Justification of Red List category
This rare and localised species is listed as Vulnerable because it is estimated to have a single small population within a broad extent of occurrence. The population is undergoing a continuing decline owing to hunting, nesting disturbance and the modification and burning of its habitat.
Population justification
The total population has been estimated at 5,000-8,000 individuals (T. Dodman in litt. 2002), and a total population estimate of fewer than 10,000 individuals is supported by Dinesen and Baker (2006). The range of 5,000-8,000 individuals roughly equates to 3,300-5,300 mature individuals.
Trend justification
There is little doubt that the species is declining in Tanzania, Zambia and Rwanda, with declines perhaps in Uganda as well, and the species may be more threatened than available information suggests (L. Dinesen in litt. 2007).
Balaeniceps rex is widely but very locally distributed in large swamps from South Sudan to Zambia. Approximate national estimates proposed by T. Dodman in litt. to Wetlands International (2002) are: c.5,000 in South Sudan (50-80% of the total population [Briggs 2007]), 100-150 in Uganda (but possibly over 200 [Briggs 2007]), 100-500 in western Tanzania (this figure also proposed by Dinesen and Baker [2006]), <500 in Zambia (Roxburgh and Buchanan [2010] gave a later estimate of 1,760, with 1,296 in the Bangweulu Swamps alone, but this is possibly an over-estimate [F. Willems in litt. 2016]), <1,000 in the Democratic Republic of Congo (DRC), irregular visitors in the Central African Republic, <50 in Rwanda and <50 in Ethiopia. In 1997, the population was estimated to be 12,000-15,000 individuals (Rose and Scott 1997), but a more recent review makes a conservative estimate of 5,000-8,000 individuals (T. Dodman in litt. to Wetlands International 2002). This figure may prove too low, depending on research into the South Sudan populations (T. Dodman in litt. to Wetlands International 2002). An estimate of 3,830 birds was given for the Sudd (including areas of Zeraf Reserve) by Fay et al. (2007). A total population of less than 10,000 individuals is supported by a literature review in which the extent of certain wetland habitats was found to have been significantly overestimated by previous studies. Surveys in September-October 2005 support the suggestion that there are a few hundred individuals in the Malagarasi region of Tanzania (Briggs 2007). There is little doubt that the species is declining in Tanzania, Zambia and Rwanda, with possible declines in Uganda as well, and the species may be more threatened than available information suggests (L. Dinesen in litt. 2007).
Behaviour This species is mostly sedentary, although it may make some movements in order to find optimal feeding habitat as water levels vary (del Hoyo et al. 1992). In South Sudan there are regular seasonal movements between feeding and breeding zones (Guillet 1978). It is very solitary. Even within the pair, male and female will often feed at opposite ends of their territory (del Hoyo et al. 1992). Loose aggregations may occasionally occur where receding water levels and large numbers of fish become concentrated in a small area (Hancock et al. 1992). It breeds solitarily, usually maintaining a density of fewer than three nests per square kilometre (Hancock et al. 1992). The breeding season is long. Eggs are laid at the end of the rains, as waters start to recede, and chicks fledge towards the end of the dry season (Hancock et al. 1992). Habitat Breeding It both breeds and forages in seasonally flooded marshes, but may utilise separate habitats for foraging and breeding (Renson 1998, Ngwenyama 2012). The vegetation in these flooded marshes is dominated by a mixture of papyrus Cyperus papyrus, reeds e.g. Phragmites spp., cattails Typha spp. and grasses, particularly Miscanthidium spp. (Hancock et al. 1992). It is often found in areas with abundant floating vegetation, often papyrus (Baker 1996). It also uses permanent non-papyrus swamps in areas such as the Malagarasi (Tanzania) (Dinesen and Baker 2006) and Lake Victoria (Uganda) (L. Dinesen in litt. 2007). Non-breeding It usually forages in shallow water (del Hoyo et al. 1992) where it makes use of clear channels among the vegetation that have been created by the movements of large mammals (del Hoyo et al. 1992). It tends to avoid areas where the vegetation is too dense to be penetrated easily, or is taller than the bird's back (Hancock et al. 1992). It is reported to prefer water that is poorly oxygenated, where fish are forced to surface to breathe, and are thus more easily caught (Guillet 1978), which is why it is thought not to frequent swamps that are characterised by papyrus alone (Guillet 1978). In South Sudan it has been known to forage on rice fields and other flooded plantations (Hancock et al. 1992). Diet When feeding, it shows a preference for lungfish Protopterus aethiopicus, but takes a variety of fish species including Senegal Bichir Polypterus senegalus, catfish Clarias spp. and tilapia Tilapia spp. (Guillet 1979, del Hoyo et al. 1992). It also preys on aquatic animals such as amphibians, young crocodiles and watersnakes (Briggs 2007, Hancock et al. 1992), and may even take rodents and young waterfowl (Hancock et al. 1992). Diet seems to vary geographically: lungfish and catfish are the main prey species in Uganda, and catfish and watersnakes the preferred diet in Zambia (Hancock et al. 1992, Mullers and Amar 2015a). Breeding site The nest is grassy construction, up to 3 m wide, on a mound of floating vegetation or a small island (Briggs 2007), and often among dense stands of papyrus (Hancock et al. 1992). The maximum clutch size is three, although usually only one nestling will survive, with rare records of two chicks fledging (Mullers and Amar 2015b). The species can live for around 50 years (although it is likely to live less long in the wild [R. Mullers in litt. 2016]), takes three to four years to reach reproductive maturity, and is monogamous.
