Saving the rare and elusive Spotted Ground Thrush

The Spotted Ground Thrush

The Spotted Ground Thrush (Zoothera guttata) is a rare, elusive and little-known bird that has a wide but discontinuous distribution across south-east and East Africa. Five races of the Spotted Ground Thrush have been described, and one of these (fischeri) occurs as a non-breeding visitor in forests on the Kenya coast between late March and November. The breeding ground of this population is found in some of the Tanzanian coastal forests and probably northern Mozambique.

The Spotted Ground Thrush is now classified as Globally Endangered. BirdLife International’s African Species Working Group has recognised it as a species of high priority and has developed international and national action plans which require improved knowledge of the status of the species. As part of this, research on the Spotted Ground Thrush has been carried out by A Rocha Kenya in support of the Ornithology Department of the National Museums of Kenya, in the Arabuko-Sokoke Forest and adjacent areas.

This research involved conducting various types of survey for the thrush. One method involved mist netting at suitable sites in a number of the study areas. Of the 516 birds mist-netted, only two were Spotted Ground Thrush, suggesting that population densities are low. A further method was to choose random points within the forest and identify all the bird species seen or heard over a 10-minute period. Of 329 point counts carried out during the survey, the Spotted Ground Thrush was observed only five times. Observers also walked around the forest making specific searches for the Spotted Ground Thrush, especially in locations with a suitable habitat.

These studies have all shown that the species is now rare within the area. This is consistent with ringing results from 2001 and 2002 when only five Spotted Ground Thrushes were found out of a total of 256 birds mist-netted and ringed.

Where the Spotted Ground Thrush was caught or seen randomly, its habitat preferences were assessed. These seem to be low altitude, moist evergreen forest with nearly complete canopy cover, deep shade, extensive moist, thick leaf litter and sparse undergrowth. The thrush avoids areas prone to disturbance.

Although more work is needed, these studies, when compared to historic records, suggest a recent and major decline in the fortunes of this species. This is presumably related to the destruction and fragmentation of the East African coastal forest and the increasing levels of human disturbance. Of the remaining portions of this once vast forest, the Arabuko-Sokoke Forest is the largest (c. 38,200 ha indigenous forest or thicket) and provides the best hope for the long-term survival of the thrush.

It is suspected that the Arabuko-Sokoke Forest, where A Rocha Kenya works, may now hold the bulk of the non-breeding population.

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Project leader: Colin Jackson. For further information contact kenya@arocha.org

Partners: BirdLife International’s African Species Working Group, National Museums of Kenya