APP Users: If unable to download, please re-install our APP.
Only logged in User can create notes
Only logged in User can create notes

General Studies 3 >> Enivornment & Ecology

audio may take few seconds to load



1. Context
Recently, Bihar has initiated a program to attach GPS trackers to greater adjutant storks, locally known as 'Garuda', in order to monitor their movements as part of conservation efforts
2. About Greater Adjutant Stork
  • The Greater Adjutant Stork (Leptoptilos dubius) is a large, scavenging stork found in parts of South and Southeast Asia. It is an impressive bird, standing tall at up to 5 feet and having a wingspan of up to 8 feet! They are considered to be one of the largest flying birds in the world.
  • These storks have a distinctive appearance. They have a bald head and neck, a long, massive bill, and a pouch of skin that hangs from their throat. Their plumage is mostly grayish-black, with a white patch on their wings. They are not known for their melodious sounds and their vocalizations have been described as grunts or croaks
  • Greater Adjutants were once found widely across southern Asia and mainland Southeast Asia. However, their populations have declined significantly in recent years, and they are now classified as Endangered by the IUCN. This decline is due to a number of factors, including habitat loss, hunting, and poisoning
3. Features of Greater Adjutant Stork

The Greater Adjutant Stork (Leptoptilos dubius) is a distinctive bird with several unique features. Here are the key characteristics:

Physical Features

  • Size: One of the largest storks, standing about 1.5 meters (5 feet) tall with a wingspan of around 2.5 meters (8 feet).
  • Weight: They typically weigh between 5 to 7 kilograms (11 to 15 pounds).
  • Appearance:
    • Head and Neck: Bare, with reddish or orange skin and no feathers, helping in thermoregulation and hygiene while feeding on carrion.
    • Throat Pouch: Prominent inflatable pouch (gular sac) used in courtship displays and possibly in thermoregulation.
    • Bill: Massive and strong, ideal for scavenging and handling large prey.
    • Plumage: Predominantly dark grey or black with some white on the underparts and tail. Juveniles have more brownish plumage.
    • Legs: Long and pale, often covered in a white powdery substance from preening, which aids in protecting them from the sun
4. Habitat of Greater Adjutant Stork

Natural Habitat

  • Wetlands: The primary habitat of the Greater Adjutant Stork includes a variety of wetland ecosystems. These wetlands provide abundant food resources and suitable nesting sites.
    • Swamps and Marshes: These areas are rich in biodiversity and offer a plentiful supply of food such as fish, amphibians, and carrion.
    • Floodplains: Seasonal floodplains provide temporary feeding grounds with an abundance of aquatic prey.
    • Riverbanks and Lakeshores: These regions are essential for feeding and nesting due to the proximity to water.

Nesting Sites

  • Large Trees: The Greater Adjutant Stork nests in large trees, which offer safety from ground predators and a vantage point for adults to watch over their chicks. These trees are often located near wetlands.
  • Human Proximity: In some regions, these storks have adapted to nesting in areas close to human settlements where large trees are available, such as in Assam and Bihar in India.

Geographic Distribution

  • India: The largest populations are found in Assam and Bihar, where they are commonly known as 'Hargila' and 'Garuda,' respectively. These regions provide the essential wetland and tree habitats needed for feeding and nesting.
  • Cambodia: Smaller populations exist, primarily in the northern plains, where conservation efforts are underway to protect and expand suitable habitats.
  • Historical Range: The species was once widespread across Southeast Asia, but habitat loss and other factors have significantly reduced their range.
5. Conservation Status of the Greater Adjutant Stork

The conservation status of the Greater Adjutant Stork (Leptoptilos dubius) is a matter of significant concern due to its declining population and various threats. Here are the key points regarding its conservation status:

IUCN Red List

  • Status: The Greater Adjutant Stork is listed as "Endangered" on the International Union for Conservation of Nature (IUCN) Red List.
  • Criteria: The species meets the criteria for this status due to a rapid population decline, estimated to be more than 50% over the past three generations, largely driven by habitat loss and degradation.
  • Current Estimates: The global population is estimated to be around 800 to 1,000 mature individuals.
  • Geographic Concentration: The majority of the population is concentrated in Assam and Bihar in India, with smaller populations in Cambodia. Historically, the species was more widely distributed across South and Southeast Asia.
6. Difference between Greater and Lesser Adjutant Stork
Feature Greater Adjutant Stork (Leptoptilos dubius) Lesser Adjutant Stork (Leptoptilos javanicus)
Size Larger, standing up to 1.5 meters (5 feet) tall with a wingspan of around 2.5 meters (8 feet) Smaller, standing about 1.2 meters (4 feet) tall with a wingspan of around 2 meters (6.5 feet)
Appearance Plumage predominantly dark grey or black, with some white on the underparts and tail. Bare head and neck with reddish-orange skin. Prominent inflatable throat pouch. Plumage mostly dark brown, with a distinctive white stripe on the throat and neck. Bare head and neck with greyish skin. Smaller throat pouch
Habitat Found primarily in wetlands, including swamps, marshes, and riverbanks. Historically widespread in Southeast Asia; now concentrated in Assam and Bihar in India, and smaller populations in Cambodia. Also inhabits wetlands but prefers more open habitats such as grasslands, floodplains, and rice fields. Found in a wider range across Southeast Asia, including India, Nepal, Sri Lanka, Southeast Asia, and Indonesia
Feeding Behavior Omnivorous scavenger, feeding on carrion, fish, amphibians, and small mammals. Will also consume refuse from human settlements. Predominantly carnivorous, feeding on a variety of prey including fish, amphibians, reptiles, and small mammals. Known to scavenge as well but to a lesser extent than the Greater Adjutant.
Conservation Status Endangered (IUCN Red List) Vulnerable (IUCN Red List)
Threats Habitat loss due to wetland drainage, deforestation, and urbanization; pollution; disturbance at nesting sites; hunting and poaching; food scarcity due to changes in waste management practices. Similar threats as the Greater Adjutant, with habitat loss and disturbance being significant concerns. Lesser affected by hunting and poaching compared to the Greater Adjutant.
Population Estimates Approximately 800 to 1,000 mature individuals globally. Population decline in recent years, with estimates varying across its range.
Notable Features Known as 'Hargila' in Assam, India. Local communities actively engaged in conservation efforts. Known for its distinctive call resembling a 'kroo-kroo' sound. Often found in mixed-species flocks with other waterbirds.
Source: The Hindu

Share to Social