Effects of habitat deterioration on the population genetics and conservation of the jaguar

Over the past century, human activities and their side effects have significantly threatened both ecosystems and resident species. Nevertheless, the genetic patterns of large felids that depend heavily on large and well-conserved continuous habitat remain poorly studied. Using the largest-ever contemporary genetic survey of wild jaguars (Panthera onca), we evaluated their genetic diversity and population structure in natural (Brazilian Amazon) and highly modified habitats (e.g. Cerrado, Caatinga) including those close to the northern (Yucatan, Mexico) and southern (Pantanal) edge of the species’ distribution range. Data from our set of microsatellites revealed a pronounced genetic structure, with four genetically differentiated geographic areas. Geographic distance was not the only factor influencing genetic differentiation through the jaguar range. Instead, we found evidence of the effects of habitat deterioration on genetic patterns: while the levels of genetic diversity in the Amazon forest, the largest continuum habitat for the species, are high and consistent with panmixia across large distances, genetic diversity near the edge of the species distribution has been reduced through population contractions. Mexican jaguar populations were highly differentiated from those in Brazil and genetically depauperated. An isolated population from the Caatinga showed the genetic effects of a recent demographic decline (within the last 20–30 years), which may reflect recent habitat degradation in the region. Our results demonstrate that the jaguar is highly sensitive to habitat fragmentation especially in human-dominated landscapes, and that in Brazil, the existing but limited genetic connectivity in the central protected areas should be maintained. These conclusions have important implications for the management of wide-ranging species with high dispersal and low population density. The restoration of ecological connectivity between populations over relatively large scales should be one of the main priorities for species conservation.Peer reviewe

Monitoring jaguar populations Panthera onca with non-invasive genetics: A pilot study in Brazilian ecosystems

The global population of jaguars Panthera onca has decreased significantly since the beginning of the 20th century. Given the scarcity of demographic and biological information, estimating population parameters is critical for the design of conservation measures. The jaguar’s elusive behaviour makes it impossible to estimate and monitor populations by direct observation. We propose a noninvasive genetic sampling approach and demonstrate its potential for large-scale monitoring. Sex identification was optimized for faecal samples of jaguars and other felids. We also optimized a set of 11 microsatellite markers for reliable identification of individuals. We estimated the effectiveness of faecal sample genotyping in two distinct Brazilian biomes: the Pantanal and the semi-arid Caatinga. Almost 90% of the samples that were molecularly identified as jaguar (n590) were successfully genotyped and were assigned to 30 individuals. Genetic diversity was generally high but was significantly lower in the Caatinga population. We show that non-invasive genetic sampling can be a reliable tool to study population parameters and to monitor the genetic status of jaguar populations in different habitats. It may also be useful for future surveys of jaguars that address ecological, behavioural and conservation issues, and could provide a baseline for non-invasive genetic studies of other wild felid populations.Peer reviewe

Note on the diet of the jaguar in central Brazil

Diet of the jaguar Panthera onca in the Cerrado, central Brazil, was investigated based on a sample of genetically identified jaguar scats. At least nine prey species were observed in 35 scat samples. Giant anteaters Myrmecophaga tridactyla contributed more than 75 % of biomass to the observed diet. Tapirs Tapirus terrestris and peccaries Tayassu pecari and Pecari tajacu contributed approximately 6 % to jaguar diet each, and small mammals contributed least to the jaguar diet. At 0.121, dietary niche breadth was narrower than reported in most other studies. Due to their physical characteristics and abundance, giant anteaters are likely the most profitable prey for jaguars in Emas National Park, and as an important prey, they should be included in jaguar conservation efforts. © 2013 Springer-Verlag Berlin Heidelberg.Peer Reviewe