Archived 2011-2012 topics: Large-billed Seed-finch (Oryzoborus crassirostris): request for information

This discussion was first published on Dec 2 2010 as part of the 2010-2011 Red List update.

Initial deadline for comments: 31 January 2012.

Link to BirdLife species factsheet for Large-billed Seed-finch

Large-billed Seed-finch Oryzoborus crassirostris is listed as Least Concern on the basis that it does not approach the thresholds for Vulnerable under any of the IUCN criteria.

The species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence less than 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). Although the population trend is suspected to be negative, owing primarily to trapping pressure for the cagebird trade (Ridgely and Tudor 1989), the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). This species is characterised as uncommon and probably patchily distributed (Stotz et al. 1996); however, the population size has not been quantified and it is not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).

This species was described by Restall et al. (2006) as scarce and localised in most of northern South America, except for Colombia where it is locally fairly common, but very rare in French Guiana and increasingly rare in Guyana and Suriname, where trapping for the cagebird trade is most severe. Recently, it was suggested that this species is still subjected to high trapping pressure for the internal cagebird trade in the Guianas at least (R. Clay in litt. 2010), whilst in Brazil it is described as very uncommon (A. C. De Luca in litt. 2010).

Up-to-date information is requested on this species, in particular the estimated rate of decline over 11 years (estimate of three generations) and the severity of trapping pressure and other potential threats. This species would be eligible for Near Threatened status if undergoing a decline approaching 30% over 11 years, and at least Vulnerable if the rate of decline is 30% or more over 11 years.

Restall, R., Rodner, C. and Lentino, M. (2006) Birds of Northern South America: An Identification Guide. London, UK: Christopher Helm.

Ridgely, R. S. and Tudor, G. (1989) The birds of South America. Austin, Texas: University of Texas Press.

Stotz, D. F., Fitzpatrick, J. W., Parker, T. A. and Moskovits, D. K. (1996) Neotropical birds: ecology and conservation. Chicago: University of Chicago Press.

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4 Responses to Archived 2011-2012 topics: Large-billed Seed-finch (Oryzoborus crassirostris): request for information

  1. Andy Symes says:

    Fundacion ProAves have provided the following information from the species’s Colombian range:

    This species is abundant in Serranía de San Lucas, where 21 individuals were captured in secondary habitats in a week at one locality (Salaman et al. 2002). It is similarly common in farmland and disturbed habitats throughout the Magdalena valley of Colombia. Cage bird captures are very low compared to populations here. We do not consider this species should be treated as threatened or near-threatened.

    Fundacion ProAves (in press) The status of various threatened or potentially threatened birds in Colombia. Conservación Colombiana 14

  2. Joe Taylor says:

    A recent analysis of the effects of projected deforestation in Amazonia on bird species population trends (Bird et al. 2011) suggests that O. crassirostris does not qualify for any category higher than Least Concern under criterion A4. For further information, please see the topic entitled ‘Input required on proposal to uplist a suite of Amazonian birds owing to predicted declines from projected forest loss’ (http://www.birdlife.org/globally-threatened-bird-forums/2011/10/input-required-on-proposal-to-uplist-a-suite-of-amazonian-birds-owing-to-predicted-declines-from-projected-forest-loss/).

  3. Nick Bayly says:

    Regarding the status of this species in Colombia, it also occurs, albeit at low densities, on the northern flank of the Sierra Nevada de Santa Marta, and in accordance with other comments, it can be observed in highly modified habitats in the Magdalena valley, suggesting that it is not particularly susceptible to habitat modification. Given the large range of this species, I would therefore agree with the other posts here, that the species does not qualify for near-threatened status.

  4. I agree with the comment of Nick Bayly and the others posts here: Large-billed Seed-finch does not qualify for near-threatened status. I registered this specie, in low densities, in several times at the Colombian East lands (Llanos orinoquenses), in the Casanare, Meta and Arauca states, municipality of San Luis de Palenque, Orocue, Paz de Ariporo (Casanare); Puerto Gaitán (Meta) and Tame (Arauca). Always it can be observed in modified habitats, even in Rice crops.

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