Grus carunculatus

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	GRUIFORMES	GRUIDAE

Scientific Name:

Grus carunculatus

Species Authority:

(Gmelin, 1789)

Common Name/s:

English	–	Wattled Crane
French	–	Grue caronculée
Spanish	–	Grulla Carunculada, Grulla Zarzo

Assessment Information [top]

Red List Category & Criteria:

Vulnerable A2acde+3cde+4acde;C1+2a(ii) ver 3.1

Year Published:

2008

Assessor/s:

BirdLife International

Reviewer/s:

Taylor, J., Butchart, S.

Contributor/s:

Leonard, P., Dean, R., Morrison, K., Mundy, P., Syvertsen, P., Dodman, T., Herremans, M., Tyler, S., Tarboton, W., Msiska, H., Dowsett-Lemaire, F., Shimelis, A., Robertson, P., Simmons, R., Pittman, J., Dyer, M., Haugaard, J.

Justification:
Although it is known that there have been some population declines, there is limited and conflicting information on trends for this species, even in key areas. Until better data can be obtained, it is listed as Vulnerable since it has a small population which appears to have undergone a rapid decline which, with threats continuing or increasing, is projected to continue.

History:

2006	–	Vulnerable
2004	–	Vulnerable
2000	–	Vulnerable
1996	–	Vulnerable
1994	–	Vulnerable

Geographic Range [top]

