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AbstractThe rodent commensal species are abundant on Argentinian poultry farms, causing economic losses and disease transmission. Preventing rodent colonization through the construction of poultry sheds with specific barriers against the entry of rodents is an alternative to the application of rodenticides. This work aimed to assess the effect of physical barriers to prevent rodent presence in experimental poultry sheds. New experimental sheds with and without physical barriers were constructed on two poultry farms. The footprint index (FI) was used as an estimator of rodent abundance. Rodent footprints were never observed inside the Experimental-barrier sheds but they were observed outside. In Experimental-without barrier sheds, rodent footprints were recorded inside and outside. In both farms there were significant differences according to the treatment in FI inside sheds, while no significant differences were found between treatments in the mean FI outside sheds. Our results suggest that physical barriers successfully prevented the colonization of rodents inside the Experimental-barrier during the studied period of 21 months. The installation of physical barriers during poultry shed construction is recommended to prevent rodent colonization and minimize the use of anticoagulant rodenticides for rodent control. [ABSTRACT FROM AUTHOR]

During the 20th century, there has been an ongoing agricultural expansion and global warming, two of the main determinants influencing biodiversity changes in Argentina. The red hocicudo mouse (Oxymycterus rufus) inhabits subtropical grasslands and riparian habitats and has increased its abundance in recent years in central Argentina agroecosystems. This paper describes the long‐term temporal changes in O. rufus abundance in Exaltación de la Cruz department, Buenos Aires province, Argentina, in relation to weather fluctuations and landscape features, as well as analyzes the spatio‐temporal structure of captures of animals. We used generalized liner models, semivariograms, the Mantel test, and autocorrelation functions for the analysis of rodent data obtained from trappings conducted between 1984 and 2014. O. rufus showed an increase in abundance across the years of study, with its distribution depending on landscape features, such as habitat types and the distance to floodplains. Capture rates showed a spatio‐temporal aggregation, suggesting expansion from previously occupied sites. O. rufus was more abundant at lower minimum temperatures in summer, higher precipitation in spring and summer, and lower precipitations in winter. Weather conditions affected O. rufus abundance, but there was local variation that differed from global patterns of climate change. [ABSTRACT FROM AUTHOR]

Mus musculus (house mouse) is a serious rodent pest in poultry farms of Argentina. In these habitats, bromadiolone is the most frequently used anticoagulant. In spite of this control, more than 90% of the farms are infested with rodents. The frequent application of anticoagulants and the permanent presence of M. musculus suggest that there are resistant rodent populations. The goal of this study was to assess bromadiolone susceptibility through a blood clotting response (BCR) test in M. musculus populations inhabiting poultry farms of Exaltación de la Cruz, Buenos Aires, Argentina. Results showed that 56.6% of wild M. musculus were responders to the BCR test. We found non-responder individuals in all the poultry farms studied. Non-responder females had at least one non-responder offspring. Since the percentages of resistant animals per poultry farm were high and considering that bromadiolone is extensively used for rodent control in these habitats, there is a potential risk of an increase in the proportion of resistant individuals and a decrease in the effectiveness of bromadiolone through time in the study area. Besides, our results suggest that this resistance has a genetic basis because non-responder mothers had non-responder offspring. [ABSTRACT FROM AUTHOR]

Mus musculus, Rattus rattus and Rattus norvegicus are pests in poultry farms, causing economic losses and transmitting diseases. Control is commonly conducted through anticoagulant rodenticides, but this control is not effective through time. We aimed to assess the effect of rodent exclosure on long-term success of rodent control in poultry farms of the pampean region, Argentina, and to evaluate indirect estimators of rodent abundance. In both exclosure and non-exclosure sheds rodent abundance decreased significantly after eradication but mice populations showed a recovery, suggesting that the eradication was not complete. Rats did not recover, but the low abundance found at the beginning of the experiment does not allow an accurate conclusion. [ABSTRACT FROM AUTHOR]

To contribute to the knowledge of the role of small mammals in the transmission cycle of tegumentary leishmaniasis caused by Leishmania braziliensis, we studied the small mammal community and its temporal and spatial association with phlebotominae, as well as small mammal infection by Leishmania spp. by PCR-RFLP analyses in an endemic area of northeastern Argentina. Ten small mammal samplings were conducted (2007-2009, 7506 Sherman trap nights and 422 cage trap nights). In two of these samplings, 16 capture stations each one consisting of a CDC light trap to capture phlebotominae, two to four Sherman traps and two cage traps were placed. We found co-occurrence of phlebotominae and small mammal captures in four stations, which were all the stations with small mammal captures and yielded 97% (2295 specimens, including 21 gravid females) of the total phlebotominae captures, suggesting that small mammals may provide a potential source of blood for phlebotominae females. One Didelphis albiventris and two Rattus rattus were associated with high captures of Nyssomyia whitmani, vector of L. braziliensis in the study area. The PCR-RFLP analyses confirm the presence of L. braziliensis in two sigmodontine small mammals ( Akodon sp. and Euryoryzomys russatus) for the first time in Argentina, to our knowledge. [ABSTRACT FROM AUTHOR]

The main goal of the paper was to determine the habitat distribution of the house mouse ( Mus musculus) within a rural landscape of Buenos Aires province, Argentina. We also studied the seasonal variation in abundance and reproductive activity. The habitats studied were poultry farms, human houses in a small village, cropfields, pastures, cropfield and pasture edges, riparian habitats (streams), railway embankments and woodlots. We captured 817 M. musculus and 690 individuals of 5 native rodent species. M. musculus was captured in poultry farms, houses, riparian habitats, cropfield and borders, but it showed a significantly higher abundance in poultry farms compared to the other habitats. Its presence outside poultry farms was significantly related to the distance to streams and poultry farms. The mean trapping success index of M. musculus did not show significant variations between periods, but the proportion of active males was significantly higher in the spring-summer period than in the autumn-winter period. All captures of M. musculus in cropfields, borders and riparian habitats occurred in the spring-summer period. The capture of M. musculus in many types of habitats suggests that it can disperse outside poultry farms, and streams may be used as corridors. [ABSTRACT FROM AUTHOR]