Addax nasomaculatus

Krausman, Paul R.; Casey, Anne L.

doi:10.1644/807.1

Cited by 9 publications

(11 citation statements)

References 23 publications

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“…There are only two reports of Pleistocene rem assigned to this species, a maxilla from Algeria described by Balout [22], which is m likely an alcelaphin, and a single deciduous tooth from Morocco described by Thom [23], which is quite undiagnostic. The addax therefore has no fossil record prior to Holocene [24][25][26]. The addax is a monotypic member of the bovid tribe Hippotragini [1,6] and location of historical samples with sample sizes in parenthesis (photo credit: E. Hempel; base map: https://www.naturalearthdata.com, accessed on 18 October 2017, generated in QGIS v2.18 https://www.qgis.org).…”

Section: Introductionmentioning

confidence: 99%

“…There are only two reports of Pleistocene remains assigned to this species, a maxilla from Algeria described by Balout [22], which is more likely an alcelaphin, and a single deciduous tooth from Morocco described by Thomas [23], which is quite undiagnostic. The addax therefore has no fossil record prior to the Holocene [24][25][26]. The addax is a monotypic member of the bovid tribe Hippotragini and diverged from its sister clade Oryx spp.~3 million years ago based on age estimates using mitochondrial genomes [27].…”

Section: Introductionmentioning

confidence: 99%

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Diversity and Paleodemography of the Addax (Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction

Hempel

Westbury

Grau

et al. 2021

Genes

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Since the 19th century, the addax (Addax nasomaculatus) has lost approximately 99% of its former range. Along with its close relatives, the blue antelope (Hippotragus leucophaeus) and the scimitar-horned oryx (Oryx dammah), the addax may be the third large African mammal species to go extinct in the wild in recent times. Despite this, the evolutionary history of this critically endangered species remains virtually unknown. To gain insight into the population history of the addax, we used hybridization capture to generate ten complete mitochondrial genomes from historical samples and assembled a nuclear genome. We found that both mitochondrial and nuclear diversity are low compared to other African bovids. Analysis of mitochondrial genomes revealed a most recent common ancestor ~32 kya (95% CI 11–58 kya) and weak phylogeographic structure, indicating that the addax likely existed as a highly mobile, panmictic population across its Sahelo–Saharan range in the past. PSMC analysis revealed a continuous decline in effective population size since ~2 Ma, with short intermediate increases at ~500 and ~44 kya. Our results suggest that the addax went through a major bottleneck in the Late Pleistocene, remaining at low population size prior to the human disturbances of the last few centuries.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Diversity and Paleodemography of the Addax (Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction

Hempel

Westbury

Grau

et al. 2021

Genes

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“…The addax ( Addax nasomaculatus , Blainville 1816) is one of the world's rarest mammals, listed as an Appendix I species by CITES and as “Critically Endangered” on the IUCN [International Union for Conservation of Nature, 2008] Red List of Threatened Species [Krausman and Casey, 2007; Newby and Wacher, 2008].…”

Section: Introductionmentioning

confidence: 99%

“…Ground and aerial surveys carried out in 2004 yielded estimates of a wild population of less than 300 animals. Around 1,700 individuals are kept in captivity around the world [Krausman and Casey, 2007; Newby and Wacher, 2008], although only 614 are registered in ISIS (International Species Information System). Only two zoos outside Africa have more than 30 animals [ISIS, 2008].…”

Section: Introductionmentioning

confidence: 99%

Genetic structure analysis of a highly inbred captive population of the African antelope Addax nasomaculatus. Conservation and management implications

et al. 2010

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The African antelope Addax nasomaculatus is a rare mammal at high risk of extinction, with no more than 300 individuals in the wild and 1,700 captive animals distributed in zoos around the world. In this work, we combine genetic data and genealogical information to assess the structure and genetic diversity of a captive population located at Parque Lecocq Zoo (N=27), originated from only two founders. We amplified 39 microsatellites previously described in other Artiodactyls but new to this species. Seventeen markers were polymorphic, with 2-4 alleles per locus (mean=2.71). Mean expected heterozygosity (He) per locus was between 0.050 (marker ETH3) and 0.650 (marker D5S2), with a global He of 0.43. The mean inbreeding coefficient of the population computed from pedigree records of all registered individuals (N=53) was 0.222. The mean coancestry of the population was 0.298 and F(IS) index was -0.108. These results reflect the importance of an adequate breeding management on a severely bottlenecked captive population, which would benefit by the incorporation of unrelated individuals. Thanks to the successful amplification of a large number of microsatellites commonly used in domestic bovids, this study will provide useful information for the management of this population and serve as future reference for similar studies in other captive populations of this species.

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“…More recently and especially as oil exploration activities have increased throughout the region, these areas are no longer free of permanent human settlement (Duncan et al., ). Addax move more slowly than other species of antelope (Krausman & Casey, ), making them easy targets for modern hunters outfitted with vehicles and armed with automatic weapons (Actman, ). Dorcas gazelle habitat, however, was located more to the south/south‐west of the Massif.…”

Section: Discussionmentioning

confidence: 99%

On the brink of extinction—Habitat selection of addax and dorcas gazelle across the Tin Toumma desert, Niger

Stabach

Rabeil

Turmine

et al. 2017

Diversity and Distributions

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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.

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Addax nasomaculatus

Cited by 9 publications

References 23 publications

Diversity and Paleodemography of the Addax (Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction

Diversity and Paleodemography of the Addax (Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction

Genetic structure analysis of a highly inbred captive population of the African antelope Addax nasomaculatus. Conservation and management implications

On the brink of extinction—Habitat selection of addax and dorcas gazelle across the Tin Toumma desert, Niger

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