Environmental and anthropogenic factors synergistically affect space use of jaguars.

Large terrestrial carnivores have undergone some of the largest population declines and range reductions of any species, which is of concern as they can have large effects on ecosystem dynamics and function.1-4 The jaguar (Panthera onca) is the apex predator throughout the majority of the Neotropics; however, its distribution has been reduced by >50% and it survives in increasingly isolated populations.5 Consequently, the range-wide management of the jaguar depends upon maintaining core populations connected through multi-national, transboundary cooperation, which requires understanding the movement ecology and space use of jaguars throughout their range.6-8 Using GPS telemetry data for 111 jaguars from 13 ecoregions within the four biomes that constitute the majority of jaguar habitat, we examined the landscape-level environmental and anthropogenic factors related to jaguar home range size and movement parameters. Home range size decreased with increasing net productivity and forest cover and increased with increasing road density. Speed decreased with increasing forest cover with no sexual differences, while males had more directional movements, but tortuosity in movements was not related to any landscape factors. We demonstrated a synergistic relationship between landscape-scale environmental and anthropogenic factors and jaguars' spatial needs, which has applications to the conservation strategy for the species throughout the Neotropics. Using large-scale collaboration, we overcame limitations from small sample sizes typical in large carnivore research to provide a mechanism to evaluate habitat quality for jaguars and an inferential modeling framework adaptable to the conservation of other large terrestrial carnivores.

Cryptorchidism in free-living jaguar (Panthera onca): first case report.

Cryptorchidism is a genital alteration wherein one or both testicles fail to descend into the scrotum and has multifactorial causes. A free-range adult male was captured twice in the Pantanal of Nhecolândia to put a GPS collar and semen collection. Pharmacological semen collection, andrological examination and semen analysis were performed. At the first capture and during the andrological examination only the left testis was found, and the male qualified as cryptorchid. The penis had no penile spines at either procedure. The semen volume obtained at first and second capture was 435 and 160 µL, respectively, with a concentration of 618 and 100 x 106 sperm/mL, progressive motility of ~ 5% and ~ 1% and total morphological sperm abnormalities of 74% and 86%. The male was monitored by a GPS collar, but the signal was lost, making it difficult to re-captures and perform new seminal and ultrasound evaluations to discard monorchidism - exceedingly rare in felids. Genetic studies to assess the individual's homozygosity are necessary to verify whether cryptorchidism in this individual has a genetic factor.

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 species' 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. There are no costs, copyright, or proprietary restrictions associated with this data set. When using this data set, please cite this article to recognize the effort involved in gathering and collating the data and the willingness of the authors to make it publicly available.

Characterization of metal-responsive transcription factor (MTF-1) from the giant rodent capybara reveals features in common with human as well as with small rodents (mouse, rat). Short communication.

From mammals to insects, metal-responsive transcription factor 1 (MTF-1) is essential for the activation of metallothionein genes upon heavy-metal load. We have previously found that human MTF-1 induces a stronger metal response than mouse MTF-1. The latter differs from the human one in a number of amino acid positions and is also shorter by 78 aa at its C-terminus. We reasoned that the weaker metal inducibility might be associated with a lesser demand for tight metal homeostasis in a low-weight, short-lived animal, and thus set out to determine the sequence of MTF-1 from the largest living rodent, the Brazilian capybara that can reach 65 kg and also has a considerably longer life span than smaller rodents. An expression clone for capybara MTF-1 was then tested for its activity in both mouse and human cells. Our analysis revealed three unexpected features: i) capybara MTF-1 in terms of amino acid sequence is much more closely related to human than to mouse MTF-1, suggesting an accelerated evolution of MTF-1 in the evolutionary branch leading to small rodents; ii) capybara MTF-1 is even 32 aa shorter at its C-terminus than mouse MTF-1, and iii) in an activity test, it is not more active than mouse MTF-1. The latter two findings might indicate that capybara has evolved in an environment with low heavy-metal load.