9 thoughts on “White-chested White-eye (Zosterops albogularis)”
It might be worth recording that there are two clutches three eggs purportedly of this species in the Western Australian Museum, taken (illegally) by an experinced egg collector on Norfolk Island 31 November 1977.
Several recent papers of relevance that detail further extensive fieldwork on threatened passerines and invasive rodents on Norfolk Island. Despite intensive field efforts by experienced observers in the period 2018-2020 no White-chested White-eye were detected.
Firstly Nance et al. 2023 [Nance, A.H., Mitchell, W.F., Dawlings, F., Cook, C.N. and Clarke, R.H. (2023) Rodent predation and specialised avian habitat requirements drive extinction risk for endemic island songbirds in the south-west Pacific. Emu 123, 217-231. doi: 10.1080/01584197.2023.2228350] outlines intensive nest searches for remaining native passerines across three breeding seasons 2018 – 2020, and monitoring of nest survival rates to demonstrate that rodent predation continues to be a key driver of nest failure in extant passerines. This included extensive camera trapping at active passerine nests to identify nest predators which also detected other cryptic and scarce bird species on Norfolk Island (e.g. Long-tailed Cuckoo -Nance, A.H. and Clarke, R.H. Photographic evidence of an adult Long-tailed Cuckoo Urodynamys taitensis’ visiting the nest of a Norfolk Island Golden Whistler ‘Pachycephala pectoralis xanthoprocta’. Australian Field Ornithology 36, 89-92. doi: 10.3316/informit.786168027676899)
Despite intensive fieldwork for 3-4 months of the year for three years by ornithologists working on passerines within the 460 ha Norfolk Island National Park and Botanic Gardens (the last large remnant of native vegetation on the island and the location of the last multi-observer sightings of the WC White-eye) the team did not detect any WC White-eyes.
The same paper also outlines an island-wide point-count survey for all passerines between 11 October and 1 November 2019. Methods for that survey were comprehensive (pasted below) and again did not detect any WC White-eyes.
“Point counts consisted of a five-minute survey whereby a single observer would arrive at a survey point and immediately begin recording species and number of focal individuals seen or heard within a 25 m radius. Individual point counts were spaced at least 100 m apart. Surveys were typically conducted between dawn and 11 am, with occasional afternoon surveys when weather conditions were favourable (mild, with little to no wind and no rain). In the National Park, we conducted surveys along ‘bait lines’ that bisect the park, which ranged from established service tracks to uncleared routes along ridgelines or through valleys. Two observers (AHN and WFM) conducted a total of 410 point counts across the three land tenures, with effort approximately proportional to the area of potential habitat: 309 point counts in the National Park and adjoining Botanical Gardens (federal land), 37 point counts across five regional reserves (local: Norfolk Island Regional Council), and 64 point counts across 22 private properties (private land).”
The following paper is also worth citing as it specifically addresses arboreal behavior of invasive rodents on Norfolk Island which is the pathway to nest predation for most passerines. Nance, A.H., Wilson, M., Burns, P., Cook, C.N. and Clarke, R.H. (2023) Arboreal activity of invasive rodents: conservation implications for the control of an island pest. Pacific Conservation Biology doi 10.1071/PC23011
We have checked the measurements of the purported clutches of white-eye eggs in the WA Museum, taken on Norfolk Island in 1977, and they are almost certainly silvereye eggs, which are smaller, so please ignore that record.
BirdLife Australia’s Threatened Species Committee has reviewed the proposal to change the status of the White-chested White-eye from ‘Critically Endangered’ to ‘Extinct’. Given the volume and reliability of the survey effort invested to detect the species with no observations, we sadly agree with the assessment that the species is extinct.
Georgia Garrard, Acting Chair, Threatened Species Committee, BLA
Based on the information presented here and particular lythe major recent survey effort indicated by Rohan Clarke, I agree with the proposed change in listing.
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.
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. White-chested White-eye is recommended to be listed as Extinct.
