8 thoughts on “Noronha Vireo (Vireo gracilirostris)”
Vireo gracilirostris is endemic to Brazil and occurs in the Fernando de Noronha archipelago. The species is restricted to the main island of the archipelago, with only occasional occurrences on secondary islands.
According to the latest Brazilian national assessment, carried out in 2019 (not yet published), there is still no robust estimate of population size, but recent preliminary information points to more than 1,000 individuals (Ricardo Krul, in personal communication to ICMBio, 2019). If this number is higher, it may disqualify VU D1.
On the other hand, AOO was calculated at 20 km², by overlaying 2 x 2 km grid cells on current, inferred, and projected recording points.
On the main island, the presence of introduced species (Tupinambis merianae) and domestic cats has become a serious problem, putting several native species at risk. This issue is being addressed by ICMBio, but there is still a lot of work to do. The assessors consider that both species have the potential to lead the species to EX or CR in a short period of time. Therefore, V. gracilirostris was categorized in the Brazilian national assessment as VU D2.
Hello, my name is Cecília Licarião and I completed my master’s degree with the Noronha Vireo and I am the coordinator of Aves Noronha, which has banded 554 Vireos since 2016. Noronha Vireo and Noronha Elaenia are the only native terrestrial island bird species in Noronha. Here I will share some of my preliminary results, which are being prepared for publication.
In 2016, I assessed the difference between the abundance of species between the National Park and the anthropogenic area through 32 listening points (16 in each area) on the main island of the archipelago. The mean abundance per sampling port of Noronha Vireo (x̅ = 1.1 ind/day x point) was higher in the National Park, as was the overall abundance ( t = 3.497, df = 28.58, p = 0.001; respectively). For Noronha Vireo, abundance was best explained by the coverage of the areas by trees and the area occupied by anthropogenic land uses (Licarião, 2017).
In 2023, we will begin analyzing capture and recapture data for banded birds and have an estimated survival per month. For Vireo we estimate 0.7. The banding method allowed measuring the average home range of Noronha Vireo in the National Park at 226m² (min = 40.3m2 and max = 2971m2). We are now evaluating capture and recapture results to estimate population density.
However, in addition to the small range of these birds, they suffer very high pressure. The presence of exotic species such as lizards, cats and rats, in addition to invasive exotic flora, are the biggest problems for these species. In 2023, we carried out an experiment with artificial nests to evaluate egg predation in the park area and in the anthropic area, and the predation rate was 80% (Licarião et al. in prep).
In 2023, natural nests were monitored from February to May (n=18). Of the Noronha Vireo nests, 56.2% were predated (n=9), after x̅=20.9 days of laying, with 34.4% (n=10; total n=29) of eggs and 36.3% predated. (n=8; total n=22) of nestlings (Licarião in prep).
Given the above, I agree with the proposal to change from NT to VU, but I believe, unfortunately, that the scenario could be even worse. But for that I will need to analyze my data. In a few months I will have estimates of the extent of occurrence; area of occupancy; population size estimate and decline estimate. But I don’t think there will be time for this phase of the evaluation. I hope next year to deliver more robust analyses that can reveal the real status of these birds, which will possibly become extinct in the next 100 years.
Licarião, C.B.L. 2017. BODY CONDITION AND ABUNDANCE OF ENDEMIC PASSERIFORMS OF THE FERNANDO DE NORONHA ARCHIPELAGO, BRAZIL. Federal University of Ceara. Masters dissertation.
I agree with Rosana that the assessors consider that both species have the potential to lead the species to EX or CR in a short period of time.
The island is very small and has many predators and large-scale real estate exploitation. The area of occurrence is 17km2, referring to the main island, as there has been no record of the species on secondary islands for decades. Although the area is 17km2, the actual area of occurrence is much smaller.
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.
We are grateful for the contributions made during this latest round of discussions, and all relevant information has been incorporated into the updated Red List assessment for this species. Based on current information the species can only be assessed as Vulnerable: there are no data to assess whether a continuing decline is occurring. However, we welcome further comments and the assessment will be refined and updated when such data becomes available. Based on available information therefore, 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.
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. Noronha Vireo is recommended to be listed as Vulnerable under Criterion D1.
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.
Vireo gracilirostris is endemic to Brazil and occurs in the Fernando de Noronha archipelago. The species is restricted to the main island of the archipelago, with only occasional occurrences on secondary islands.
