16 research outputs found

    Demographic influences on the behavior of chimpanzees

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    Recent research has revealed substantial diversity in the behavior of wild chimpanzees. Understanding the sources of this variation has become a central focus of investigation. While genetic, ecological, and cultural factors are often invoked to explain behavioral variation in chimpanzees, the demographic context is sometimes overlooked as a contributing factor. Observations of chimpanzees at Ngogo, Kibale National Park, Uganda, reveal that the size and structure of the unit group or community can both facilitate and constrain the manifestation of behavior. With approximately 150 individuals, the Ngogo community is much larger than others that have been studied in the wild. We have taken advantage of the unusual demographic structure of this community to document new and intriguing patterns of chimpanzee behavior with respect to hunting, territoriality, and male social relationships. Chimpanzees at Ngogo hunt often and with a considerable degree of success. In addition, male chimpanzees there frequently patrol the boundary of their territory and engage in repeated bouts of lethal intergroup aggression. By forming two distinct subgroups, male chimpanzees at Ngogo also develop social bonds above the level of dyadic pairs. While the sheer number of chimpanzees contributes to differences in hunting, patrolling, mating, and subgrouping at Ngogo, the demographic situation may also constrain behavioral interactions. At Ngogo, male chimpanzees who are closely related genetically through the maternal line do not appear to affiliate or cooperate with each other. Demographic constraints may be responsible for this finding. In this paper, I use these examples to illustrate how the demographic context affects the possible range of behavioral options open to individuals and ultimately contributes to the explanation of behavioral diversity in chimpanzees.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41615/1/10329_2005_Article_139.pd

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The Hunting Behavior and Carnivory of Wild Chimpanzees

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    The pursuit, capture and consumption of small- and medium-sized vertebrates appear to be typical of all chimpanzee (Pan troglodytes) populations, although large variation exists. Red colobus monkeys (Piliocolobus sp.) appear to be the preferred prey, but intensity and frequency of hunting varies from month to month and among populations. Hunting is a predominately male activity and is typically opportunistic, although there is some evidence of searching for prey. The degree of cooperation during hunting, as well as prey selection, varies between East and West African populations and may be related to the way the kill is divided: in West Africa, hunters often collaborate, with kills tending to be shared according to participation, whereas in East Africa, cooperation in hunting is more limited and the kill is typically consumed selfishly, or divided in response to harassment (begging) by others. In some cases it may be shared tactically, trading meat with other males to strengthen alliances. The adaptive function of chimpanzee hunting is not well understood and a variety of hypotheses have been proposed. Ideas that chimpanzees hunt to make up for nutritional shortfalls, or to acquire meat to trade for sex, have failed to find empirical support, while recent work favors nutritional benefits of some kind. Nevertheless, cross-population studies evaluating multiple hypotheses are in their infancy, and there is much to be learned. In particular, very little is known about hunting of non-primates, particularly ungulates, or the impact that variation in levels of hunting, and of carcasses to share and consume, has on patterns of chimpanzee behavior. If one goal of studying this topic is to shed light on the behavioral ecology of hominins, then efforts to understand the diversity of hunting and carnivory in wild chimpanzees are needed

    Design and deployment of relational geodatabase on mobile GIS platform for real-time COVID-19 contact tracing in Ghana

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    This study reviewed the design and deployment of relational geodatabase on mobile GIS application, using collector for ArcGIS and survey 123 for ArcGIS platforms for COVID-19 contact tracing in Ghana during the lockdown. The study assessed whether cases spread by physical neighborhood contacts, defined by a 2km buffer of initial known 60 cases location. The application was deployed on the android tablet, which was used by field workers. Application Post-deployment review shows that from 30th March to 4th April 2020, 828 samples were collected with 34 confirmed cases, of which 61% occurred outside the 2km buffer. From 1-30 April 2020, 8,748 individuals with 16,087 contacts were tested within the physical neighbourhoods, 2.4% turned positive. Similarly, 7,501 individuals with 17,071 contacts were tested outside the physical neighbourhoods with 4.3% positives.  Results suggest that more infections occurred outside the case’s physical neighbourhoods possibly due to; (1) existence of unknown cases prior to lockdown; (2) cases were moving outside their physical neighborhood and infecting others; (3) panic movements of cases within the 3 days window between announcement and enforcement of lockdown; (4) movement of cases into the country through unapproved routes.  New cases were identified outside the lockdown areas, which could not be explained. This study raises questions about (1) the understanding of the mode of spread of the virus (2) the implementation of the lockdown, including the geographic coverage and timing. It is recommended that future decisions on contact tracing and lockdown should be guided by an understanding of the disease geography.&nbsp
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