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

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	C2a(ii)

Red List history

Year	Category	Criteria
2020	Vulnerable	C2a(ii)
2018	Vulnerable	B2ab(iii,v);C2a(ii)
2016	Vulnerable	B2ab(iii,v);C2a(ii)
2012	Vulnerable	B2ab(iii,v);C2a(ii)
2010	Vulnerable	B2a+b(iii,v); C2a(ii)
2008	Vulnerable	B2a+b(iii,v); C2a(ii)
2007	Vulnerable
2005	Vulnerable
2004	Vulnerable
2000	Vulnerable
1994	Lower Risk/Near Threatened
1988	Near Threatened

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type	shelf island	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	549,000 km2	medium
Extent of Occurrence (non-breeding)	1,110,000 km2	medium
Area of Occupancy (breeding/resident)	1,700 km2	medium
Number of locations	11-20	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	8000 mature individuals	medium	estimated	2015
Population trend	decreasing	poor	inferred	2009-2024
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	5.1 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Partners in Flight (2019) estimate the population of Synthliboramphus craveri to total 8,000 mature individuals, or 12,000 individuals. Such estimates are marginally less than Gaston and Jones's (1998) older estimate of  15,000-20,000 birds and Pitman et al.'s (1995) at-sea survey estimate of c.22,000 birds, as would be expected given the moderate ongoing population declines.

Trend justification: Moderate ongoing declines are suspected owing to the various threats acting throughout the species's population.

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

Country/Territory	IBA Name
Mexico	Archipiélago Bahía de los Angeles
Mexico	Isla Tiburón-Canal Infiernillo-Estero Santa Rosa

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Coastal/Supratidal	Sea Cliffs and Rocky Offshore Islands	major	breeding
Marine Neritic	Pelagic	marginal	resident
Marine Oceanic	Epipelagic (0-200m)	suitable	non-breeding
Altitude	0 - 50 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Fishing & harvesting aquatic resources - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species mortality
Biological resource use	Fishing & harvesting aquatic resources - Unintentional effects: (subsistence/small scale) [harvest]	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 - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Reduced reproductive success
Pollution	Agricultural & forestry effluents - Herbicides and pesticides	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Unknown		Past Impact
		Stresses Ecosystem degradation, Reduced reproductive success
Pollution	Agricultural & forestry effluents - Nutrient loads	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Species mortality
Pollution	Industrial & military effluents - Oil spills	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Reduced reproductive success, Species mortality

Purpose	Scale
Food - human	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Craveri's Murrelet Synthliboramphus craveri. Downloaded from https://datazone.birdlife.org/species/factsheet/craveris-murrelet-synthliboramphus-craveri 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.