Facial asymmetry tracks genetic diversity among Gorilla subspecies

Mountain gorillas are particularly inbred compared to other gorillas and even the most inbred human populations. As mountain gorilla skeletal material accumulated during the 1970s, researchers noted their pronounced facial asymmetry and hypothesized that it reflects a population-wide chewing side preference. However, asymmetry has also been linked to environmental and genetic stress in experimental models. Here, we examine facial asymmetry in 114 crania from three Gorilla subspecies using 3D geometric morphometrics. We measure fluctuating asymmetry (FA), defined as random deviations from perfect symmetry, and population-specific patterns of directional asymmetry (DA). Mountain gorillas, with a current population size of about 1000 individuals, have the highest degree of facial FA (explaining 17% of total facial shape variation), followed by Grauer gorillas (9%) and western lowland gorillas (6%), despite the latter experiencing the greatest ecological and dietary variability. DA, while significant in all three taxa, explains relatively less shape variation than FA does. Facial asymmetry correlates neither with tooth wear asymmetry nor increases with age in a mountain gorilla subsample, undermining the hypothesis that facial asymmetry is driven by chewing side preference. An examination of temporal trends shows that stress-induced developmental instability has increased over the last 100 years in these endangered apes

Facial asymmetry tracks genetic diversity among Gorilla subspecies

Electronic Accessibility Statement: SUNY Oneonta is committed to providing equal access to college information by ensuring our digital content is accessible by everyone regardless of physical, sensory, or cognitive ability. This item has been checked by Adobe Acrobat Accessibility Check and remediated with the following result: [Remediation: language, title, tagged, reading order / Hazards: alt text]. To request further accessibility remediation on this SOAR repository item for your specific needs, please contact [email protected] gorillas are particularly inbred compared to other gorillas and even the most inbred human populations. As mountain gorilla skeletal material accumulated during the 1970s, researchers noted their pronounced facial asymmetry and hypothesized that it reflects a population-wide chewing side preference. However, asymmetry has also been linked to environmental and genetic stress in experimental models. Here, we examine facial asymmetry in 114 crania from three Gorilla subspecies using 3D geometric morphometrics. We measure fluctuating asymmetry (FA), defined as random deviations from perfect symmetry, and population-specific patterns of directional asymmetry (DA). Mountain gorillas, with a current population size of about 1000 individuals, have the highest degree of facial FA (explaining 17% of total facial shape variation), followed by Grauer gorillas (9%) and western lowland gorillas (6%), despite the latter experiencing the greatest ecological and dietary variability. DA, while significant in all three taxa, explains relatively less shape variation than FA does. Facial asymmetry correlates neither with tooth wear asymmetry nor increases with age in a mountain gorilla subsample, undermining the hypothesis that facial asymmetry is driven by chewing side preference. An examination of temporal trends shows that stress-induced developmental instability has increased over the last 100 years in these endangered apes.VoRSUNY OneontaAnthropologyN/

Protected areas and rural livelihoods: Contrasting systems of wildlife management in the Democratic Republic of Congo

This multi-disciplinary study examines the ecological, social and economic consequences of wildlife management within the Garamba ecosystem in the north east of the Democratic Republic of Congo. This protected area system comprises a national park, which is formally managed by state conservation authorities and where human resource use and settlement is prohibited. The national park is surrounded by hunting reserves, which contain resident human populations. The wildlife in the reserves is informally managed by socially defined user groups who derive financial and other benefits from wildlife resources. These systems are used to compare how different wildlife management practices meet conservation and local development objectives. Long term ecological data are used to examine spatial and temporal variations in species distribution and abundance in relation to wildlife management and human related activities. Using ground transect and remote sensing techniques, spatial variations in species richness and abundance are compared to the presence of agricultural communities, local markets and wildlife protection areas. Sampled aerial count data, collected over two decades by the Park authorities, are analysed to compare the temporal variations in animal abundance under different wildlife protection regimes. These ecological findings indicate that centralised wildlife protection meets conservation objectives because regulation is associated with high species richness and abundance. However, an analysis of local resource use priorities indicates that the existing protectionist approaches implemented by the centralised authorities cannot contribute to local development objectives. Against this ecological background, several hypotheses are tested to examine the extent to which existing forms of wildlife management and utilisation can meet both conservation and development priorities. Analyses, using survey data from local households, hunters, and markets, provide the basis for examining the significance of wild foods to local livelihoods and the potential for sustainable harvesting and local regulation of wildlife offtake. Patterns of resource use at the household level are analysed to understand the relationship between wealth status and resource use. Conservation behaviour amongst hunters is examined by testing the evidence for restraint during the hunt. These modes of enquiry provide a basis for understanding people's motivation to exploit natural resources sustainably. Analysis of the bushmeat trade using anthropological methods (exploring bushmeat commodity chains, or filières) and economic models shows that the use of bushmeat is socially regulated by local power relations between traditional, civil and military authorities. The period of intense conflict in the region between 1996 and 1997 reveals the patterns of wildlife offtake in the absence of state and informal regulatory systems. The combination of long term ecological data with detailed socio economic variables provides an innovative approach to examining the impacts of centralised and informal systems of wildlife management. This study makes a direct contribution to current debates surrounding the impact of regulatory and consumption based models of wildlife management

Do wildlife laws work? Species protection and the application of a prey choice model to poaching decisions.