Range Description:	Grus carunculatus is found in Ethiopia, (c.200^23,25), Tanzania (c.200²⁵), Democratic Republic of Congo (probably around 500²⁵), Zambia (c.4,500²⁵), Angola (c.500, perhaps declining^5,25), Malawi (c.15 pairs^7,13 or 40 individuals²⁵), Mozambique (c.300²⁵, 120 pairs in the Zambezi Delta region³⁸), Zimbabwe (c.200²⁵), Botswana (c. 111 breeding pairs in a total of 1,300 individuals^22,25), Namibia (c.250 birds²⁵ including probably less than 10 pairs¹⁷), and South Africa (c.235^25,27,35, with a 35% decline in the last 20 years³⁵, but possibly stable now²⁷). The total population appeared stable from the mid-1980s to mid-1990s⁴, however when estimates from the 1980s are compared with those from 2006, it is judged to have declined significantly³⁴, perhaps indicating declines in the last 10 years. The key Zambian population at the Kafue Flats reportedly fell in the mid-1990s^1,4 and was estimated at c.1,000 individuals in 2002²⁰. The comparison of 2002 estimates with those from 1993 suggests marked declines in Mozambique, Zambia and possibly Botswana²⁵. The substantial reduction in numbers since 1993 apparently reflects real declines at individual sites and regions, although the 2002 estimate may be influenced by an improvement in accuracy relative to previous estimates²⁵. The total population was thought to be presently stable²⁸, but was more recently stated to be in decline in nine range states³⁹. Its present world population has been variously estimated at 7,990 individuals²³, 7,700 individuals³⁵ or less^34,40, not more than 8,000 individuals³⁹ and 6,000-8,000 individuals²⁵. It exists in three disjunct populations, the large south-central population and small Ethiopian and South African populations^31,35, which may be relicts from its former range²⁵.
Countries:	Native: Angola; Botswana; Congo, The Democratic Republic of the; Ethiopia; Malawi; Mozambique; Namibia; South Africa; Tanzania, United Republic of; Zambia; Zimbabwe Vagrant: Guinea-Bissau; Lesotho
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Its present world population has been variously estimated at 7,990 individuals (Beilfus et al. 2005), 7,700 individuals (Pittman 2007) or less (Morrison and van der Spuy 2006; Motsumi et al. 2007), less than 8,000 individuals (Beilfuss et al. 2007) and 6,000-8,000 individuals (Hancock et al. 2003).
Population Trend:	Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	Behaviour This species is generally not migratory but those that inhabit seasonal wetlands are irregularly nomadic in response to water availability⁴⁰. The Ethiopian population, however, does appear to migrate locally¹. It breeds in May-October, leaving the breeding area in November-December when the wetlands dry up, and returning with the rains in May-June¹. Other populations breed in territorial pairs⁴¹ between July and December with a peak during the months of August and September coinciding with the peak of the floods¹. The most southerly populations often breed a little earlier in July-August¹. During the non-breeding season the species is fairly congregatory, occurring regularly in flocks of 10-50 individuals⁴², and there are reports of flocks of up to 1000 in the Okovango delta in April-May⁴¹. Habitat In South Africa this species was found to occupy large home ranges of approximately 16 sq. km, which consist largely (75%) of grassland with a small core of essential wetland breeding habitat³³. Breeding It nests in shallow sedge-dominated wetlands, often above 2000m altitude⁴⁰. In South Africa and Zimbabwe it breeds on undisturbed small permanent wetlands surrounded by grassland or miombo (Brachystegia) woodland in high rainfall areas with plateau topography⁴¹, where human disturbance is minimal¹. Ephemeral and seasonal wetlands may be used opportunistically by breeding pairs or serve as important post-breeding dispersal areas¹. In South Africa it relies on relatively undisturbed mid-altitude wetland-grassland mosaics³³. Elsewhere in its range it breeds on large low-lying tropical, seasonal flood plains such as the Okovango delta⁴¹ where wetlands are bordered by grasslands¹. It may use man-made habitats such as dams⁴¹. The Ethiopian population uses high-altitude wetlands in the Bale Mountains¹. Non-breeding During the non-breeding season the species continues to rely on wetland habitats surrounded by grassland³³. It congregates at large wetlands on riparian floodplains, but also requires pristine or semi-pristine, high-altitude wetlands and grasslands in some places^1,3,12. It frequents dambos (depressions), permanently isolated wetlands³⁴, and vleis²⁵ as well as using grasslands, pastures, and occasionally cultivated fields for foraging⁴¹. Dams and pans are used as roosting sites during the non-breeding season⁴¹. The Ethiopian population is less dependent on wetlands during this season, generally moving to drier, lower elevation habitats including ploughed fields¹. Birds that breed in the Okovango delta often move to recently burnt ground in the dry season⁴¹. Diet The species feeds on rhizomes, roots and bulbs of sedges (Cyperus and Eleocharis species), and grass sward and seed⁴¹. It will also take animals including small aquatic snails, fish and frogs⁴¹. Chicks are reported to eat insects²⁵. Breeding site Preferred nesting sites are where grass and sedge marshes are bordered by drier, flat to sloping grassland meadows, with medium height vegetation and water up to 1m in depth⁴². The nest is a large mound of plant material (reeds and sedges), one metre in diameter and protruding 20 cm above the water surface, usually with a moat of open water about a metre in diameter around it. A significant proportion of nests in the Okavango Delta are on small mud islands two or three metres in diameter, exposed by 20-30 cm as floodwaters recede, and in these cases, the eggs are laid on few pieces of reed or sedge stems. Fidelity to the previous year's nesting area is suspected. The clutch size is one or two (68% and 32% of nests respectively, in Botswana)²⁵, however only one chick is raised from clutches of two and the other egg is abandoned³⁵. If a clutch or chick is lost, pairs may attempt to breed again²⁵. The incubation period is 33-36 days²⁵. Natural levels of nest predation appear to be high³⁰. The first-hatched chick leaves the nest on its first day^25,30, and may be particularly susceptible to predation at this time³⁰. The fledging period is 135 days, but immature birds usually accompany their parents for their first year²⁵. Reproductive maturity is reached at about the age of seven and the species is monogamous, pairing for life.
Systems:	Terrestrial; Freshwater

Habitat and Ecology:

