Himalayan vulture or better known as the Himalayan griffon vulture (Gyps himalayensis Hume) that is restricted to the Himalayas and the Tibetan plateau and is not dependent too heavily upon livestock carcass as their principal dietary source; and the Eurasian griffon (Gyps fulvus Hablizil) which is under the least concern category. The facts clearly indicate that the vultures belonging to the genus Gyps are most readily impacted and also these species are distributed predominantly in the river valleys, great northern and western plain lands and the plateau region of the subcontinent with significant agronomic activities and substantial livestock populations. Hence the biomagnification poisoning through diclofenac has been identified as one of the most devastating factors decimating the vulture populations in the Indian subcontinent in addition to several other anthropogenic factors mentioned above.

Several vulture rehabilitation, breeding and reintroduction centers have been established in India being alarmed with the sharp decline of the vulture populations and a few more are coming or are being proposed. However, their numbers are too meager compared to the need from the context of species revival. Some success has been documented in the breeding, rearing and reintroduction of different vulture species in the wild in various parts of their former home ranges; however, much needed to be done. Steps have been taken in removing diclofenac as the preferred veterinary drug by the cattle handlers and livestock operators with other alternatives having much lower impacts on the vulture populations has been recommended and/or prescribed. But the drug is continued to be used in small to moderate numbers till date across the home range of the vultures. Lack of education and awareness; as also lack of care and empathy for the long term sustainability of the local ecosystem and environment by agricultural workers, cattle handlers and livestock operators have been another serious concern that needs to be addressed sincerely by the vulture conservation agencies. It will be necessary to completely ban this drug from the livestock industry and strong monitoring and surveillance will be necessary to evaluate the wild populations of vultures in the coming decades. Unless a comprehensive conservation, rehabilitation and reintroduction policy is adopted with strong legislative measures and effective wildlife management strategy is implemented and practiced in saving the Indian vultures, their future looks extremely grim and vulnerable with dangers of extinction in the wild.

Article contributed by: Saikat Kumar Basu

Wetland birds: A conservation priority for Iran

Wetlands are considered as environmental lifeline giving an opportunity to fisheries, climate mitigation, efficient water supply for crop productivity, recreational activities and for their significant role in maintaining the delicate ecological balance. However, the health of these valuable ecosystems is being increasingly threatened due to severe anthropogenic pressures exerted through agriculture, industrial and infrastructure developments, rapid urbanization, untreated urban waste water discharges, non-judicious exploitation of wetland resources and their poor management around the planet. Furthermore excessive diversion of water for agricultural purposes, uncontrolled inflow of wastewater, sewage, and solid wastes from both industrial and domestic sources into the wetlands, and using up wetland vegetation for food, fuel, fodder and fertilizer purposes are additional anthropogenic activities that have significantly reduced areas of wetlands; specifically in developing and under developed countries where conservation of wetland ecosystems are not widely practiced.

Iranian wetlands and aquatic ecosystems are considered to be important natural resources having significant role in maintaining ecological balance and biodiversity, natural mitigation of climate changes and in terms of biosecurity with reference to drought or flood control from a regional and/or global perspective. The Ramsar convention held in 1971 at the coastal city of Ramsar in Iran constitutes the global slogan of ‘wetlands for our future’ as the tagline for global wetland conservation initiatives. Iran comprises of 250 wetlands constituting ~2.5 million hectares; however, only 22 of them (8.8%) representing an area of1,481,187 hectares have been registered under the Ramsar Convention so far. These wetlands are distributed in different parts of Iran with nine within interior provinces, seven along the coastal line of Caspian Sea, five along coastal line of Persian Gulf, and one along the coastal line of the Oman Sea. In addition, there is one more frontier wetland known as Hamoon-Hirmand wetland located between Iran and Afghanistan.

Source:  Google Images

Now 13 out of the 22 (59%) Iranian wetlands registered under the Ramsar Convention, have been included in the Montreux List. In terms of the quantity and area occupied they constitute ~59 and 41% respectively of the Iranian wetlands. The 48 wetlands from 27 countries that are now included in the Ramsar Convention-Montreux Record (Red List); Greece, Iran and Czech Republic constitute the highest number of endangered wetlands.


Biodiversity of wetland species of Iran 1

Iranian wetlands serve as habitats for over 140 species of migratory and resident birds constituting 30% avifauna of Iran. About 63 species of local birds nest and breed in these wetland ecosystems and around 77 species reside in these primary habitats during the winter and autumn. Recently 20 wetland avian species have been reported to be threatened with the dangers of eventual extinction as their numbers have depleted critically below that necessary for maintaining healthy and sustainable populations. It is estimated that between 1-2 million aquatic and shore birds pass through the Iranian wetlands during the winter. The Iranian wetlands are pristine habitats for a number of different species of ducks, geese, swans, cormorants, pelicans, grebes, herons, egrets, kingfishers, black-crowned night-heron, great bittern, greater and lesser flamingoes, ibises, spoonbills, storks, cranes, oystercatchers, rails, crakes, gallinules and coots to name only a handful. The marshy and swampy areas adjoining wetlands have rich habitats for different pheasants and other ground nesting birds and the ospreys and other raptors frequently visit the wetland areas for preying upon different aquatic birds and their chicks and wetland fishes.


