Data Zone
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.
| Critically Endangered | Endangered | Vulnerable |
|---|---|---|
| - | A2bc+4bc | A2bc+4bc |
| Year | Category | Criteria |
|---|---|---|
| 2020 | Endangered | A2bc+4bc |
| 2018 | Endangered | A2bc+3bc+4bc |
| 2016 | Endangered | A2bc+3bc+4bc |
| 2012 | Endangered | A2bc+3bc+4bc |
| 2008 | Endangered | A2b,c; A3b,c; A4b,c |
| 2006 | Endangered | |
| 2004 | Least Concern | |
| 2000 | Lower Risk/Least Concern | |
| 1994 | Lower Risk/Least Concern | |
| 1988 | Lower Risk/Least Concern |
| Migratory status | not a migrant | Forest dependency | Does not normally occur in forest |
| Land mass type | Average mass | - |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence breeding/resident (km2) | 758,000 | medium |
| Extent of Occurrence non-breeding (km2) | 192,000 | medium |
| Number of locations | 11-100 | - |
| Severely Fragmented | - |
| Value | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| No. of mature individuals | medium | estimated | 2017 | |
| Population trend | Decreasing | unknown | estimated | - |
| 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) | 50-79 | - | - | - |
| Number of subpopulations | 2-100 | - | - | - |
| Percentage in largest subpopulation | - | - | - | |
| Generation length (yrs) | 3.98 | - | - | - |
Population justification: The global population size has been estimated at 175,000 individuals (Meese 2017), up slightly from the estimate of 145,000 individuals in 2014 (Meese 2014), indicating that the global population is considerably below 200,000 individuals.
Trend justification: Agelaius tricolor has undergone extremely rapid population declines in the past. Declines were thought to reach a maximum between 2008-2014 where statewide surveys in California (which comprises over 95% of the global population) revealed a 63% decline, equivalent to an ~86% decline across three generation lengths (12 years) (Meese 2015). However, tentative population increases have been suggested in the years since, particularly between 2014-2017 (Meese 2017, R. Meese in litt. 2020, Meehan et al. 2018) and as such, it is thought that such rapid declines may be historic. A new statewide population survey scheduled for early 2020 was postponed and as such, the population trend is retained here within the band 50-79% to reflect the recent, rapid declines but also possible recovery in the past few years.
| Country/Territory | Occurrence status | Presence | Resident | Breeding | Non-breeding | Passage |
|---|---|---|---|---|---|---|
| Mexico | N | Extant | Yes | |||
| USA | N | Extant | Yes |
| Country/Territory | IBA Name |
|---|---|
| Mexico | Sierra de San Pedro Mártir |
| Mexico | Sierra Juárez |
| USA | San Pasqual Valley - Lake Hodges |
| USA | Santa Ana River Valley |
| USA | Santa Clara River Valley |
| USA | San Antonio Valley |
| USA | Byron Area |
| USA | Grasslands Ecological Area |
| USA | La Grange - Waterford Grasslands |
| USA | South Fork Kern River Valley |
| USA | Panoche Valley |
| USA | Sand Ridge - Tulare Lake Bed (incl. Pixley and Kern NWRs, Creighton Ranch) |
| USA | Yolo Bypass Area |
| USA | San Jacinto Valley |
| USA | San Joaquin Hills |
| USA | Edwards Air Force Base |
| USA | Antelope Valley (Lancaster) |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Artificial/Terrestrial | Arable Land | major | resident |
| Wetlands (inland) | Bogs, Marshes, Swamps, Fens, Peatlands | major | resident |
| Altitude | 0 - 1300 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 | Majority (50-90%) | Rapid Declines | Medium Impact: 7 | ||||||
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| Agriculture & aquaculture | Livestock farming & ranching - Agro-industry grazing, ranching or farming | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Rapid Declines | Medium Impact: 7 | ||||||
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| Biological resource use | Hunting & trapping terrestrial animals - Persecution/control | Timing | Scope | Severity | Impact | ||||
| Past, Unlikely to Return | Majority (50-90%) | Slow, Significant Declines | Past Impact | ||||||
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| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Bubulcus ibis | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Unspecified species | Timing | Scope | Severity | Impact | ||||
| Future | Majority (50-90%) | Slow, Significant Declines | Low Impact: 4 | ||||||
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| Pollution | Agricultural & forestry effluents - Type Unknown/Unrecorded | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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Recommended citation
BirdLife International (2022) Species factsheet: Agelaius tricolor. Downloaded from
http://www.birdlife.org on 05/07/2022.
Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 05/07/2022.
