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Overview

Brief Summary

Biology

Generally a solitary bird, the lesser adjutant only forms groups during the breeding season. This occurs at the beginning of the dry season, which varies geographically. Small, loose colonies of lesser adjutant construct their nests in patches of tall trees that have a thick undergrowth of bamboo and are located on the edge of suitable wetlands. Courtship is lengthy, starting three months before eggs are laid. The nest consists of a large, flat platform of sticks lodged between thick branches of a tall tree. The male selects the nest site, carrying twigs to it to indicate his choice, as nests usually remain intact from one year to the next. Between one and four eggs are laid and are incubated for 28 to 30 days. The hatchlings emerge weak and sparsely feathered. Both parents tend to the eggs and bring food to the hatchlings (3). The lesser adjutant feeds on frogs, fish and small reptiles (3).
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Description

Once a widespread and common species, the lesser adjutant has undergone a rapid decline in numbers recently, and is now rare throughout its range (3). This very large stork has long legs, neck and beak, and an upright posture. It is dark grey to black on the wings and back, and white on the underside. The head and neck are naked and yellow, but red in breeding males. Juveniles are duller and less glossy with more down on the head and neck (2).
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Distribution

Range Description

Leptoptilos javanicus has an extensive range across South and South-East Asia (BirdLife International 2001). Substantial populations remain only in Cambodia (over 600 known pairs at Tonle Sap and the northern forests [Goes in press] and a national total estimated withing the range 1,500-3,500 pairs [Bird et al. 2007, Goes in press, S. Mahood in litt. 2013], with probably many more as recently as the early 1990s [R. Timmins in litt. 2013]), India (mostly in Assam, with c.2,000 birds [Choudhury 2000], West Bengal and Bihar, where 42 nests had breeding confirmed in 2004 [Mishra et al. 2004], but present across much of the country [Rahmani 2012]) and Indonesia (c.2,000 in 1993, the majority on Sumatra, but apparently far fewer since [M Iqbal in litt. 2013]). There are smaller breeding populations in Nepal (300-1,000 birds, most in the east, with 188-268 birds in and around Royal Chitwan National Park in 2009 [C. Inskipp and H. S. Baral in litt. 2013]), Malaysia (c.500 individuals; Li et al. 2007), Sri Lanka, Bangladesh (18 adults at a colony in Thakurgaon district in 2012 and small numbers of non-breeders in the Sundarbans; Chowdhury and Sourav 2012), Myanmar (small numbers in many areas; Rahmani 2012), Laos, Brunei, Vietnam and Thailand (very small numbers and possibly only one remaining breeding site; Rahmani 2012). It has also been recorded in Bhutan (Choudhury 2005), but is thought to be extinct in China and in Singapore.

Formerly common and widespread, it has declined dramatically across its range and has been extirpated from many areas in recent decades owing a variety of threats including the persistent and unregulated harvesting of eggs and chicks at nesting colonies, loss of nesting trees and loss and degradation of wetland habitats. However, some populations at least seem to be relatively stable, e.g. numbers in the Matang Mangrove Forest, Malaysia have remained relatively constant for 20 years (Li et al. 2006), and numbers are increasing at Prek Toal, Cambodia owing to nest and colony protection (S. Mahood in litt. 2013). The global population may previously have been underestimated and may number c.5,500-10,000 mature individuals

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Range

India and Sri Lanka to s China, Indochina and Indonesia.

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Range

Found in India and Southeast Asia, but no longer found in China (1) (3).
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Inland, birds inhabit natural and human-modified wetlands, both open and forested. Coastal populations frequent mangroves and intertidal flats. It nests colonially in large trees, and historically on cliffs, often at traditional sites in or adjacent to wetlands. It utilises small wetlands within Asian dry forest, and can breed some distance from these; shrinking of pools during the dry season and limited availability can lead to overlap with human uses and resulting disturbance.