Behaviour This species is generally not migratory but those that inhabit seasonal wetlands are irregularly nomadic in response to water availability⁴⁰. The Ethiopian population, however, does appear to migrate locally¹. It breeds in May-October, leaving the breeding area in November-December when the wetlands dry up, and returning with the rains in May-June¹. Other populations breed in territorial pairs⁴¹ between July and December with a peak during the months of August and September coinciding with the peak of the floods¹. The most southerly populations often breed a little earlier in July-August¹. During the non-breeding season the species is fairly congregatory, occurring regularly in flocks of 10-50 individuals⁴², and there are reports of flocks of up to 1000 in the Okovango delta in April-May⁴¹. Habitat In South Africa this species was found to occupy large home ranges of approximately 16 sq. km, which consist largely (75%) of grassland with a small core of essential wetland breeding habitat³³. Breeding It nests in shallow sedge-dominated wetlands, often above 2000m altitude⁴⁰. In South Africa and Zimbabwe it breeds on undisturbed small permanent wetlands surrounded by grassland or miombo (Brachystegia) woodland in high rainfall areas with plateau topography⁴¹, where human disturbance is minimal¹. Ephemeral and seasonal wetlands may be used opportunistically by breeding pairs or serve as important post-breeding dispersal areas¹. In South Africa it relies on relatively undisturbed mid-altitude wetland-grassland mosaics³³. Elsewhere in its range it breeds on large low-lying tropical, seasonal flood plains such as the Okovango delta⁴¹ where wetlands are bordered by grasslands¹. It may use man-made habitats such as dams⁴¹. The Ethiopian population uses high-altitude wetlands in the Bale Mountains¹. Non-breeding During the non-breeding season the species continues to rely on wetland habitats surrounded by grassland³³. It congregates at large wetlands on riparian floodplains, but also requires pristine or semi-pristine, high-altitude wetlands and grasslands in some places^1,3,12. It frequents dambos (depressions), permanently isolated wetlands³⁴, and vleis²⁵ as well as using grasslands, pastures, and occasionally cultivated fields for foraging⁴¹. Dams and pans are used as roosting sites during the non-breeding season⁴¹. The Ethiopian population is less dependent on wetlands during this season, generally moving to drier, lower elevation habitats including ploughed fields¹. Birds that breed in the Okovango delta often move to recently burnt ground in the dry season⁴¹. Diet The species feeds on rhizomes, roots and bulbs of sedges (Cyperus and Eleocharis species), and grass sward and seed⁴¹. It will also take animals including small aquatic snails, fish and frogs⁴¹. Chicks are reported to eat insects²⁵. Breeding site Preferred nesting sites are where grass and sedge marshes are bordered by drier, flat to sloping grassland meadows, with medium height vegetation and water up to 1m in depth⁴². The nest is a large mound of plant material (reeds and sedges), one metre in diameter and protruding 20 cm above the water surface, usually with a moat of open water about a metre in diameter around it. A significant proportion of nests in the Okavango Delta are on small mud islands two or three metres in diameter, exposed by 20-30 cm as floodwaters recede, and in these cases, the eggs are laid on few pieces of reed or sedge stems. Fidelity to the previous year's nesting area is suspected. The clutch size is one or two (68% and 32% of nests respectively, in Botswana)²⁵, however only one chick is raised from clutches of two and the other egg is abandoned³⁵. If a clutch or chick is lost, pairs may attempt to breed again²⁵. The incubation period is 33-36 days²⁵. Natural levels of nest predation appear to be high³⁰. The first-hatched chick leaves the nest on its first day^25,30, and may be particularly susceptible to predation at this time³⁰. The fledging period is 135 days, but immature birds usually accompany their parents for their first year²⁵. Reproductive maturity is reached at about the age of seven and the species is monogamous, pairing for life.

