5 thoughts on “Mauritius Cuckooshrike (Lalage typica)”
After discussions with S. Henshaw, V. Tatayah and C. Jones, new data has been compiled and summarised below.
Population size: The species has a particularly low detectability and therefore the passerine surveys conducted on the mainland between 2011-2014, from which the population size in the forum topic is taken, may have underestimated the population size of this species. Since then, territory mapping surveys have only detected healthy populations on the mainland. The core population is located in the Brise Fer – Macchabée area, in the southwest of Mauritius, where the highest population density is found. It comprises one third of the total mainland population, with approximately 70 pairs (140 mature individuals). This equates to a total mainland population of 210 pairs (420 mature individuals). However, this number is based on estimates from the area with the highest population density in the species’ range, and it is therefore considered to represent the maximum total population size possible for this species.
Range: the species’ range is considered to still be similar to its range 30 years ago, including all the gorges of the Bel Ombre area, which is part of the Black River Gorges National Park, and areas adjacent to the Park, such as Chamarel and Case-Noyale, and including both peripheral and core areas for the species which are privately owned.
There is however a doubt as to its occurrence in the Combo region, where it is likely to be present, but at very low densities. It is absent from the Bambou Mountains in the east of Mauritius, with a cessation of the reintroduction programme in Ferney Valley in 2019, and no individuals recorded there for the past three years. The reintroduction programme is still planned, but is not currently a priority.
Habitat: : This species can be relatively flexible in terms of the proportion of invasive non-native plant species present within its forest habitat, as long as it is not solely composed of non-native plant species. The population density of the Mauritius Cuckooshrike reduces with the increase in percentage of non-native plant species in forest habitat.
Trend: Considering the above regarding differences in density and habitat quality, and the fact that habitat in continuing to degrade with the invasion of non-native plant species, and loss of some of the peripheral habitats to development, such as deer ranching and construction, it is therefore inferred that there is a likely small continuing decline in the species’ population size.
Conservation measures: The Brise Fer region has benefitted from large scale control of invasive non-native plant species, which is likely to benefit the species. In addition, intensive rat control over an area of 10 ha within Brise Fer will benefit the breeding productivity of the Mauritius Cuckooshrike, especially as this 10 ha area overlaps with one of the areas of highest population density for the species.
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 28 October 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 28 October 2024, when discussions will re-open.
Many thanks to Sion, Vikash and Carl for their input into this topic.
Based on available information, our preliminary proposal for the 2025 Red List would be to list Mauritius Cuckooshrike as Endangered under Criterion C2a(ii).
The species’ population size is very small, but not as small as previously estimated, now considered to be at a likely maximum of 420 mature individuals, all contained within one subpopulation (as defined by IUCN Guidelines). A continuing decline in its population size is inferred, partly as the threats which have led to declines in the past have not ceased, and due in particular to the ongoing spread of invasive non-native plant species which, despite concerted conservation efforts, continue to spread in forests in Mauritius, leading to a decrease in population density in these areas.
There is now a period for further comments until the final deadline on 10 November 2024, after which the recommended categorisations will be put forward to IUCN.
The final Red List categories will be published on the BirdLife and IUCN websites in 2025, 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 a final decision on this species’ Red List category will be posted on this page on 18 November 2024.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Mauritius Cuckooshrike is recommended to be listed as Endangered under Criterion C2a(ii).
Many thanks for everyone who contributed to the 2025.1 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites in 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
After discussions with S. Henshaw, V. Tatayah and C. Jones, new data has been compiled and summarised below.
Population size: The species has a particularly low detectability and therefore the passerine surveys conducted on the mainland between 2011-2014, from which the population size in the forum topic is taken, may have underestimated the population size of this species. Since then, territory mapping surveys have only detected healthy populations on the mainland. The core population is located in the Brise Fer – Macchabée area, in the southwest of Mauritius, where the highest population density is found. It comprises one third of the total mainland population, with approximately 70 pairs (140 mature individuals). This equates to a total mainland population of 210 pairs (420 mature individuals). However, this number is based on estimates from the area with the highest population density in the species’ range, and it is therefore considered to represent the maximum total population size possible for this species.
Range: the species’ range is considered to still be similar to its range 30 years ago, including all the gorges of the Bel Ombre area, which is part of the Black River Gorges National Park, and areas adjacent to the Park, such as Chamarel and Case-Noyale, and including both peripheral and core areas for the species which are privately owned.
There is however a doubt as to its occurrence in the Combo region, where it is likely to be present, but at very low densities. It is absent from the Bambou Mountains in the east of Mauritius, with a cessation of the reintroduction programme in Ferney Valley in 2019, and no individuals recorded there for the past three years. The reintroduction programme is still planned, but is not currently a priority.
Habitat: : This species can be relatively flexible in terms of the proportion of invasive non-native plant species present within its forest habitat, as long as it is not solely composed of non-native plant species. The population density of the Mauritius Cuckooshrike reduces with the increase in percentage of non-native plant species in forest habitat.
Trend: Considering the above regarding differences in density and habitat quality, and the fact that habitat in continuing to degrade with the invasion of non-native plant species, and loss of some of the peripheral habitats to development, such as deer ranching and construction, it is therefore inferred that there is a likely small continuing decline in the species’ population size.
Conservation measures: The Brise Fer region has benefitted from large scale control of invasive non-native plant species, which is likely to benefit the species. In addition, intensive rat control over an area of 10 ha within Brise Fer will benefit the breeding productivity of the Mauritius Cuckooshrike, especially as this 10 ha area overlaps with one of the areas of highest population density for the species.
– Claire Rutherford
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 28 October 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 28 October 2024, when discussions will re-open.
Preliminary proposal
Many thanks to Sion, Vikash and Carl for their input into this topic.
Based on available information, our preliminary proposal for the 2025 Red List would be to list Mauritius Cuckooshrike as Endangered under Criterion C2a(ii).
The species’ population size is very small, but not as small as previously estimated, now considered to be at a likely maximum of 420 mature individuals, all contained within one subpopulation (as defined by IUCN Guidelines). A continuing decline in its population size is inferred, partly as the threats which have led to declines in the past have not ceased, and due in particular to the ongoing spread of invasive non-native plant species which, despite concerted conservation efforts, continue to spread in forests in Mauritius, leading to a decrease in population density in these areas.
There is now a period for further comments until the final deadline on 10 November 2024, after which the recommended categorisations will be put forward to IUCN.
The final Red List categories will be published on the BirdLife and IUCN websites in 2025, 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 a final decision on this species’ Red List category will be posted on this page on 18 November 2024.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Mauritius Cuckooshrike is recommended to be listed as Endangered under Criterion C2a(ii).
Many thanks for everyone who contributed to the 2025.1 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites in 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.