According to the latest Brazilian national assessment, carried out in 2019 (not yet published), there is still no robust estimate of population size, but recent preliminary information points to more than 1,000 individuals (Ricardo Krul, in personal communication to ICMBio, 2019). If this number is higher, it may disqualify VU D1.
On the other hand, AOO was calculated at 20 km², by overlaying 2 x 2 km grid cells on current, inferred, and projected recording points.
On the main island, the presence of introduced species (Tupinambis merianae) and domestic cats has become a serious problem, putting several native species at risk. This issue is being addressed by ICMBio, but there is still a lot of work to do. The assessors consider that both species have the potential to lead the species to EX or CR in a short period of time. Therefore, V. gracilirostris was categorized in the Brazilian national assessment as VU D2.
https://www.gov.br/icmbio/pt-br/centrais-de-conteudo/publicacoes/planos/planos_de_acao_para_o_controle_de_gatos_em_fernando_de_noronha.pdf
https://www.parnanoronha.com.br/single-post/retorno-do-controle-populacional-de-tejus-em-noronha
https://jornal.usp.br/ciencias/ciencias-biologicas/teius-ja-sao-considerados-hospedes-indesejados-em-fernando-de-noronha/
I agree with Rosana Subirá’s comments.
Hello, my name is Cecília Licarião and I completed my master’s degree with the Noronha Vireo and I am the coordinator of Aves Noronha, which has banded 554 Vireos since 2016. Noronha Vireo and Noronha Elaenia are the only native terrestrial island bird species in Noronha. Here I will share some of my preliminary results, which are being prepared for publication.
In 2016, I assessed the difference between the abundance of species between the National Park and the anthropogenic area through 32 listening points (16 in each area) on the main island of the archipelago. The mean abundance per sampling port of Noronha Vireo (x̅ = 1.1 ind/day x point) was higher in the National Park, as was the overall abundance ( t = 3.497, df = 28.58, p = 0.001; respectively). For Noronha Vireo, abundance was best explained by the coverage of the areas by trees and the area occupied by anthropogenic land uses (Licarião, 2017).
In 2023, we will begin analyzing capture and recapture data for banded birds and have an estimated survival per month. For Vireo we estimate 0.7. The banding method allowed measuring the average home range of Noronha Vireo in the National Park at 226m² (min = 40.3m2 and max = 2971m2). We are now evaluating capture and recapture results to estimate population density.
However, in addition to the small range of these birds, they suffer very high pressure. The presence of exotic species such as lizards, cats and rats, in addition to invasive exotic flora, are the biggest problems for these species. In 2023, we carried out an experiment with artificial nests to evaluate egg predation in the park area and in the anthropic area, and the predation rate was 80% (Licarião et al. in prep).
In 2023, natural nests were monitored from February to May (n=18). Of the Noronha Vireo nests, 56.2% were predated (n=9), after x̅=20.9 days of laying, with 34.4% (n=10; total n=29) of eggs and 36.3% predated. (n=8; total n=22) of nestlings (Licarião in prep).
Given the above, I agree with the proposal to change from NT to VU, but I believe, unfortunately, that the scenario could be even worse. But for that I will need to analyze my data. In a few months I will have estimates of the extent of occurrence; area of occupancy; population size estimate and decline estimate. But I don’t think there will be time for this phase of the evaluation. I hope next year to deliver more robust analyses that can reveal the real status of these birds, which will possibly become extinct in the next 100 years.
Licarião, C.B.L. 2017. BODY CONDITION AND ABUNDANCE OF ENDEMIC PASSERIFORMS OF THE FERNANDO DE NORONHA ARCHIPELAGO, BRAZIL. Federal University of Ceara. Masters dissertation.
I agree with Rosana that the assessors consider that both species have the potential to lead the species to EX or CR in a short period of time.
The island is very small and has many predators and large-scale real estate exploitation. The area of occurrence is 17km2, referring to the main island, as there has been no record of the species on secondary islands for decades. Although the area is 17km2, the actual area of occurrence is much smaller.
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
We are grateful for the contributions made during this latest round of discussions, and all relevant information has been incorporated into the updated Red List assessment for this species. Based on current information the species can only be assessed as Vulnerable: there are no data to assess whether a continuing decline is occurring. However, we welcome further comments and the assessment will be refined and updated when such data becomes available. Based on available information therefore, 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.
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. Noronha Vireo is recommended to be listed as Vulnerable under Criterion D1.
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.