Legislation for the protection of species is a global conservation tool. However, in many developing countries lack of resources means that effectiveness relies on voluntary compliance, leading to contradictory assumptions. On one hand, laws introduced without effective enforcement mechanisms carry an implicit assumption that voluntary compliance will occur. On the other hand, it is often openly assumed that, without enforcement, there will in fact be no compliance. Which assumption holds has rarely been rigorously tested. Here we show that laws for the protection of some species of large mammal have no effect on the prey choice patterns of primarily commercial hunters in the Democratic Republic of Congo, confirming the second assumption. We established this result by using an optimal diet model to predict the pattern of prey choice in the absence of regulation. Prey choice patterns predicted by the model were accurate across a range of conditions defined by time, space and type of hunting weapon. Given that hunters will not comply voluntarily, the protection of vulnerable species can only take place through effective enforcement, for example by wildlife authorities restricting access to protected areas, or by traditional authorities restricting the sale of protected species in local markets

Viability analysis for population reinforcement of Grauer's gorillas at Mount Tshiaberimu, Democratic Republic of Congo

Reintroduction and translocation programs have been sparingly used for the management of endangered primate populations. Mount Tshiaberimu in eastern Democratic Republic of the Congo (DRC) contains 6 Grauer's gorillas (Gorilla beringei graueri) with only 2 adult females. Without intervention, this population is at high risk of extinction. We designed population viability analysis models to compare different release scenarios of wild-born captive female gorillas housed at the Gorilla Rehabilitation and Conservation Education (GRACE) Center in the DRC. We identified the minimum number of females needed to maintain a viable population in this habitat. We used a stochastic Leslie matrix model and a more complex individual-based model to project population growth. We used published demographic parameters for mountain gorillas (Gorilla b. beringei) corresponding to a 3.2% annual growth rate, and then applied a correction factor to female fertility to obtain parameters consistent with 1% and 2% growth rates. We ran each scenario over a 50-year time period (1,000 simulations) to determine the final population size and risk of local extinction. Results from our optimistic (3.2% growth) and conservative (1% growth) individual-based model projections indicated that the extinction risk dropped below 1% with the release of at least 2 or 3 females, respectively. Both approaches predicted similar extinction risks for all scenarios; however, the variance in final population size was higher with the individual-based model. For long-lived mammals like primates, we recommend the use of individual-based models, which can incorporate life-history parameters such as long gestation and nursing periods. Our analysis suggests a translocation of ≥3 females to rescue the Tshiaberimu gorilla population in the short term. Factors such as inbreeding depression, habitat quality, disease risks, and anthropogenic pressures will need to be evaluated in later stages of population reinforcement planning

Viability analysis for population reinforcement of Grauer's gorillas at Mount Tshiaberimu, Democratic Republic of Congo

Reintroduction and translocation programs have been sparingly used for the management of endangered primate populations. Mount Tshiaberimu in eastern Democratic Republic of the Congo (DRC) contains 6 Grauer's gorillas (Gorilla beringei graueri) with only 2 adult females. Without intervention, this population is at high risk of extinction. We designed population viability analysis models to compare different release scenarios of wild-born captive female gorillas housed at the Gorilla Rehabilitation and Conservation Education (GRACE) Center in the DRC. We identified the minimum number of females needed to maintain a viable population in this habitat. We used a stochastic Leslie matrix model and a more complex individual-based model to project population growth. We used published demographic parameters for mountain gorillas (Gorilla b. beringei) corresponding to a 3.2% annual growth rate, and then applied a correction factor to female fertility to obtain parameters consistent with 1% and 2% growth rates. We ran each scenario over a 50-year time period (1,000 simulations) to determine the final population size and risk of local extinction. Results from our optimistic (3.2% growth) and conservative (1% growth) individual-based model projections indicated that the extinction risk dropped below 1% with the release of at least 2 or 3 females, respectively. Both approaches predicted similar extinction risks for all scenarios; however, the variance in final population size was higher with the individual-based model. For long-lived mammals like primates, we recommend the use of individual-based models, which can incorporate life-history parameters such as long gestation and nursing periods. Our analysis suggests a translocation of ≥3 females to rescue the Tshiaberimu gorilla population in the short term. Factors such as inbreeding depression, habitat quality, disease risks, and anthropogenic pressures will need to be evaluated in later stages of population reinforcement planning

Population viability analysis for Grauer's gorillas

This study was developed to help plan the reinforcement of a small population of Grauer's gorillas (Gorilla beringei graueri) found in Mount Tshiaberimu, Democratic Republic of the Congo (DRC). We designed population viability analysis models to compare different release scenarios of wild-born captive female gorillas housed at the Gorilla Rehabilitation and Conservation Education (GRACE) Center in DRC. We used both a stochastic Leslie matrix model as well as a more complex individual-based model to project population growth. The compressed folder inlcudes a README file, three R code files, and sub-folders with datasets used in this project. The README document provides descriptions of each of these files and subfolders. </p