Spatial and temporal patterns of brown rat (Rattus norvegicus) abundance variation in poultry farms

Abstract

The temporal and spatial patterns of rat abundance variations were studied, and which factors might affect these patterns in poultry farms. Forty-eight poultry farms were sampled from spring 1999 to winter 2001 in Buenos Aires, Argentina. Environmental variables of farms, meteorological variables and distances among farms were registered to evaluate a possible association with rat abundance estimated by trap success. Rattus norvegicus was the dominant rat species in the study area. Rat abundance did not vary temporally and there was reproduction at all times. Trap success was more similar among neighboured farms than among farms further apart. Contrary to the abundance of other small rodents, rat abundance was not significantly related to farm characteristics. The lack of coincidence between rats and other small rodents suggests the existence of a differential response of rats to environmental factors of the poultry farms.

Small rodent species on pig and dairy farms: habitat selection and distribution

“…A study on habitat selection of R. norvegicus using spool‐and‐line technique in two of the study farms yielded very similar results . Our results support the hypothesis that R. norvegicus do not use patches regardless of their predation risk because microsites with low vegetation height avoided by this pest species represents patches with greater predation risk (being more visible to dogs, cats and other predators); and that the availability of food sources and water are key factors for its establishment . As a result, we agree with the recommendations of concentrating efforts in maintaining short vegetation mainly around dwellings as we found this species avoided sites with low vegetation height and by reducing potential refuges such as deprecated elements that generates trash to diminish R. norvegicus populations .…”

Evaluation of habitat requirements of small rodents and effectiveness of an ecologically‐based management in a hantavirus‐endemic natural protected area in Argentina

“…The observed effect of rain with a time lag of 1 month on the abundance of small rodents is probably due to an increase in primary productivity which results in an increase in the availability of food resources, as suggested by other authors (Jaksic & Lima 2003;Gómez Villafañe & Busch 2007). Increases in rodent abundance towards spring and summer, followed by a decrease towards autumn and early winter, show a slight drift from the typical pattern observed in sylvan populations of central Argentina (Mills et al 2001;Andreo et al 2009).…”

Changes in rodent communities according to the landscape structure in an urban ecosystem

“…C. aperea, A. azarae and O. flavescens are more abundant in less disturbed habitat like road and crop field borders. Calomys species are more abundant in crop fields and M. musculus and Rattus species are rare in these habitats and are common in farms (Busch and Kravetz, 1992;Gómez Villafañe and Busch, 2007;Mills et al, 1991;Miño et al, 2007). In crop borders systems sigmodontine species exhibit variations in abundance with a minimum in spring, peaks in late autumn, and decreases in winter (Busch and Kravetz, 1992;Mills et al, 1991).…”