Late stage dynamics of a successful feral goat eradication from the UNESCO World Heritage site of Aldabra Atoll, Seychelles

Bunbury, Nancy; Brandis, R. von; Currie, Jock C.; Crommenacker, Janske van de; Accouche, Wilna; Birch, Darryl; Chong-Seng, Lindsay; Doak, Naomi; Haupt, Philip; Haverson, Peter J.; Jean-Baptiste, M.; Fleischer‐Dogley, Frauke

doi:10.1007/s10530-017-1657-0

Cited by 7 publications

(3 citation statements)

References 21 publications

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“…On the atoll, giant tortoises are unevenly distributed across the three largest islands (Polymnie, the smallest main island, has no tortoises) due to environmental differences (e.g., terrain, food, freshwater resources, and shade availability) and differences in exploitation history (Bourn & Coe, 1978;Turnbull et al, 2015;Walton et al, 2019). Effective conservation management measures saving the species from extinction in the late 19th century included the reintroduction of tortoises to Picard and atoll-wide invasive species control (Bourn et al, 1999;Bunbury et al, 2018;Stoddart & Peake, 1979;Turnbull et al, 2015). The largest population lives on Grande Terre, with the second largest on Malabar.…”

Section: Study Systemmentioning

confidence: 99%

Low‐coverage reduced representation sequencing reveals subtle within‐island genetic structure in Aldabra giant tortoises

Çilingir

Hansen

Bunbury

et al. 2022

Ecology and Evolution

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Aldabrachelys gigantea (Aldabra giant tortoise) is one of only two giant tortoise species left in the world and survives as a single wild population of over 100,000 individuals on Aldabra Atoll, Seychelles. Despite this large current population size, the species faces an uncertain future because of its extremely restricted distribution range and high vulnerability to the projected consequences of climate change. Captive‐bred A. gigantea are increasingly used in rewilding programs across the region, where they are introduced to replace extinct giant tortoises in an attempt to functionally resurrect degraded island ecosystems. However, there has been little consideration of the current levels of genetic variation and differentiation within and among the islands on Aldabra. As previous microsatellite studies were inconclusive, we combined low‐coverage and double‐digest restriction‐associated DNA (ddRAD) sequencing to analyze samples from 33 tortoises (11 from each main island). Using 5426 variant sites within the tortoise genome, we detected patterns of within‐island population structure, but no differentiation between the islands. These unexpected results highlight the importance of using genome‐wide genetic markers to capture higher‐resolution genetic structure to inform future management plans, even in a seemingly panmictic population. We show that low‐coverage ddRAD sequencing provides an affordable alternative approach to conservation genomic projects of non‐model species with large genomes.

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Section: Study Systemmentioning

confidence: 99%

Low‐coverage reduced representation sequencing reveals subtle within‐island genetic structure in Aldabra giant tortoises

Çilingir

Hansen

Bunbury

et al. 2022

Ecology and Evolution

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show abstract

“…terrain, food, freshwater resources, shade availability) and differences in exploitation history (Bourn & Coe, 1978;Turnbull et al, 2015;Walton et al, 2019). Effective conservation management measures saving the species from extinction in the late 19th century included the reintroduction of tortoises to Picard and atoll-wide invasive species control (Bourn et al, 1999;Bunbury et al, 2018;Stoddart & Peake, 1979;Turnbull et al, 2015). The largest population lives on Grande Terre, with the second-largest on Malabar.…”

Section: Study Systemmentioning

confidence: 99%

Low-coverage reduced representation sequencing reveals subtle within-island genetic structure in Aldabra giant tortoises

