| Citation |
BirdLife International. 2016. Antigone antigone. The IUCN Red List of Threatened Species 2016: e.T22692064A93335364. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22692064A93335364.en. Accessed on 19 May 2022. Brinkman, J.J., van der Ven, W., Allen, D., Hutchinson, R., Jensen, A.E., Perez, C. (2021): Checklist of birds of the Philippines. Wild Bird Club of the Philippines. www.birdwatch.ph |
Description |
JUSTIFICATION
This crane is listed as Vulnerable because it is suspected to have suffered a rapid population decline, which is projected to continue, as a result of widespread reductions in the extent and quality of its wetland habitats, exploitation and the effects of pollutants.
RANGE DESCRIPTION
Antigone antigone has three disjunct populations in the Indian subcontinent, South-East Asia and northern Australia, with a total world population estimated at 15,000-20,000 individuals (Archibald et al. 2003). The nominate subspecies (c.8,000-10,000 birds) inhabits northern and central India, Nepal and Pakistan (although now thought to be extinct as a breeding species there [Archibald et al. 2003]), with occasional vagrants in Bangladesh. Its range has contracted towards the north and west of the Subcontinent (Sundar et al. 2000) and its population is considered to be in decline (Archibald et al. 2003). The north Indian state of Uttar Pradesh remains the speciess stronghold, with a population estimated at over 6,000 individuals (Sundar 2008). Subspecies sharpii occurs in South-East Asia where its range has declined dramatically, now being confined to Cambodia, extreme southern Laos, south Vietnam (c.800-1,000 birds between these three countries [Wetlands International 2006]), and Myanmar (c.500-800 birds [Wetlands International 2006]). Despite past declines, recent counts have shown some increase in the South-East Asian population, however Population Viability Analysis of cranes in Tram Chin shows the population is highly unstable and prone to extinction if current rates of habitat degradation continue (Archibald et al. 2003). Since 2001, a coordinated census has been held each year in Cambodia and Vietnam in the late dry season. In 2009, 455 individuals were counted at six sites, around 30% fewer than in the previous year. Early dry season counts (562 individuals), however, were higher than in 2008 (Evans et al. 2009). The Australian population (gilliae) is confined to the north and east of the country. It was estimated at fewer than 10,000 breeding adults in 2000 (Garnett and Crowley 2000, R. Jaensch in litt. 2005 to Wetlands International 2006), and has been put as low as 5,000 individuals (Archibald et al. 2003). The highest number recorded in surveys in north Queensland was in October 2000, when an estimated minimum of 3,000 individuals was present on Atherton Tablelands (E. Scambler in litt. 2007). These, and other published data, suggest that the Australian population is >5,000 individuals (E. Scambler in litt. 2016). During recent years, fluctuations in recruitment and numbers visiting the Atherton Tablelands have been noted, and are thought to be related to variation in annual rainfall in the Gulf of Carpentaria and Cape Regions (J. Grant in litt. 2007). It is extinct in Thailand, Malaysia, the Philippines and probably China.
DESCRIPTION
There are thought to be 8,000-10,000 individuals in India, Nepal and Pakistan; 800-1,000 in Cambodia, Laos and Vietnam, 500-800 in Myanmar (unpublished information supplied by Wetlands International Specialist Groups 2006), and about 10,000 breeding adults in Australia (Garnett and Crowley 2000, R. Jaensch in litt. 2005 to Wetlands International 2006). The population size thus totals 19,000-21,800 individuals, roughly equivalent to 13,000-15,000 mature individuals.
Trend Justification: This speciess population is suspected to have decreased, owing to the loss and degradation of wetlands, as a result of drainage and conversion to agriculture, ingestion of pesticides, and the hunting of adults and collection of eggs and chicks for trade, food, medicinal purposes and to help limit damage to crops.
