||Zosterops mouroniensis Milne-Edwards & Oustalet, 1885
||Mount Karthala White-eye, Comoro White-eye, Karthala White-eye
||Oiseau-lunettes du Mont Karthala
||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
||13 cm. Medium-sized, warbler-like bird. Dull olive-brown upperparts with narrow white eye-ring. Yellowish-green underparts, brighter on throat and vent. Similar spp. Madagascar White-eye Z. maderaspatanus much brighter yellow below and greener above, but range rarely overlaps. Voice Noisy, with continual contact by typical buzzy white-eye calls and twitterings. Hints Gregarious, restless.
|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Benstead, P., Ekstrom, J., Pilgrim, J., Shutes, S., Symes, A., Taylor, J., Warren, B. & Westrip, J.
This species is classified as Vulnerable since it has a very small range, confined to the top of an active volcano. The population is suspected to have declined since 1985 owing to a reduction in the Area of Occupancy as a result of volcanic activity, however the extent of habitat is expected to recover through natural regeneration so the species is not suspected to be undergoing a continuing decline. Nevertheless, the limited range and small population of this species render it extremely susceptible to future threats, most notably, a serious eruption. In such a case the species may warrant uplisting to Critically Endangered.
|Previously published Red List assessments:|
- 2012 – Vulnerable (VU)
- 2008 – Vulnerable (VU)
- 2004 – Vulnerable (VU)
- 2000 – Vulnerable (VU)
- 1996 – Critically Endangered (CR)
- 1994 – Critically Endangered (CR)
- 1988 – Threatened (T)
|Population:||The range estimate of 2,500-9,999 individuals is supported by recent surveys that estimated densities of 1,500 birds/km2, suggesting the population size is towards the high end of this range (C. Marsh in litt. 2007). This estimate equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.|
Trend Justification: Surveys in 2005 indicated that densities had remained stable since 1985 (C. Marsh in litt. 2007). However, the population is suspected to have declined at an unknown rate since 1985 owing to a reduction in the extent of habitat as a result of volcanic activity. The extent of habitat is expected to recover through natural regeneration (C. Marsh in litt. 2007).
|Current Population Trend:||Decreasing|
|♦ Number of mature individuals:||1500-7000||♦ Continuing decline of mature individuals:||No|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ No. of subpopulations:||1||♦ Continuing decline in subpopulations:||No|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||Yes|
|♦ No. of individuals in largest subpopulation:||100|
Large patches of heath near the summit of Mt Karthala were burnt in 1958, probably as a result of volcanic activity (Benson 1960). Following eruptions in 2005, a reduction in the area of Philippia habitat was observed, particularly within and just around the crater above 2,500 m (C. Marsh in litt. 2007). A future eruption could be catastrophic for the species. Tree-heath is threatened by browsing cattle and by fire used to stimulate growth of palatable shoots (Safford 2001). In 2005, cattle grazing was judged to be limited in extent (C. Marsh in litt. 2007). With this island's large, increasing human population (Louette et al. 1988), clearance of forest for agriculture is occurring on all but the poorest soils. Since 1983, intact forest may have declined by over 25% as agriculture has advanced steadily up the slopes of Mt Karthala towards the habitat of this species. Secondary forest in the agricultural belt is dominated by exotic plants, particularly strawberry guava Psidium cattleianum, which could spread into and degrade remaining native forest. If plans to build a road to Mt Karthala's crater are resurrected, exploitation and fragmentation of the forest, and the spread of exotic species, could be accelerated (Safford 2001). Introduced rats may act as nest predators or food competitors (Safford 2001). The lower boundary of Philippia, and thus the species's range, may be pushed upwards by an expansion of the forest owing to a future rise in global temperatures (C. Marsh in litt. 2007).