Systems:

Terrestrial; Freshwater

Threats [top]

Major Threat(s):	The primary threat is loss and degradation of wetlands as a result of intensified agriculture, drainage, rice cultivation, and flooding by dam construction^4,5,33,34. Other threats include hydroelectric schemes, nest disturbance^11,14,33, grass-burning regimes^6,9,17,34 (though in the non-breeding season burnt floodplains are used for feeding in some areas )²⁵, poisoning, collision with utility lines⁴, persecution, and traditional medicine¹⁶. Increasing livestock, wars, desertification and agrochemicals are additional threats to the species's habitats³⁴. Nest destruction through trampling by livestock is believed to be a problem³⁴. The population is threatened by the illegal removal of eggs and chicks for international trade³⁵. Adults are also taken for trade and are hunted³⁴. The level of exports from Tanzania is believed to exceed known legal exports³⁴. The destruction of vegetation by fires probably leaves adults more susceptible to predation and hunting, and flood levels in turn influence the extent and intensity of fires³⁴. Recent potential threats that could extensively affect a large portion of the Okavango Delta include the proposed hydroelectric scheme at Popa Falls in Namibia, papyrus cutting, channel modification, and the extensive aerial spraying of pesticide to eradicate the tsetse fly²⁵. The extent of suitable breeding habitat in the Zambezi Delta (Mozambique) and the suitability of remaining habitat for feeding is believed to have declined as a result of the interruption of the natural flooding regime by the Cahorra Bassa (Tete province) and Kariba (Zimbabwe) dams upstream, and hunting is also a threat in this country^36,38.Breeding success appears to be low in the species^24,29. A pre-fledging chick: adult ratio of 5.8% on the Okavango Delta in January 2003 indicates a low chick survival rate²⁴. However, each pair of this long-lived species needs to raise only two chicks that survive to adulthood over the course of their lifetimes for the population to remain stable²⁵. The species is highly sensitive to human disturbance and may abandon home ranges which are impacted by adjacent land-use⁴³.

Major Threat(s):

The primary threat is loss and degradation of wetlands as a result of intensified agriculture, drainage, rice cultivation, and flooding by dam construction^4,5,33,34. Other threats include hydroelectric schemes, nest disturbance^11,14,33, grass-burning regimes^6,9,17,34 (though in the non-breeding season burnt floodplains are used for feeding in some areas )²⁵, poisoning, collision with utility lines⁴, persecution, and traditional medicine¹⁶. Increasing livestock, wars, desertification and agrochemicals are additional threats to the species's habitats³⁴. Nest destruction through trampling by livestock is believed to be a problem³⁴. The population is threatened by the illegal removal of eggs and chicks for international trade³⁵. Adults are also taken for trade and are hunted³⁴. The level of exports from Tanzania is believed to exceed known legal exports³⁴. The destruction of vegetation by fires probably leaves adults more susceptible to predation and hunting, and flood levels in turn influence the extent and intensity of fires³⁴. Recent potential threats that could extensively affect a large portion of the Okavango Delta include the proposed hydroelectric scheme at Popa Falls in Namibia, papyrus cutting, channel modification, and the extensive aerial spraying of pesticide to eradicate the tsetse fly²⁵. The extent of suitable breeding habitat in the Zambezi Delta (Mozambique) and the suitability of remaining habitat for feeding is believed to have declined as a result of the interruption of the natural flooding regime by the Cahorra Bassa (Tete province) and Kariba (Zimbabwe) dams upstream, and hunting is also a threat in this country^36,38.Breeding success appears to be low in the species^24,29. A pre-fledging chick: adult ratio of 5.8% on the Okavango Delta in January 2003 indicates a low chick survival rate²⁴. However, each pair of this long-lived species needs to raise only two chicks that survive to adulthood over the course of their lifetimes for the population to remain stable²⁵. The species is highly sensitive to human disturbance and may abandon home ranges which are impacted by adjacent land-use⁴³.