Systems
  • Terrestrial
  • Freshwater
  • Marine
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Inhabits fresh and saltwater wetlands, including riverbeds, floodplains, swamps, forest pools, lakes and paddy fields (3).
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Life History and Behavior

Life Expectancy

Lifespan, longevity, and ageing

Maximum longevity: 31.1 years (captivity) Observations: One captive specimen lived to be 31.1 years of age (Brouwer et al. 1992).
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Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Leptoptilos javanicus

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
VU
Vulnerable

Red List Criteria
A2cd+3cd+4cd

Version
3.1

Year Assessed
2013

Assessor/s
BirdLife International

Reviewer/s
Butchart, S.

Contributor/s
Browne, S., Clements, T., Evans, T., Sourav, S., Choudhury, A., Baral, H., Goes, F., Robson, C., Iqbal, M., Mahood, S., Gray, T., Chowdhury, S., Duckworth, J.W., Timmins, R. & Inskipp, C.

Justification
This stork is listed as Vulnerable because its population is suspected to be rapidly declining as a result of a variety of threats including hunting pressure, loss of nesting trees, conversion and degradation of wetlands and agricultural changes and intensification. Conservation action is benefiting one key population in Cambodia, but rapid declines are likely to be ongoing elsewhere across the range.


History
  • 2012
    Vulnerable
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Status

The lesser adjutant is classified as Vulnerable (VU) on the IUCN Red List 2007 (1).
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Population

Population
A total population of 5,000 individuals was previously estimated by Hancock (1993), Choudhury (2000) and BirdLife International (2001). However, more extensive survey effort in recent years has led to upward revisions of some national totals: in particular the Cambodian population is now thought to number perhaps 1,500-3,500 pairs or 3,000-7,000 mature individuals (Goes in press, S. Mahood in litt. 2013). Taking this total and perhaps 1,200 mature individuals in India, c.300 in Malaysia and 200-700 in Nepal, plus an unknown number in Indonesia (previously estimated at 2,000 individuals in 1993 but may have severely declined since), and assuming only very small numbers elsewhere, the global population probably numbers 5,500-10,000 mature individuals (roughly equating to 8,000-15,000 individuals).

Population Trend
Decreasing
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Threats

Major Threats
Several threats are contributing to its decline, with their relative importance varying across its range. The loss of nest-sites through the felling of colony nest-trees is a major threat, particularly in Assam - extensive nesting colonies outside protected areas in the 1990s recorded drastic declines owing to the cutting down of trees and drying up of some feeding sites (A. Choudhury in litt. 2012). In many areas, drainage and conversion of wetland feeding areas, agricultural intensification, increased pesticide use and disturbance, the collection of eggs and chicks and the hunting of adults are major threats, while the spread of invasive water hyacinth Eichhornia crassipes may be an additional threat at least in Nepal. A recent and very serious threat, recorded in Nepal and Cambodia, is the practice of poisoning pools to catch fish, which leads to incidental mortality of this species (Gyawali 2004, S. Browne in litt. 2005). Coastal populations are threatened by large-scale development, including aquaculture and the clearance of mangroves, while lowland wetlands are likely to be subject to a variety of threats including sea level rise, both directly but also through displacement of people, and conversion for plantation agriculture (J. W. Duckworth in litt. 2013). Key threats in Indonesia include the conversion of mangrove forest to fishponds and peatswamp forest to acacia plantations (M. Iqbal in litt. 2013). Longer term, massive dam projects in the Mekong catchment may threaten the persistence of Tonle Sap Great Lake (J. W. Duckworth in litt. 2013).

