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

Taxonomic note
Two subspecies recognized.

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

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	A2bc+4bc

Red List history

Year	Category	Criteria
2024	Vulnerable	A2bc+4bc
2016	Least Concern
2012	Least Concern
2009	Least Concern
2008	Least Concern
2004	Least Concern
2000	Lower Risk/Least Concern
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	4,200,000 km2	medium
Extent of Occurrence (non-breeding)	15,100,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	270000 mature individuals	medium	estimated	2023
Population trend	decreasing	-	estimated	2010-2037
Rate of change over the past 10 years/3 generations (longer of the two periods)	20-49%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	20-49%	-	-	-
Generation length	9.05 years	-	-	-
Number of subpopulations	2	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The global population is estimated to number 270,000 mature individuals (Partners in Flight 2023), and is assumed to be structured into two subpopulations that accord with the two species recognised in the species.

A combination of monitoring data from breeding, migration and especially non-breeding sites indicates that there is currently a rapid population reduction underway (Ziolkowski et al. 2022, Muñoz-Salas et al. 2023, Smith et al. 2023).

Trend justification:

Data from the North American Breeding Bird Survey (BBS) indicate declines of c.17% in the three-generation period 1994-2021, with no indication the rate is slowing (Ziolkowski Jr. et al. 2022). Incorporating a combination of U.S. Geological Survey and Canadian Wildlife Service analyses of BBS survey data through 2021, an overall reduction of 31.0% (-43.8 to -16.4%) within three generations was estimated in the Avian Conservation Assessment Database December 2023 update (Partners in Flight 2023). There appear to have been an acceleration in the rates of reduction in the past few years, with the Prairie Potholes Bird Conservation region (the core part of the breeding range) showing a sustained and worsening trend, although an increase is noted for the smaller population in the Badlands/Prairies Bird Conservation Region (Ziolkowski Jr. et al. 2022, N. Warnock in litt. 2024). 

Surveys of migratory stopover locations throughout North America (Smith et al. 2023) support the fact that a moderately rapid to rapid reduction is taking place, with an estimated reduction of 28.9% in three generations. However this trend has poor precision and the majority of the population is not sampled by the network of sites involved: the trend has wide confidence intervals of -75.9% to +55.0% (Smith et al. 2023). 

The most concerning data come from monitoring of non-breeding areas. Wintering populations of Marbled Godwits in north-west Mexico and California are thought to have declined by 7.7% annually based on Migratory Shorebird Project data during 2011–2019 (Muñoz-Salas et al. 2023). This is equivalent to a three-generation reduction of c.89%, and it is suspected that about half of the non-breeding population is expected to occur in this area. Elsewhere however, trends appear to be stable. Christmas Bird Count data (Meehan et al. 2022) show a relatively stable/slightly increasing trend overall for the three-generation period to 2021. Also, there are well-studied sites on the west coast that have remained stable, for example Tomales Bay (Warnock et al. 2021): it is possible this represents a high-quality site that attracts individuals up to the carrying capacity of the site, hence counts would remain constant while other sites see declining numbers. An alternative possible explanation for the conflicting trends may be ‘short-stopping’, where fewer individuals complete the expected full distance of their migration and instead stay in sites closer to breeding areas, although declines noted further south are not offset by stability at some sites further north.

Overall, based on data sources that cover most of the species’ range, the population decline is estimated to fall within the band 20-49% for the past and current three generations, up to 2037 (based on trend data accelerating after 2010). Uncertainty over the future rate of decline means that a value for the future three generations is not determined.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Bahamas	extant	native				yes
Belize	extant	native				yes
Canada	extant	native		yes	yes	yes
Cayman Islands (to UK)	extant	native				yes
Colombia	extant	native				yes
Costa Rica	extant	native			yes	yes
Cuba	extant	native				yes
El Salvador	extant	native			yes	yes
Grenada	extant	vagrant
Guadeloupe (to France)	extant	vagrant
Guatemala	extant	native			yes	yes
Honduras	extant	native			yes	yes
Jamaica	extant	native				yes
Mexico	extant	native			yes	yes
Nicaragua	extant	native			yes
Panama	extant	native			yes	yes
St Pierre and Miquelon (to France)	extant	vagrant
USA	extant	native		yes	yes	yes
Virgin Islands (to UK)	extant	vagrant
Virgin Islands (to USA)	extant	vagrant

Country/Territory	IBA Name
Costa Rica	Nicoya Gulf mangroves and coastal areas
Mexico	Agiabampo
Mexico	Área de San Quintín
Mexico	Bahía Magdalena-Almejas
Mexico	Bahía Navachiste
Mexico	Bahía Santa María
Mexico	Bahía Todos Santos
Mexico	Complejo Lagunar Ojo de Liebre
Mexico	Complejo Lagunar San Ignacio
Mexico	Delta del Río Colorado
Mexico	Ensenada de la Paz
Mexico	Ensenada de Pabellones
Mexico	Estero Lobos
Mexico	Marismas Nacionales
Mexico	Sistema Tóbari
Mexico	Zonas Húmedas de Yávaros
USA	Bear River Bay UT02
USA	Salton Sea

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Temperate	major	breeding
Marine Intertidal	Mud Flats and Salt Flats	major	non-breeding
Marine Intertidal	Salt Marshes (Emergent Grasses)	suitable	non-breeding
Marine Intertidal	Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc	suitable	non-breeding
Marine Neritic	Estuaries	major	non-breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	major	breeding
Altitude	0 - 150 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion, Reduced reproductive success
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Species mortality
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Reduced reproductive success
Natural system modifications	Dams & water management/use - Abstraction of surface water (agricultural use)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Transportation & service corridors	Utility & service lines	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Reduced reproductive success, Species mortality

Purpose	Scale
Food - human	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Marbled Godwit Limosa fedoa. Downloaded from https://datazone.birdlife.org/species/factsheet/marbled-godwit-limosa-fedoa on 23/12/2024.
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 23/12/2024.