Data Zone
Justification of Red List category
This species is classified as Vulnerable as it is suspected to have undergone a rapid population decline within the past 36 years (three generations), primarily due to habitat loss and degradation, and trapping for domestication or illegal trade. Both the population and range are large. The available data on the species indicate that the severe declines have slowed greatly and if this welcome trend continues those declines will no longer meet threatened thresholds. The species does not appear to be increasing. Careful but extensive monitoring will be essential to ensure that the threats that are still affecting the species do not once again combine to cause further sudden declines and range contraction.
Population justification
The western sub-population (B. p. pavonina) is thought to number 20,000 to 25,000 individuals in Chad alone (Defos Du Rau et al. in prep. 2024) following the survey of new sites in the south and east of the country (Beilfuss 2019). All other country estimates for this subpopulation date to 2004, with an additional total of approximately 9,400 individuals (Beilfuss et al. 2005). The previous total estimate for this subspecies was approximately 15,000 in 2004 (Beilfuss et al. 2005), but the recently recorded birds are thought to be in addition to previous estimates and probably do not represent redistribution, as this area had simply not been surveyed before.
The eastern subpopulation (B. p. ceciliae) was estimated at 28,000-55,000 individuals in 2004 (Beilfuss et al. 2007), but remains dominated by the large count of 36,823 individuals derived from aerial surveys of the Sudd, South Sudan (Mefit-Babtie 1983). Recent investigations into the population present in Gambella, south-west Ethiopia (and close to the Sudd) reveal a large dry season population of 9,138 to 19,849 individuals (Aticho et al. 2024). More recent surveys of the population size at Lake Tana in Ethiopia in 2015-2016 estimate the population size in that region at approximately 2,100 to 2,600 individuals, in wet and dry seasons, respectively (Zelelew et al. 2020). The previous estimate for this site was 1,500-2,000.
This gives a total suspected population size of 66,000-111,000 individuals, roughly equivalent to 44,000-74,000 mature individuals.
Trend justification
This long-lived species suffered a rapid population reduction due to drought and associated habitat loss and increased pressure from people across the range, including trapping for trade (Fry 1987, Williams et al. 2003, Beilfus et al. 2007, Kone et al. 2007, Morrison 2019, Archibald et al. 2020). Rapid losses occurred throughout northern Nigeria, prior to the 1990s (Fry 1987, Meine and Archibald 1996) where it was previously 'plentifully distributed north of 10 degrees latitude' (Walkenshaw 1964) and considered to hold a large population (Morrison 2009). In Mali the population was estimated at 7,000-8,000 in 1985 (Urban 1988) but fell very rapidly to 600 by 2000/2001 (Williams et al. 2003) and has continued to decline to below 500 individuals (Beilfuss et al. 2007), while in Burkina Faso where 1,400-1,500 in the 1970s fell to approximately 50 by 2004 (Beilfuss et al. 2007). In Ghana it was previously not uncommon (Grimes 1987) but was noted to be declining very rapidly (Tréca 1996) while by 2001 there were thought fewer than 50 and declining (Williams et al. 2003). While these very rapid reductions in the western part of the range appear to have stabilised by the mid-1990s (Archibald and Meine 1996, Williams et al. 2003, Archibald et al. 2020), threats have not ceased and there is particular uncertainty over current trends due to the limited recent data from the Sudd swamp in South Sudan (Beilfuss et al. 2007). The single largest count of 36,823 was made at this site, which formed the bulk of a previous population estimate of 50,000–70,000 for the eastern subpopulation (Beilfuss et al. 2007) and creates large uncertainty in population and trend estimates. Despite large numbers being newly documented at Gambella in western Ethiopia (9,138–19,849 in the dry season) (Aticho et al. 2024) the trend of this subpopulation remains highly uncertain until large-scale monitoring can be carried out. New investigations have located large concentrations previously unrecorded in south eastern Chad (Beilfuss 2019) and documented the occurrence of large numbers at Gambella in south-west Ethiopia (Aticho et al. 2024), neither of which are likely to have been included in previous published population estimates.
With the very long three-generation length for the species, 36 years, still reaching back into the period of rapid reductions due to drought and habitat changes in the 1980s, a precautionary range of the past rate of population reduction since 1988 is -31.3% to -6%, based on revised 1985 population sizes in Beilfuss et al. (2007) (see population size section) compared with updated values based on the 2004 data (Beilfuss et al. 2007) and including the same additional and updated values.
Black Crowned Crane still faces several ongoing threats, including some with high impact such as habitat loss and degradation, hunting, poaching and trapping, and disturbance, and emerging threats such as the development of energy infrastructure (Diop 2015, Diagana and Diawara 2015, Lecoq et al. 2015, Diagana 2016). While the discovery of large numbers of Black Crowned Cranes at new sites is encouraging, they do not appear to relate to increases in the total population. Hence, while the rapid reductions seen in the past appear to have slowed, it is plausible that there is still a slow ongoing reduction in the population.
Balearica pavonina occurs in disjunct population pockets through the Sahel and Sudan-Guinea savanna zones of Africa, with records from as far south as the Democratic Republic of Congo, but was once more numerous and widespread.