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Continuing destruction of wetlands and the felling of trees suitable as nesting sites has resulted in the rapid decline of this species. Foraging areas are being lost to urban and industrial expansion and hunting and capture for the pet trade are contributing to the ongoing population reduction (3).
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Management

Conservation Actions

Conservation Actions
Conservation Actions Underway
Important nesting colonies are found in India at Kaziranga and Dibru-Saikhowa National Parks and Laokhowa Wildlife Sanctuary, Assam and D'Ering Sanctuary, Arunachal Pradesh. In Cambodia, the breeding colonies at Prek Toal and Moat Khla/Boeng Chhma are core areas in the Tonle Sap Biosphere Reserve. Conservation programmes at Prek Toal and in Preah Vihear have effectively protected colonies from egg and chick harvesting since the early 2000s (Goes in press, S. Mahood in litt. 2013). It is included in conservation awareness material in Laos and Cambodia. In parts of Cambodia financial incentives have been offered to local residents by conservation organisations if nesting attempts at known waterbird colonies are not disrupted (T. Evans in litt. 2006). It occurs in Chitwan and Bardia National Parks and in Koshi Tappu Wildlife Reserve in Nepal. Recent initiatives in Assam include nest surveys, a nest-tree replanting scheme and conservation awareness campaigns.

Conservation Actions Proposed
Monitor key colonies, and conduct searches for others. Protect nesting colonies outside protected areas. Promote control of pesticide use around feeding areas. Establish a wildlife protection office at Tonle Sap lake. Investigate alternative livelihoods for people dependent on harvesting eggs and chicks. Draft and enforce laws prohibiting hunting, trapping and poisoning. Expand conservation awareness programmes. Research the species's use of and dependence upon agricultural landscapes including rice paddies (Baral 2005). List the species in Nepal under the National Parks and Wildlife Conservation Act (Gyawali 2004, Baral 2005). Protect key sites in Nepal.

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Conservation

Whilst the lesser adjutant is protected by law in all areas of India, Bangladesh, Burma, Thailand, Malaysia and Indonesia, and occurs in many protected areas, enforcement of this protection is weak. Much research has been carried out on the distribution and population numbers of this species and the focus must now switch to the protection of this bird. Education programmes have been shown to help in safeguard of any nest sites, and a plantation programme of nest-tree species was launched in India in 1993 (3).
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Wikipedia

Lesser adjutant

The lesser adjutant (Leptoptilos javanicus) is a large wading bird in the stork family Ciconiidae. Like other members of its genus, it has a bare neck and head. It is however more closely associated with wetland habitats where it is solitary and is less likely to scavenge than the related greater adjutant. It is a widespread species found from India through Southeast Asia to Java.

Description[edit]

Detail of head

A large stork with an upright stance, a bare head and neck without a pendant pouch, it has a length of 87–93 cm (34–37 in) (outstretched from bill-to-tail measurement), weighs from 4 to 5.71 kg (8.8 to 12.6 lb) and stands about 110–120 cm (43–47 in) tall.[2][3][4] The only confusable species is the greater adjutant, but this species is generally smaller and has a straight upper bill edge (culmen), measuring 25.8–30.8 cm (10.2–12.1 in) in length, with a paler base and appears slightly trimmer and less hunch-backed. The skullcap is paler and the upper plumage is uniformly dark, appearing almost all black. The nearly naked head and neck have a few scattered hair-like feathers. The upper shank or tibia is grey rather than pink, the tarsus measures 22.5–26.8 cm (8.9–10.6 in). The belly and undertail are white. Juveniles are a duller version of the adult but have more feathers on the nape.[5] During the breeding season, the face is reddish and the neck is orange. The larger median wing coverts are tipped with copper spots and the inner secondary coverts and tertials have narrow white edging. The wing chord measures 57.5–66 cm (22.6–26.0 in) in length. Like others in the genus, they retract their necks in flight. In flight, the folded neck can appear like the pouch of the greater adjutant.[6] Males and females appear similar in plumage but males tend to be larger and heavier billed.[4][7]

