Justification of Red List Category
Based on a model of future deforestation in the Amazon basin, it is suspected that the population of this species will decline by 25-30% over the next three generations, and it has therefore been uplisted to Near Threatened.
The global population size has not been quantified, but this species is described as 'fairly common' (Stotz et al. (1996).
This species is suspected to lose 28.4-29.7% 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 a rate approaching 30% over three generations.
C. b. bicolor Coastal from N Colombia E along coast, including Margareta Island and Trinidad, Guyana, French Guiana, Suriname and locally along the Brazil coast to Sao Paulo. Also locally along the Rio Branco in Brazil
C. b. minus in shrubby younger successional stages of vegetation on river islands and riverbanks of the River Amazon, and a few major tributaries in NE Peru, SE Colombia and Brazil, possibly to the mouth of the Amazon.
C. b. bicolor is closely associated with mangroves even if occasionally seen in adjacent low flooded forest. Occurs in pairs or small family parties and not associated with mixed-species flocks. May be competitively excluded by or exclude the resident individuals of Yellow Warbler (Setophaga petechia) in mangroves, apparently the two species do not occur together. Typically in mid to upper levels of foliage foraging for small arthropods amongst leaf clusters. Breeds between February and May in N Colombia. The nest is a deep cup of grass mixed with feathers 0.3-4m up in mangrove, clutch of 2 eggs. In Trinidad often parasitized by Shiny Cowbird Molothrus bonariensis.
C. b. minus gleans for small arthropods in foliage on river islands and may investigate damaged Cecropia leaves.
Projected deforestation is the primary threat affecting this species (Soares-Filho et al. 2006, Bird et al. 2011); destruction of mangrove outside of protected areas is the most significant threat for C. b. bicolor, whereas the rather ephemeral river island habitat of C. b. minus may be at relatively low risk of significant habitat destruction. Proposed changes to the Brazilian Forest Code reduce the percentage of land a private landowner is legally required to maintain as forest (including, critically, a reduction in the width of forest buffers alongside perennial steams) and include an amnesty for landowners who deforested before July 2008 (who would subsequently be absolved of the need to reforest illegally cleared land) (Bird et al. 2011).
Conservation Actions Underway
In Colombia C. b. bicolor occurs in Salamanca National Park and probably Corales del Rosario National Park. In Venezuela the species occurs in Morrocoy National Park and in Suriname at Wia-Wia and Galibi National Parks.
Conservation Actions ProposedExpand the protected area network to effectively protect IBAs. Effectively resource and manage existing and new protected areas, utilising emerging opportunities to finance protected area management with the joint aims of reducing carbon emissions and maximizing biodiversity conservation. Conservation on private lands, through expanding market pressures for sound land management and preventing forest clearance on lands unsuitable for agriculture, is also essential (Soares-Filho et al. 2006).
11.4cm, 10.5-11g. Dull bluish-grey conebill with a thin curved bill. C. b. bicolor has upperparts dull blue-grey and underparts dingy pale greyish-buff, with the throat and lower underparts palest. Iris is a dull orange-red to dark red. C. b. minus is similar but is slightly smaller and shows a rufescent tinge to the ear coverts and underparts, especially the undertail coverts. Similar spp. Pearly-breasted Conebill C. margaritae is very similar, but lacks the buff tones on the underparts of C. bicolor and is slightly paler, almost faded grey on the upperparts. Voice Variably complex series of squeaky, high-pitched phrases repeated in a somewhat jerky and sputtering manner. Always slower and shorter than songs of C. margaritae. Soft foraging calls include a high, sibilant tsiik.
Text account compilers
Butchart, S., Ekstrom, J. & Symes, A.
BirdLife International (2023) Species factsheet: Conirostrum bicolor. Downloaded from http://www.birdlife.org on 26/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/03/2023.