Contents

ƒ Mauritian reptiles Restoring island biodiversity: ƒ Mauritian reptiles ƒ Restoration and research the reintroduction of endemic Mauritian reptiles ƒ Skinks and geckos ƒ The Darwin Initiative project Dr Nicholas Cole University of Bristol ƒ Project protocol and timetable Dr Carl Jones Durrell Wildlife Conservation Trust Mauritian Wildlife Foundation

Mauritian reptiles Mauritian reptiles

ƒ Once one of the richest reptile diversities in the World ƒ This adaptive radiation caused the formation of a unique ecosystem ƒ In the absence of terrestrial mammals the reptiles evolved to occupy all available niches dependent upon reptiles

ƒ Allowed adaptive radiation of: ƒ Tortoises ƒ Nocturnal and diurnal geckos ƒ Skinks ƒ Reptiles occupied all main functional ƒ Snakes groups:

Mauritian reptiles Mauritian reptiles

ƒ Predators: ƒ Prey:

1 Mauritian reptiles Mauritian reptiles

ƒ Grazers and browsers: ƒ Seed dispersers:

Mauritian reptiles Mauritian reptiles

ƒ Pollinators: ƒ Human related disturbances over the past 400 years: ƒ Extensive habitat destruction ƒ Introduction of non-native predators and competitors ƒ More than 60% of reptile species lost from the main island through extinction or extirpation ƒ The majority of the extant species are now confined to offshore islands

Mauritian reptiles Restoration and research

ƒ Remaining island populations: ƒ Round Island ƒ Most intact reptile fauna of the Mascarenes ƒ Restricted and/or fragmented distributions ƒ Never invaded by predatory mammals or reptiles ƒ The loss of ecological links and food webs ƒ Habitat destruction caused by rabbits and goats - ƒ loss of stability deleterious affect on reptiles

ƒ Vulnerable to further disturbances ƒ Vulnerable to further disturbances ƒ 30 years ago: ƒ Purposeful and accidental introductions ƒ Restore island communities ƒ Anthropogenic and stochastic events ƒ Translocate reptiles ƒ Maintain Round Island for comparative studies

2 Restoration and research Restoration and research

ƒ 30 years ago: ƒ Extensive research on Mauritian reptiles over the 30yrs ƒ Recipient islands unsuitable and little known ƒ > 40 peer-reviewed publications ƒ Donor populations too vulnerable ƒ ecology ƒ Little known about the ecological requirements, ƒ conservation distribution and taxonomy of the species ƒ taxonomy ƒ The need for restoration & translocation repeated ƒ genetics e.g. Hartley, Bloxam, Tonge, Bullock, Arnold, Cheke, Merton, Bell ƒ disease and health ƒ past and present distributions ƒ Forestry Service, DWCT, MWF and NPCS the driving force: driving force: ƒ Many unpublished reports ƒ Habitat restoration ƒ Numerous academic studies Ph.D., M.Sc., B.Sc.. ƒ Eradication of mammalian predators and herbivores

Restoration and research Skinks and geckos

ƒ The next step in the restoration process: ƒ Essential to start with the ecological building blocks (most widespread and abundant) ƒ The skinks ƒ Re-establishing reptile communities ƒ Bojer’s skink, Gongylomorphus bojerii ƒ Telfair’s skink, Leiolopisma telfairii ƒ The geckos ƒ Durrell’s night gecko, Nactus durrelli ƒ Lesser night gecko, Nactus coindemirensis

SI Bojer’s skink RI PHR Most widely Skinks and geckos FI GI distributed skink

ƒ Re-establishing populations of Bojer’s GQ skink, Gongylomorphus bojerii Historical accounts and Mauritius fossil records for 3 islands and throughout

IAF the mainland IDLP Principle causes IV of decline: Wolf snakes IAA Shrews Rats

3 Skinks and geckos Skinks and geckos

ƒ Freeman (2003) demonstrated ƒ Ilot Vacoas skink population ƒ Bojer’s skinks in high densities ƒ Show a significant genetic separation from other ƒ Bojer’s skinks in high densities populations ƒ Risks of inbreeding depression prevented by low ƒ Must treat as a separate conservation management level migration, thus maintaining genetic variation unit

ƒ However: ƒ At great risk from further disturbances ƒ no migration for Ilot Vacoas and a great risk of ƒ Their future survival is dependent upon translocation inbreeding depression ƒ With up to 490 skinks translocations will have to be small and repetitive

Skinks and geckos Skinks and geckos

ƒ Ile aux Fouquets ƒ Re-establishing populations of Telfair’s ƒ Most ideal site for first translocation ƒ Skinks present until at least 1972 skink, Leiolopisma telfairii ƒ Shrews no longer present

