The jaguar ( Panthera onca ), the largest felid in the American Continent, is currently threatened by habitat loss, fragmentation and human persecution. We have investigated the genetic diversity, population structure and demographic history of jaguars across their geographical range by analysing 715 base pairs of the mitochondrial DNA (mtDNA) control region and 29 microsatellite loci in ≈ ≈ ≈ ≈ 40 individuals sampled from Mexico to southern Brazil. Jaguars display low to moderate levels of mtDNA diversity and medium to high levels of microsatellite size variation, and show evidence of a recent demographic expansion. We estimate that extant jaguar mtDNA lineages arose 280 000 -510 000 years ago (95% CI 137 000 -830 000 years ago), a younger date than suggested by available fossil data. No strong geographical structure was observed, in contrast to previously proposed subspecific partitions. However, major geographical barriers such as the Amazon river and the Darien straits between northern South America and Central America appear to have restricted historical gene flow in this species, producing measurable genetic differentiation. Jaguars could be divided into four incompletely isolated phylogeographic groups, and further sampling may reveal a finer pattern of subdivision or isolation by distance on a regional level. Operational conservation units for this species can be defined on a biome or ecosystem scale, but should take into account the historical barriers to dispersal identified here. Conservation strategies for jaguars should aim to maintain high levels of gene flow over broad geographical areas, possibly through active management of disconnected populations on a regional scale.
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.
Between July 1980 and February 1984, six jaguars (two males, four females) were fitted with radio‐collars and monitored for a cumulative total of 105 months, in the Pantanal region of southwestern Brazil. Mean home range size (minimum convex polygon) for five of them (one male, four females) was 142‐ 1 km2. Mean home range size during the dry season was 54·3 km2, whereas in the wet season it was significantly smaller, 12·8 km2. Mean home range overlap of the four females was 42%. Use of gallery forest and forest patches exceeded the availability of these habitat types in the animals' home ranges, whereas open forest and grassland were used less than expected on the basis of their availability. Mean distance moved between locations on consecutive days was 2·4 km (0.2‐10·4 km). The mean one‐day movement of the male jaguar was significantly (P<0·001) larger than that of the females. Mean distance travelled by all animals during one‐day intervals in the dry season was significantly greater (P<0·001) than that travelled in other months. Jaguars were more active during daytime than night‐time (P<0·001). Overall level of activity for the wet season did not differ from that of the dry season. With their larger body size, jaguars in the Pantanal may require more food than jaguars in other areas of the species' range. This, in addition to differences in prey availability and the annual availability of dry land, appear to influence the difference in home range size between jaguar populations.
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.
In spite of the worldwide occurrence of domestic cats and dogs, and their close relationship with humans, the number of published papers on free-ranging cats Felis catus and dogs Canis familiaris, is small. The diet of both species was estimated in a suburban and rural environment in July 2002 and January 2003. Visual observations and scat collection of both species were accomplished along a 10 km transect line in the Campus 'Luiz de Queiroz', University of Sa˜o Paulo, Piracicaba, south-eastern Brazil. The diet of both species was determined by analysis of sterilized, washed, dried and sorted scats. Estimated abundances of free-ranging cats and dogs in the sampled area were 81 ( AE 4.32) and 42 ( AE 2.96), respectively. Cats and dogs were more abundant in the suburban than in the rural environment (t= 3.78, Po0.001, N = 55; t= 8.38, Po0.001, N = 55, respectively) and cats were more abundant than dogs in the suburban environment (t= 6.76, Po0.001, N = 55), even though there was no significant difference between the abundance of both species in the rural environment (t = 0.82, P= 0.46, N= 55). Invertebrates were the most commonly consumed item by both species, followed by mammals (cats: 63.24 and 20.51%; dogs: 57.05 and 25.15%, respectively). Niche breadth was 0.4892 for cats and 0.4463 for dogs. Niche overlap was almost complete (0.97108). The consumption of mammals was estimated to be between 16.76 and 25.42 kg individual À1 year À1 for dogs and between 2.01 and 2.9 kg individual À1 year À1 for cats. These data might be useful to establish a management program to minimize the predation pressure of free-ranging cats and dogs on wildlife.
Building bridges between environmental and political agendas is essential nowadays in face of the increasing human pressure on natural environments, including wetlands. Wetlands provide critical ecosystem services for humanity and can generate a considerable direct or indirect income to the local communities. To meet many of the sustainable development goals, we need to move our trajectory from the current environmental destructive development to a wiser wetland use. The current article contain a proposed agenda for the Pantanal aiming the improvement of public policy for conservation in the Pantanal, one of the largest, most diverse, and continuous inland wetland in the world. We suggest and discuss a list of 11 essential interfaces between science, policy, and development in region linked to the proposed agenda. We believe that a functional science network can booster the collaborative capability to generate creative ideas and solutions to address the big challenges faced by the Pantanal wetland.
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