INVESTIGATING HABITAT CHARACTERISTICS OF TERRESTRIAL (INVASIVE) HERPETOFAUNA ON STATIA WENDY A.M. JESSE VU UNIVERSITY AMSTERDAM PROJECT OVERVIEW • Duration: 4-year PhD project • Goal: Building theoretical framework of island invasibility • Why do some species invade and others don’t? • Which islands are susceptible? • What are the consequences of these invasions? • (Field)study area: Both the Leeward and Windward islands within the Dutch Caribbean region SPECIES COMPOSITION ON ISLANDS IS INFLUENCED BY HUMANS • Land modification • Facilitation of exotic colonization NATIVE SPECIES EXOTIC SPECIES HUMAN INFLUENCED ISLAND BIOGEOGRAPHY Native SR Exotic SR THE IMPORTANCE OF STATIA! • No recent exotic invaders • Invaders seem to have limited effect on native species • “Pure” effect of human impact on native communities • Baseline habitat utilization for species/genera that also occur on the neighboring islands STATIA INVADERS • House gecko (Hemidactylus mabouia) • Brahimy blind snake (Ramphotyphlops braminus) • Johnstone’s whistling frog (Eletherodactylus johnstonei) STATIA NATIVES • Schwartz’ anole/Little tree lizard (Anolis schwartzi) • Panther anole/Green tree lizard (Anolis bimaculatus) • Lesser Antillean iguana (Iguana delicatissima) STATIA NATIVES • Ground lizard (Ameiva erythrocephala) • Island least gecko (Sphaerodactulys sputator) • Saba least gecko (Sphaerodactylus sabanus) STATIA NATIVES • Red-bellied racer (Alsophis rufiventris) • Turinip-tailed gecko (Thecadactylus rapicauda) THE FIRST TWO WEEKS • 49 plots • Habitat and microhabitat data • SpeciesSoil moisture • PerchCanopy height Cover • PerchVegetation diameter height • PerchVegetation substrate structure • PerchLight intensity orientation • Sun/shadedTemperature perch • Litter depth 80 m2 plot, searched for 80 observer minutes. OUR FIRST OBSERVATIONS • Higher than expected diversity and abundances in town locations • Diversity and abundances decrease once Coralita invades OUR FIRST OBSERVATIONS • Higher than expected diversity and abundances in town locations • Diversity and abundances decrease once Coralita invades • Neutral to potentially positive effect of Leucaena invasion OUR FIRST OBSERVATIONS • Higher than expected diversity and abundances in town locations • Diversity and abundances decrease once Coralita invades • Neutral to potentially positive effect of Leucaena invasion • Species communities differ per habitat • All herpetological species have now been found on the island! THANK YOU STATIA! • Jacintha Ellers • Maarten Eppinga • Elizabeth Haber • Brittany Bernik • Jasper Bekema • Tobia de Scisciolo • Rotem Zilber • Pepita Cannegieter • Masru Spanner • Johan Stapel • Hanna Madden • Ambrosius van Zanten.