Telfair’s skink RI Restricted to FI Round Island Skinks and geckos

GQ Historical ƒ Highly abundant - 10-15,000 accounts and ƒ Robust generalist along the three fossil records Mauritius for 2 islands important niche parameters (Food, and Space, Time) throughout the mainland ƒ Adaptable to change – an ideal candidate ƒ An important component of the pristine IDLP Principle cause Mauritian ecosystem: of decline: Evidence for Rats IAA other islands ƒ Predator / Prey / Seed Disperser / Pollinator

4 Skinks and geckos Skinks and geckos

ƒ Telfair’s repeatedly identified for translocation to: ƒ Telfair’s repeatedly identified for translocation to: ƒ Ile aux Aigrettes ƒ Ile aux Aigrettes ƒ Gunner’s Quoin ƒ Ideal habitat (possibly more suitable than Round Is) ƒ Flat Island ƒ Cats and rats eradicated by 1991 ƒ Ile Marianne ƒ Ile aux Fouquets ƒ An abundant food source: invertebrates, fruits and reptiles ƒ Ile de la Passe ƒ Potential impact upon exotics: ƒ Predation of African land snails and wolf snakes ƒ Competitive exclusion of the shrew (may allow further re-introductions?)

ƒ Ecotourism & education - increasing awareness of biodiversity issues

Skinks and geckos Skinks and geckos

ƒ Telfair’s repeatedly identified for translocation to: ƒ Some have highlighted concerns for the lesser night gecko, Nactus coindemirensis ƒ Ile aux Aigrettes ƒ Gunner’s Quoin ƒ Suitable diversity of habitat types ƒ Rats eradicated in 1995 ƒ An abundant food source: invertebrates, fruits and reptiles ƒ Replacement of a lost predator ƒ Potential prey item for future reintroductions ƒ Disperser of Pandanus seeds and pollinator of Latania ƒ Co-existed with Telfair’s skink, then rats from the 1860s for 130 yrs ƒ Demonstrate anti-predatory behaviours ƒ Mostly active in different time niche ƒ Significant population growth post rat eradication

Skinks and geckos Skinks and geckos Encounter rates Nactus coindemirensis ƒ Telfair’s repeatedly identified for translocation to: ƒ Ile aux Aigrettes ƒ Cats, mice and rats eradicated 1998 Gunner’s Quoin 1982 1993 1996 2003/4 ƒ Gunner’s Quoin Central Flacourtia thicket - - 0* 4* ƒ Flat Island ƒ Need sufficient time for recovery of Eastern cliffs - - 0* 24.5 ƒ Ile Marianne orange tail skinks Latania/Pandanus slopes - - 0* 36.0 ƒ Ile aux Fouquets Northern cliffs - - 0* 13.0 ƒ Management plan for the vulnerable ƒ Ile de la Passe population of lesser night Northern peninsula - - 1* 45.5 geckos Pandanus slopes - - 2.5 47.5 Southern peninsula 0.8 0.0 2.5 38.5 Summit - - 0* 35.5 Bullock et al 1985 Valley - - 0* 18.0 Bullock 1986 Western cliffs - - 0* 35.0 Arnold & Jones 1994

Ilot Vacoas - - - 49.0 Dulloo et al 1996

Pigeon House Rock - - - 58.0 Cole 2005

5 Skinks and geckos Skinks and geckos

ƒ Telfair’s repeatedly identified for translocation to: ƒ Ile aux Aigrettes and Gunners Quoin ƒ Ile aux Aigrettes ƒ Gunner’s Quoin most suitable sites for translocations ƒ Flat Island ƒ Ile Marianne ƒ Habitat currently unsuitable ƒ Ile aux Fouquets ƒ Ile de la Passe ƒ Initially more valuable for establishing smaller reptile species

Skinks and geckos Skinks and geckos

ƒ Re-establishing populations of night ƒ The night geckos: geckos: ƒ Lesser night gecko, Nactus coindemirensis ƒ Three Nactus species

Skinks and geckos Skinks and geckos

ƒ The night geckos: ƒ The night geckos: ƒ Durrell’s night gecko, Nactus durrelli ƒ Serpent Island night gecko, Nactus serpensinsula

6 Nactus serpensinsula Night geckos Nactus durrelli Skinks and geckos Nactus coindemirensis Relict populations ƒ The most abundant reptiles in pristine Mauritius Habitat ƒ Would have been an important prey item Mauritius destruction & for other reptiles and birds mammalian predators unlikely to be ƒ Catastrophic reduction in range the sole cause of declines ƒ Now extremely fragmented distribution Nactus coindemirensis