HABITAT AND ECOLOGY
Indian birds inhabit open wet and dry grasslands, agricultural fields, marshes and pools, while in South-East Asia and Australia the species shows a preference for dry savannah woodlands with ephemeral pools during the breeding season, frequenting open and man-made wetlands during the non-breeding season (Archibald et al. 2003). In India, the species is increasingly forced to use suboptimal rice paddies as breeding habitat because of the deterioration and destruction of its natural wetland habitat (Meine and Archibald 1996, Sundar 2009). In Australia, cattle pastures and maize stubble are important foraging habitats in the non-breeding season (J. Grant in litt. 2007). It prefers a mixture of flooded, partially flooded and dry ground for foraging, roosting and nesting. It is omnivorous, feeding on a variety of roots and tubers as well as invertebrates and amphibians. In some locations in the Indian subcontinent and in Australia, birds disperse seasonally in response to available water. Breeding in India may take place virtually year-round if conditions are suitable, but there is a major peak in July-October, with egg laying in August-September, and a much smaller peak in February-March (K. S. G. Sundar in litt. 2007). It breeds during respective wet seasons in South-East Asia and Australia, migrating to key non-breeding sites during the dry season where birds form sizeable aggregations (Archibald et al. 2003). In India and Nepal, breeding pairs maintain discrete territories, year-round in areas with an adequate water supply throughout the year, while non-breeding birds are generally found in flocks that use larger wetlands to roost (K. S. G. Sundar in litt. 2007). Successful breeding pairs generally raise one or two chicks, with three chicks being extremely rare. Flock sizes in India are a function of wetland availability with the largest flocks seen in summers when wetlands are much reduced (K. S. G. Sundar in litt. 2007).
THREATS
The main threats are a combination of loss and degradation of wetlands, as a result of drainage and conversion to agriculture (for example wet rice paddy into dry sugarcane or soya bean [Archibald et al. 2003]), ingestion of pesticides (K. S. G. Sundar in litt. 2007), and the hunting of adults and collection of eggs and chicks (particularly in Indo-China but increasingly in India and Pakistan) for trade, food, medicinal purposes and, in some areas, to help prevent damage to crops (Sundar et al. 2000, Khacher 2006, K. S. G. Sundar in litt. 2007). These factors may be the cause of low recruitment in India, and can rapidly extirpate localised populations (Sundar et al. 2000). In Vietnam and Cambodia, large areas of the Mekong Delta, which supported key dry season habitat, have been reclaimed for agriculture in recent decades (Archibald et al. 2003). From 2001 to 2006, much of the seasonally inundated floodplains of the Ha Tien Plain, were lost, mostly due to the expansion of shrimp farms (Tran 2006a). The mechanisation of farming practices may threaten birds breeding on agricultural land (Sundar et al. 2000). Collision with powerlines may be a significant threat in parts of its range, with observations from India suggesting that 2.5-20 % of cranes are affected (Sundar et al. 2000, Sundar and Choudhury 2001), mostly non-breeding birds, equating to almost 1% of the total population (Sundar and Choudhury 2005). High human usage of wetlands results in a high rate of disturbance to cranes and considerably limits breeding success (Sundar and Choudhury 2003). Anecdotal observations suggest that chick predation by dogs and egg predation by corvids is increasing as their populations increase following the decline of vultures on the Indian subcontinent (K. S. G. Sundar in litt. 2007). The vast majority of the Australian population breed and winter in non-protected areas (J. Grant in litt. 2007). In the Gulf of Carpentaria region of northern Australia, proposals to increase cropping would entail conversion of land currently grazed by cattle, which is breeding habitat for the species, and would also involve impoundment of water currently available in wetland habitats (J. Grant in litt. 2007). At Lake Tinaroo, Australia, grazing is forbidden in some areas in the interests of water quality, and such sites have now become overgrown with dense vegetation and abandoned by the species (E. Scambler in litt. 2007). It is also threatened by the increasing subdivision of the shoreline grazing land at Lake Tinaroo for residential development, which is accompanied by increasing disturbance, e.g. from the use of speedboats (E. Scambler in litt. 2007). Each year there are one or two reports of individuals killed by powerlines on the Atherton Tableland, although this threat has not been investigated or quantified (E. Scambler in litt. 2007).
