• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
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.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Stotz, D. F.; Fitzpatrick, J. W.; Parker, T. A.; Moskovits, D. K. 1996. Neotropical birds: ecology and conservation. University of Chicago Press, Chicago.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2016	Near Threatened	D2
2012	Near Threatened	D2
2008	Near Threatened	D2
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Threatened

Migratory status	not a migrant	Forest dependency	Medium
Land mass type		Average mass	8 g

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	150	medium
Number of locations		-
Fragmentation		-

	Estimate	Data quality	Derivation	Year of estimate
No. of mature individuals		good	observed	0
Population trend	Unknown		not applicable	-
Decline (3 years/1 generation past)		-	-	-
Decline (5 years/1 generation past)		-	-	-
Decline (10 years/1 generation past)		-	-	-
Decline (10 years/3 generation future)		-	-	-
Decline (10 years/3 generation past and future)		-	-	-
Number of subpopulations		-	-	-
Largest subpopulations	100	-	-	-
Generation length (yrs)	3.5	-	-	-

Population justification: Partners in Flight estimated the population to number fewer than 50,000 individuals (A. Panjabi in litt. 2008), thus it is placed in the band 20,000-49,999 individuals here.

Trend justification: The population trend is difficult to determine because of uncertainty over the impacts of habitat modification on population sizes. The population may now be increasing in southern Socorro following sheep and cat eradication efforts (J.E. Martínez-Gómez in litt. 2016) however further evidence is required to confirm this increasing trend.

Country/Territory	Occurrence status	Presence	Resident	Breeding	Non-breeding	Passage
Mexico	N	Extant	Yes

Country/Territory	IBA Name
Mexico	Islas Revillagigedo

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	resident
Shrubland	Subtropical/Tropical Dry	major	resident
Altitude	0 - 1050 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Ovis aries	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2020) Species factsheet: Troglodytes sissonii. Downloaded from http://www.birdlife.org on 26/01/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/01/2020.