RESUMO
Designing mitigation strategies for invasive species requires a clear understanding of their ecology and behaviour. Chilla (or grey fox; Lycalopex griseus) were introduced to Isla Grande de Tierra del Fuego (Tierra del Fuego Island) in 1951 to control European rabbit (Oryctolagus cuniculus) populations. Although this management strategy was unsuccessful, the chilla spread across the island and are now considered invasive. Despite this, there is a lack of research concerning their ecology and behavioural patterns, particularly on the Argentinian side of the island. We assessed the detection rates and temporal activity patterns of chillas using camera traps in the Argentinian region of Tierra del Fuego Island. Chilla had average detection rates of 61.7 (SD ± 33.3, range = 13.5-105.7) per 100 trap nights. Although analysis by clock time suggested cathemeral activity patterns, when analysed by sun time the chillas exhibited distinct nocturnal activity patterns. These findings offer the first information on the detection rates of chilla on the Argentinian side of Tierra del Fuego Island and reveal new insights into their temporal activity patterns, providing an important basis for future research that may aid the development of more effective management and conservation strategies.
RESUMO
Brucella abortus (Br abortus) es una de las principales causas de abortos y pérdidas reproductivas en el ganado bovino. Los fetos abortados y sus fluidos fetales son la mayor fuente de infección. Es así como la enfermedad puede llegar a animales silvestres cuando ingieren esos tejidos. El objetivo de este trabajo fue determinar la prevalencia serológica de brucelosis en el zorro gris pampeano (Pseudalopex gymnocercus). Se tomaron muestras de sangre de 41 zorros de la región centro-este de la provincia de La Pampa, Argentina. Para determinar la presencia de anticuerpos específicos contra Br abortus se utilizaron las Pruebas de Polarización de la Fluorescencia (FPA), Seroaglutinación en Microplaca (SAP) y Seroaglutinación en Microplaca con 2-mercaptoetanol (2-ME). Sobre un total de 41 sueros procesados por FPA, en 7 (17,1%) se detectaron anticuerpos contra Br abortus. Sólo 34 sueros fueron analizados por las pruebas de SAP y 2-ME, encontrando 5 (14,7%) y 4 (11,8%) muestras positivas, respectivamente. Los resultados permiten inferir que el zorro gris pampeano es susceptible a infectarse con Br. abortus a una tasa de incidencia importante. Es necesario realizar futuros estudios para establecer el rol del zorro en la transmisión de la enfermedad y sus consecuencias en esta especie.
Brucellosis is produced by several species of Brucella. Brucella abortus causes abortion and reproductive loss in bovine cattle. In the epidemiology of brucellosis, aborted fetus and their fetal fluids are the main source of infection and dissemination. Although the biological cycle and the disease consequences to domestic cattle have been widely studied, it is not the case with wild fauna. The objective of this study was to determine the serologic prevalence to brucellosis in the grey fox of the pampas (Pseudalopex gymnocercus). To that purpose, 41 foxes were sampled in the centre-east area of La Pampa province (Argentina). Blood samples for serologic studies were collected. A test of agglutination in microplate (SAP), another SAP with the addition of 2-mercapto-etanol (2-ME) and a test of polarization of the fluorescence (FPA) were used for the diagnosis of antibodies against Brucella abortus. For this, 17.1%, 14.7% and 11.8% was the prevalence found by FPA, SAP and SAP with 2-ME. More studies will be necessary to know the role of foxes in disease transmission and maintenance as well as the consequence of the diseases in foxes.