›› 2008, Vol. 51 ›› Issue (3): 328-335.doi:

• RESEARCH PAPERS • Previous Articles     Next Articles

Climatic changes and shifting species boundaries of Drosophilids in the Western Himalaya


  • Online:2010-07-27 Published:2008-03-20

Abstract: Population dynamics studies under shifting environmental conditions over a longer time scale can help to determine how different species react to new biotic and abiotic conditions. Two different field surveys with similar collection methods as well as sites in the western Himalayas (1961–1962 and 2003–2004) were compared on the basis of relative abundance and dominance indices of different Drosophila species. Climatic data for the last fifty years involves a significant change in average temperature (Tave) of western Himalayas, which has affected the distribution and boundaries of various Drosophilids in this region. Current study reports a significant decline in the number of Drosophila nepalensis and other cold adapted species from lower ranges; and introduction of Drosophila ananassae and other warm adapted species to lower and mid mountainous ranges. For D. nepalensis, species abundance is negatively correlated (r=-0.93±0.03) with Tave of the localities of origin and while reverse trend was observed for Drosophila ananassae (r=0.90±0.05). Thus, climatic changes over long periods (42 years) have affected invasive ability of different Drosophila species in the western Himalayas.

Key words: Drosophilids, Western Himalayas, temperature profile, shifting species boundaries, cold and warm adapted species