6 thoughts on “East Andean Antbird (Drymophila caudata)”
Given the species’ restricted (and discontinuous) geographical range and the fact that Drymophila antbirds are relatively uncommon, it is possible that the true global population and effective population sizes are smaller than inferred. Although the NT categorization did not make any sense in the absence of any estimation, the LC category does not seem to represent the situation of the species realistically. I think this categorization will change as soon as more field data can be obtained.
To illustrate how unreliable a categorization may be whenever high-quality information is lacking, consider a calculation of the species population size using a recent density estimate for another congener, Santa Marta Antbird. We estimated a density of ~2 ind/km2, which could be increased to ~4 ind/km2 if we consider that our calculation is probably an underestimation (Botero-Delgadillo et al. in review). Based on these values, the number of mature individuals for East Andean Antbird (7920–10560) would be basically at the VU threshold.
I mildly disagree with this proposal, and note it is based on inaccuracies and potentially an over-estimate of the species’ range. Note the northern population is very small and virtually unknown outside the Yariguies area nowadays; some of the records on ebird relate to another species, Klages’ Antbird or the Central Andean one.
In the southern part of its range, your map also seems over-stated. Recent records are all at least 50 km south of Neiva, but yours goes north to the latitude of Cali.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now temporarily closed and we are unable to accept any more comments until 6 February 2023. We will now analyse and interpret new information, and we will post a preliminary decision on this species’ Red List status on this page on 6 February 2023, when discussions will re-open.
Following comments submitted via this discussion forum, the species’ range map has been updated and the distribution limits of the northern and southern subpopulations refined. EOO and maximum AOO have been recalculated, though they do not meet or approach the thresholds required. The rate of tree cover loss in the remapped range remained 2% over ten years but given that the species might have strict habitat requirements it is now suspected that this is driving a slow population reduction.
The population size has been extrapolated to the area of tree cover in the newly mapped range (assuming that 25% of forests are occupied) using the population density of Santa Marta Antbird as a basis. The total population is now inferred to number 3,000-6,700 mature individuals, and thus considerably smaller than assumed for the above assessment. While this meets the numerical threshold for a listing as Vulnerable under C, the level of data quality of the inferred population size prevents a listing as threatened under this criterion. Moreover, despite the suspected population reduction mentioned above there is no evidence of a continuing decline*, which would require a qualifier of inferred* or higher.
The subpopulation structure has likewise been reassessed; based on the range area it is assumed that the northern subpopulation holds up to 10% of the total population (i.e., 300-670 mature individuals), while the majority is found in the south (2,700-6,030 mature individuals). Applying subcriterion C2 however shows that the species meets neither 2a(i), as the largest subpopulation contains more than 1,000 mature individuals, nor 2a(ii), as there are two separate subpopulations (albeit one being likely small).
If evidence is presented that the species forms more than two subpopulations and that the largest of those number less than 1,000 mature individuals, a listing as Near Threatened, approaching thresholds under Criterion C2a(i), could be justified, despite considerable uncertainty around the overall population size. Based on the currently available information however, our preliminary proposal for the 2023 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 12 February 2023, after which the recommended categorisations will be put forward to IUCN.
The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret available information, and we will post a final decision on this species’ Red List status on this page on 20 February 2023.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. East Andean Antbird is recommended to be listed as Least Concern.
Many thanks for everyone who contributed to the 2023.1 GTB Forum process. The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Given the species’ restricted (and discontinuous) geographical range and the fact that Drymophila antbirds are relatively uncommon, it is possible that the true global population and effective population sizes are smaller than inferred. Although the NT categorization did not make any sense in the absence of any estimation, the LC category does not seem to represent the situation of the species realistically. I think this categorization will change as soon as more field data can be obtained.
To illustrate how unreliable a categorization may be whenever high-quality information is lacking, consider a calculation of the species population size using a recent density estimate for another congener, Santa Marta Antbird. We estimated a density of ~2 ind/km2, which could be increased to ~4 ind/km2 if we consider that our calculation is probably an underestimation (Botero-Delgadillo et al. in review). Based on these values, the number of mature individuals for East Andean Antbird (7920–10560) would be basically at the VU threshold.
Quantitative information is urgently needed.
I mildly disagree with this proposal, and note it is based on inaccuracies and potentially an over-estimate of the species’ range. Note the northern population is very small and virtually unknown outside the Yariguies area nowadays; some of the records on ebird relate to another species, Klages’ Antbird or the Central Andean one.
In the southern part of its range, your map also seems over-stated. Recent records are all at least 50 km south of Neiva, but yours goes north to the latitude of Cali.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now temporarily closed and we are unable to accept any more comments until 6 February 2023. We will now analyse and interpret new information, and we will post a preliminary decision on this species’ Red List status on this page on 6 February 2023, when discussions will re-open.
Preliminary proposal
Following comments submitted via this discussion forum, the species’ range map has been updated and the distribution limits of the northern and southern subpopulations refined. EOO and maximum AOO have been recalculated, though they do not meet or approach the thresholds required. The rate of tree cover loss in the remapped range remained 2% over ten years but given that the species might have strict habitat requirements it is now suspected that this is driving a slow population reduction.
The population size has been extrapolated to the area of tree cover in the newly mapped range (assuming that 25% of forests are occupied) using the population density of Santa Marta Antbird as a basis. The total population is now inferred to number 3,000-6,700 mature individuals, and thus considerably smaller than assumed for the above assessment. While this meets the numerical threshold for a listing as Vulnerable under C, the level of data quality of the inferred population size prevents a listing as threatened under this criterion. Moreover, despite the suspected population reduction mentioned above there is no evidence of a continuing decline*, which would require a qualifier of inferred* or higher.
The subpopulation structure has likewise been reassessed; based on the range area it is assumed that the northern subpopulation holds up to 10% of the total population (i.e., 300-670 mature individuals), while the majority is found in the south (2,700-6,030 mature individuals). Applying subcriterion C2 however shows that the species meets neither 2a(i), as the largest subpopulation contains more than 1,000 mature individuals, nor 2a(ii), as there are two separate subpopulations (albeit one being likely small).
If evidence is presented that the species forms more than two subpopulations and that the largest of those number less than 1,000 mature individuals, a listing as Near Threatened, approaching thresholds under Criterion C2a(i), could be justified, despite considerable uncertainty around the overall population size. Based on the currently available information however, our preliminary proposal for the 2023 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 12 February 2023, after which the recommended categorisations will be put forward to IUCN.
The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret available information, and we will post a final decision on this species’ Red List status on this page on 20 February 2023.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. East Andean Antbird is recommended to be listed as Least Concern.
Many thanks for everyone who contributed to the 2023.1 GTB Forum process. The final 2023 Red List categories will be published on the BirdLife and IUCN websites in December 2023, following further checking of information relevant to the assessments by both BirdLife and IUCN.