Biodiversity of wetland species of Iran 2

An overview of the current situation of the Iranian wetlands (protected, non-protected and international) indicates that numerous factors as mentioned below have caused the decrease, drying, destruction and loss of vulnerable wetland areas. The factors include:

  1. Lack of improved management indices
  2. Poor management
  3. Lack of consistent and reliable data on the local wetlands
  4. Soil erosion
  5. Sedimentation
  6. Flooding
  7. Drought
  8. Deterioration of wetland soil physical, chemical and biological characteristics
  9. Poor land use and management (construction of dams and implementation of developmental projects like building surface infrastructure in the watersheds areas or in the environmentally sensitive coastal-marine areas, farming and aquaculture e.g. shrimp farming, oil exploration in coastal wetlands etc.)
  10. Non-judicious exploitation (illegal fishing and/or poaching, issuing hunting license without any serious attention towards long term wetland conservation plans, promoting tourism along or within wetlands, indiscriminate use of wetland’s water, using wetlands as agricultural water repositories,  introduction of exotic species etc.)


Anzali Lagoon, Guilan Province

Einak Wetland, Guilan Province

Einak Wetland, Guilan Province

Gandoman Wetland, Chaharmahal and Bakhtiari Province

Gavkhoni Wetland, Isfahan Province

Gavkhoni Wetland, Isfahan Province

Although Iranian wetlands have a spectacular diversity of water birds including both the resident and annual migratory species that visit the country on their long journey to tropical and sub-tropical destinations. However, in spite of this spectacular biodiversity observed across wetlands in Iran, the future of the avian species does not look too rosy due to unrestricted poaching and illegal capture of birds by the local poachers. A number of the local wetlands are seriously threatened with the extinction of rare and endangered local bird species. Poor economic development in the distant rural regions with fewer opportunities of regular employment has pushed several men into the vicious cycle of poaching. Although Iranian authorities are doing their best to reduce poaching and capture of these precious bird species; however, the ground realities are that the situation has been deteriorating over the time. The environmental and conservation agencies in the country have far less personnel available in the job than that what is needed to deal with the situations effectively. Conservation priorities have often been misplaced due to the dire need for the local infrastructural developments and constructions works that has damaged several wetland areas and the birds have shifted their range to deal with the challenges of their fragmented habitats.


Ghorigol Wetland, West Azarbaijan Province

Hamoon Frontier Wetland, Sistan & Balochestan Province

Hamoon Frontier Wetland, Sistan & Balochestan Province

Mighan Wetland, Markazi Province

Mighan Wetland, Markazi Province

Shadegan Wetland, Khozestan Province

Lack of education and awareness in the remote rural region and forest fringes as well as poor economic situations have been an important factor promoting the poaching and illegal capture and trade of wetland birds in the country. To make the conservation efforts to reach desirable effect, it will be important to reduce the anthropogenic footprints on the fragile wetland ecosystems. Unless the economic situation of the local rural communities is substantially improved the challenges of the conservation will be considerable for protecting the different endangered and vulnerable wetland avian species. With improvements of the local resident communities the anthropogenic pressures on the wetland will go down considerably. More vigilant and stringent monitoring and surveillance of the wetland areas and detailed maintenance of record of the population dynamics of different avian species of the region will be necessary. Modern conservation management, collection and storage of detailed survey data on the wetlands and proper training and education of the personnel for the environmental protection and conservation agencies will also be necessary to empower them in tackling the ground situations more effectively. The government needs to allocate specific funds for the purpose and the involvement of different stakeholders such as the government, non-government organizations, local rural residents and community members, public and members of the conservation and environment protection agencies. It will be important for all of them to come together on a common platform to design some long term and sustainable management plan or policy for efficient and effective conservation of the avian members surviving in the Iranian wetlands.


Natural Lake in Kamalmahalleh Rurar, Shaft County, Guilan Province

Biodiversity of Iranian Wetlands 3

Selkesar Wetland located just below the Anzali lagoon, Guilan Province

Biodiversity of Iranian Wetlands 4

Photo credits: Peiman Zandi, Saikat Kumar Basu & Rahul Ray

 

Further readings

The birds of Iran (2015) Available at: http://www.iranian-bird.blogfa.com/cat-73.aspx[Accessed on 4th March, 2015]

Adekola O, Mitchell G (2011) The Niger Delta Wetlands: Threats to Ecosystem Services, their Importance to Dependent Communities and Possible Management Measures. International Journal of Biodiversity Science, Ecosystem Services & Management, 7(1): 50-68.

The Ramsar convention on wetlands (2015) http://ramsar.rgis.ch/cda/en/ramsar-documents-list-ramsar-list-of/main/ramsar/1-31-218%5E7791_4000_0__ [Accessed on 4 March 2015]

Lin T, Xue X, Lu C (2007) Analysis of Coastal Wetland Changes Using the “DPSIR”  Model: A Case Study in Xiamen, China. Coastal Management, 35:289–303.

Kimmel  K. Kull A, Salm J, Mander Ü (2010) The Status, Conservation and Sustainable Use of Estonian Wetlands. Wetlands Ecological Management,18: 375-395.

Behrouzirad B (2006) Challenges and problems of Iranian wetlands and their ecosystem management indicators. 3rd Iranian Congress on Environment Crises and their Rehabilitation Methodology, 27-29 Dec. 2006, Islamic Azad University of Ahvaz-Science and research branch, Ahvaz.

Behrouzirad B (1992) On the Movement of Greater Flamingo in IRAN. zoology in Middles, London.

Behrouzirad B (2004) Diversity of Fish Eating Birds of South Caspian Sea coasts, Proceeding of Fourth International Iran & Russian Conference, Agriculture and Natural Resources” 8-10 September 2004, Shahrekord University, Shahrekord, Iran.

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