Where do Norway rats live? Movement patterns and habitat selection in livestock farms from Argentina.

MONTES DE OCA, D.; LOVERA, R.; CAVIA, R.

WILDLIFE RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2017

1035-3712

Context. The Norway rat (Rattus norvegicus) is recognised as one of the most harmful invasive mammal species innatural, urban and rural environments worldwide. Prevention and control of pest species in livestock farms is necessary toprotect animal and human health, but control practices usually do not take into account the biology and ecology of thespecies to be controlled. The understanding of the biological requirements of Norway rats is necessary for the implementationof efficient management actions.Aims. The aim of this research was to study movement patterns and habitat selection of Norway rats on livestock farmsin central Argentina. We hypothesised that rats selected specific areas within the farms according to the farm?s structure andto the availability of resources.Methods. We conducted live-trapping of rats in a pig farm and a dairy farm, during each of four seasons over 1 year.Traps were active for three consecutive days at each trapping session. Movements and habitat selection were assessedby spool-and-line technique combined with environmental surveys and GIS tools.Key results. We captured a total of 133 Norway rats and evaluated the movements of 47 individuals. The mean lengthtravelled, registered for one night, was 84.28 38.21 m. They did not travel great linear distances within the farms, butinstead performed tortuous trajectories around specific sites. Norway rats selected sites containing food, water and refuges;and avoided travelling across areas with short vegetation. Sites containing food sources were most preferred.Conclusions. Because food sources for rats were present ad libitum in farms, our findings strongly support the ideathat management strategies of prevention and control of this species must include adequate rodent-proof food storage.Also, because rats are found close to livestock, improvement in preventing rats? access to animal sheds is necessary toprevent contamination of livestock feeders with pathogens carried by rats.Implications. The present study provides novel information about the ecology of Norway rats on livestock farms.We encourage farmers to follow our recommendations in order to improve rodent-control strategies.