Ephippiorhynchus asiaticus

Geographic Range

Black-necked storks ( Ephippiorhynchus asiaticus ) are native to the Oriental region and Australian region. Their geographic distribution includes Pakistan, India, Nepal, Bhutan, Sri Lanka, Bangladesh, Burma, Viet Nam, Thailand, Cambodia, Loas, Sri Lanka, Indonesia, Papua New Guinea, and Australia. The largest known congregation of black-necked storks is in the state of Uttar Pradesh, in northern India.

• Biogeographic Regions
• oriental oriental
  • native native
• australian australian
  • native native

Habitat

Black-necked storks inhabit wetlands, such as freshwater marshes, lakes, large rivers, mangrove forests, and flooded grasslands or agriculture fields. They build large nests (an average of 109.3 cm in diameter and 133.84 cm deep) at the top of large trees that are in or near water. They often abandon nesting sites if water levels get too low.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• rainforest rainforest

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Wetlands
• marsh marsh

• Other Habitat Features
• agricultural agricultural

Physical Description

Black-necked storks have black beaks and iridescent black plumage on their heads and necks that appears green or purple in certain lights. Their bodies are white with black coverts, rumps and tail feathers. They have long legs and toes that are orangish-pink in color. In flight, they can be distinguished by their dark heads and necks, white bodies and wings, and black underwing coverts.

Juvenile black-necked storks initially have light and dark brown plumage, and they gradually develop the characteristic white and black coloration as they mature. There is slight sexual dimorphism, with males having dark brown irises and females having yellow irises. Adult black-necked storks weigh around 4 kg, are an average of 150 cm tall, and measure 110 cm to 137 cm in length.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

Reproduction

Black-necked storks are considered to be monogamous and iteroparous, breeding seasonally between September and December. Mating pairs perform "up-down" courtship dances during which they stand face to face, flapping their wings rapidly and clattering their bills. Up-down dances are a common greeting display when mating pairs are nesting. Males will also perform a "flap-dash" where they stand up straight, flap their wings, run through the water away from their mate, turn around, and run back, stopping one to two meters away with their wings held up. During copulation, males mount females and females hold their wings out for balance. Males typically shake their heads and clatter their bills during copulation.

• Mating System
• monogamous monogamous

Black-necked storks breed seasonally, although exact time of year varies depending on geographic location. Generally, individuals in the northern parts of their range, such as India, breed from late summer through fall (September to December), while individuals in southern regions, such as Australia, breed from late spring through summer (May to August). Black-necked storks breed in wetlands or flooded grasslands, building nests in the canopies of tall trees. Brood size ranges from one to four eggs. In northern regions, chicks begin to hatch around mid-January and begin fledging around mid-March, while in southern regions, hatching starts in mid-October and fledging starts in mid-December. Chicks require parental care for around 12 months before they are fully independent.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Black-necked storks invest a significant amount of time and energy in rearing young. Both parents participate in nest building, incubation, and hatchling care. Incubation time is not known exactly, but is estimated to be around 30 days, based on other stork species such as woolly-necked storks ( Ciconia episcopus ). Young storks leave the nest after around 3 to 4 months, but juveniles remain in their natal territories until they are older, leaving at around 14 to 18 months old.

• Parental Investment
• precocial precocial
• male parental care male parental care
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

There is limited information on the longevity of wild black-necked storks. The longest recorded lifespan for a captive individual was 34 years. Wild black-necked storks may also live as long as 30 years, but lifespan is likely reduced by factors such as predation, disease, and environmental extremes.

Behavior

Black-necked storks are solitary and non-migratory. They are highly territorial, especially in situations where water levels and food availability are low. Black-necked storks are also defensive of their nests during breeding season. If intruders approach their nests, black-necked storks will perform a defense display, jumping several times before flying upwards.

• Key Behaviors
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial

Home Range

During the breeding season, black-necked storks stay within small territories near the trees where they nest. Otherwise, they remain near wetlands, where they have access to food sources.

Communication and Perception

Black-necked storks communicate and perceive their environment primarily with visual and acoustic stimuli, although tactile and chemical stimuli are also important. Mating pairs participate in courtship displays to establish bonds during the breeding season. Courtship displays mostly involve wing flapping and bill clattering. Black-necked storks are highly territorial during breeding season, or when there is competition for resources. Aggressive behaviors are more common when water levels are low, between February and March. Black-necked storks show aggression not only towards conspecifics, but also towards other animals, such as spoonbills (genus Platalea )

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Black-necked storks are generalist carnivores, eating a variety of fish, frogs, water birds, snakes, aquatic insects, crustaceans, and mollusks. They typically forage in water up to 35 cm deep, standing still for long periods of time and ambushing prey that swims nearby. Black-necked storks hunt individually or in pairs. Food sources are typically most abundant after the monsoon season (July to October).

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • piscivore piscivore
  • insectivore insectivore
  • eats non-insect arthropods
  • molluscivore molluscivore

• Animal Foods
• birds
• amphibians
• reptiles
• fish
• mollusks
• aquatic crustaceans

Predation

Black-necked storks are prey to jungle cats ( Felis chaus ), greater spotted eagles ( Aquila clanga ), and eastern imperial eagles ( Aquila heliaca ). They avoid terrestrial predators by nesting in tall trees in or around wetlands. When threatened, they will flap their wings and jump repeatedly.

Ecosystem Roles

Black-necked storks act as both predators and prey in their habitats. They prey on a variety of fish, birds, reptiles, amphibians, arthropods, and mollusks in wetlands and agricultural areas. Black-necked storks are also prey for mammalian and avian predators.

