Boiga irregularis in the Solomon Islands

1. Boiga irregularisin the Solomon Islands Biodiversity and Conservation of Mountain Forests Tomas Piatak Universität für Bodenkultur Wien Institute of Forest Ecology

3. Basics about Boiga irregularis Names: Boiga irregularis (brown tree snake) Native range: eastern Indonesia, New Guinea, Solomon Islands and the coastal areas of northern and eastern Australia • Known introduced range: Taiwan, Cocos Island, Hawai, Marshall island, Spain, Guam • Habitat: tropical evergreen forests, montane forests, lowland tropical forests, mangroves, montane savanna • trees, caves, and near limestone cliffs, but comes down to the ground to forage at night, crowns of palms, hollow logs, rock crevices, caves and even the dark corners of thatched houses near the roof,

4. Spreading of brown snake Aircraft – great climber, hidding in small dark holes, wheels of planes, months without food Biological control – artificial spreading by man against rats Military – cargo transport, increase of commercial and military shipments within the tropical western Pacific (Pet) trade – drab poor pet Sea-freight – potential stowaway

5. General impacts - nominated as one of the 100 the "World's Worst" invaders • Reduction in Native Biodiversity • local extinction of over half of native bird, lizard and bats • eliminating native pollinators - "cascading" effects on ecosystems • reducing native plant regeneration and coverage • Human Health – mildly venomus snake • potential health hazard to infants and young children • Increase in chance to be infect by insect (mosqitoes - dengue) • Tourism decrease • Agriculture – no insect control by birds ->decrease of yields

6. Management of protection Physical Control - crawfish or minnow traps, live-mouse lures Barriers – building of small plots without snakes biodiversity rats chew holes -> destroyed by storms Chemical - toxic bait (small dead newborn mouse) acetaminophen tablets, other species can be affected (Corvus kubaryi – crow) Thermal - can be killed by excessively cold or hot temperatures - thermal fumigation Biological Control - native predators (Cane toads and poisonous red-bellied black snakes) – may pray occasionally unacceptable risk

7. Management of protection continue Reproductive inhibition Use of genetic engineering to inhibit specific proteins associated with reproductive function Integrated Pest Management (IPM) Conservation via artificial pollination and planting flora Restoring conditions for natural pollination managing reproduction of vertebrate-pollinated plants

8. List of references Amand, A. (2000) Boiga irregularis (Brown Tree Snakes) on Guam and Its Effect on Fauna. Student On-line Journal. Vol.6, No.6 Campbell, E.W. (1990) Barriers to movements of the brown treesnake (Boiga irregularis). Cornell University Press, Ithaca, NY. 534p Gordon, H. et al. (1999) An Overview of the Biology of the Brown Treesnake* (Boiga irregularis), a Costly Introduced Pest on Pacific Islands. USDA National Wildlife Research Center – Start Publications. Gordon, H. Rodda and Julie A. Savidge.(2007) Biology and Impacts of Pacific Island Invasive Species. 2. Boiga irregularis, the Brown Tree Snake (Reptilia: Colubridae). Pacific Science 61(3):307-324 Rodda, G. H. et al.(1999) Population trends and limiting factors in Boiga irregularis. Cornell University Press, Ithaca, NY. 534p The Brown Tree Snake Control Committee. (1996) Brown Tree Snake Control Plan. Aquatic Nuisance Species Task Force Rodda, G.H. et al. (2000) Practical concerns in the eradication of island snakes. IUCN, Gland, Switzerland and Cambridge, UK. Rodder, D. Lotters, S. (2010) Potential Distribution of the Alien Invasive Brown Tree Snake, Boiga irregularis (Reptilia: Colubridae). Pacific Science 64(1):11-22. 2010