Restoration of a tropical island: Cousine Island, Seychelles

Samways, Michael J.; Hitchins, Peter; Bourquin, Orty; Henwood, Jock

doi:10.1007/s10531-008-9524-z

Cited by 47 publications

(14 citation statements)

References 17 publications

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“…Even though tortoises have been stolen from the island, or have died, this project is partly a success from a tourism point of view, but the effects on the ecosystem have been little studied (Stoddart et al 1982, Samour et al 1987, Hambler 1994), and worryingly include the dispersal by tortoises of invasive plants (Hambler 1994). On Cousine, introduced tortoises have been credited with restoring large‐herbivore grazing, seed dispersal, and creating or maintaining habitat for endangered invertebrates (Samways et al 2010). Several other islands harbour (re)introduced A. gigantea tortoises, including Bird, Denis, Silhouette, and Moyenne (Gerlach 2004, Hansen unpubl.).…”

Section: Lessons From Tortoise Reintroductions Translocations and Tmentioning

confidence: 99%

Ecological history and latent conservation potential: large and giant tortoises as a model for taxon substitutions

Hansen¹,

Donlan²,

Griffiths³

et al. 2010

Ecography

142

150

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Starting in the late 1970s, ecologists began unraveling the role of recently extinct large vertebrates in evolutionary ecology and ecosystem dynamics. Three decades later, practitioners are now considering the role of ecological history in conservation practice, and some have called for restoring missing ecological functions and evolutionary potential using taxon substitutes Á extant, functionally similar taxa Á to replace extinct species. This pro-active approach to biodiversity conservation has proved controversial. Yet, rewilding with taxon substitutes, or ecological analogues, is now being integrated into conservation and restoration programmes around the world. Empirical evidence is emerging that illustrates how taxon substitutions can restore missing ecological functions and evolutionary potential. However, a major roadblock to a broader evaluation and application of taxon substitution is the lack of practical guidelines within which they should be conducted. While the International Union for Conservation of Nature's reintroduction guidelines are an obvious choice, they are unsuitable in their current form. We recommend necessary amendments to these guidelines to explicitly address taxon substitutions. A second impediment to empirical evaluations of rewilding with taxon substitutions is the sheer scale of some proposed projects; the majority involves large mammals over large areas. We present and discuss evidence that large and giant tortoises (family Testudinidae) are a useful model to rapidly provide empirical assessments of the use of taxon substitutes on a comparatively smaller scale. Worldwide, at least 36 species of large and giant tortoises went extinct since the late Pleistocene, leaving 32 extant species. We examine the latent conservation potential, benefits, and risks of using tortoise taxon substitutes as a strategy for restoring dysfunctional ecosystems. We highlight how, especially on islands, conservation practitioners are starting to employ extant large tortoises in ecosystems to replace extinct tortoises that once played keystone roles.

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Section: Lessons From Tortoise Reintroductions Translocations and Tmentioning

confidence: 99%

Ecological history and latent conservation potential: large and giant tortoises as a model for taxon substitutions

Hansen¹,

Donlan²,

Griffiths³

et al. 2010

Ecography

142

150

View full text Add to dashboard Cite

show abstract

“…The islands protected will be small, but some extremely small islands support important biodiversity (Samways et al. ), and these methods may help conservation organizations pinpoint them.…”

Section: Discussionmentioning

confidence: 99%

“…Although we focused here on islands, these methods could also be used for continental regions with clearly defined areas and unusually high biodiversity, such as mountain sky islands (e.g., Samways et al. , ).…”

Section: Introductionmentioning

confidence: 99%

Benefits to poorly studied taxa of conservation of bird and mammal diversity on islands

Aslan

Holmes²,

Tershy

et al. 2014

Conservation Biology

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Protected area delineation and conservation action are urgently needed on marine islands, but the potential biodiversity benefits of these activities can be difficult to assess due to lack of species diversity information for lesser known taxa. We used linear mixed effects modeling and simple spatial analyses to investigate whether conservation activities based on the diversity of well-known insular taxa (birds and mammals) are likely to also capture the diversity of lesser known taxa (reptiles, amphibians, vascular land plants, ants, land snails, butterflies, and tenebrionid beetles). We assembled total, threatened, and endemic diversity data for both well-known and lesser known taxa and combined these with physical island biogeography characteristics for 1190 islands from 109 archipelagos. Among physical island biogeography factors, island area was the best indicator of diversity of both well-known and little-known taxa. Among taxonomic factors, total mammal species richness was the best indicator of total diversity of lesser known taxa, and the combination of threatened mammal and threatened bird diversity was the best indicator of lesser known endemic richness. The results of other intertaxon diversity comparisons were highly variable, however. Based on our results, we suggest that protecting islands above a certain minimum threshold area may be the most efficient use of conservation resources. For example, using our island database, if the threshold were set at 10 km(2) and the smallest 10% of islands greater than this threshold were protected, 119 islands would be protected. The islands would range in size from 10 to 29 km(2) and would include 268 lesser known species endemic to a single island, along with 11 bird and mammal species endemic to a single island. Our results suggest that for islands of equivalent size, prioritization based on total or threatened bird and mammal diversity may also capture opportunities to protect lesser known species endemic to islands.

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“…), and giant tortoise translocation has been successfully implemented on Indian Ocean islands (Samways et al. ; Griffiths et al. ).…”

Section: Methodsmentioning

confidence: 99%

Rewilding the tropics, and other conservation translocations strategies in the tropicalAsia‐Pacific region

Louys

Corlett

Price

et al. 2014

Ecology and Evolution

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Alarm over the prospects for survival of species in a rapidly changing world has encouraged discussion of translocation conservation strategies that move beyond the focus of ‘at-risk’ species. These approaches consider larger spatial and temporal scales than customary, with the aim of recreating functioning ecosystems through a combination of large-scale ecological restoration and species introductions. The term ‘rewilding’ has come to apply to this large-scale ecosystem restoration program. While reintroductions of species within their historical ranges have become standard conservation tools, introductions within known paleontological ranges—but outside historical ranges—are more controversial, as is the use of taxon substitutions for extinct species. Here, we consider possible conservation translocations for nine large-bodied taxa in tropical Asia-Pacific. We consider the entire spectrum of conservation translocation strategies as defined by the IUCN in addition to rewilding. The taxa considered are spread across diverse taxonomic and ecological spectra and all are listed as ‘endangered’ or ‘critically endangered’ by the IUCN in our region of study. They all have a written and fossil record that is sufficient to assess past changes in range, as well as ecological and environmental preferences, and the reasons for their decline, and they have all suffered massive range restrictions since the late Pleistocene. General principles, problems, and benefits of translocation strategies are reviewed as case studies. These allowed us to develop a conservation translocation matrix, with taxa scored for risk, benefit, and feasibility. Comparisons between taxa across this matrix indicated that orangutans, tapirs, Tasmanian devils, and perhaps tortoises are the most viable taxa for translocations. However, overall the case studies revealed a need for more data and research for all taxa, and their ecological and environmental needs. Rewilding the Asian-Pacific tropics remains a controversial conservation strategy, and would be difficult in what is largely a highly fragmented area geographically.

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Restoration of a tropical island: Cousine Island, Seychelles

Cited by 47 publications

References 17 publications

Ecological history and latent conservation potential: large and giant tortoises as a model for taxon substitutions

Ecological history and latent conservation potential: large and giant tortoises as a model for taxon substitutions

Benefits to poorly studied taxa of conservation of bird and mammal diversity on islands

Rewilding the tropics, and other conservation translocations strategies in the tropicalAsia‐Pacific region

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