46 research outputs found
Model of invasion of a population by transposable elements presenting an asymmetric effect in gametes
Model of invasion of a population by transposable elements presenting an asymmetric effect in gametes
International audienc
The geographical distribution of P-M hybrid dysgenesis in Drosophila melanogaster
International audienc
SystÚme P-M de dysgénésie des hybrides, polymorphisme génétique et évolution des populations de Drosophila melanogaster
International audienc
SystÚme P-M de dysgénésie des hybrides, polymorphisme génétique et évolution des populations de Drosophila melanogaster
The distribution of the P-M system in Drosophila melanogaster strains from the People's Republic of China
Detecting predators and locating competitors while foraging: an experimental study of a medium-sized herbivore in an African savanna
Vigilance allows individuals to escape from predators, but it also reduces time for other activities which determine fitness, in particular resource acquisition. The principles determining how prey trade time between the detection of predators and food acquisition are not fully understood, particularly in herbivores because of many potential confounding factors (such as group size), and the ability of these animals to be vigilant while handling food. We designed a fertilization experiment to manipulate the quality of resources, and compared awareness (distinguishing apprehensive foraging and vigilance) of wild impalas (Aepyceros melampus) foraging on patches of different grass height and quality in a wilderness area with a full community of predators. While handling food, these animals can allocate time to other functions. The impalas were aware of their environment less often when on good food patches and when the grass was short. The animals spent more time in apprehensive foraging when grass was tall, and no other variable affected apprehensive behavior. The probability of exhibiting a vigilance posture decreased with group size. The interaction between grass height and patch enrichment also affected the time spent in vigilance, suggesting that resource quality was the main driver when visibility is good, and the risk of predation the main driver when the risk is high. We discuss various possible mechanisms underlying the perception of predation risk: foraging strategy, opportunities for scrounging, and inter-individual interference. Overall, this experiment shows that improving patch quality modifies the trade-off between vigilance and foraging in favor of feeding, but vigilance remains ultimately driven by the visibility of predators by foragers within their feeding patches
Deconstructing compassionate conservation
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public
Africaâs drylands in a changing world: Challenges for wildlife conservation under climate and land-use changes in the Greater Etosha Landscape
Proclaimed in 1907, Etosha National Park in northern Namibia is an iconic dryland system with a
rich history of wildlife conservation and research. A recent research symposium on wildlife
conservation in the Greater Etosha Landscape (GEL) highlighted increased concern of how
intensification of global change will affect wildlife conservation based on participant responses to
a questionnaire. The GEL includes Etosha and surrounding areas, the latter divided by a veteri nary fence into large, private farms to the south and communal areas of residential and farming
land to the north. Here, we leverage our knowledge of this ecosystem to provide insight into the
broader challenges facing wildlife conservation in this vulnerable dryland environment. We first
look backward, summarizing the history of wildlife conservation and research trends in the GEL
based on a literature review, providing a broad-scale understanding of the socioecological pro cesses that drive dryland system dynamics. We then look forward, focusing on eight key areas of
challenge and opportunity for this ecosystem: climate change, water availability and quality,
vegetation and fire management, adaptability of wildlife populations, disease risk, human wildlife conflict, wildlife crime, and human dimensions of wildlife conservation. Using this
model system, we summarize key lessons and identify critical threats highlighting future research
needs to support wildlife management. Research in the GEL has followed a trajectory seen
elsewhere reflecting an increase in complexity and integration across biological scales over time.
Yet, despite these trends, a gap exists between the scope of recent research efforts and the needs of
wildlife conservation to adapt to climate and land-use changes. Given the complex nature of
climate change, in addition to locally existing system stressors, a framework of forward-thinking
adaptive management to address these challenges, supported by integrative and multidisciplinary
research could be beneficial. One critical area for growth is to better integrate research and
wildlife management across land-use types. Such efforts have the potential to support wildlife
conservation efforts and human development goals, while building resilience against the impacts
of climate change. While our conclusions reflect the specifics of the GEL ecosystem, they have
direct relevance for other African dryland systems impacted by global change