Lethal intergroup encounters occur in many species because of sexual selection. While documented in mountain gorillas, they are absent in western gorillas as, instead, it is predicted by their higher feeding (frugivory) and mate competition (single-vs. multi-male groups).
View Article and Find Full Text PDFBackground: Alzheimer's disease (AD) is a neurodegenerative disease that remains uncured. Its pathogenesis is characterized by the formation of β-amyloid (Aβ) plaques. The use of antigen-specific regulatory T cells (Tregs) through adoptive transfer has shown promise for the treatment of many inflammatory diseases, although the effectiveness of polyspecific Tregs is limited.
View Article and Find Full Text PDFThe forkhead family transcription factor (FOXP3) is an essential regulator for the development of regulatory T cells (Tregs) and orchestrates both suppressive function and Treg lineage identity. Stable expression of FOXP3 enables Tregs to maintain immune homeostasis and prevent autoimmunity. However, under pro-inflammatory conditions, FOXP3 expression in Tregs can become unstable, leading to loss of suppressive function and conversion into pathogenic T effector cells.
View Article and Find Full Text PDFBackground: Regulatory T cells (Tregs) play an important role in the maintenance of immune homeostasis and the establishment of immune tolerance. Since Tregs do not secrete endogenous IL-2, they are especially dependent on external IL-2. IL-2 deficiency leads to lower Treg numbers, instability of the Treg phenotype and loss of immune regulation.
View Article and Find Full Text PDFAfrican large carnivores have undergone significant range and population declines over recent decades. Although conservation planning and the management of threatened species requires accurate assessments of population status and monitoring of trends, there is evidence that biodiversity monitoring may not be evenly distributed or occurring where most needed. Here, we provide the first systematic review of African large carnivore population assessments published over the last two decades (2000-2020), to investigate trends in research effort and identify knowledge gaps.
View Article and Find Full Text PDFLarge carnivores increasingly inhabit human-affected landscapes, which exhibit heterogeneity in biotic resources, anthropogenic pressures, and management strategies. Understanding large carnivore habitat use in these systems is critical for their conservation, as is the evaluation of competing management approaches and the impacts of significant land-use changes. We used occupancy modeling to investigate habitat use of an intact eastern African large carnivore guild across the 45,000 km Ruaha-Rungwa landscape in south-central Tanzania.
View Article and Find Full Text PDFConservation translocations have become an important management tool, particularly for large wildlife species such as the lion (). When planning translocations, the genetic background of populations needs to be taken into account; failure to do so risks disrupting existing patterns of genetic variation, ultimately leading to genetic homogenization, and thereby reducing resilience and adaptability of the species. We urge wildlife managers to include knowledge of the genetic background of source/target populations, as well as species-wide patterns, in any management intervention.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2018
Protected areas (PAs) play an important role in conserving biodiversity and providing ecosystem services, yet their effectiveness is undermined by funding shortfalls. Using lions () as a proxy for PA health, we assessed available funding relative to budget requirements for PAs in Africa's savannahs. We compiled a dataset of 2015 funding for 282 state-owned PAs with lions.
View Article and Find Full Text PDFMitochondrial DNA A DNA Mapp Seq Anal
April 2018
Once found throughout Africa and Eurasia, the leopard (Panthera pardus) was recently uplisted from Near Threatened to Vulnerable by the International Union for the Conservation of Nature (IUCN). Historically, more than 50% of the leopard's global range occurred in continental Africa, yet sampling from this part of the species' distribution is only sparsely represented in prior studies examining patterns of genetic variation at the continental or global level. Broad sampling to determine baseline patterns of genetic variation throughout the leopard's historical distribution is important, as these measures are currently used by the IUCN to direct conservation priorities and management plans.
View Article and Find Full Text PDFThe geographic distribution and habitat association of most mammalian polymorphic phenotypes are still poorly known, hampering assessments of their adaptive significance. Even in the case of the black panther, an iconic melanistic variant of the leopard (Panthera pardus), no map exists describing its distribution. We constructed a large database of verified records sampled across the species' range, and used it to map the geographic occurrence of melanism.
View Article and Find Full Text PDFThe PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2017
Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data.
View Article and Find Full Text PDFThe leopard's (Panthera pardus) broad geographic range, remarkable adaptability, and secretive nature have contributed to a misconception that this species might not be severely threatened across its range. We find that not only are several subspecies and regional populations critically endangered but also the overall range loss is greater than the average for terrestrial large carnivores. To assess the leopard's status, we compile 6,000 records at 2,500 locations from over 1,300 sources on its historic (post 1750) and current distribution.
View Article and Find Full Text PDFWe compiled all credible repeated lion surveys and present time series data for 47 lion (Panthera leo) populations. We used a Bayesian state space model to estimate growth rate-λ for each population and summed these into three regional sets to provide conservation-relevant estimates of trends since 1990. We found a striking geographical pattern: African lion populations are declining everywhere, except in four southern countries (Botswana, Namibia, South Africa, and Zimbabwe).
View Article and Find Full Text PDFThe evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage.
View Article and Find Full Text PDFThe African lion has declined to <35,000 individuals occupying 25% of its historic range. The situation is most critical for the geographically isolated populations in West Africa, where the species is considered regionally endangered. Elevating their conservation significance, recent molecular studies establish the genetic distinctiveness of West and Central African lions from other extant African populations.
View Article and Find Full Text PDFThe trophy hunting of lions Panthera leo is contentious due to uncertainty concerning conservation impacts and because of highly polarised opinions about the practice. African lions are hunted across at least ~558,000 km(2), which comprises 27-32% of the lion range in countries where trophy hunting of the species is permitted. Consequently, trophy hunting has potential to impart significant positive or negative impacts on lions.
View Article and Find Full Text PDFPacker et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small.
View Article and Find Full Text PDFThe slow life histories of great apes (hereafter 'apes') combined with a growing inventory of predation incidents suggest that apes may be strongly affected by direct predation, as well as by predation risk. Predation risk may shape and increase behavioural flexibility by forcing individuals to adapt their behaviour to predator patterns. Forest leopards are an apex predator of primates in African rain forests and may represent a significant risk to ape populations.
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