Archived 2010-2011 topics: Black-billed Flycatcher (Aphanotriccus audax): downlist to Least Concern?

Black-billed Flycatcher Aphanotriccus audax is restricted to east Panama (Panamá and Darién) and north Colombia (from north Antioquia to Guajira), where it is uncommon to locally common and perhaps overlooked. It is listed as Near Threatened on the IUCN Red List because it was thought to have a restricted range that approaches the threshold for listing as Vulnerable (<20,000 km2) combined with severely fragmented habitat or occurrence at approximately ten or fewer locations and a continuing decline in its habitat, population size or number of locations/sub-populations.

However, this species has been mapped by Natureserve/BirdLife International as having an estimated Extent of Occurrence (EOO) of 122,000 km2, hence it does not appear to approach the IUCN thresholds and appears to warrant downlisting to Least Concern. However, if the species has experienced declines over the past three generations (11 years, BirdLife International unpubl. data) approaching 30% it may warrant listing as Near Threatened under the A criterion (population declines). Given its relatively large range size it seems unlikely that this species will have a population approaching 10,000 mature individuals so it would not qualify as threatened or Near Threatened on population size under the C criterion.

Comments on the population trends of this species and its proposed downlisting are welcomed.

Aphanotriccus audax está restringida al este de Panamá (Panamá y Darién) y norte de Colombia (desde Antioquia hasta la Guajira), donde su abundancia varía de poco común a común localmente, aunque posiblemente pasa fácilmente desapercibida. Su extensión de la presencia (EOO) calculada es de 122.000 km2

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3 Responses to Archived 2010-2011 topics: Black-billed Flycatcher (Aphanotriccus audax): downlist to Least Concern?

  1. Andy Symes says:

    Thomas Donegan posted the following on Sooty Ant-tanager, which contains information relevant to Black-billed Flycatcher (March 2010):

    Comments on proposal to downlist Sooty Ant-Tanager Habia gutturalis from NT to LR:

    General comments:

    Habia gutturalis apparently does not meet NT status based on the data presented for its Extent of Occurrence (Category B1). However, its status under Category A and under Category B2b/c (Area of Occupancy) should be re-assessed prior to downlisting.

    Habia gutturalis is a species which is easy to observe and relatively numerous in suitable habitat within its range. Birders which make visits to such habitats are likely to see it. The species is also pretty resilient to fragmentation and can persist, e.g. in scrub along rivers where surrounding forest has otherwise been largely deforested and in relatively small fragments (the Bajo Simacota locality mentioned below is a c. 50 ha fragment). It is also frequently found at forest borders. These factors all give some hope for conservation.

    However, deforestation in the Caribbean lowland region of Colombia, the distribution of this species, has been severe (estimated at over 90% by Colombian government). The nature of such deforestation is generally under the philosophy of “leave not a single tree standing”. (In the Andean region, in contrast, one tends to find forest patches on steep slopes and at locally higher elevations in deforested regions.)
    Furthermore, virtually none of the range of this species is protected. Examples of protected areas that include populations of this species are ProAves’ Pauxi pauxi and El Paujil nature reserves, as well as CORANTIOQUIA’s reserves in foothills below Anorí. These are all Andean foothill localities. Other lowland forest in the species range, such as in Chocó department and Serranía de San Lucas is unprotected and being rampantly destroyed for palm oil and agriculture (in the first case) and ‘non-agricultural’ crops, agriculture and gold mining (in the second case).

    Viable populations of H. gutturalis are mostly now found in forest fragments of foothills bordering the Magdalena and (less so) Cauca valleys. The species’ Area of Occupancy, if only remaining natural habitat is used as a basis for calculating that, may approach or fall under the level for VU status.

    Some of these comments are also relevant to Black-billed Flycatcher, which has a similar range but more fussy habitat requirements.

  2. The NatureServe range map for Panama for this species is approximately correct, although some details are in error. However, the range for Colombia is much more extensive than that shown in Hilty and Brown’s Guide to the Birds of Colombia. It is unclear what data this is based on.

    A proposal for downlisting should be based on primary data on distribution, not on generalized range maps such as those on NatureServe. In my opinion, the grounds proposed are insufficient, and the status quo should be maintained in the absence of primary data.

    I would estimate that at least fifty percent of the known range of this species within Panama has been deforested within the last 30 years, and deforestation is continuing rapidly in the area. Deforestation is also severely affecting the species’ Colombian range, and this needs to be assessed with regard to evaluating the species’ status.

  3. Andy Symes says:

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

    Aphanotriccus audax is locally uncommon within primary forest, especially stream gullies in El Paujil Bird Reserve, where after four years of monthly mist-net studies this species was never caught outside primary closed-canopy forest. It is unlikely to be overlooked as it is non-sulking, vocal, understory to midstory species. It is clearly dependent on lowland humid forest and only known from 15 specimens in Colombia (www.BioMap.net). The EOO is large (but 122,000 km2 seems excessively large). Its known range coincides with one of the most transformed landscapes in NW South America, where severe habitat loss and fragmentation in recent decades has destroyed much of the species’ habitat and projected habitat loss will lead to continue population declines. We estimate 30% population declines have taken place in the past 11 years to warrant listing as Near Threatened. Studies on the species (responses well to playback) are warranted to assess population densities and ecological requirements to assess the global population.

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

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