Zoothera salimalii

Zoothera salimalii, commonly known as the Himalayan Forest Thrush, is a species of passerine bird belonging to the thrush family Turdidae. It inhabits the montane forests of the eastern Himalayas and adjoining regions of China. The species was formally recognised as distinct in 2016, following detailed taxonomic research that separated it from the Plain-backed Thrush (Zoothera mollissima). The name honours the eminent Indian ornithologist Dr Sálim Ali, in recognition of his immense contributions to Indian bird studies.

Background and Discovery

The discovery of Zoothera salimalii is a landmark in modern ornithology, as it highlights how detailed field observation, sound analysis, and genetic study can reveal cryptic diversity. For decades, the Himalayan Forest Thrush was grouped under Zoothera mollissima (Plain-backed Thrush). However, researchers noticed distinct differences in song, structure, and habitat preferences between populations in forested and alpine regions. These observations led to the formal description of Zoothera salimalii as a new species in 2016, thereby expanding the known diversity of Himalayan avifauna.

Taxonomy and Classification

• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• Order: Passeriformes
• Family: Turdidae
• Genus: Zoothera
• Species: Zoothera salimalii
• Common name: Himalayan Forest Thrush

It is closely related to the Alpine Thrush (Zoothera mollissima), but differs in its ecological niche and physical characteristics.

Physical Description

The Himalayan Forest Thrush is a medium-sized thrush with adaptations suited to dense forest environments. Its key identifying features include:

• A rich brownish upper plumage with subtle russet tones.
• A finely patterned underside with streaks or mottled markings on the breast and flanks.
• A shorter tail and wings compared to its alpine counterpart, enabling better manoeuvrability in forested areas.
• A slender, slightly curved bill adapted for foraging among leaves and forest litter.
• A distinct, melodious song, softer and more musical than that of the Alpine Thrush, serving as an important behavioural distinction.

Distribution and Habitat

Zoothera salimalii is found primarily in the eastern Himalayas, including regions of Sikkim, Arunachal Pradesh, Darjeeling, and extending into southern Tibet and north-western Yunnan in China. It inhabits coniferous and mixed montane forests at elevations typically between 2,400 and 3,800 metres. Unlike its alpine relative, which occupies open high-altitude grasslands, the Himalayan Forest Thrush prefers dense forest canopies and shaded slopes.
The species breeds in the summer months, nesting in tree hollows, rock crevices, or among roots. During the winter, it may move to slightly lower altitudes, though long-distance migration has not been observed.

Behaviour and Ecology

The Himalayan Forest Thrush feeds primarily on insects, earthworms, and small invertebrates, occasionally supplementing its diet with berries and fruits. It forages on the forest floor, turning over leaf litter to uncover prey.
The species is solitary or found in pairs, particularly during the breeding season. Its song, consisting of clear, flute-like notes, is used to defend territory and attract mates. The distinct difference in song between this species and its alpine relative played a major role in its recognition as a separate species.

Conservation Status

Zoothera salimalii is currently classified as a species of Least Concern due to its wide distribution and relatively stable population. However, ongoing threats such as deforestation, habitat degradation, and climate change could impact its long-term survival. Conservation of Himalayan forest ecosystems is essential to safeguard its habitat.

Significance of Discovery

The identification of Zoothera salimalii is an important achievement in the field of biodiversity research. It demonstrates how integrated taxonomy—combining genetics, morphology, and vocalisation studies—can uncover hidden species diversity even among well-known bird groups.
The discovery also underscores the ecological richness of the Himalayan region, one of the world’s biodiversity hotspots, and highlights the importance of continued field research in these sensitive environments. Naming the species after Dr Sálim Ali, the “Birdman of India,” symbolises the enduring legacy of Indian ornithology and its global contributions to avian science.

Ecological Importance

As a forest-dwelling thrush, Zoothera salimalii plays a vital ecological role in maintaining forest health. Through insect predation, it helps regulate pest populations, and by consuming and dispersing fruit seeds, it contributes to forest regeneration. Its presence serves as an indicator of the ecological integrity of Himalayan forest ecosystems.