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The Indian Desert, situated on the eastern-most boundary of the Saharo-Rajasthan Desert, is of recent origin and offers considerable scope for ecological studies of fundamental and economic importance. RAO (1957) records evidence on the hunting of rhinoceros (which inhabits humid regions) in the Indus Valley by the Mugals as late as in 1519. At present, however, the prevailing climatic as well as the habitat conditions in this desert can only support predominantly xerophile and xerobiont fauna. Inspite of the interesting zoogeographical and evolutionary importance of the Indian Desert, adequate attention has not been paid so far to the zoology of the region. For instance, the Mammal Survey of India, Burma and Ceylon, conducted by the Bombay Natural History Society, did not include the Indian Desert. Realizing this lacuna in our knowledge of the fauna of the Indian desert, Dr. DAYA KRISHNA, formerly Professor of Zoology at the Jaswant College, Jodhpur, moved the UNESCO to finance a project on the ‘Ecological studies of vertebrates of the Indian Desert’. The author had the privilege to be associated with it from 1953 to 1955. These ecological studies were carried out mainly on reptiles and mammals and their findings were incorporated in university dissertations (DAVE, 1961; PRAKASH, 1957).

Rodents constitute one of the largest mammalian groups in the Rajasthan desert, India, both in total number and in the number of species represented. They exhibit a great plasticity in respect of their choice of a wide spectrum of desert habitats and their impact on the desert ecosystems is all too prominent. The rodents’ role in the intensification of desertic conditions may be comprehended from the fact that a single species, viz. Meriones hurrianae***, is able to excavate about 61,400 kg of stabilised soil per km2 per day during summer and deposit it outside its burrow openings in a loose formation. This dug-up soil is easily blown away by the strong desert winds. The rodents, thus, are a prime biotic factor for soil erosion. Their impact on the desert vegetation as a result of their gnawing, debarking, cutting and feeding propensities is easily discernible throughout the tract. In the desert region, orchards, crop fields and rangelands cannot attain their optimum productivity without a rodent control programme. The rodents are, therefore, regarded to be the most potent enemies of man in the desert in his endeavours for maximizing output from this inhospitable terrain. In view of the considerable economic importance of a large number of desert vertebrates, and especially rodents, a study was initiated in the Rajasthan desert in 1953 with financial assistance of the Unesco***. Later on, in 1959, the Central Arid Zone Research Institute at Jodhpur provided a small cell of workers to study the ecology of the rodents and to devise means of their control in the Rajasthan desert. A brief review of our work on the population structure of rodents, their ecological distribution, home ranges, food, predators and reproduction aspects has been presented here. The control aspects of our work have been deliberately left out of this review.

I. The Desert as a Habitat.- Distribution.- Soils.- Climate.- Vegetation.- References.- II. The Ecology of Rodents in the northern Sudan.- Desert Species.- Jebel Species.- Riverine Species.- Commensal Species.- Reproduction.- Other Adaptations for Life in the Desert.- Discussion.- Acknowledgements.- References.- III. The Rodents of the Iranian Deserts.- The Rodents: northern and southern Types.- Annual Rhythm.- Population Densities.- Some Peculiarities.- References.- IV. Comparative Ecological Notes on Afghan Rodents.- Results.- Discussion.- Summary.- References.- V. The Population Ecology of the Rodents of the Rajasthan Desert, India.- Population Structure.- Ranges of Movements.- Food.- Predator-Prey Relationship.- Breeding Season and Litter Size.- References.- VI. Outbreaks of Rodents in Semi-Arid and Arid Australia: Causes, Preventions, and Evolutionary Considerations.- Climates in Central Australia.- The Study-Area: Habitats and Rodents.- Populations.- Conclusions and Discussion.- Acknowledgements.- References.- VII Observations of Argentine Desert Rodent Ecology, with Emphasis on Water Relations of Eligmodontia typus.- The Argentine Monte and some of its Rodents.- Methods and Materials.- Results and Discussion.- Acknowledgements.- References.- VIII. La diversite des Gerbillides.- IX. Some Observations on Ecological Adaptations of Desert Rodents and Suggestions for further Research work.- The Desert Environment.- Ecological Adaptations.- Need for further Research.- References.- X. The Behavior Patterns of Desert Rodents.- The Evolution of Desert Adaptations.- A Comparison of Behavior Patterns.- A Comparison of Behavior Patterns in : Meriones, Gerbillus and Perognathus.- Spacing and Communication.- Acknowledgements.- References.- XI Activity Patterns of a Desert Rodent.- Methods.- The Microdosimeter and the Index of Activity.- Variation in Activity.- Climatological Variables and Animal Activity.- Analysis.- Discussion.- Summary.- References.- XII. Patterns of Food, Space and Diversity.- Resource Allocation by Seed Selection.- Habitat Selection in Space.- The Pattern of Local Species Diversity.- Acknowledgements.- References.- XIII. Desert Coloration in Rodents.- Desert Coloration.- Acknowledgements.- References.- XIV. The Biology of some Desert-Dwelling Ground Squirrels.- Reproduction.- Food Habits.- Population Characteristics.- Habitat Factors.- References.- XV. Reproductive Biology of North American Desert Rodents.- Reproductive Biology: Species Summaries.- References.- XVI. Rodent Faunas and Environmental Changes in the Pleistocene of Israel.- The Main Biogeographical Changes in the Near-East since the Miocene.- The Composition of the Rodents Faunas in the Pleistocene of Israel.- The Main Ecological Changes in the Quarternary of Israel.- Analysis of the Main Habitats Occupied by the Pleistocene Rodents of Israel.- Note on the Origin of the Israeli Desert Rodents.- References.- XVII. Prehistoric Rodents of the Middle East.- Prehistoric Rodents.- Discussion.- Acknowledgements.- References.- Addenda.- XVIII. Desert Rodents : Physiological Problems of Desert Life.- Problems of Temperature Regulation.- Water Balance, Intake and Loss.- References.- XIX. Ecophysiology of Water and Energy in Desert Marsupials and Rodents.- Methods.- Ecophysiology of Water and Energy.- Discussion.- References.- XX. Thermo-Regulation and Water Economy in Indian Desert Rodents.- Methods.- Thermo-Regulation.- Water Economy.- Conclusion.- References.- XXI. The Physiological Adaptations of Desert Rodents.- Water Conservation in Desert Rodents.- Structure and Concentrating Mechanisms in the Desert Rodent Kidney.- Tolerance to Heat and Thermo-Regulation of Desert Rodents.- Reproduction in Desert Rodents.- References.- XXII. Nematode Parasites of the Indian Desert Rodents.- Material and Methods.- Nematode Parasites of the Indian Desert Rodents.- Discussion.- References.- XXIII. Ecology of the Desert Rodents of the U.S.S.R. (Jerboas and Gerbils).- Jerboas.- Gerbils.- References.- Author Index.- Genus and Species Index.