Mauritian Reptiles Mauritian Reptiles
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Reptile conservation in Mauritius: Reptile conservation in Mauritius: Restoring island biodiversity IslandRestoring Biodiversity island biodiversity & Extinction • TheIslandsIsolated isolation, and animals reptile uniqueness and extinction plants, and such dependency as those thatof island • Mauritius:speciesnaturally upon colonise An islandone anotherislands, of unique makesoften reptiles co-evolve them vulnerable and adapt to • Theextinctionto utilise need all for available reptile conservation resources and translocation • SinceThisRe-building drives the 17 speciationendemicth Century reptile and75% theof communities all formation animal extinctions of unique • haveTheecosystems future been islandfor Mauritian endemics reptiles • Islands therefore maintain some of the richest biodiversity in the World Nik Cole Island Biodiversity & Extinction Mauritian reptiles • Although the Mascarenes have lost more species • OfAlthoughTherePreventing the have28 reptilethe furtherbeen loss extinctions more ofloss species reptile of reptile over is extinctions relatively species,the past few,in400 the years,the than anywhere else, Mauritius still maintains one of allcurrentMascarenesparticularly but one loss have island ofthan reptile occurred anywhere endemics, diversity on else islandsis istherefore occurring of atgreat an the richest reptile diversities in the World alarmingimportance rate in and maintaining considered global as a biodiversity GLOBAL CRISIS! Fiji Africa Extinct MauritianNew Zealand Giant Tortoise Cylindraspis inepta Canary Islands Seychelles12 Extinct Giant Mauritian Skink CapeLeiolopisma Verde Islands mauritiana 10 8 6 4 Caribbean Mascarenes 2 ? Reptile extinction events 0 1600- 1700- 1800- 1900- 2000- 1699 1799 1899 1999 2099 Mauritian reptiles the formation of an ecosystem with: • TheThisBefore reptiles allowed the arrival and an adaptivebirds of man, therefore radiation some 400filled of years all the ago, roles there in • REPTILIAN PREYPREDATORSHERBIVORESSEED forDISPERSERS other oflarger birds, reptiles &reptiles POLLINATORS and and birds invertebrates thewere ecosystem no mammals usually in Mauritius occupied accept by mammals for bats allowingmaintaining habitat the natural regeneration habitat through browsing & grazing Giant tortoises Geckos Skinks Snakes 1 A MauritianUnfortunately ecosystem that Extensive destruction of was dependent upon reptiles natural habitat • A system rarely seen anywhere else The arrival of people in Mauritius has led to the near destruction of much of this unique ecosystem IntroductionExtensive destruction of numerous of These disturbances caused non-nativenatural habitat species • The loss of more than 60% of the unique reptile species from the mainland Reptilian predators and competitors Reptilian predators and competitors Mammalian predators Mammalian predators The offshore islands TheRound offshore Island islands • DisturbanceManyBut as reptile island tospecies use the increased, offshore lost from islands disturbance the mainland occurred increased: continued at a • RemoteBut as island and relatively use increased, difficult disturbance to access increased: slowerto– surviveRemaining rate on reptile the islands populations declined – Remaining reptile populations declined rats and other introduced predators responsible for – Many island populations disappeared = further extinction – Many island populations disappeared = further extinction reptile extinction never reached the island – But some of the more remote and least disturbed island – But some of the more remote and least disturbed island populations continued to persist populations continued to persist – For example: – For example: 2 Round Island The need for conservation • 30 years ago it was recognised that: • andTheBecame theisland last the also locationlast supports location where onhealthy the Earth burrowing populations to find: boa, of other Bolyeriaendemic multocarinataand native reptilewas species seen in 1975 KeeledGunthers scaled gecko, boa, Phelsuma Casarea dussumieriguentheri Ornate day gecko, Phelsuma ornata Bojer’s skink, Gongylomorphus bojerii HOME TO THE LAST SEMI-INTACT REPTILE COMMUNITY TheTo safeguardRoundTheIntroduced future Island againstsurvival goatsreptile further ofand community this rabbits disturbance reptile WITHIN THE MASCARENES andwasthatdominated ultimately uniquewere destroying andecosystem reptile extremely extinction the was reptiles’ important at great populations habitat risk Durrell’sTelfairs nightskink,Bouton’s gecko, Leiolopisma skink, Nactus telfairii durrelli shouldfor thebe re-establishedbiodiversityhad to be removedof backthe region to other islands Cryptoblepharus boutonii Bullock & North 1975 The need for conservation