Bird diversity in the Gori-Ganga Valley: Patterns, Mechanisms and Conservation Significance
- Rashid H. Raza, Senior Research Fellow

Gori-Ganga valley captures the entire gradient of Himalayan habitats ranging from subtropical Sal to Alpine meadows within a distance of about a hundred km of the river from its confluence to source. A total of 246 (212 Summer resident, forest dependent) bird species in 34 families and 135 genera, representing more than 45% of the breeding bird diversity of the Western Himalaya and nearly 55% of breeding bird species of the Kumaon Himalaya have been recorded in the region. Birds of this assemblage are grouped along the altitude gradient. The groups correspond to Subtropical, Temperate, Sub alpine and Alpine bioclimatic zones. The bird zonation corresponds well with vegetation zones. Higher richness occurs in the Temperate zone. Bird communities differ in terms of biogeographic affinities along the altitude gradient, and point to different source pools.

Organization of the assemblage in terms of species richness, composition and biogeographic affinities and distribution patterns are discussed in the presentation. Gori-Ganga valley forms a part of Askot WLS and Nanda Devi Biosphere Reserve. The Birdlife International under the Important Bird Area programme has proposed it as an ‘IMPORTANT BIRD AREA’. Cheer Pheasant (Vulnerable), and Satyr Tragopan (Near Threatened) occur in the area, in addition to the ‘Restricted Range’, White throated Tit. The area is well represented by species restricted to different global biomes (‘BIOME RESTRICTED SPECIES’ the IMPORTANT BIRD AREA PROGRAMME criterion) with 90 species representing Eurasian High mountain, Sino-Himalayan Temperate Forest & Sino-Himalayan subtropical forest - biomes. The assemblage represents 46% of the Sino-Himalayan Temperate Forest, species found in India, and is particularly important for them.

Less than 4% of the area falls under the Subtropical zone, however a number of bird species are altitudinal migrants and depend on this zone. This zone also faces a high level of pressure from anthropogenic factors and occurs patchily. Conservation of the contiguity of this exceptional biological gradient from Subtropical to Alpine zones is of prime concern.