VU
Short-legged Ground-roller Brachypteracias leptosomus



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
- - A3cd+4cd

Red List history
Year Category Criteria
2023 Vulnerable A3cd+4cd
2016 Vulnerable A3bcd
2012 Vulnerable A3cd
2008 Vulnerable A3c,d
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type shelf island
Average mass 185 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 210,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 10000-25000 mature individuals poor estimated 2023
Population trend decreasing medium inferred 2016-2031
Rate of change over the past 10 years/3 generations (longer of the two periods) 25-29% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 30-49% - - -
Generation length 5.15 years - - -
Number of subpopulations 2-100 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The species can be easily overlooked, and a study on Masoala Peninsula estimated a density of 4 territories per km2, which would equate to a maximum of approximately 8,800 pairs in the peninsula alone (Thorstrom and Lind 1999). Knowing this, but considering the species' high specialisation in undisturbed damp forest, and continuing habitat loss, deterioration and fragmentation, and the detrimental effect of the latter on the occurrence of the species (Benjara et al. 2021), a conservative measure of 10-25% occupancy of the range (approximately 48,900 km2) at a precautionary 1 territory per km2, can be assumed. This results in a total estimate of 4,900-12,200 pairs, or approximately 9,800-24,500 mature individuals, and the species' population size is therefore placed in a rounded band of 10,000-25,000 mature individuals.

Trend justification: The species is highly dependent on primary, undisturbed forest, and is considered absent from degraded forest, and forest with a majority of secondary growth (Woog et al. 2006, Langrand and Kirwan 2020). Studies have found that it does not occur in habitats that have been sufficiently degraded, does not occur in patches within the forest that have been cleared for small-scale agriculture (Woog et al. 2006, Rocha et al. 2015), and does not occur in medium to small forest fragments (Rakotoarisoa and Capparella 2013). 
Loss of tree cover within the species' range (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein) over the past three generations, due primarily to clearance for subsistence cultivation, human pressure and commercial logging (Jenkins 1987, Stattersfield et al. 1998, ZICOMA 1999), has been estimated at approximately 25%, and suspected to accelerate to a rate of approximately 31% between 2016 and 2031. Based on a rate of decline of approximately 2% over the past five years, and the continuing threats to this habitat, it is therefore suspected that the loss of forest habitat within the species' range will continue at a rate of approximately 31% over the next three generations.
Considering the species' high dependence on forest habitats, and sensitivity to its degradation and reduction in size, combined with the ongoing forest loss within its range, the current population size is therefore inferred to be undergoing a continuing declining due to the loss of suitable key habitats and increase in forest edge. It is suspected that the species' rate of decline in population size is in line with the rate of forest loss.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Madagascar extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Madagascar Daraina Forest
Madagascar Tsaratanana Strict Nature Reserve and extension
Madagascar South Anjanaharibe Special Reserve and extension
Madagascar Marojejy National Park
Madagascar Masoala National Park
Madagascar Anjanaharibe Classified Forest
Madagascar Upper Rantabe Classified Forest
Madagascar Mananara-North Biosphere Reserve
Madagascar Ambatovaky Special Reserve
Madagascar Bezavona Classified Forest
Madagascar Zahamena National Park and Strict Reserve
Madagascar Betampona Strict Nature Reserve
Madagascar Mangerivola Special Reserve
Madagascar Sihanaka Forest
Madagascar Mantadia National Park and Analamazaotra Special Reserve
Madagascar Ankeniheny Classified Forest
Madagascar Onive Classified Forest
Madagascar Anjozorobe Forest
Madagascar Andohahela National Park - Section I
Madagascar Ranomafana National Park and extension
Madagascar Andringitra National Park
Madagascar Vondrozo Classified Forest NPA
Madagascar Midongy South National Park

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane suitable resident
Altitude 0 - 1500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Shifting agriculture Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
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%) Unknown Unknown
Stresses
Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Rapid Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - non-trivial recent

Recommended citation
BirdLife International (2024) Species factsheet: Brachypteracias leptosomus. Downloaded from https://datazone.birdlife.org/species/factsheet/short-legged-ground-roller-brachypteracias-leptosomus on 19/03/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 19/03/2024.