CONSERVATION ACTIONS
Conservation Actions Underway
CITES Appendix II. CMS Appendix II. It occurs in a number of protected areas throughout its range, importantly Ang Trapeang Thmor, Cambodia, and Tram Chim National Park, Vietnam, which seasonally support the majority of the Indochinese population. A proposed 238,374-ha conservation reserve for the species in the Kampong Trach IBA, Cambodia, was demarcated in 2006, awaiting a ministerial decree (Anon. 2006b). Patrols have since been carried out, and environmental education is ongoing in the area (Anon. 2006b). Following the discovery of a major non-breeding population in the Basaac river floodplain of the Mekong Delta, in Borei Chulsar and Koh Andeth districts, Takeo province, during surveys in 2001-2002, a workshop was organised and a 9,275-ha protected area was proposed and subsequently went for approval (Anon. 2002). In 2003, protection was proposed for Hon Chong grassland (Anon 2003). Conservation awareness campaigns have been initiated in India, Nepal, Laos and Cambodia. Nest protection schemes in India have proven successful (Sundar and Choudhury 2003). In 2004–2005 protection of 22 nests by volunteer in the Kota district, Rajasthan resulted in the successful fledging of 19 chicks (Kaur et al. 2008). National surveys have recently been conducted in India and Cambodia, and detailed studies on species requirements are ongoing in India and Nepal (K. S. G. Sundar in litt. 2007). In Myanmar, Buddhist monks have increased local respect for cranes and many nests are protected when they would otherwise be destroyed to prevent damage to rice paddies (Archibald et al. 2003). Since 1997, annual roost counts have been conducted on the Atherton Tableland in the far north of Queensland during the non-breeding season (E. Scambler in litt. 2007). In 2008 the Atherton Tablelands Important Bird Area was established based on population distribution data from the annual counts, and continuing counts from 2009 monitor the IBA and surrounding sites. Authorities have flagged particular sections of powerline after Sarus Crane deaths or injuries were reported by concerned observers in the IBA. The Australian Crane Network (website http://ozcranes.net/) established in 2005, remains a contact point for crane researchers, landowners and interested individuals, including international networks; and provides updates on ongoing and completed research and conservation issues (E. Scambler in litt. 2016). Although state and federal authorities list Sarus Crane as “Common” or “Least Concern” wildlife, it is included as a migratory species covered by international treaties to which Australia is a signatory (E. Scambler in litt. 2016). Proponents of development proposals must therefore address potential impacts and conservation groups are approved parties to submit objections at both state and federal levels In Thailand, a captive breeding programme is underway at Nakhon Ratchasima Zoo with the intention of establishing a wild population in the country (Siri-Arunrat 2009).
Conservation Actions Proposed
Conduct further surveys in northern Cambodia, southern Laos and southern Vietnam to identify key sites. Control pesticide use and industrial effluent disposal around feeding areas. Upgrade to CITES Appendix I, and strictly control local, national and international trade (Sundar and Choudhury 2003). Target further conservation awareness campaigns at communities in and around important sites (Sundar et al. 2000, Sundar and Choudhury 2003, Khacher 2006), and educate private landowners (Sundar and Choudhury 2003). Encourage a mosaic of small natural wetlands in heavily farmed areas (Sundar et al. 2000), as pairs will nest in wetlands as small as 1 ha (Archibald et al. 2003). Collect baseline data on ecology (Sundar et al. 2000). Improve protection of wetlands and other key habitats (Sundar and Choudhury 2003). Carry out restoration of deteriorating wetlands (Sundar and Choudhury 2003). Encourage nest protection by farmers and amateur ornithologists (Khacher 2006). Consider compensating farmers for real or expected crop damage (Khacher 2006), although this may change attitudes to the species to its detriment (K. S. G. Sundar in litt. 2007). Captive rearing programmes could be considered (Khacher 2006), although opinion is split (Sundar and Choudhury 2003), and such efforts may be futile in the face of existing threats (K. S. G. Sundar in litt. 2007). Establish a more certain estimate of the Australian population and its trends (Grant 2005). |
