VU
Appert's Tetraka Xanthomixis apperti



Justification

Justification of Red List category
This species is suspected to have a small population that is experiencing a rapid decline due to ongoing forest loss and degradation. It is therefore currently classified as Vulnerable.

Population justification
The population size has not been quantified. The species is highly localised, but during surveys of Zombitse-Vohibasia National Park in 1996 it was considered locally common at Ambiamena and Andranamaitso and rare in Vohibasia Forest (Mustoe et al. 2000). It was not recorded during extensive ornithological surveys of the northern part of the Mikea Forest (Raherilalao et al. 2004), but may prove to be more widespread than currently thought. Therefore, the population is preliminarily suspected to fall into the band 1,000-2,499 individuals. This equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification
The speciess population has previously been suspected to be stable owing to the cessation of forest clearance in the Zombitse-Vohibasia National Park in 1994 (ZICOMA 1999) and the species' apparent resistance to very low levels of forest degradation, at least (Mustoe et al. 2000). Tree cover loss within the extant range has previously been as high as 32% in the past ten years, although has slowed to a current estimate of 10% (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Given its high forest-dependency and its susceptibility to fragmentation and edge effects, future population declines are likely faster than the rate of tree cover loss suggests, and are therefore here tentatively placed in the band 10-19% over the next ten years.

Distribution and population

This species has a very localised distribution in south-west Madagascar. It was known from only a limited number of possible sites: Zombitse-Vohibasia National Park (type locality) (found in both Zombitse and Vohibasia), Analavelona Classified Forest, and recently at dry spiny forest at Salary Bay (ZICOMA 1999, Langrand and von Bechtolsheim 2009, Hawkins and Sartain 2013). During surveys of Zombitse-Vohibasia National Park in 1996 the species was considered common at Ambiamena and Andranamaitso and rare in Vohibasia Forest (Mustoe et al. 2000). It was not recorded during extensive ornithological surveys of the northern part of the Mikea Forest (Raherilalao et al. 2004).

Ecology

This species is found in family groups of between 2 and 8 individuals, sometimes associating with flocks of Bernieria madagascariensis (Langrand 1990). At Zombitse-Vohibasia it is found in the dense underbrush of undisturbed, dry, deciduous forest at about 600 to 800 m (Morris and Hawkins 1998). Analavelona is a tract of relict evergreen forest on an isolated massif at about 1,300 m (ZICOMA 1999). The species feeds on small invertebrates gleaned from the leaves and branches of low shrubs and on the ground (Langrand 1990, Morris and Hawkins 1998). Observations suggest that the species tolerates low levels of selective exploitation (Mustoe et al. 2000). The sightings at Salary Bay in 2009 were made in low altitude coastal dry spiny forest thicket, raising the possibility that the species is either a resident with a broader habitat tolerance than previously known, or possibly that it undertakes localised altitudinal movements (Langrand and von Bechtolsheim 2009).

Threats

Forest clearance for maize and manioc and some charcoal production is the main threat to this species (Mustoe et al. 2000, ZICOMA 1999, F. Hawkins in litt. 2022). Parts of the Zombitse-Vohibasia National Park have been heavily selectively logged in the past and some areas of forest are exploited for building materials and used for cattle-grazing (Mustoe et al. 2000). Burning is carried out in some open areas to encourage grass regeneration for grazing, and there is a danger of fire spreading to nearby areas of degraded forest. If fires penetrate and destroy gallery woodland such areas would be at risk of losing surface water and consequently could experience desertification. During surveys in the Zombitse-Vohibasia National Park in 1996, it was noted that the species was encountered most frequently in an area that had a recent history of intensive selective logging, perhaps indicating that it benefits from such habitat alteration, at least temporarily (Mustoe et al. 2000). Analavelona is not managed as a protected area, but is relatively isolated, and forest clearance is not thought currently to present a threat. This species may be vulnerable to climate change (R. Andriamasimanana in litt. 2016).

Conservation actions

Conservation Actions Underway
Zombitse-Vohibasia Forest has been gazetted as a National Park (Morris and Hawkins 1998). Analavelona is unprotected but may be included in the activities of the WWF Zombitse-Vohibasia Conservation Project in the future (ZICOMA 1999).

Conservation Actions Proposed
Conduct studies to estimate its population size (ZICOMA 1999). Carry out surveys for the species at Upper Mangoky and Ankazohabo Forests (M. Rabenandrasana in litt. 2007). Carry out surveys to determine whether it has a largely continuous distribution between Zombitse-Vohibasia-Isoky, Analavelona, and Salary Bay, and study birds at these sites at different seasons (including genetic analysis and/or banding) to determine whether there are seasonal movements between sites or whether they are isolated subpopulations (Langrand and von Bechtolsheim 2009). Design and carry out regular surveys to monitor population trends, starting in Zombitse Forest near Andranamaitso (Mustoe et al. 2000). Study the impact of moderate to high levels of forest exploitation on the species (Mustoe et al. 2000). Monitor rates of forest clearance and degradation within its range.
Target conservation efforts on Ambiamena Forest (Mustoe et al. 2000). Train park guards to carry out population surveys. Promote ecotourism and use revenues to fund surveys (Mustoe et al. 2000). Regularly liaise with the more isolated communities in the Zombitse-Vohibasia National Park to help reconcile their needs and aspirations with conservation efforts (Mustoe et al. 2000).

Identification

15 cm. Small, mainly terrestrial babbler-like bird. Greenish upperparts, with darker flight feathers and tail. Greyish crown, nape and rear ear-coverts, with short dull off-white supercilium. Whitish throat, and variably-washed peachy-orange breast and upper belly. Whitish lower belly and vent. Pale pink bill with darker culmen, pale pinkish-grey legs. Similar spp. Differs from Long-billed Greenbul B. madagascariensis by smaller size, grey head, white throat, slimmer and shorter bill.

Acknowledgements

Text account compilers
Rotton, H.

Contributors
Andriamasimanana, R., Ekstrom, J., Evans, M., Hawkins, F., Langrand, O., Rabenandrasana, M., Shutes, S., Starkey, M., Symes, A., Taylor, J. & Westrip, J.R.S.


Recommended citation
BirdLife International (2024) Species factsheet: Appert's Tetraka Xanthomixis apperti. Downloaded from https://datazone.birdlife.org/species/factsheet/apperts-tetraka-xanthomixis-apperti on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/11/2024.