Skinks and geckos Skinks and geckos

ƒ Declines attributed to the introduced common house ƒ Comparisons of habitat, diet and temporal activity: gecko, Hemidactylus frenatus ƒ Ecologically very similar to all night geckos ƒ Competition for: ƒ Refugia ƒ Microhabitats based on thermal properties ƒ Invertebrate prey

ƒ Enclosure experiments ƒ excluded the night geckos from refugia ƒ attacked and predated the night geckos

ƒ Responsible for the exclusion of night geckos

Nactus serpensinsula Night geckos Nactus durrelli only exist in House gecko absence of the Skinks and geckos Nactus coindemirensis house gecko

Flat Island ƒ Beneficial to translocate night gecko unique situation species to the same island separated by species to the same island differences in morphology and microhabitat ƒ Lesser night gecko would have existed Ile Marianne with the ancestor of the larger two night geckos Ilot Chat At risk from further invasion

Nactus coindemirensis ƒ The ancestor was most similar to Few islands left for translocation Durrell’s night gecko

7 Skinks and geckos Skinks and geckos

ƒ Comparisons of habitat, diet and temporal activity ƒ Enclosure experiments demonstrated:

ƒ Partitioning of these niches past competition ƒ The lesser and Durrell’s night gecko did not compete between the species past co-existence ƒ Had no impact upon one another ƒ Experiment to short to demonstrate that competition ƒ Serpent Island and Durrell’s night geckos may have been acting over a longer period ƒ Very little partitioning ƒ Differences - 10,000 yrs of isolation on different islands ƒ Need to investigate the long term co-existence ƒ Lesser night gecko and the larger night geckos ƒ Partitioning of habitat and diet based on size ƒ Ilot Chat is ideal for trial translocation of the two ƒ Evidence of past competition and thus co-existence night geckos and test co-existence ƒ Could they co-exist today?

Skinks and geckos The Darwin Initiative project

ƒ Three decades of work to get to this stage ƒ Ilot Chat ƒ An opportunity to take island restoration one step ƒ No introduced competitors or predators further ƒ Suitable habitat and prey abundance ƒ Small (0.036 ha) easily controlled and monitored

Round Ilot ƒ DWCT years of translocation experience Island Vacoas ƒ Mark Stanley-Price – IUCN guidelines Durrell’s Lesser night night ƒ Support of numerous international experts: gecko Ilot Chat gecko ƒ Dr Nick Arnold, Dr Jeremy Austin, Anthony Cheke, Prof. Steven Harris, Dr Gordon Rodda, Dr Thomas Fritts, Dr Gerald Kuchling, Dr Julian Pender-Hume

The Darwin Initiative project The Darwin Initiative project

ƒ Purpose: ƒ Outputs: ƒ The establishment of ƒ The re-establishment of sustainable reptile ƒ The establishment of ƒ The re-establishment of sustainable reptile ƒ Telfair’s on Gunner’s Quoin & Ile aux Aigrettes communities ƒ Bojer’s on Ile aux Fouquets ƒ Secure future reptile populations ƒ Night geckos on Ilot Chat ƒ Restore functional island ecosystems ƒ Training of MWF and NPCS ƒ Herpetological conservation ƒ Island Species-Led Action course ƒ To build capacity for further translocations ƒ Obtain greater public awareness of biodiversity issues and the work by MWF and NPCS

8 The Darwin Initiative project The Darwin Initiative project

ƒ Seasonal Monitoring: ƒ Seasonal Monitoring: ƒ Translocated and donor populations ƒ Resident vertebrate populations ƒ Comparing: ƒ Impact upon native and non-native species ƒ Diet ƒ Microhabitat use ƒ Health ƒ Invertebrate abundance ƒ Translocated populations ƒ Comparison of prey selection between ƒ Survival and recruitment translocated and donor populations ƒ Dispersal and home range

Project protocol and timetable Project protocol and timetable

ƒ Preliminary timetable: ƒ Preliminary timetable: ƒ July-September 2006 ƒ January 2007 ƒ 1st Bojer’s translocation 10-20 to Ile aux Fouquets (2.5ha) ƒ Set up transects and survey populations ƒ February 2007 ƒ October 2006 ƒ Telfair’s translocation 220 to Ile aux Aigrettes (26ha) and ƒ Translocate 80 night geckos to Ilot Chat (0.036ha) 250 to Gunners Quoin (76ha) ƒ 30 Telfair’s to the aviaries for screening Monitoring of ƒ December 2006 ƒ February/March 07/08/09 resident vertebrates ƒ Release the 30 Telfair’s on Ile aux Aigrettes ƒ June/July 07/08 & invertebrates, ƒ October/November 07/08 translocated & donor populations

Thank you for listening and your support in this project

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