18 research outputs found
Mercury content in the fur of jaguars (Panthera onca) from two areas under different levels of gold mining impact in the Brazilian Pantanal
<div><p>ABSTRACT The Pantanal is the largest inland wetland in the world and is under increasing anthropogenic threats, including long-term regionally intensive gold mining practices. Gold mining activities are known to cause the release of harmful pollutants such as mercury (Hg) to the surrounding environment. Jaguars (Panthera onca (Linnaeus, 1758)) are apex predators, and therefore show great potential to accumulate Hg by biomagnification. We hypothesize that total Hg content in the fur of jaguars from two sites within the Brazilian Pantanal would be significantly different as a function of distance from active gold mining operations. The Hg content was determined by fluorescence spectrometry. The mean ± SD Hg content in jaguars from the study site influenced by gold mining (SB) was compared to jaguars sampled in the area free of gold mining activities (CA) using a one-way ANOVA. The mean Hg content in jaguars from SB (673.0 ± 916.8 ”g g-1) is significantly different from jaguars sampled in CA (29.7 ± 23.3 ”g g-1), p = 0.03. The maximum recorded content of Hg was 2,010.4 ± 150.5 ”g g-1, highest level ever recorded in a wild animal. The data indicate that Hg is an important threat to jaguars within at-risk regions of the Pantanal.</p></div
Boxplot and Posterior Density Estimates for male and female home range (log km<sup>2</sup>) [A and B], home range crossing time (log days) [C and D], velocity autocorrelation timescale (h) [E and F], and average distance traveled (Km/day) [G and H].
<p>Black line represents the difference between the posterior distribution of males and females, red represents the posterior distribution of females and blue represents the posterior distribution of males.</p
Space Use and Movement of a Neotropical Top Predator: The Endangered Jaguar - Fig 2
<p>(A) Variogram of a resident jaguar. Notice that the animalâs semi-variance reaches an asymptote within a few days, roughly representing the time to cross its home range. The red line represents the fitted model and the red shading represents the 95% CI. (B) A non-resident jaguar. Note the lack of a clear asymptote despite the fact that the animal was monitored for a long period (591 days). This lack of asymptote indicates that this animal is not range resident and thus a home range analysis for this individual is not appropriate. For both A and B, the fraction of the variogram displayed is 65% of the duration of each dataset.</p
Data from: Jaguar Movement Database: a GPS-based movement dataset of an apex predator in the Neotropics
The field of movement ecology has rapidly grown during the last decade, with important advancements in tracking devices and analytical tools that have provided unprecedented insights into where, when, and why species move across a landscape. Although there has been an increasing emphasis on making animal movement data publicly available, there has also been a conspicuous dearth in the availability of such data on large carnivores. Globally, large predators are of conservation concern. However, due to their secretive behavior and low densities, obtaining movement data on apex predators is expensive and logistically challenging. Consequently, the relatively small sample sizes typical of large carnivore movement studies may limit insights into the ecology and behavior of these elusive predators. The aim of this initiative is to make available to the conservation-scientific community a dataset of 134,690 locations of jaguars (Panthera onca) collected from 117 individuals (54 males and 63 females) tracked by GPS technology. Individual jaguars were monitored in five different range countries representing a large portion of the speciesâ distribution. This dataset may be used to answer a variety of ecological questions including but not limited to: improved models of connectivity from local to continental scales; the use of natural or human-modified landscapes by jaguars; movement behavior of jaguars in regions not represented in this dataset; intraspecific interactions; and predator-prey interactions. In making our dataset publicly available, we hope to motivate other research groups to do the same in the near future. Specifically, we aim to help inform a better understanding of jaguar movement ecology with applications towards effective decision making and maximizing long-term conservation efforts for this ecologically important species
Map of study areas in Brazil and on the border of Brazil and Argentina.
<p>Source: mma.gov.br and wwf.org</p
Movement parameters and home range sizes for GPS-collared jaguar across Brazil and Argentina biomes.
<p>Home ranges were estimated via 95% Kernel Density Estimates (KDE) and Autocorrelated Kernel Density Estimates (AKDE)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0168176#t002fn001" target="_blank"><sup>1</sup></a>.</p
Extent and conservation status of remaining habitat in Brazilâs major biomes and a portion of Atlantic Forest in Argentina.
<p>Jaguars are considered vulnerable in the Amazon and Pantanal, endangered in the Cerrado and critically endangered in the Atlantic Forest and Caatinga [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0168176#pone.0168176.ref014" target="_blank">14</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0168176#pone.0168176.ref015" target="_blank">15</a>].</p