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Changes in Habitat Structure May Explain Decrease in Reintroduced Mohor Gazelle Population in the Guembeul Fauna Reserve, Senegal.

Moreno E, Sane A, Benzal J, Ibáñez B, Sanz-Zuasti J, Espeso G - Animals (Basel) (2012)

Bottom Line: In spite of recent reviews, it is difficult to reach general conclusions about its value as a conservation tool, as authors are reluctant to publish unsuccessful results.The population grew progressively, albeit slowly, during the first 20 years after release, but then declined dramatically, until the population in 2009 was estimated at no more than 13-15 individuals.Our results show that the Mohor gazelle in Guembeul is found in open habitats with less developed canopy where the grass is shorter, suggesting the possibility that changes in habitat structure have taken place during the time the gazelles have been in the Reserve, reducing the amount of suitable habitat.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas, CSIC, Carretera de Sacramento s/n, La Cañada de San Urbano, E-04120 Almería, Spain. emoreno@eeza.csic.es.

ABSTRACT
Reintroduction is a widespread method for saving populations of endangered species from extinction. In spite of recent reviews, it is difficult to reach general conclusions about its value as a conservation tool, as authors are reluctant to publish unsuccessful results. The Mohor gazelle is a North African gazelle, extinct in the wild. Eight individuals were reintroduced in Senegal in 1984. The population grew progressively, albeit slowly, during the first 20 years after release, but then declined dramatically, until the population in 2009 was estimated at no more than 13-15 individuals. This study attempts to determine the likelihood of gazelle-habitat relationships to explain why the size of the gazelle population has diminished. Our results show that the Mohor gazelle in Guembeul is found in open habitats with less developed canopy where the grass is shorter, suggesting the possibility that changes in habitat structure have taken place during the time the gazelles have been in the Reserve, reducing the amount of suitable habitat. Reintroduction design usually concentrates on short-term factors that may affect survival of the released animals and their descendants (short-term achievement), while the key factors for assessing its success may be those that affect the long-term evolution of the population.

No MeSH data available.


Map of the Reserve of Fauna of Guembeul showing plots where habitat structure has been sampled (15°55'N; 16°28'W). The central lagoon divides the Reserve into a western part and an eastern part, each of them containing seven sampling plots (1W–7W; 1E–7E). The white line around denotes a perimetral fence. Photo taken from Google©.
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animals-02-00347-f001: Map of the Reserve of Fauna of Guembeul showing plots where habitat structure has been sampled (15°55'N; 16°28'W). The central lagoon divides the Reserve into a western part and an eastern part, each of them containing seven sampling plots (1W–7W; 1E–7E). The white line around denotes a perimetral fence. Photo taken from Google©.

Mentions: The RF Guembeul (a 720-ha fenced off area; 15°55'N; 16°28'W) is about 12 km south of Saint Louis (Sahelian zone in northern Senegal). Created in 1983, it is one of the three connected reserves in the network of lagoons and creeks which follow the Senegal River to its mouth. It was set aside primarily to protect a variety of resident and migrant water birds. In 1986, it was designated as a Ramsar Wetlands. The centerpiece of the Reserve (about 1/3 of its total area) is a large lagoon which divides RF Guembeul in two (called “West” and “East” for the purposes of this study, Figure 1). It is in a shallow depression with sandy shores surrounded by thorn-bush savannah dominated by Acacia sp. and Balanites aegyptiaca [29], and scattered Boscia senegalensis, Salvadora persica and Commiphora africana shrubs, among others. Opuntia tuna thickly covers some parts of the Reserve. In the eighties, it was restricted to a small area in the southwest [14], but as an exotic weed, this cactus species has become more widespread, especially in the West where it appears quite evenly distributed.


Changes in Habitat Structure May Explain Decrease in Reintroduced Mohor Gazelle Population in the Guembeul Fauna Reserve, Senegal.

Moreno E, Sane A, Benzal J, Ibáñez B, Sanz-Zuasti J, Espeso G - Animals (Basel) (2012)

Map of the Reserve of Fauna of Guembeul showing plots where habitat structure has been sampled (15°55'N; 16°28'W). The central lagoon divides the Reserve into a western part and an eastern part, each of them containing seven sampling plots (1W–7W; 1E–7E). The white line around denotes a perimetral fence. Photo taken from Google©.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494292&req=5

animals-02-00347-f001: Map of the Reserve of Fauna of Guembeul showing plots where habitat structure has been sampled (15°55'N; 16°28'W). The central lagoon divides the Reserve into a western part and an eastern part, each of them containing seven sampling plots (1W–7W; 1E–7E). The white line around denotes a perimetral fence. Photo taken from Google©.
Mentions: The RF Guembeul (a 720-ha fenced off area; 15°55'N; 16°28'W) is about 12 km south of Saint Louis (Sahelian zone in northern Senegal). Created in 1983, it is one of the three connected reserves in the network of lagoons and creeks which follow the Senegal River to its mouth. It was set aside primarily to protect a variety of resident and migrant water birds. In 1986, it was designated as a Ramsar Wetlands. The centerpiece of the Reserve (about 1/3 of its total area) is a large lagoon which divides RF Guembeul in two (called “West” and “East” for the purposes of this study, Figure 1). It is in a shallow depression with sandy shores surrounded by thorn-bush savannah dominated by Acacia sp. and Balanites aegyptiaca [29], and scattered Boscia senegalensis, Salvadora persica and Commiphora africana shrubs, among others. Opuntia tuna thickly covers some parts of the Reserve. In the eighties, it was restricted to a small area in the southwest [14], but as an exotic weed, this cactus species has become more widespread, especially in the West where it appears quite evenly distributed.

Bottom Line: In spite of recent reviews, it is difficult to reach general conclusions about its value as a conservation tool, as authors are reluctant to publish unsuccessful results.The population grew progressively, albeit slowly, during the first 20 years after release, but then declined dramatically, until the population in 2009 was estimated at no more than 13-15 individuals.Our results show that the Mohor gazelle in Guembeul is found in open habitats with less developed canopy where the grass is shorter, suggesting the possibility that changes in habitat structure have taken place during the time the gazelles have been in the Reserve, reducing the amount of suitable habitat.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas, CSIC, Carretera de Sacramento s/n, La Cañada de San Urbano, E-04120 Almería, Spain. emoreno@eeza.csic.es.

ABSTRACT
Reintroduction is a widespread method for saving populations of endangered species from extinction. In spite of recent reviews, it is difficult to reach general conclusions about its value as a conservation tool, as authors are reluctant to publish unsuccessful results. The Mohor gazelle is a North African gazelle, extinct in the wild. Eight individuals were reintroduced in Senegal in 1984. The population grew progressively, albeit slowly, during the first 20 years after release, but then declined dramatically, until the population in 2009 was estimated at no more than 13-15 individuals. This study attempts to determine the likelihood of gazelle-habitat relationships to explain why the size of the gazelle population has diminished. Our results show that the Mohor gazelle in Guembeul is found in open habitats with less developed canopy where the grass is shorter, suggesting the possibility that changes in habitat structure have taken place during the time the gazelles have been in the Reserve, reducing the amount of suitable habitat. Reintroduction design usually concentrates on short-term factors that may affect survival of the released animals and their descendants (short-term achievement), while the key factors for assessing its success may be those that affect the long-term evolution of the population.

No MeSH data available.