LC
White-backed Duck Thalassornis leuconotus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2024 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency does not normally occur in forest
Land-mass type Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 25,900,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 8500-20000 mature individuals poor suspected 2021
Population trend decreasing - inferred -
Rate of change over the future 10 years/3 generations (longer of the two periods) 10-19% - - -
Generation length 5.55 years - - -
Number of subpopulations 2-20 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The species is locally common, but has declined in parts of its range, such as Uganda (Carswell et al. 2005). The West African population was suspected to number less than 1,000 individuals at the start of the century (Kear 2005), and less than 500 individuals in 2006 (Dodman 2007, Wetlands International 2021). The overall population in Eastern and Southern Africa was estimated in 2002 to be between 10,000 and 25,000 individuals (Wetlands International 2021), with censuses of 500 individuals at both Lake Naivasha in Kenya and Kafue Flats in Zambia (Dowsett 2008). Subspecies insularis has historically been widespread across Madagascar, but may now be rarer due to local extinctions, with the most recent estimate of 2,500-5,000 individuals (Dodman 2007, Wetlands International 2021). Based on these estimates, the total population size is suspected to be between 13,000 and 30,000 individuals, which is equal to 8,666-20,000 mature individuals, rounded to 8,500-20,000.

Trend justification: The overall trend is decreasing, although some populations may be stable (Wetlands International 2021). The West African population seems to be decreasing with less than 1,000 individuals at the start of the century (Kear 2005), and less than 500 individuals in 2006 (Dodman 2007, Wetlands International 2021), although coverage is poor is this region. Similarly, local extinctions in Madagascar, such as at Lake Alaotra (Bamford et al. 2015) are likely contributing to a decreasing population size of subspecies insularis. Climate change modelling has projected this species will be likely to suffer a range contraction by 2050, with its current range reduced by up to 30% over approximately 50 years (Nagy et al. 2021), equivalent to 10 to 11 % over three generations. Considering the potential for additional reductions due to localised hunting, and assuming that the rate of habitat loss as measured directly relates to features that limit the species' population, future reductions are suspected to occur at a rate of between 10-19 %.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Angola extant native yes
Benin extant vagrant
Botswana extant native yes
Burkina Faso extant vagrant
Burundi extant native yes
Cameroon extant native yes
Chad extant native yes
Congo extant native yes
Congo, The Democratic Republic of the extant native yes
Eswatini extant native yes
Ethiopia extant native yes
Kenya extant native yes
Lesotho extant native yes
Madagascar extant native yes
Malawi extant native yes
Mali extant native yes
Mauritania extant vagrant
Mozambique extant native yes
Namibia extant native yes
Nigeria extant native yes
Rwanda extant native yes
Senegal extant native yes
Somalia extant vagrant
South Africa extant native yes
South Sudan extant native yes
Sudan extant vagrant
Tanzania extant native yes
Togo extant vagrant
Uganda extant native yes
Zambia extant native yes
Zimbabwe extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Botswana Okavango Delta
South Africa Grasslands
South Africa Nyl River Floodplain
Zambia Sumbu National Park and Tondwa Game Management Area

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Wetlands (inland) Permanent Freshwater Lakes (over 8ha) suitable resident
Wetlands (inland) Permanent Freshwater Marshes/Pools (under 8ha) major resident
Wetlands (inland) Seasonal/Intermittent Freshwater Lakes (over 8ha) suitable resident
Altitude 0 - 3000 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Fishing & harvesting aquatic resources - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Biological resource use Hunting & trapping terrestrial animals - Unintentional effects (species is not the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines Low Impact: 3
Stresses
Species disturbance, Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Minority (<50%) Rapid Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Ecosystem degradation
Pollution Agricultural & forestry effluents - Soil erosion, sedimentation Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation

Utilisation
Purpose Scale
Food - human subsistence, national

Recommended citation
BirdLife International (2024) Species factsheet: White-backed Duck Thalassornis leuconotus. Downloaded from https://datazone.birdlife.org/species/factsheet/white-backed-duck-thalassornis-leuconotus on 23/12/2024.
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 23/12/2024.