Çilingir

Hansen

Bunbury

et al. 2021

Preprint

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Aldabrachelys gigantea (Aldabra giant tortoise) is one of only two giant tortoise species left in the world and survives as a single wild population of over 100,000 individuals on Aldabra Atoll, Seychelles. Despite this large current population size, the species faces an uncertain future because of its extremely restricted distribution range and high vulnerability to the projected consequences of climate change. Captive-bred A. gigantea are increasingly used in rewilding programs across the region, where they are introduced to replace extinct giant tortoises in an attempt to functionally resurrect degraded island ecosystems. However, there has been little consideration of the current levels of genetic variation and differentiation within and among the islands on Aldabra. As previous microsatellite studies were inconclusive, we combined low-coverage and double digest restriction associated DNA (ddRAD) sequencing to analyze samples from 33 tortoises (11 from each main island). Using 5,426 variant sites within the tortoise genome, we detected patterns of population structure within two of the three studied islands, but no differentiation between the islands. These unexpected results highlight the importance of using genome-wide genetic markers to capture higher-resolution genetic structure to inform future management plans, even in a seemingly panmictic population. We show that low-coverage ddRAD sequencing provides an affordable alternative approach to conservation genomic projects of non-model species with large genomes.

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“…Aldabrachelys gigantea, commonly known as the Aldabra giant tortoise, is a critically endangered species of tortoise native to the Aldabra Atoll in the Seychelles [1][2][3]. Currently, ongoing conservation measures are crucial to ensure the long-term survival of this species [4,5].…”

Section: Introductionmentioning

confidence: 99%

Comparison of Subcutaneous versus Intramuscular Dexmedetomidine–Midazolam–Ketamine–Morphine (DMKM) Mixture as Chemical Restraint for Endoscopic Sex Determination in Aldabra Giant Tortoises (Aldabrachelys gigantea)

Masi,

Vetere,

Casalini

et al. 2023

Animals

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Sex identification through coelioscopy is a minimally invasive surgical technique used to determine the sex of chelonians by directly visualizing their internal reproductive organs. An adequate anaesthesiologic plan is essential to guarantee patient immobilization and proper analgesia during the entire surgical procedure. In this study, we evaluated the effects of a combination of dexmedetomidine (0.05 mg/kg), midazolam (1 mg/kg), ketamine (8 mg/kg), and morphine (1 mg/kg) (DMKM) randomly delivered intramuscularly (IM) or subcutaneously (SC) in twenty-one Aldabra giant tortoise (Aldabrachelys gigantea) into the right antebrachium for celioscopic sex identification. Heart rate (HR), respiratory rate (RR), and body temperature (BT) were measured, along with the skeletal muscle tone of the thoracic and pelvic limbs, neck retraction reflex, palpebral reflex, and jaw tone every 15 min. The anaesthesiologic plan was considered to be adequate at the loss of the thoracic and pelvic limb retraction reflexes. After a 45 min interval, if the anaesthetic plan was deemed insufficient for the celioscopic procedure, a 5 mg/kg dose of propofol was administered intravenously into the subcarapacial venous plexus. At the end of the procedure, atipamezole (0.5 mg/kg) and flumazenil (0.05 mg/kg) were administered intramuscularly into the left antebrachium as reversal agents. Both HR and RR decreased from baseline to both 15 and 30 min. Due to the persistence of thoracic and pelvic limb retraction reflexes 45 min after DMKM administration, 6/11 (55%) cases in the SC group required the additional administration of propofol, in contrast to only 1/10 (10%) cases in the IM group (p = 0.05). The recovery times were comparable between the successfully induced animals in the IM and SC groups. In this study, the intramuscular administration of a DMKM combination quickly produced chemical restraint, suitable for celioscopic sex determination.

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Late stage dynamics of a successful feral goat eradication from the UNESCO World Heritage site of Aldabra Atoll, Seychelles

Cited by 7 publications

References 21 publications

Low‐coverage reduced representation sequencing reveals subtle within‐island genetic structure in Aldabra giant tortoises

Low‐coverage reduced representation sequencing reveals subtle within‐island genetic structure in Aldabra giant tortoises

Low-coverage reduced representation sequencing reveals subtle within-island genetic structure in Aldabra giant tortoises

Comparison of Subcutaneous versus Intramuscular Dexmedetomidine–Midazolam–Ketamine–Morphine (DMKM) Mixture as Chemical Restraint for Endoscopic Sex Determination in Aldabra Giant Tortoises (Aldabrachelys gigantea)

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