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Addax

The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Peter Leimgruber – 1st expert on this subject based on the ideXlab platform

  • on the brink of extinction habitat selection of Addax and dorcas gazelle across the tin toumma desert niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.

  • On the brink of extinction—Habitat selection of Addax and dorcas gazelle across the Tin Toumma desert, Niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.

Tim Wacher – 2nd expert on this subject based on the ideXlab platform

  • VIEWPOINT Fiddling in biodiversity hotspots while deserts burn? Collapse of the Sahara’s megafauna
    , 2020
    Co-Authors: Sarah M. Durant, Mohanad Abdelgadir, Tim Wacher, Rosie Woodroffe, Paul De Ornellas, C Ransom, John Newby, Bashir, Jonathan E. M. Baillie, M. Beddiaf

    Abstract:

    Biodiversity hotspots understandably attract considerable conservation attention. However, deserts are rarely viewed as conservation priority areas, due to their relatively low productivity, yet these systems are home to unique species, adapted to harsh and highly variable environments. While global attention has been focused on hotspots, the world’s largest tropical desert, the Sahara, has suffered a catastrophic decline in megafauna. Of 14 large vertebrates that have historically occurred in the region, four are now extinct in the wild, including the iconic scimitar-horned oryx (Oryx dammah). The majority has disappeared from more than 90% of their Saharan range, including Addax (Addax nasomaculatus), dama gazelle (Nanger dama) and Saharan cheetah (Acinonyx jubatus hecki) – all now on the brink of extinction. Greater conservation support and scientific attention for the region might have helped to avert these catastrophic declines. The Sahara serves as an example of a wider historical neglect of deserts and the human communities who depend on them. The scientific community can make an important contribution to conservation in deserts by establishing baseline information on biodiversity and developing new approaches to sustainable management of desert species and ecosystems. Such approaches must accommodate mobility of both people and wildlife so that they can use resources most efficiently in the face of low and unpredictable rainfall. This is needed to enable governments to deliver on their commitments to halt further degradation of deserts and to improve their status for both biodiversity conservation and human well-being. Only by so-doing will deserts be able to support resilient ecosystems and communities that are best able to adapt to climate change.

  • on the brink of extinction habitat selection of Addax and dorcas gazelle across the tin toumma desert niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.

  • On the brink of extinction—Habitat selection of Addax and dorcas gazelle across the Tin Toumma desert, Niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.

Thomas D Mueller – 3rd expert on this subject based on the ideXlab platform

  • on the brink of extinction habitat selection of Addax and dorcas gazelle across the tin toumma desert niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.

  • On the brink of extinction—Habitat selection of Addax and dorcas gazelle across the Tin Toumma desert, Niger
    Diversity and Distributions, 2017
    Co-Authors: Jared A Stabach, Tim Wacher, Thomas Rabeil, Vincent Turmine, Thomas D Mueller, Peter Leimgruber

    Abstract:

    Aim
    To assess the distribution and occurrence of Addax (Addax nasomaculatus), the most critically endangered ungulate species globally, and dorcas gazelle (Gazelle dorcas), for which the ecology in the southern Sahara is virtually unknown.

    Location
    Tin Toumma desert, Niger

    Methods
    Integrating field surveys, collected over a 7-year period (2008–2014), with remote sensing-derived measures of vegetation productivity (NDVI) and surface roughness, we fit models in a generalized linear regression framework to predict and evaluate the occurrence of Addax and dorcas gazelle.

    Results
    Addax declined significantly over the course of the study, strongly affecting the outcomes of our regression models. Other factors, namely surface roughness and the occurrence of the perennial grass Stipagrostis acutiflora, were important in predicting Addax occurrence. Dorcas gazelle, inhabiting areas further to the south of our study area, were more positively associated with increases in vegetation productivity than Addax. Both species were observed to have a strong negative response to human disturbance. Predictive models, relying only on remotely sensed derived variables, provided insight into areas of habitat suitability and highlighted niche partitioning across the Sahelo-Saharan biome.

    Main conclusions
    Our results provide improved insight into the factors contributing to the occurrence of this critically endangered (Addax) and vulnerable (dorcas gazelle) species and may help guide future field surveys across the region to locate small and geographically isolated populations. Developing statistically based ecological habitat models provide a first-step towards improved management and policy development for the long-term conservation of these species and complement field surveys conducted across the region to monitor species that are increasingly being pushed to extinction.