Distribution and habitat[edit]

in flight at Sundarban, West Bengal

The lesser adjutant tends to be widely dispersed and is very local. It is often found in large rivers and lakes inside well wooded regions. It is found in India, Nepal,[8] Sri Lanka, Bangladesh (A colony with about 6 nests and 20 individuals was discovered near Thakurgaon in 2011.[9]), Myanmar, Thailand, Vietnam, Malaysia, Laos, Singapore,[10] Indonesia and Cambodia. The largest population is in India in the eastern states of Assam, West Bengal and Bihar. It may occur as a vagrant on the southern edge of Bhutan.[11] They are extremely rare in southern India.[12][13]

Behaviour and ecology[edit]

The lesser adjutant stalks around wetlands feeding mainly on fish, frogs, reptiles and large invertebrates. They rarely feed on carrion. They may also take small birds and rodents particularly during the breeding season. They are solitary except during the breeding season when they form loose colonies.[2] The breeding season is February to May in southern India and November to January in north-eastern India.[14] The nest is a large platform of sticks placed on a tall tree. The nest diameter is more than a metre and up to a metre deep.[2] The clutch consists of three to four eggs.[14][15] They are silent but have been noted to clatter their bill, hiss and moan at the nest.[6]

Images[edit]

References[edit]

  1. ^ BirdLife International (2013). "Leptoptilos javanicus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013. 
  2. ^ a b c Ali, S & SD Ripley (1978). Handbook of the Birds of India and Pakistan. Volume 1 (2 ed.). New Delhi: Oxford University Press. pp. 107–109. 
  3. ^ Elliot, A. (1994). "Order Ciconiiformes. Family Ciconiidae (Storks)". In del Hoyo, J., A. Elliot & J. Sargatal. Handbook of the Birds of the World. Volume 1. Ostrich to Ducks. Barcelona, Spain: Lynx Edicions. pp. 436–465. 
  4. ^ a b Hancock & Kushan, Storks, Ibises and Spoonbills of the World. Princeton University Press (1992), ISBN 978-0-12-322730-0
  5. ^ Blanford, WT (1898). The Fauna of British India. Birds. Volume 4. London: Taylor and Francis. pp. 374–375. 
  6. ^ a b Rasmussen PC & JC Anderton (2005). Birds of South Asia. The Ripley Guide. Volume 2. Washington DC and Barcelona: Smithsonian Institution and Lynx Edicions. p. 64. 
  7. ^ Weckauf R & M Handschuh (2011). "A method for identifying the sex of lesser adjutant storks Leptoptilos javanicus using digital photographs". Cambodian Journal of Natural History (1): 23–28. 
  8. ^ Baral HS (2005). "Surveys for Lesser Adjutant Leptoptilos javanicus in and around Koshi Tappu Wildlife Reserve, Nepal". Forktail 21: 190–193. 
  9. ^ Sayam U. Chowdury & MSH Sourav (2012). Discovery of a Lesser Adjutant Leptoptilos javanicus breeding colony in Bangladesh journal=BirdingASIA 17 (17). pp. 57–59. 
  10. ^ Subaraj R and A. F. S. L. Lok (2009). "Status of the Lesser Adjutant Stork (Leptoptilos javanicus)". Nature in Singapore 2: 107–113. 
  11. ^ Choudhury, A. (2005). "First record of Lesser Adjutant Leptoptilos javanicus for Bhutan". Forktail 21: 164–165. 
  12. ^ Andheria, A. P. (2001). J. Bombay Nat. Hist. Soc. 98 (3): 443–445. 
  13. ^ Andheria, A. (2003). "First sighting of lesser adjutant-stork Leptoptilos javanicus from Sanjay Gandhi National Park, Mumbai". J. Bombay Nat. Hist. Soc. 100 (1): 111. 
  14. ^ a b Baker, ECS (1929). Fauna of British India. Birds. Volume 6 (2 ed.). London: Taylor and Francis. pp. 329–330. 
  15. ^ Maust, M., Clum, N. and Sheppard, C. (2007). "Ontogeny of chick behavior: a tool for monitoring the growth and development of lesser adjutant storks". Zoo Biol. 26 (6): 533–538. doi:10.1002/zoo.20156. PMID 19360599. 
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