NT
Vogelkop Owlet-nightjar Aegotheles affinis



Taxonomy

Taxonomic note
Aegotheles bennettii and A. affinis (del Hoyo and Collar 2014) were previously lumped as A. bennettii following Sibley and Monroe (1990, 1993) but considerable genetic distance coupled with morphological differences (notably in size) and the geographical position of affinis suggest that treatment as a separate species is warranted (Dumbacher et al. 2003); this argument accepted here pending more detailed morphological comparisons and the establishment of vocal evidence. Subspecies terborghi previously placed in A. affinis but now moved to A. bennettii. Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2023. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v8_Dec23.zip.

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

Red List history
Year Category Criteria
2023 Near Threatened B1b(iii)+2b(iii)
2016 Not Recognised
2012 Not Recognised
2008 Not Recognised
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
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) 100 km2
Area of Occupancy (breeding/resident) 96 km2
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing - suspected 2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-9% - - -
Generation length 3.48 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: This species is very poorly known and the global population size has not been quantified, but it is thought to be uncommon (Cleere 2010, Kirwan et al. 2020).

Trend justification: Although the species is very poorly known, it inhabits lowland and hill forest and as such is precautionarily suspected to be declining due to ongoing forest loss within its range. Remote sensing data indicate that forest loss is slow but ongoing within the range, equivalent to c.2% in the three generations to 2021 (Global Forest Watch 2023, using data from Hansen et al. [2013] and methods disclosed therein). Tentatively, declines are placed here in the range 1-9% in three generations.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 80 - 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 Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation
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

Recommended citation
BirdLife International (2024) Species factsheet: Vogelkop Owlet-nightjar Aegotheles affinis. Downloaded from https://datazone.birdlife.org/species/factsheet/vogelkop-owlet-nightjar-aegotheles-affinis on 06/12/2024.
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 06/12/2024.