Browsing by Author "Mukherjee, Shomen"
Item Habitat Use by Rodents in a Sandy Habitat Around Sam, Western Rajasthan(Wildlife Institute of India, Dehradun, 1999) Mukherjee, Shomen; Goyal, S.P.Earlier studies on rodents in the Thar have recorded only the broad habitat types in which the different species occur. Except Rogovin el al. (1994), no other study has looked into microhabitat use by rodents. The present study aims to look at habitat use by three species of gerbils in a sandy habitat: The macro and microhabitat use by three species of rodents viz. Gerbillus gleadowi, G.nanus and Meriones hurrianae, in a sandy habitat, receiving rainfall of around 100-200 mm, was studied in Thar desert. Three distinct sandy habitats (Stabilized dunes Barren dune and Interdune), within 4 sq. km. area around Sam, Jaisalmer. was selected for the study. Due to zero captures after 500 trap nights, the use of Sherman traps was discontinued. Instead, circular track plots made out of chalk powder were used for looking at microhabitat use within each of the habitats. Track identification, up to species level, was first standardized from live specimens in captivity and then used in field. A total of sixteen variables representing habitat complexity (vertical), heterogeneity (horizontal) and phenology were enumerated around each plots. G. gleadowi was found to be the most abundant species, occupying all the three habitats. G. nanus was found to inhabit the Stabilised and Interdunal areas, while M. hurrianae was present only in the Interdune. Factor analysis using principle component extraction was used to determine the microhabitat characteristics. G. gleadowi was the sole occupant of Barren dune, where it did not show preference for any particular microhabitat. ' During winter, in Stabilised and Interdune, G. gleadowi was found using areas with relatively less compact soil, lower mean vegetation height and fewer number of hummocks compared to G. nanus. In summer, the species still continued using areas with relatively lower soil compactness, mean vegetation height and fewer hummocks compared to G. nanus, but showed higher use of areas with more ground cover (vegetation) compared to winter. G. nanus was found using areas with relatively more compact soil, higher mean vegetation height and greater number of hummocks. Overall, G. gleadowi was found to use the maximum range of microhabitats compared to the other two species. The summer niche space of G. gleadowi was found to be greater than its winter niche. During summer it was found using areas with more ground cover, higher percentage mature leaves, young leaves and fruits. M hurrianae was found to have a strict association with Capparis decidua tree, under which it burrows. The species is probably facing microhabitat loss due to collection of C. decidua poles by villagers.