A quantitative study of diet in three species of rodents in natural and irrigated savanna fields

Abstract

A quantitative study of diet in three species of rodents in natural and irrigated savanna fields (Wroughton, 1906) from natural, savanna fields in Nigeria, and 528 Aruicanthis and 367 Mastomys from nearby irrigated fields, where Tatera was never trapped. The materials were processed and microscopically analyzed to determine patterns of diet selection. Sites were sampled for vegetative cover and rodent food resources. More than 90% of the stomach materials could be identified to one of four categories: dicots (vegetative), monocots (vegetative), seeds, and insects. Seeds constituted approximately 50% by mass of foods consumed by all species in both sites during the rains. Mastomys (in both sites) and Tatera maintained the same levels of seed intake year around. Unlike Mastomys, the amount of seeds consumed by Aruicanthis was enhanced by irrigation. In both sites during the rains, monocots and insects made up 12-46% and 14-26% of the rodents diet respectively, but their importance diminished in the natural site during the dry seasons. Tests of MANOVA indicated significant species differences and effects of site, season and their interactions on foods selected. A few plant species dominated the vegetative cover, and dramatic differences in the quality of seasonal herbage were observed.

Demographic response of the Gambian Gerbil to seasonal changes in Savannah fallow fields

“…Perhaps, it is important to note some changes in the systematics of Gerbilliscus over the past 15 years or so. The savannah gerbil in the present study, G. gambianus, Thomas, 1910, is the same as Tatera valida in earlier works in the same area by Rabiu and Rose, (1997; and presumably in other contemporary publications at the time. The genus Tatera now belongs entirely to the Indian subcontinent, while Gerbilliscus includes all African species previously named with Tatera (Musser and Carleton, 2005).…”

“…There is a good representation of the genus Gerbilliscus (Syn. Gerbillurus, Granjon et al, 2012), across many regions of Africa (Arslan et al, 2013;Colangelo et al, 2007;Granjon and Dobigny, 2003;Lötter, 2010;Massawe et al, 2011;Musser and Carleton, 2005;Rabiu and Rose, 1997;Ziegler et al, 2002), with the species of interest in the present study, Gerbilliscus gambianus, amongst the commoner ones in the grassland and semi-arid belts, but also noted in forest clearings (Ikeh et al, 1995) though, on the whole showing greater preference for drier savannah than the humid, derived savanna to the south of Nigeria (Happold, 1987). The species also shows considerable tendency towards seasonal reproduction in many regions, usually during the rains, e.g., in Nigeria (Rabiu and Rose, 1997), and in eastern Africa (Delany, 1986).…”

“…Gerbillurus, Granjon et al, 2012), across many regions of Africa (Arslan et al, 2013;Colangelo et al, 2007;Granjon and Dobigny, 2003;Lötter, 2010;Massawe et al, 2011;Musser and Carleton, 2005;Rabiu and Rose, 1997;Ziegler et al, 2002), with the species of interest in the present study, Gerbilliscus gambianus, amongst the commoner ones in the grassland and semi-arid belts, but also noted in forest clearings (Ikeh et al, 1995) though, on the whole showing greater preference for drier savannah than the humid, derived savanna to the south of Nigeria (Happold, 1987). The species also shows considerable tendency towards seasonal reproduction in many regions, usually during the rains, e.g., in Nigeria (Rabiu and Rose, 1997), and in eastern Africa (Delany, 1986). Aside from being a potential crop pest (Taylor, 1984), G. gambianus along with other rodent species (Meerburg et al, 2009) represents a reservoir of bacillus (Yersinia pestis) plague with transmission to other wild rodents (Gratz, 1997;Gratz and Arata, 1975); of Phlebotomus fever virus (Ikeh et al, 1995); and leishmaniosis parasites (Dedet et al, 1979;Ikeh et al, 1995).…”

Five stages of progressive β-cell dysfunction in the laboratory Nile rat model of type 2 diabetes

“…(i) Diabetes develops spontaneously on chow diet; native diet consists of predominantly flowering plants and seeds (Rabiu & Rose 1997). In captivity and fed standard rodent diets (higher in calories and lower in fiber compared with their native diet), they develop a metabolic syndromelike phenotype characterized by hyperinsulinemia preceding hyperglycemia (insulin resistance), as well as other landmark features of metabolic syndrome, including abdominal adiposity and weight gain, increased plasma triglycerides, and elevated cholesterol and hypertension (Chaabo et al 2010).…”

Crop damage and yield loss caused by two species of rodents in irrigated fields in northern Nigeria

“…Since the development of large-scale irrigation facilities in the northern parts of Nigeria in the early 1970s, rodent species have become increasingly troublesome and have been documented as eating cereal crops (Rabiu and Rose, 1997). The objectives of this study were: (1) to assess the damage done by A. niloticus and M. natalensis to rice and wheat crops at different stages of development in the irrigated fields, (2) estimate crop losses, and (3) compare the magnitude of damage done to rice (grown for the most part during the rainy season) with that in wheat fields (a winter crop grown under irrigation during the dry season).…”