FOOD HABITS, POPULATION STRUCTURE AND REPRODUCTION PATTERNS OF COMMENSAL SMALL MAMMALS OF RURAL POTHWAR, PAKISTAN

Abstract

Small mammals (rodents and shrews) occur worldwide and affect a variety of habitats. Some rodents are commensal both in urban and rural situations. They are among the important pest species causing losses to stored grains and other eatables especially in rural areas of developing countries. The status and the impact of small mammals in the rural human habitation of Pothwar plateau is not known. The present study was aimed at knowing the food habits, population structure and reproductive patterns of small mammals (rodents and shrews) that live in and around human dwellings of rural Pothwar. Four villages (study sites) were selected from Pothwar, and small mammal trapping was conducted seasonally between 2012 and 2014. At each site, trapping was conducted in three types of structures (village households, shops and farmhouses) for four consecutive nights. For population structure, sex ratio and age structure were measured. To study food habits, stomach contents of the trapped animal were analyzed using microhistological and DNA barcoding techniques. Three measures of abundance were calculated which were: species richness, diversity and trap success. The reproduction status of each of the specimens was noted. A total of 746 small mammals, representing eight rodent species (Musmusculus,Rattusrattus,Tateraindica,Millardiameltada, Golundaellioti,Bandicotabengalensis,Nesokiaindica,andMusbooduga) and one insectivore species (Suncusmurinus) were captured in 7680 trap nights from the three types of rural structures; the trap success being 9.7%. M. musculus was the most abundant species at the three sites, except site III, where R. rattus was the dominant species. M. musculus showed seasonal variation in its abundance with relatively more capture in winter and autumn seasons. The sex ratio was female biased in M. musculusspecies, and unbiased in R. rattusand S. murinusspecies. Overall, more adults and few juveniles were present in the xxii populations of the three commensal species. Food analysis showed that wheat (Triticumaestivum) was the major food item in the diet of two rodent species, followed by insects. In shrews, insects were the major food item, but stored grains were also consumed. The findings from both the food analysis techniques were generally in agreement, but the detection of prey type with each technique was different. Reproductive assessment of the species showed that the three commensal species bred year round,and with more reproductively active individuals were in the population as compared to inactive individuals. The present study showed that rural human dwellings support an abundant population of commensal small mammals, andthese pest species were probably affecting rural human population through the consumption of different stored grains. This study generated useful information on the distribution pattern and the biology of major indoor pest species living in rural areas, and these results of the present study will be helpful in developing effective and environment friendly management plans for the indoor pest species present in the region.