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.
It might be worth recording that there are two clutches three eggs purportedly of this species in the Western Australian Museum, taken (illegally) by an experinced egg collector on Norfolk Island 31 November 1977.
Several recent papers of relevance that detail further extensive fieldwork on threatened passerines and invasive rodents on Norfolk Island. Despite intensive field efforts by experienced observers in the period 2018-2020 no White-chested White-eye were detected.
Firstly Nance et al. 2023 [Nance, A.H., Mitchell, W.F., Dawlings, F., Cook, C.N. and Clarke, R.H. (2023) Rodent predation and specialised avian habitat requirements drive extinction risk for endemic island songbirds in the south-west Pacific. Emu 123, 217-231. doi: 10.1080/01584197.2023.2228350] outlines intensive nest searches for remaining native passerines across three breeding seasons 2018 – 2020, and monitoring of nest survival rates to demonstrate that rodent predation continues to be a key driver of nest failure in extant passerines. This included extensive camera trapping at active passerine nests to identify nest predators which also detected other cryptic and scarce bird species on Norfolk Island (e.g. Long-tailed Cuckoo -Nance, A.H. and Clarke, R.H. Photographic evidence of an adult Long-tailed Cuckoo Urodynamys taitensis’ visiting the nest of a Norfolk Island Golden Whistler ‘Pachycephala pectoralis xanthoprocta’. Australian Field Ornithology 36, 89-92. doi: 10.3316/informit.786168027676899)
Despite intensive fieldwork for 3-4 months of the year for three years by ornithologists working on passerines within the 460 ha Norfolk Island National Park and Botanic Gardens (the last large remnant of native vegetation on the island and the location of the last multi-observer sightings of the WC White-eye) the team did not detect any WC White-eyes.
The same paper also outlines an island-wide point-count survey for all passerines between 11 October and 1 November 2019. Methods for that survey were comprehensive (pasted below) and again did not detect any WC White-eyes.
“Point counts consisted of a five-minute survey whereby a single observer would arrive at a survey point and immediately begin recording species and number of focal individuals seen or heard within a 25 m radius. Individual point counts were spaced at least 100 m apart. Surveys were typically conducted between dawn and 11 am, with occasional afternoon surveys when weather conditions were favourable (mild, with little to no wind and no rain). In the National Park, we conducted surveys along ‘bait lines’ that bisect the park, which ranged from established service tracks to uncleared routes along ridgelines or through valleys. Two observers (AHN and WFM) conducted a total of 410 point counts across the three land tenures, with effort approximately proportional to the area of potential habitat: 309 point counts in the National Park and adjoining Botanical Gardens (federal land), 37 point counts across five regional reserves (local: Norfolk Island Regional Council), and 64 point counts across 22 private properties (private land).”
The following paper is also worth citing as it specifically addresses arboreal behavior of invasive rodents on Norfolk Island which is the pathway to nest predation for most passerines. Nance, A.H., Wilson, M., Burns, P., Cook, C.N. and Clarke, R.H. (2023) Arboreal activity of invasive rodents: conservation implications for the control of an island pest. Pacific Conservation Biology doi 10.1071/PC23011
We have checked the measurements of the purported clutches of white-eye eggs in the WA Museum, taken on Norfolk Island in 1977, and they are almost certainly silvereye eggs, which are smaller, so please ignore that record.
BirdLife Australia’s Threatened Species Committee has reviewed the proposal to change the status of the White-chested White-eye from ‘Critically Endangered’ to ‘Extinct’. Given the volume and reliability of the survey effort invested to detect the species with no observations, we sadly agree with the assessment that the species is extinct.
Georgia Garrard, Acting Chair, Threatened Species Committee, BLA
Based on the information presented here and particular lythe major recent survey effort indicated by Rohan Clarke, I agree with the proposed change in listing.
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.
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. White-chested White-eye is recommended to be listed as Extinct.
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.