Biology and Control of the Cotton Rat, Sigmodon hispidus

Abstract

Abstract There was a severe outbreak of rodents in the San Bernardo valley of southern Honduras in 1974–5. Extensive damage was inflicted on a variety of field crops grown in close proximity and maturing in succession. The identity of the rodent species concerned was not established during the outbreak but only the grey-bellied cotton rat, Sigmodon hispidus griseus Allen, was found later in rice, maize, sugarcane and cotton fields. Damage to these and to other crops grown in Central American countries and in southern areas of the USA has been similarly attributed to cotton rats, but there is no reliable data on the actual losses incurred. Crop damage is most severe when cotton rat populations have cycled to peak abundance or when there is large-scale movement due to exceptional climatic conditions. The outbreak in cultivated fields in Honduras followed the flooding of peripheral lowlands. In this paper widely scattered literature on the population biology and control of the cotton rat has been collated. The distribution, reproduction and behaviour of cotton rats is reviewed together with existing recommended land management and chemical control practices. Attention is drawn to potential preventative measures requiring further investigation.