Throughout most of its range, the species is threatened by habitat destruction and degradation, disturbance, hunting, and capture for the bird trade (see Collar and Stuart 1985, Baker 1996, T. Dodman in litt. 2002). Suitable habitat is being converted for cultivation and pasture, and cattle have been known to trample nests (Briggs 2007), while in Uganda and the Sudd exploration for oil may impact this species by altering its habitat and the oil polluting the environment (Dodman 2013). Pollution may also be significant in Uganda, where agrochemicals and tannery effluents run off or are disposed of into Lake Victoria (Dodman 2013). The species is hunted for food and cultural reasons, for example it may be viewed as a bad omen. It is also captured for the zoo trade, which is a problem especially in Tanzania where trading of the species is still legal (Briggs 2007). Interviews with people in the Bangweulu Wetlands (Zambia) indicate that eggs and chicks are taken for consumption and sale, probably to zoos or collectors (Roxburgh et al. 2006). Five chicks per month were estimated as taken for trade in one district in 2011, with only two individuals surviving the transit (D. Ngwenyama in litt. 2011). In 2007, an undisclosed number of specimens, illegally imported from Tanzania, were confiscated by the Danish authorities in Copenhagen (L. Dinesen in litt. 2007) and at least two birds were exported from Tanzania to a zoo in the USA (T. Dodman in litt. 2007). Small-scale trading poses a serious threat to small local populations rather than the global population (Briggs 2007), though recent reports suggest that levels of disturbance and trade are not sustainable in Zambia (T. Dodman in litt. 2011). Breeding success may be as low as 10% annually in Bangweulu, mainly due to human disturbance (Mullers and Amar 2015b). During the 2011-2013 breeding seasons, only 10 out of 25 chicks successfully fledged: four chicks were killed in fires, one was depredated and 10 were taken by humans (R. Muller in litt. 2016). In Zambia, fire and drought threaten habitat (especially in Bangweulu, where a decline is apparent) (T. Dodman in litt. 2002), there is some evidence for trapping and persecution (T. Dodman in litt. 2002), and nests are trampled by large herbivores feeding in the swamps (Renson 1998). Conflict in Rwanda and DRC has disrupted protected areas (e.g. Akagera National Park) that support the species (T. Dodman in litt. 2002), and the proliferation of firearms has greatly facilitated hunting. In South Sudan, its stronghold, it has been said to be very much endangered by destruction of papyrus swamps by cattle and fire (Nikolaus 1987). Between 1952 and 1980 the area of the Sudd swamps of South Sudan increased (Howell et al. 1988) from 6,700 km2 to 19,200 km2. Whilst this habitat was earlier threatened by drainage due to plans for the Jonglei Canal, these plans are no longer supported, though canalisation and related schemes for the oil industry do pose a threat (T. Dodman in litt. 2008). The construction of several dams along the lower Nile will allow artificial manipulation of water levels in the Sudd (Briggs 2007). In the Malagarasi, large areas of miombo woodland adjacent to swamps are being cleared for tobacco farming and agriculture, and the human population, which includes fishermen, farmers and semi-nomadic pastoralists, has increased very rapidly in recent decades (Dinesen and Baker 2006). In this region, dry-season burning and cattle-grazing in the species's core area are severe and expanding, and the first rice paddies have appeared at the edge of the species's key swamps. Over four years only 7 of 13 nests were successful at this location (John et al. 2012). Also in Malagarasi, a railway line has bisected swamps and rice paddies in some of its core areas (L. Dinesen in litt. 2007). Records of birds outside their core areas may be due to the displacement of birds by fires in dry years (Dinesen and Baker 2006).
Conservation Actions Underway
CITES Appendix II. A Single Species Conservation Action Plan was developed in 2012 (Dodman 2013), including a stakeholder workshop, with representatives of all range states. Also, a conservation management plan (Mullers 2014) is currently implemented by the Bangweulu Wetlands Management Board. Steps are being taken in South Sudan to understand the population better and improve the status of protected areas. Several key Shoebill sites are designated Ramsar sites in South Sudan, Uganda, Tanzania and Zambia. In Bangweulu Wetlands local fishermen are employed as guards to protect Shoebill nests, and this raises local awareness, as well as increasing breeding success (Mullers and Amar 2015b).
Conservation Actions Proposed
Identify key areas for monitoring and conduct regular surveys. Select important areas for protection. Reduce disturbance and establish buffer zones in protected areas (L. Dinesen in litt. 2007). Enforce legislation in protected areas (L. Dinesen in litt. 2007). Create community-based environmental awareness programmes focussed on generating Shoebill-pride to discourage hunting. Encourage further development of ecotourism based around this species. Investigate the potential occurrence of seasonal movements (Briggs 2007). Monitor rates of habitat conversion across its range. Re-submit the proposal to upgrade the species to CITES Appendix I, and implement trade control. Determine the Sudd swamps population size and trend (T. Dodman in litt. to Wetlands International 2002), and refine the national and global population estimates. Assess the viability of the population in Gambella, Ethiopia, an area under high pressure from agricultural developments.
120 cm. Large grey, stork-like waterbird with a fantastically unique bill. Unmistakable.
Text account compilers
Symes, A., Taylor, J., Westrip, J., Benstead, P., Evans, M., Ashpole, J, Khwaja, N., Martin, R., Pilgrim, J., Robertson, P., Ekstrom, J.
Contributors
Dodman, T., Roxburgh, L., Dinesen, L., Morrison, K., Brouwer, K., Melamari, L., Baker, N., Mullers, R., Fishpool, L., Ndang'ang'a, P., Willems, F.
Recommended citation
BirdLife International (2024) Species factsheet: Shoebill Balaeniceps rex. Downloaded from
https://datazone.birdlife.org/species/factsheet/shoebill-balaeniceps-rex on 22/12/2024.
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 22/12/2024.