No abstract

No abstract

Camera-trap surveys were carried out at two different sites within the Atlantic Forest of Misiones province, Argentina, to study the density, habitat use and activity patterns of ocelots. At Urugua-´ı Provincial Park, 17 different individuals were captured (nine females, six males, two of unknown sex) during a 3-monthlong survey (34 camera stations, 1409 trap days). At Iguazu´National Park, 34 different individuals were trapped (20 adult females, nine adult males, two subadult females and three of unknown sex) during the survey (39 sampling stations, 1631 trap days). Population density estimates ( AE SE) for Urugua-´ı, in an area of between 150 and 259 km 2 (depending on the buffer used to estimate the area effectively sampled), range from 7.7 AE 1.4 to 13.4 AE 2.6 individuals  100 km À2 , whereas at Iguazu´, in an area of between 275 and 428 km 2 , a population density of between 12.8 AE 2.7 and 20.0 AE 4.2 individuals  100 km À2 was estimated. Minimum observed range estimates for individuals with 43 capture sites range from 3.19 to 37.09 km 2 for four males and from 4.17 to 7.11 km 2 for three females, but underestimate the true home range size. Ocelots were captured more frequently along old roads than on new trails opened with machetes. Ocelots were captured more frequently at night than during the day and reduce their use of roads and trails during the week previous to and during full moon nights, a behavior previously reported for Amazonian ocelots. Population density estimates for ocelots in the Upper Paran´a Atlantic Forest ecoregion are lower than those at other neotropical sites. The whole Green Corridor contains a population of about 1280 individuals. This estimate should bring our attention to the larger cats (pumas and jaguars) that live at lower population densities because the future of their local populations is compromised if protected areas are not urgently created and properly managed.

Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with evidence of recent allelic loss in local areas. Although some migrant and admixed individuals were identified, our results indicate that recent large-scale habitat removal and fragmentation among these areas has been sufficiently strong to promote differentiation induced by drift and loss of alleles at each site. Low estimated effective sizes supported the inference that genetic drift could have caused this effect within a short time frame. These results indicate that jaguars' ability to effectively disperse across the human-dominated landscapes that separate the fragments is currently very limited, and that each fragment contains a small, isolated population that is already suffering from the effects of genetic drift.

The jaguar is the top predator of the Atlantic Forest (AF), which is a highly threatened biodiversity hotspot that occurs in Brazil, Paraguay and Argentina. By combining data sets from 14 research groups across the region, we determine the population status of the jaguar and propose a spatial prioritization for conservation actions. About 85% of the jaguar’s habitat in the AF has been lost and only 7% remains in good condition. Jaguars persist in around 2.8% of the region, and live in very low densities in most of the areas. The population of jaguars in the AF is probably lower than 300 individuals scattered in small sub-populations. We identified seven Jaguar Conservation Units (JCUs) and seven potential JCUs, and only three of these areas may have ≥50 individuals. A connectivity analysis shows that most of the JCUs are isolated. Habitat loss and fragmentation were the major causes for jaguar decline, but human induced mortality is the main threat for the remaining population. We classified areas according to their contribution to jaguar conservation and we recommend management actions for each of them. The methodology in this study could be used for conservation planning of other carnivore species.

Accurately estimating home range and understanding movement behavior can provide important information on ecological processes. Advances in data collection and analysis have improved our ability to estimate home range and movement parameters, both of which have the potential to impact species conservation. Fitting continuous-time movement model to data and incorporating the autocorrelated kernel density estimator (AKDE), we investigated range residency of forty-four jaguars fit with GPS collars across five biomes in Brazil and Argentina. We assessed home range and movement parameters of range resident animals and compared AKDE estimates with kernel density estimates (KDE). We accounted for differential space use and movement among individuals, sex, region, and habitat quality. Thirty-three (80%) of collared jaguars were range resident. Home range estimates using AKDE were 1.02 to 4.80 times larger than KDE estimates that did not consider autocorrelation. Males exhibited larger home ranges, more directional movement paths, and a trend towards larger distances traveled per day. Jaguars with the largest home ranges occupied the Atlantic Forest, a biome with high levels of deforestation and high human population density. Our results fill a gap in the knowledge of the species’ ecology with an aim towards better conservation of this endangered/critically endangered carnivore—the top predator in the Neotropics.

There is a tendency for non-native English scientists to publish exclusively in English, assuming that this will make their articles more visible and cited. We tested this hypothesis by comparing the effect of language on the number of citations of articles published in six natural sciences journals from five countries that publish papers in either English or other languages. We analyzed the effect of language (English vs non-English), paper length, and year of publication on the number of citations. The articles published in English have a higher number of citations than those published in other languages, when the effect of journal, year of publication, and paper length are statistically controlled. This may result because English articles are accessible to a larger audience, but other factors need to be explored. Universities and scientific institutions should be aware of this situation and improve the teaching of English, especially in the natural sciences.

No abstract