Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Emberizidae

Scientific Name: Oryzoborus crassirostris
Species Authority: (Gmelin, 1789)
Common Name(s):
English Large-billed Seed-finch, Large-billed Seed Finch, Large-billed Seed-Finch
Taxonomic Source(s): SACC. 2006. A classification of the bird species of South America. Available at: #

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Symes, A. & Butchart, S.
Contributor(s): Acevedo , O., Bayly, N., Sharpe, C J, De Luca, A. & Clay, R.
Facilitator/Compiler(s): Butchart, S., Ekstrom, J., Fisher, S., Harding, M., Sharpe, C J
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/near threatened (LR/nt)
1988 Near Threatened (NT)

Geographic Range [top]

Range Description: This species occurs in north and east Colombia (in humid Caribbean lowlands west to Córdoba and locally east of the Andes), where it may be expanding its range following deforestation (Stiles et al. 1999), Venezuela (not recorded from the north-west or from most of the llanos region), Guyana, Suriname, French Guiana, Amazonian Brazil (south only to the Amazon), and north-east Peru (Loreto to Huánuco); it may persist in small numbers on Trinidad, Trinidad and Tobago (ffrench 1992, Ridgely and Tudor 1989).
Countries occurrence:
Brazil; Colombia; Ecuador; French Guiana; Guyana; Peru; Suriname; Trinidad and Tobago; Venezuela, Bolivarian Republic of
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 2530000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 700
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population size has not been quantified, but this species is described as 'uncommon and patchily distributed' (Stotz et al. 1996).

Trend Justification:  This species is suspected to lose 11.3-11.5% of suitable habitat within its distribution over three generations (11 years) based on a model of Amazonian deforestation (Soares-Filho et al. 2006, Bird et al. 2011). It is therefore suspected to decline by <25% over three generations.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: Unknown Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: The species inhabits freshwater marshes, riparian thickets and second-growth scrub, mostly below 500 m but it has been recorded to 700 m (Ridgely and Tudor 1989, Stotz et al. 1996).
Systems: Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 3.8
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): The principal threat is the depletion of local populations by bird trappers (Ridgely and Tudor 1989, R. Clay in litt. 2010, C. J. Sharpe in litt. 2011), although this is not considered a threat in Colombia (F. G. Stiles in litt. 1999).

Citation: BirdLife International. 2012. Oryzoborus crassirostris. The IUCN Red List of Threatened Species 2012: e.T22723527A39956667. . Downloaded on 10 October 2015.
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