Taita thrush

The Taita thrush (Turdus helleri), also known as the Taita olive thrush or Heller's ground thrush, is an endangered bird from the family of thrushes (Turdidae), endemic to the Taita Hills in Kenya.

Description
The Taita thrush was previously classified as subspecies of the olive thrush (Turdus olivaceus), but it is regarded as distinct species since 1985. It reaches a length between 20 and 22 centimetres. Head, breast and upperparts are coloured darkly. The underparts are white and the flanks have a rufous hue. The eyes and the bill exhibit a pale orange coloration. It was named after zoologist Edmund Heller (1875–1939) a workmate of the American ornithologist Edgar Alexander Mearns (1856–1916) who described this species scientifically in 1913.

Distribution
The Taita thrush is a forest-dependent endemic bird confined to four forests in the Taita Hills (in the south east of Kenya): Mbololo, Chawia, Yale and Ngangao. The forests cover a tiny 342 ha. Conservationists are using birds – with the thrush as the flagship species – to champion the conservation of the Taita Hills forests.

Ecology
It is restricted to montane moist forests. Despite its natural native habitat having been severely logged in the past, it has avoided forests with secondary growth, shrub vegetation, and cultivated areas. Extensive research has shown only very few migrations between the fragmented populations.

Conservation
The Taita Thrush, facing a precarious status with an estimated population of about 1,400 individuals, encountered a notable decline over recent years. Various population assessments suggest decreases, particularly in subpopulations across Mbololo, Ngangao, and Chawia. However, these figures come with uncertainties due to assumptions about habitat density and the use of estimation models. Urgent conservation actions are imperative to protect the Taita Hills' environment and address habitat degradation, fragmentation, and invasive species threats to secure the thrush's future.

Habitat Pressures
The Taita Thrush faces significant habitat challenges in the Taita Hills, where indigenous forests have been largely cleared for agriculture and non-native timber cultivation. Despite some segments being protected, ongoing forest loss remains a concern within the species' range. The quality of the remaining larger forest fragments is relatively good, but low connectivity between patches poses a problem for the thrush population, potentially leading to inbreeding issues.

Sex Ratio Imbalance
An imbalanced sex ratio, particularly in the Chawia subpopulation, with only 10% of birds being female, raises concerns about long-term survival. This skewed sex ratio may result in a lower-than-expected reproductive rate, potentially affecting the thrush population's sustainability.