Captive black-necked storks have been reported to carry trematode parasites in the genus Lypersoma , possibly contracted from fish in their diets.

Economic Importance for Humans: Positive

Black-necked storks benefit the ecotourism industry throughout their range. Adults have striking coloration and elaborate mating displays that make them interesting to watch and study. There are captive individuals in several Indian zoos, the Bombay, New Delhi, and Trivandrum Zoos.

Black-necked storks feed on a variety of species in wetlands and agricultural areas, so it is possible that they help control crop pest populations.

• Positive Impacts
• ecotourism ecotourism

Economic Importance for Humans: Negative

Black-necked storks are known to forage in agricultural lands, potentially disturbing crop growth. However, they are not herbivorous, so these impacts may be minimal. Further conflicts between humans and black-necked storks may arise as humans further encroach on stork habitats.

Conservation Status

Black-necked storks are listed as "near threatened" on the IUCN Red List, with a decreasing population trend. Populations in southeast Asia are under great conservation threats compared to Australian populations, which are considered to have stable population sizes.

Threats to black-necked storks include habitat deterioration and loss, encroachment by agricultural practices, and overfishing. There are also recorded instances of egg-stealing by humans. However, there are ongoing conservation efforts for black-necked storks throughout their range. There is ongoing research focused on breeding behavior, with the goal of creating captive breeding programs. Furthermore, local governments have put protections on wetland habitats that are important to black-necked storks.

Additional Links

Encyclopedia of Life

Contributors

Caitlin Shaw (author), University of Wisconsin Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, Galen Burrell (editor), Special Projects.

References

BirdLife International, 2024. "Black-necked Stork (Ephippiorhynchus asiaticus)" (On-line). Accessed January 24, 2024 at https://datazone.birdlife.org/species/factsheet/black-necked-stork-ephippiorhynchus-asiaticus/text .

Christidis, L., G. Clancy, S. Garnett, G. Maheswaran, G. Sundar. 2016. "Ephippiorhynchus asiaticus" (On-line). Accessed April 28, 2017 at http://www.iucnredlist.org/details/22697702/0 .

Clancy, G. 2009. Species review - The Black-necked stork ephippiorhynchus asiaticus: An overview. Australian Field Ornithology , 26: 110-115.

G., M., R. A.R. 2001. Effects of water level changes and wading bird abundance on the foraging behaviour of blacknecked storks Ephippiorhynchus asiaticus in Dudwa National Park, India. J. Biosei , 26/3: 373-382.

Hume, A., E. Oates. 1889. The nests and eggs of Indian birds . London: R.H. Porter. Accessed May 04, 2017 at https://archive.org/details/nestseggsofindia03humerich .

Ishtiaq, F., A. Rahmani, S. Javed, M. Coulter. 2004. Nest-Site Characteristics of Black-necked Stork ( Ephippiorhynchus asiaticus ) and White-necked stork ( Ciconia episcopus ) in Keoladeo National Park, Bharatpur, India. Journal of the Bombay Natural History Society , 101 (1): 90-95.

Kahl, M. 1973. Comparative Ethology of the Ciconiidae. Part 6. The Blacknecked, Saddlebill, and Jabiru Storks (Gnera Xenorhynchus, Ephippiorhynchus, and Jabru). The Condor , 75: 17-27.

Kahl M., P. 1987. An Overview of the Storks of the World. Colonial Waterbirds , 10: 131-134.

Maheswaran, G., R. Asad R.. 2005. Breeding Behaviour of the Black-necked Stork Ephippiorhynchus asiaticus in Dudhuwa National Park, India. Journal of the Bombay Natural History Society , 102 (3): 305-312.

Maheswaran, G., A. Rahmani. 2008. Foraging technique and prey-handling time in black-necked stork ( Ephippiohynchus asiaticus ). Integrative Zoology , 3: 274-279.

Parasani, H., R. Momin, R. Sahu, B. Patel. 2002. Prevalence of Gastro-intestinal Parasites in Captive Birds at Kamla Nehru Zoological Garden, Kankaria Zoo, Ahmedabad, Gujarat. Zoo's Print Journal , 18 (1): 987-992.

R, S., M. C, A. JM, C. JG. 2015. "Avitourism and Australian Important Bird and Biodiversity Areas" (On-line). Accessed May 02, 2017 at https://www.ncbi.nlm.nih.gov/pubmed/26701779 .

Rahmani, A. 1989. Status of the Black-necked Stork Ephippiorhynchus asiaticus in the Indian subcontinent. Forktail , 5: 99-110.

Sundar, G., G. Clancy. 2006. "Black-necked stork (Ephippiorhynchus asiaticus)" (On-line). Accessed April 29, 2017 at http://www.arkive.org/black-necked-stork/ephippiorhynchus-asiaticus/ .

Sundar, G. 2011. Agricultural intensification, rainfall patterns, and large waterbird breeding success in the extensively cultivated landscape of Uttar Pradesh, India. Biological Conservation , 114/12: 3055-3063.

Sundar, G. 2003. Notes on the breeding biology of the Black-necked Stork Ephippiorhynchus asiaticus in Etawah and Mainpuri districts, Uttar Pradesh, India. Forktail , 19: 15-20.

2016. " Ephippiorhynchus asiaticus Jabiru" (On-line). Encyclopedia of Life. Accessed May 11, 2017 at http://eol.org/pages/1049152/details .