Conservation Actions [top]

Conservation Actions:	Conservation Actions Underway CITES Appendix II. CMS Appendix II. Protected areas (including Ramsar Sites) have been established in several key wetlands, notably in Zambia, Namibia and Botswana^4,6. In South Africa, and some other countries, action has included legal protection, marking and relocation of powerlines, awareness programmes, and encouragement of habitat protection and management by private landowners^1,3,4. A conservation group is conducting aerial surveys, field research and a community awareness programme in the Kafue Flats²⁰. Aerial surveys, nest monitoring^24,28,30 and monitoring of adult:juvenile ratios^24,29 take place annually on the Okavango Delta. In 1993, an action plan was developed for the species at the African Crane and Wetland Training workshop²⁵. A continent-wide programme for the species was launched in 2001 to monitor the species's status and threats, and help develop effective conservation programmes for the management of wetland systems³⁴. National conservation plans have been developed for Botswana, Namibia, South Africa and Zimbabwe, and research projects are being conducted in Malawi, Mozambique and Zambia³⁴. In South Africa, abandoned eggs from clutches of two are harvested, and a total of 60 chicks have been fledged from these eggs since 1986³⁵. Between 1995 and 2000, feasibility trials involved the release of 13 captive-reared birds in South Africa³⁵. In 1995, a captive breeding programme was started in South Africa²⁷. Following a workshop in July 2000, the Wattled Crane Recovery Programme was initiated in South Africa^34,35. In 2006 management for the programme was shifted to the Johannesburg Zoo and a dedicated chick-rearing facility was built. Ten captive management facilities throughout South Africa now participate in the breeding programme, which is designed to produce South African origin birds for release once a stock of 40 adults has been achieved (the captive population in South Africa stood at 29 birds in late 2007)³⁵. It had been proposed that the severely declining South African population be supplemented with eggs from captive birds of the south-central population, however analyses have discovered a high degree of genetic isolation between these populations, which indicates that they should be treated separately, and no significant loss of genetic diversity was detected in the South African population³¹. The taxonomy of the species is being investigated across its range³¹. Fund raising is ongoing for the construction of a dedicated breeding facility. Poor fertility remains a major obstacle to captive-breeding. However, on 1 September 2006, a captive-bred chick hatched at Johannesburg Zoo, after a period of nearly 10 years of unsuccessful breeing³⁵. In November 2003, three birds were successfully captured and ringed on the Boro floodplain (Botswana), and following this it was suggested that a project memorandum and funding proposal be put forward for a satellite tracking project, perhaps concentrating on young 'floaters' rather than established pairs²⁶. In 2005, it was announced that a veterinary fence would be constructed to the east of the Makgadikgadi Pans National Park in Botswana, effectively extending the park boundary and protecting grasslands used by the species from the high density of livestock in the area³². Conservation Actions Proposed Develop a coordinated range-wide action plan¹⁵. Coordinate range-wide surveys and long-term monitoring⁴, partly in order to understand population movements between sites and countries⁶. Continue and expand ecological research^4,18,25. Strengthen key protected areas, especially in the Kafue Flats and Bangweulu Swamps (Zambia)⁴. Improve protection of birds outside of protected areas such as the Jao/Boro rivers of Botswana²². Increase educational campaigns¹⁶, targeting landowners with breeding cranes⁴. Assess viability of artificial nest-platforms^8,14. Transfer species to CITES Appendix I³. Employ satellite tracking to study the species's movements across its range^26,34. In South Africa, work with farming communities to conserve natural grasslands that surround wetlands³³. Investigate whether the South African³⁴ and Ethiopian³¹ populations represent separate subspecies. Assess the levels of legal and illegal trade in the species³⁴. Study the extent and control of Mimosa, which is invading a number of large wetland systems³⁴. Assess the impacts of fire and management on the species³⁴. Study the impact of indigenous game compared with domestic cattle³⁴. Plan and conduct research into semen cryopreservation, genetic fingerprinting, eggshell membrane sexing and nutrition³⁴. In South Africa, supplement existing wild populations with captive-bred fledglings of South African origin³⁷.

