Wildlife uses and perceptions by residents from two surrounding neighborhoods of the Otamendi Natural Reserve in Campana, Argentina

La Reserva Natural Otamendi (RNO), ubicada en el partido de Campana, Provincia de Buenos Aires, posee ambientes propios de la Región Pampeana y del Delta del Paraná. La matriz del paisaje está formada por agroecosistemas, y la RNO preserva, por ejemplo, parches de pastizal pampeano, parches de bosque de tala (Celtis tala) y parches de bosque ribereño. En la comunidad aledaña a la reserva se evaluaron las referencias al uso de fauna silvestre y las percepciones de dicha fauna. Se llevaron a cabo entrevistas a pobladores locales, contactados a través de la Administración de Parques Nacionales. Además, para ampliar la muestra se utilizó la técnica "bola de nieve". Los resultados mostraron tres usos principales de la fauna silvestre: para alimento, para comercialización o como mascotas. Los mamíferos resultaron ser los animales más importantes para los pobladores que cazan fauna silvestre. Las especies más referenciadas y, por lo tanto, de mayor valor de uso fueron el coipo (Myocastor coypus), el carpincho (Hydrochaeris hydrochaeris) y el ciervo de los pantanos (Blastocerus dichotomus). Se constató la práctica de la caza en la zona aledaña a la RNO y se identificaron los conflictos que esta práctica genera entre los pobladores y las autoridades de la zona. A partir de este trabajo, se sugiere ampliar los estudios acerca de los usos de fauna en el área. Asimismo, se estima importante que en los espacios comunes de reunión de los pobladores locales se refuerce la divulgación del estado de conservación de las especies con valor de uso en la región, con el fin de establecer y evaluar bases sustentables para su conservación.The Otamendi Natural Reserve (ONR), located in Campana, Buenos Aires, has environments of the Pampa Region and the Paraná Delta. The landscape matrix in this area is composed by agroecosystems, the ONR for example, and preserves patches of Pampean pastureland, tala (Celtis tala) forest and riparian forest. In the community nearby the reserve, evaluation was made through the references made in the use of wildlife and people´s perception of the mentioned fauna. Interviews were made to locals by the National Parks Administration and, in order to get a wider sample, the “snowball” technique was used. The results showed three main uses: as food, trade or as pets. For the people who hunt wildlife, mammals seem to be the most important animals. Three species were the most referenced, and so they represent a greater use value: the coipus (Myocastor coypus), the capybara (Hydrochaeris hydrochaeris) and the marsh deer (Blastocerus dichotomus). Hunting is confirmed in the surroundings of the ONR as well as conflicts between the authorities and locals of this activity. We suggest to extend the studies about wildlife use in this area and also, it is very important, among locals using people’s communal areas, to strengthen the dissemination of the conservation status of species with high use value in the region, all this to establish and to evaluate sustainable basis for their conservation

Reproductive ecology of coypu (Myocastor coypus Molina, 1782) in the Middle Delta of the Paraná River, Argentina

The objective of this study was to estimate and compare some important reproductive parameters of Myocastor coypus over time (June 2006-May 2008), in wetlands of the Middle Delta of the Paraná River (MD) Entre Ríos province, R. Argentina. Within the original coypu distribution range, the MD is among the areas of highest habitat suitability for the species. Coypus were captured and the following reproductive parameters were estimated on a monthly, seasonal and annual basis: pregnancy rate (PR), litter size (LS), gross productivity (GP) and annual production (AP). Statistical non-parametric tests were used for comparisons. Additionally, the expected birth date of each embryo and fetus was estimated by assigning it to a developmental stage category and considering the gestation period of the species. All the parameters showed high values and PR and LS differed significantly between the dry (2006) and humid years (2007). Two peaks of birth were detected, one in spring and another one in mid-autumn. The implications of these results for ensuring the sustainable management of this rodent are discussed

ReCuSum: A polyvalent method to monitor tropical forest disturbances

Change detection methods based on Earth Observations are increasingly used to monitor rainforest in the intertropical band. Until recently, deforestation monitoring was mainly based on remotely sensed optical images which often face limitations in humid tropical areas due to frequent cloud coverage. This leads to late detections of disturbance events. Since the launch of Sentinel-1 acquiring images with a revisit time of 12 days and a spatial resolution of 5 x 20 m in Brazil, Synthetic Aperture Radar (SAR) images have been increasingly used to monitor deforestation. In this study, we propose a multitemporal version of the change detection method we previously applied to timeseries of Sentinel-1 SAR images, to monitor deforestation/degradation in the Congo rainforest. Our approach is based on a Cumulative Sum (CuSum) method combined with a spatial recombination of Critical Thresholds (CuSum cross-Tc). The newly developed multitemporal CuSum method (ReCuSum) was applied to a time-series of 82 dual polarization (VH, VV) Ground Range Detected (GRD) Sentinel-1 images acquired in the Para State, in the Brazilian Amazonia, from 29/09/2016 to 01/07/2019. The ReCuSum method consists of iteratively applying the CuSum cross-Tc to monitor multiple changes in a time-series by splitting the time-series at each date of detected change and by independently iterating over the time periods resulting from the splits. The number of changes in the time-series was then analysed according to the vegetation type (Forest, non-forest vegetation) determined by visual inspection of optical Sentinel-2 image and PlanetScope monthly mosaic. This showed a difference between non-forest vegetation and forested areas. A threshold based on the number of changes (Tnbc) was then developed to differentiate forest from non-forest disturbances. The ability to monitor non-forest vegetation was analysed: the CuSum cross-Tc detected up to 90% of the total non-forest vegetation area over the study region in the past period. After removing past disturbances and past non-forest vegetation, then removing the pixels covered with non-forest vegetations based on Tnbc, the application of the ReCuSum led to a precision of 81%, a recall of 68%, a kappa coefficient of 0.72 and a F1-score of 0.74 in forest disturbance monitoring. According to these results, ReCuSum applied to Sentinel-1 time-series of images can be used for efficient forest disturbance monitoring and for generating a forest / non-forest map after the application of newly developed post-processing steps. Sentinel-1 imagery can be used for both Forest / Non-forest mapping and for forest disturbance detection. ReCuSum was released as an open-source GIT project available at: https://forgemia. inra.fr/bertrand.ygorra/cusum-deforestation_monitoring

Reproductive ecology of coypu (Myocastor coypus Molina, 1782) in the Middle Delta of the Paraná River, Argentina

The objective of this study was to estimate and compare some important reproductive parameters of Myocastor coypus over time (June 2006-May 2008), in wetlands of the Middle Delta of the Paraná River (MD) Entre Ríos province, R. Argentina. Within the original coypu distribution range, the MD is among the areas of highest habitat suitability for the species. Coypus were captured and the following reproductive parameters were estimated on a monthly, seasonal and annual basis: pregnancy rate (PR), litter size (LS), gross productivity (GP) and annual production (AP). Statistical non-parametric tests were used for comparisons. Additionally, the expected birth date of each embryo and fetus was estimated by assigning it to a developmental stage category and considering the gestation period of the species. All the parameters showed high values and PR and LS differed significantly between the dry (2006) and humid years (2007). Two peaks of birth were detected, one in spring and another one in mid-autumn. The implications of these results for ensuring the sustainable management of this rodent are discussed