Scaled Spinetail (Cranioleuca muelleri) - BirdLife species factsheet

Scaled Spinetail Cranioleuca muelleri

Current view: Data table and detailed info

Taxonomy

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.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

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	Endangered	A3c
2012	Endangered	A3c
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	high
Land-mass type		Average mass	-

Range

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	465,000 km²	medium
Severely fragmented?	no	-

Population

	Estimate	Data quality	Derivation	Year of estimate
Population size	10000-19999 mature individuals	poor	suspected	2021
Population trend	decreasing	-	suspected	2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	2.8 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: This is a poorly known species and no population estimates are available. It appears to be uncommon, and the population may be relatively small (Remsen and Sharpe 2020). Based on the paucity of records, it is precautionarily suspected that the population numbers between 10,000 and 19,999 mature individuals, but an accurate quantification of the population size is urgently needed.

Trend justification: The species is suspected to be in decline as forested habitat within the range is lost, degraded and fragmented.
Over the past ten years, roughly 6% of tree cover has been lost from the range, but since 2016 this rate has been increasing to 8% over ten years (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Given its high forest-dependency and its susceptibility to fragmentation and edge effects, population declines are likely faster than the rate of tree cover loss suggests, and are therefore here tentatively placed in the band 10-19% over ten years.

Country/territory distribution

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

Important Bird and Biodiversity Areas (IBA)

Country/Territory	IBA Name
Brazil	Ilha de Marajó
Brazil	Várzeas de Monte Alegre
Brazil	Várzeas do Médio Rio Amazonas

Habitats & altitude

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Swamp	major	resident
Altitude	0 - 200 m	Occasional altitudinal limits

Threats & impact

Threat (level 1)

Threat (level 2)

Impact and Stresses

Agriculture & aquaculture

Annual & perennial non-timber crops - Agro-industry farming

Timing

Scope

Severity

Impact

Ongoing

Majority (50-90%)

Slow, Significant Declines

Medium Impact: 6

Stresses
Ecosystem degradation, Ecosystem conversion