8 thoughts on “Peruvian Recurvebill (Syndactyla ucayalae)”
This species is certainly very patchily distributed and probably restricted to a swathe of southern Amazonian forests along the Arc of Deforestation, like several other bamboo specialists. It is also seemingly becoming harder to find in Brazil – the species was recorded at several sites around Alta Floresta, MT by Zimmer et al. (1997) but the species is seemingly unrecorded there in the last 20 or so years despite it being one of the most intensely sampled areas in the region – there are no records on WikiAves and no recent records from eBird. The species seemingly deserts regions after major bamboo masting events and it is possible that habitat fragmentation may have a particularly negative impact on this taxon as it may prevent individuals reaching live bamboo stands.
Zimmer, K.J., Parker III, T.A., Isler, M.L. and Isler, P.R., 1997. Survey of a southern amazonian avifauna: the Alta Floresta region, Mato Grosso, Brazil. Ornithological Monographs, pp.887-918.
Based on inference from other species of birds associated with Guadua bamboos, which often have masting intervals lasting decades, we might consider that the criterion of “extreme fluctuations” could be met in this species.
Another species also associated with Guadua bamboos (Purple-winged Ground Dove, Paraclaravis geoffroyi), and likely with associated population fluctuations, is now probably extinct despite a large amount of habitat remaining within its range in the Atlantic Forest. The recurvebill is not approaching such a severe situation yet, with plenty of records per year in recent years across many sites, especially in Perú, but there is a risk of species like this (with relatively large EOO, no detailed information to estimate population size, but low density and specific ties to patchy habitats) falling through the cracks of the red list process.
Analysis of citizen science data, such as list length analysis (Horns et al. 2018), could be a way forward for detecting any marked decline in species such as this and Rondônia Bushbird.
Horns, J.J., Adler, F.R, Şekercioğlu, C.H. (2018) Using opportunistic citizen science data to estimate avian population trends. Biological Conservation 221: 151-159. https://doi.org/10.1016/j.biocon.2018.02.027.
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 until 12 February 2024. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List status on this page on 12 February 2024, when discussions will re-open.
Based on available information, our preliminary proposal for the 2024 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 18 February 2024, after which the recommended categorisations will be put forward to IUCN.
The final 2024 Red List categories will be published on the BirdLife and IUCN websites in December 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Recurvebills also use early floodplain (river-edge) Gynerium cane dominated habitat to move between bamboo patches, and represent important movement corridors for these and other bamboo specialists.
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 the information, and we will post a final decision on this species’ Red List status on this page on 26 February 2024.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Peruvian Recurvebill is recommended to be listed as Least Concern.
First, the concern for the loss of the species from Alta Floresta is noted and the proposal recognises that the specialism on Guadua stands may lead to steeper declines than would be suspected from rates of forest cover loss. With the evidence of the apparent loss of a subpopulation in combination with recorded ongoing habitat loss a continuing decline in the number of mature individuals can be inferred. However, even with allowance for this the low current rates of forest loss within the range mean that rates of population reduction exceeding 20% over three generations are very unlikely. Secondly, apologies to Huw Lloyd for overlooking his work including this species in Tambopata province SE Peru. This indicated a population of between 1,043-3,961 individuals in PN Bahuaja-Sonene and RN Tambopata and up to 8,285 individuals within Tambopata province (Lloyd 2004). This represents around one third by area of the western portion of the range, while the size of the eastern populations (Serra dos Carajas and any that remain in Alta Floresta) now likely far smaller. Based on this estimate, we can infer that a lower bound of the overall population size could be below 10,000 mature individuals, although obviously this inference is uncertain. But more than 1,000 mature individuals are estimated to be present in the western subpopulation, hence the species does not meet (or for this subcriterion, approach) threatened thresholds under Criterion C. This is an assessment that falls close to being considered Near Threatened, and repeating density surveys or indeed using list-length analysis as suggested by Ben Phalan is important work to detect any deterioration in the species’ status.
Many thanks for everyone who contributed to the 2024.1 GTB Forum process. The final 2024 Red List categories will now be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.