Behaviour The species is largely a resident, but undergoes local daily and seasonal movements of up to several dozen kilometres (del Hoyo et al. 1996, Meine and Archibald 1996, E. T. C. Williams in litt. 2000). It breeds during the wet season months of May-December in West Africa, and July-January in East Africa (subject to local seasonal variation), nesting in single pairs in territories 0.5-1 km2 (Urban et al. 1986). During the dry (non-breeding) season it is more congregatory, forming large flocks of up to several hundred individuals (Urban et al. 1986, del Hoyo et al. 1996). In South Sudan it begins to flock along the Nile in November, reaching a peak in late February and March (Urban et al. 1986). In Chad it gathers in concentrations after breeding, and then moves south (Urban et al. 1986). In Nigeria it was subject to local movements with seasonal changes in water levels (Urban et al. 1986), though it no longer occurs in the country. It forages singly, in pairs or in small groups (Urban et al. 1986). Habitat Breeding This species is found in wet and dry open habitats, but prefers freshwater marshes, wet grasslands, and the peripheries of water-bodies (Meine and Archibald 1996). In South Sudan it is especially found in areas with water up to 1 m in depth, and knee-high to hip-high vegetation dominated by Cyperus, Eleocharis, Scirpus, Setaria, Cynodon and various leguminous and rosaceous plants (Johnsgard 1983). It always remains near wetlands, but is rarely associated with deep, open water (Urban et al. 1986). It often prefers to forage on dry ground with short grass (Johnsgard 1983) and, particularly in West Africa, it will sometimes forage and nest in upland areas (del Hoyo et al. 1996), rice fields, wet crop fields and even abandoned fields (Meine and Archibald 1996). It prefers to roost in large trees, but will use small trees or shallow water when necessary (Johnsgard 1983). Non-breeding During the non-breeding season it congregates in larger permanent wetlands, and often forages near herds of domestic livestock (del Hoyo et al. 1996, Meine and Archibald 1996) or even in rubbish dumps (Johnsgard 1983). Diet This species is a generalist omnivore (Williams et al. 2003). Its primary food source is small grain crops (45%), with small plants, small invertebrates and small vertebrates also featuring in the diet (Williams et al. 2003). It will take insects (grasshoppers, flies), molluscs, millipedes, crustaceans, fish, amphibians, reptiles, seed heads, grass tips and agricultural grain (corn, rice, millet) (Urban et al. 1986, del Hoyo et al. 1996). Breeding site Nests are built on the ground in densely vegetated wetlands (del Hoyo et al. 1996, Meine and Archibald 1996). The nest consists of a round, loosely constructed platform of reeds and grasses placed in short grass marsh in several centimetres of water, or occasionally on dry land (Urban et al. 1986). Its base is often over a metre in diameter (Urban et al. 1986). Clutch-size is c.2.5 eggs per nest. Incubation lasts 22-25 days, and chicks are able to fly when 35-40 days old (Dodman et al. 2014).
Habitat loss and degradation are significant threats, occurring through drought, wetland drainage and conversion for agriculture, overgrazing, fire, agricultural and industrial pollution, industrial construction and dam construction (flooding wetlands upstream and dessicating those downstream) (Meine and Archibald 1996, Williams et al. 2003, Beilfuss et al. 2007, T. Dodman in litt. 2009, Zelelew et al. 2020). Droughts have both directly and indirectly impacted this species' habitat, since they force people to migrate to relatively moist, less populated regions, which are then subjected to the associated pressures mentioned above (Williams et al. 2003).
Hunting pressures also exist in parts of the species' range (P. Hall in litt. 1999, Beilfuss et al. 2007, Kone 2007, Morrison 2019), including capture and sale of live birds, some destined for legal international markets (over 7,000 birds since 1985 when the species was listed in CITES Appendix II [UNEP-WCMC CITES Trade Database, January 2005]). Parts of dead Black Crowned-cranes, notably the head and wings, are used in traditional healing (Williams et al. 2003).
In addition, indiscriminate pesticide application may be leading to harmful bio-accumulation of toxins, and direct poisoning to reduce crop depredation has been reported in East Africa (Williams et al. 2003, Morrison 2019). Warfare and political instability affects nations across the species' range, and may have a significant impact upon the species' populations, with indiscriminate shootings and the inability to implement conservation measures (Williams et al. 2003, Morrison 2019). Oil exploration in and near wetlands also poses a threat (Williams et al. 2003).
Conservation Actions Underway
CITES Appendix II. Listing in Appendix I has been pursued in the past (R. Beilfuss in litt. 2004), and CITES suspended trade in this species in Sudan, South Sudan and Guinea (Anon. 2013). A collaborative project was launched in 1999 to determine the population size and trend, distribution and threats, and an action plan for the species was then produced (Williams et al. 2003). There have been subsequent small-scale conservation projects including surveys/awareness (in the rice-growing region of the coastal zone of West Africa from Senegal to Guinea-Bissau, and in Ethiopia), assessments (Senegal Delta, Nigeria), monitoring at various sites across the range and investigations into trade and other threats (Mali, Guinea, Sudan) (Aynalem et al. 2014, Dodman et al. 2014, T. Dodman in litt. 2016). Updated species reviews have been produced (Morrison 2019), and some West African countries have developed national action plans for this species (Diagana et al. 2015, Diop 2015, Lecoq et al. 2015, Diagana 2016).
Text account compilers
Martin, R., Rutherford, C.A.
Contributors
Beilfuss, R., Dodman, T., Evans, M., Hall, P., Morrison, K., Symes, A., Taylor, J., Westrip, J.R.S., Williams, E.T.C., du Rau, P. & van Niekerk, M.
Recommended citation
BirdLife International (2024) Species factsheet: Black Crowned Crane Balearica pavonina. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-crowned-crane-balearica-pavonina on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.