Conservation Actions:

Conservation Actions Underway
CITES Appendix II. CMS Appendix II. Protected areas (including Ramsar Sites) have been established in several key wetlands, notably in Zambia, Namibia and Botswana^4,6. In South Africa, and some other countries, action has included legal protection, marking and relocation of powerlines, awareness programmes, and encouragement of habitat protection and management by private landowners^1,3,4. A conservation group is conducting aerial surveys, field research and a community awareness programme in the Kafue Flats²⁰. Aerial surveys, nest monitoring^24,28,30 and monitoring of adult:juvenile ratios^24,29 take place annually on the Okavango Delta. In 1993, an action plan was developed for the species at the African Crane and Wetland Training workshop²⁵. A continent-wide programme for the species was launched in 2001 to monitor the species's status and threats, and help develop effective conservation programmes for the management of wetland systems³⁴. National conservation plans have been developed for Botswana, Namibia, South Africa and Zimbabwe, and research projects are being conducted in Malawi, Mozambique and Zambia³⁴. In South Africa, abandoned eggs from clutches of two are harvested, and a total of 60 chicks have been fledged from these eggs since 1986³⁵. Between 1995 and 2000, feasibility trials involved the release of 13 captive-reared birds in South Africa³⁵. In 1995, a captive breeding programme was started in South Africa²⁷. Following a workshop in July 2000, the Wattled Crane Recovery Programme was initiated in South Africa^34,35. In 2006 management for the programme was shifted to the Johannesburg Zoo and a dedicated chick-rearing facility was built. Ten captive management facilities throughout South Africa now participate in the breeding programme, which is designed to produce South African origin birds for release once a stock of 40 adults has been achieved (the captive population in South Africa stood at 29 birds in late 2007)³⁵. It had been proposed that the severely declining South African population be supplemented with eggs from captive birds of the south-central population, however analyses have discovered a high degree of genetic isolation between these populations, which indicates that they should be treated separately, and no significant loss of genetic diversity was detected in the South African population³¹. The taxonomy of the species is being investigated across its range³¹. Fund raising is ongoing for the construction of a dedicated breeding facility. Poor fertility remains a major obstacle to captive-breeding. However, on 1 September 2006, a captive-bred chick hatched at Johannesburg Zoo, after a period of nearly 10 years of unsuccessful breeing³⁵. In November 2003, three birds were successfully captured and ringed on the Boro floodplain (Botswana), and following this it was suggested that a project memorandum and funding proposal be put forward for a satellite tracking project, perhaps concentrating on young 'floaters' rather than established pairs²⁶. In 2005, it was announced that a veterinary fence would be constructed to the east of the Makgadikgadi Pans National Park in Botswana, effectively extending the park boundary and protecting grasslands used by the species from the high density of livestock in the area³².

Conservation Actions Proposed
Develop a coordinated range-wide action plan¹⁵. Coordinate range-wide surveys and long-term monitoring⁴, partly in order to understand population movements between sites and countries⁶. Continue and expand ecological research^4,18,25. Strengthen key protected areas, especially in the Kafue Flats and Bangweulu Swamps (Zambia)⁴. Improve protection of birds outside of protected areas such as the Jao/Boro rivers of Botswana²². Increase educational campaigns¹⁶, targeting landowners with breeding cranes⁴. Assess viability of artificial nest-platforms^8,14. Transfer species to CITES Appendix I³. Employ satellite tracking to study the species's movements across its range^26,34. In South Africa, work with farming communities to conserve natural grasslands that surround wetlands³³. Investigate whether the South African³⁴ and Ethiopian³¹ populations represent separate subspecies. Assess the levels of legal and illegal trade in the species³⁴. Study the extent and control of Mimosa, which is invading a number of large wetland systems³⁴. Assess the impacts of fire and management on the species³⁴. Study the impact of indigenous game compared with domestic cattle³⁴. Plan and conduct research into semen cryopreservation, genetic fingerprinting, eggshell membrane sexing and nutrition³⁴. In South Africa, supplement existing wild populations with captive-bred fledglings of South African origin³⁷.

Citation:	BirdLife International 2008. Grus carunculatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 21 May 2012.
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