Yellow-margined Flatbill (Tolmomyias assimilis) | Details

Yellow-margined Flatbill Tolmomyias assimilis

Current view: Data table and detailed info

Taxonomy

Taxonomic note
Tolmomyias assimilis and T. flavotectus (del Hoyo and Collar 2016) were previously lumped as T. assimilis (see AOU [1998 & supplements], SACC [2005 & updates], Sibley & Monroe [1990, 1993] and Stotz et al. [1996]).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and 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
2022	Least Concern
2016	Least Concern
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	high
Land-mass type		Average mass	-

Range

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	6,880,000 km²	medium
Severely fragmented?	no	-

Population

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	suspected	2016-2026
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	2.93 years	-	-	-

Population justification: The global population size has not been quantified given recent taxonomic splits. Prior to being split, the species has been described as 'fairly common' (Stotz et al. 1996).

Trend justification: The population trend has not been investigated. Tree cover loss within the range is low (3% over ten years; Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Population declines are therefore likely equally low and localised; they are here tentatively placed in the band 1-9% over ten years.

Country/territory distribution

Country/Territory	Presence	Origin	Resident
Bolivia	extant	native	yes
Brazil	extant	native	yes
Colombia	extant	native	yes
Ecuador	extant	native	yes
French Guiana	extant	native	yes
Guyana	extant	native	yes
Peru	extant	native	yes
Suriname	extant	native	yes
Venezuela	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 Swamp	major	resident
Altitude	0 - 1300 m	Occasional altitudinal limits

Recommended citation
BirdLife International (2024) Species factsheet: Yellow-margined Flatbill Tolmomyias assimilis. Downloaded from https://datazone.birdlife.org/species/factsheet/yellow-margined-flatbill-tolmomyias-assimilis 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.