Standing tall on their long legs, with an upright posture, storks bear a faint resemblance to us humans. Across millennia, these large and iconic birds have lived alongside us, around our wetlands, farms and settlements. Their food preferences, comprising of animals that are considered agricultural pests or deemed vile or dangerous, meant that they were welcomed in most parts of the world.

With the industrial age, this relationship has strained, much against the favour of storks. Wetlands have disappeared or have been repurposed. Tall trees, the essential ingredient to start new life in the storks’ world, have been felled. Though many stork species are declining in numbers, there is still hope. In Karnataka, bird sanctuaries like Ranganathittu and Ankasamudra offer protection to the nesting birds in secure habitats. Villages like Kokkarebellur and Kaggaladu, where people welcome Painted Storks to nest on tall trees in the village, bear testimony to the age-old coexistence. Woolly-necked Storks have been observed adapting to human landscapes and nesting successfully around agricultural landscapes.

Storks are easily identified by their long beak and legs, and short tail. They often soar with their broad and long wings, with the neck outstretched (barring the Lesser Adjutant). They are mostly diurnal, though they have been known to hunt nocturnally in areas prone to disturbance. They are sexually dimorphic is size, with males being slightly larger than females. Storks don’t call often, owing to their variably degenerate syrinxes. Clattering and snapping of their mandibles, with occasional hissing and grunting, is used for communication in adult birds. Young Painted Storks make a harsh grating sound while begging for food from their parents. In most species, fish, amphibians, molluscs, reptiles, insects and small mammals make up their diet.

Karnataka has six species of storks. Three species – Painted Stork, Asian Openbill and Woolly-necked Stork – are resident breeding birds. Lesser Adjutant has been recorded throughout the year from the state. Black Stork and European White Stork are relatively rare winter migrants.

Lesser Adjutant (Leptoptilos javanicus)

The Lesser Adjutant possibly breeds in the state and has been mostly recorded along the Western Ghats, with a few records across the rest of the state. The name is inspired by the military rank of the same name.

The Lesser Adjutant’s head is rather bare of feathers, much like a vulture. Storks of the genus Leptoptilos are known to scavenge on carrion, like vultures. The Lesser Adjutant, though, prefers hunting for small prey around wetlands and is known to scavenge only rarely. They are usually solitary, except in the nesting season. When they fly, unlike other storks, they retract their necks. This could be an adaptation due to their heavy beaks.

This is the most threatened of Karnataka’s storks, rated as Vulnerable by IUCN. The global population is estimated to be around 5,500-10,000 individuals. Habitat modification and destruction is a key factor contributing to its decreasing population trend.

Painted Stork (Mycteria leucocephala)

With their bright and contrasting colours and large breeding colonies, Painted Storks are arguably the most popular birds in heronry-based bird sanctuaries. The breeding season is highly variable across its geographic range, beginning anytime between August and March. Reasons for this are not fully understood. Since the Painted Stork is primarily piscivorous, availability of fish near the nesting sites could be one of the factors.

After a month of incubation, young ones hatch and are on the nest for the next couple of months. Since the nests are often out in the open, adults often use their wings to protect the young ones against the harsh mid-day sun. When the juveniles leave the nest, their plumage is dull brown in colour. It takes 2-3 years for them to attain the bright colours.

Due to the downcurved beak, it was initially thought that the Painted Stork was a relative of the ibises. The tip of the beak is highly sensitive to locate prey by touch, as they wade through murky waters moving their half-open beaks from side to side. They often kick their legs forward and backward in the water to dislocate stationary fish and other prey.

Asian Openbill (Anastomus oscitans)

The characteristic gap between the mandibles of its beak makes the smallest Indian stork an easy bird to identify. Justifiably, the specific name oscitans translates to “yawning” in Latin. The gap between the mandibles is an adaptation that helps the bird feed on its main prey – molluscs of the Pila genus. Unlike what seems the apparent explanation, the gap is not used to crush the snail. It is believed that the gap helps generate more force in the beak tip to separate out the snail’s body from its shell. In fact, young birds don’t have a gap between the mandibles; it appears only as the birds grow older.

In breeding plumage, the bird has whitish upperparts with black wings, causing confusion with a European White Stork from a distance. In non-breeding plumage, the white is replaced by dull grey.

Black Stork (Ciconia nigra)

The Black Stork is a rare winter migrant to Karnataka, with most observations of the bird recorded over the past two decades. In summers, they are widespread from Eastern Asia to Europe, where they breed. An isolated population is also resident in southern Africa. Most of the European population migrates to Africa in winter, while the east-Asian population migrates to China and South-east Asia. The west Asian population winters in India and Africa.

They have been seen in small groups around rivers, reservoirs and water bodies in forests. They are easily recognised by the dark upperparts and head, white underparts and bright red beak and legs. Young ones have a duller colouration.

Woolly-necked Stork (Ciconia episcopus)

Episcopus, the specific name, means “bishop” in Latin, rather apt for a bird with dark glossy wings and dark cap, contrasting with its white feathery neck. The Woolly-necked Stork is widely distributed across South Asia, South-east Asia and sub-Saharan Africa (sometimes treated as a different species). They are usually solitary or in pairs, sometimes forming small family groups of 4-5 individuals.

This is one of the few bird species in the world whose IUCN status was downgraded from Vulnerable to Near Threatened. Surveys indicated that the population of this bird was severely undercounted earlier. From an estimated 20,000 individuals across South and South-east Asia, the revised numbers of between 1,20,000 to 3,00,000 birds in South Asia provided hope and data to downgrade the IUCN listing.

This bird is adapting its nesting behavior to human development, building nests on cell-phone towers and high-tension pillion towers. It is also a world record holder – a pair in Haryana raised a brood of six, the highest ever recorded from a single nest in the stork kingdom!

European White Stork (Ciconia ciconia)

The iconic European White Stork is a rare winter migrant to Karnataka. They winter in larger groups, upto around 50 individuals, than the Black Stork. In summer, they breed in Europe and parts of Western Asia. The latter population is believed to largely migrate to India, though further studies are needed on this.

In many European cultures, the stork is culturally significant, often associated with bringing babies home to new parents. Their pest control capabilities are remarkable; one bird was recorded eating 25-30 crickets every minute.

 

References:

  1. Praveen, J, Subramanya, S., Raj, V. M., 2016. A checklist of the birds of Karnataka. Indian BIRDS 12 (4&5): 89–118
  2. Richard Gimmett, Carol Inskipp, Tim Inskipp, 2011. Birds of the Indian Subcontinent. Second Edition; Oxford University Press
  3. Ali, S; SD Ripley (1978). Handbook of the Birds of India and Pakistan. Volume 1 (2nd ed.). New Delhi: Oxford University Press. pp. 91–110.
  4. SoIB 2020. State of India’s Birds factsheet: Lesser Adjutant Leptoptilos javanicus https://www.stateofindiasbirds.in/species/lesadj1/