This species is certainly very patchily distributed and probably restricted to a swathe of southern Amazonian forests along the Arc of Deforestation, like several other bamboo specialists. It is also seemingly becoming harder to find in Brazil – the species was recorded at several sites around Alta Floresta, MT by Zimmer et al. (1997) but the species is seemingly unrecorded there in the last 20 or so years despite it being one of the most intensely sampled areas in the region – there are no records on WikiAves and no recent records from eBird. The species seemingly deserts regions after major bamboo masting events and it is possible that habitat fragmentation may have a particularly negative impact on this taxon as it may prevent individuals reaching live bamboo stands.
Zimmer, K.J., Parker III, T.A., Isler, M.L. and Isler, P.R., 1997. Survey of a southern amazonian avifauna: the Alta Floresta region, Mato Grosso, Brazil. Ornithological Monographs, pp.887-918.
Based on inference from other species of birds associated with Guadua bamboos, which often have masting intervals lasting decades, we might consider that the criterion of “extreme fluctuations” could be met in this species.
Another species also associated with Guadua bamboos (Purple-winged Ground Dove, Paraclaravis geoffroyi), and likely with associated population fluctuations, is now probably extinct despite a large amount of habitat remaining within its range in the Atlantic Forest. The recurvebill is not approaching such a severe situation yet, with plenty of records per year in recent years across many sites, especially in Perú, but there is a risk of species like this (with relatively large EOO, no detailed information to estimate population size, but low density and specific ties to patchy habitats) falling through the cracks of the red list process.
Analysis of citizen science data, such as list length analysis (Horns et al. 2018), could be a way forward for detecting any marked decline in species such as this and Rondônia Bushbird.
Horns, J.J., Adler, F.R, Şekercioğlu, C.H. (2018) Using opportunistic citizen science data to estimate avian population trends. Biological Conservation 221: 151-159. https://doi.org/10.1016/j.biocon.2018.02.027.
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 until 12 February 2024. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List status on this page on 12 February 2024, when discussions will re-open.
Preliminary proposal
Based on available information, our preliminary proposal for the 2024 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 18 February 2024, after which the recommended categorisations will be put forward to IUCN.
The final 2024 Red List categories will be published on the BirdLife and IUCN websites in December 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Density estimates for this species in Lloyd (2004).
Recurvebills also use early floodplain (river-edge) Gynerium cane dominated habitat to move between bamboo patches, and represent important movement corridors for these and other bamboo specialists.
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 the information, and we will post a final decision on this species’ Red List status on this page on 26 February 2024.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Peruvian Recurvebill is recommended to be listed as Least Concern.
First, the concern for the loss of the species from Alta Floresta is noted and the proposal recognises that the specialism on Guadua stands may lead to steeper declines than would be suspected from rates of forest cover loss. With the evidence of the apparent loss of a subpopulation in combination with recorded ongoing habitat loss a continuing decline in the number of mature individuals can be inferred. However, even with allowance for this the low current rates of forest loss within the range mean that rates of population reduction exceeding 20% over three generations are very unlikely. Secondly, apologies to Huw Lloyd for overlooking his work including this species in Tambopata province SE Peru. This indicated a population of between 1,043-3,961 individuals in PN Bahuaja-Sonene and RN Tambopata and up to 8,285 individuals within Tambopata province (Lloyd 2004). This represents around one third by area of the western portion of the range, while the size of the eastern populations (Serra dos Carajas and any that remain in Alta Floresta) now likely far smaller. Based on this estimate, we can infer that a lower bound of the overall population size could be below 10,000 mature individuals, although obviously this inference is uncertain. But more than 1,000 mature individuals are estimated to be present in the western subpopulation, hence the species does not meet (or for this subcriterion, approach) threatened thresholds under Criterion C. This is an assessment that falls close to being considered Near Threatened, and repeating density surveys or indeed using list-length analysis as suggested by Ben Phalan is important work to detect any deterioration in the species’ status.
Many thanks for everyone who contributed to the 2024.1 GTB Forum process. The final 2024 Red List categories will now be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.