The need for conservation • But…Most of 30 the years populations ago little werewas knowntoo vulnerable about: • ThereThisTheseIslandLittleOver researchwasthe hasrestorationactions past known been threehashave extensive about anddemonstrated decadesbeen reptile the the researchother theresearchbackbone Forestrytheislands into need is to reptilenow Service, forisland there- establishingecology,restorationfoundationDWCT,– was there conservation, MWF tosuitable island whatand captiv NPCS habitat?reptilewase suggested husbandry, thecommunities driving genetics, 30 force: years taxonomy, ago: health and disease, and past and present distributions – RestoreRoundwereHabitat other Islandrestorationmissing vulnerable reptile ecological populations reptiles processes present? have and increased island biodiversity TRANSLOCATION – EnhancedramaticallywereEradication exotic the ofpredators/competitorslong-term mammalian survival predators of endangered present? and herbivores reptiles – Some islands now suitable for reptile re-establishment TheThere reptiles’ were not pastecologicaltaxonomydistribution sufficient co-existence requirements numbers to remove and re-establish elsewhere The needTranslocation for conservation Translocation • TheIsland movement restoration of anda species reptile from research one location is now the with • Re-introductionThe two most importantand re-stocking initial stepsare common are: freefoundation release to in what another was –suggested 3 types: 30 years ago: and1) Determinepowerful and conservation remove the causes tools of initial species loss – Introduction: species release outside its natural range 2) Determine the ecological requirements of the species – Re-introduction:TRANSLOCATION species release within its past former range • However, some question the validity of this tool – Re-stocking: species release within an existing population • forIt reptiles,is also essential because that success post-translocation and impact has beenmonitoring poorly documented! is conducted to assess – success of establishing a new population • The– theInternational impact to the resident Union species for the Conservation of Nature– the need and for Natural further action Resources – restocking(IUCN) have set guidelines for species translocation 3 Re-building reptile communities Re-building reptile communities • In 2006 (Darwin Initiative funding) we initiated the • Telfair’s skink Leiolopisma telfairii first reptile translocations in the Indian Ocean – Restricted to Round Island, but once widespread – Dec 06 to Feb 07 – The mainland and other island populations destroyed by • It was essential that we chose species based on – rats250260 skinks to IleGunners aux Aigrettes Quoin – needsuitability for conservation of potential islands: action “vulnerability to extinction” – Re-establishing this skink back to other islands – current• suitable stability habitat within the donor populations represents an important step in restoring island ecosystems – knowledge• food availability of their ecology and role in the ecosystem • lack of introduced predators – As we are reinstating a lost predator, seed disperser, • stable populations of resident endemic species pollinator and potential prey item • Four reptile species and four islands were selected: Re-building reptile communities Re-building reptile communities • Ilot Vacoas Bojer’s Skink, Gongylomorphus bojerii sp. – Restricted to Ilot Vacoas, only 1ha! • Night geckosgeckos, Nactus spp. – 400 skinks inhabit the island – AJan sub-species 07 to the Bojer’s restricted to the N islands – 20 skinks to Ile aux Fouquets • Nactus– These small coindemirensis geckos were once widespread and possibly the most abundant vertebrates in pristine Mauritius – Underwent catastrophic reduction in range following the introduction of the house gecko, Hemidactylus frenatus – Once widespread in the SE – IncludingThis is the the first neighbouring of several annual islands translocations until the 1930s from & 70sIlot – TheseVacoas island to Ile populationsaux Fouquets predated • Nactus durrelli by shrews and elsewhere by wolf snakes Re-building reptile communities Re-building reptile communities • Nactus coindemirensisonly survive on restrictedislands where to: the house • Nactus durrelli restricted to Round Island gecko• Ilot has Vacoas not reached Pigeon Rock • Both night geckos are now segregated from one Flat Island Round • Gunners Quoin another Island Gunners Quoin • A small area of rock on Flat Island • Translocation is limited, because of house gecko • Pigeon Rock distribution • Beneficial to translocate both night geckos to the same island • But could we successfully translocate both night geckos to the same island at the same time? Ilot Vacoas 4 Re-building reptile communities Re-building reptile communities • OctIlot