NATURAL HISTORY GUIDE TO AMERICAN SAMOA rd 3 Edition NATURAL HISTORY GUIDE This Guide may be available at: www.nps.gov/npsa Support was provided by: National Park of American Samoa Department of Marine & Wildlife Resources American Samoa Community College Sport Fish & Wildlife Restoration Acts American Samoa Department of Commerce Pacific Cooperative Studies Unit, University of Hawaii American Samoa Coral Reef Advisory Group National Oceanic and Atmospheric Administration Natural History is the study of all living things and their environment. Cover: Ofu Island (with Olosega in foreground). NATURAL HISTORY GUIDE NATURAL HISTORY GUIDE TO AMERICAN SAMOA 3rd Edition P. Craig Editor 2009 National Park of American Samoa Department Marine and Wildlife Resources Pago Pago, American Samoa 96799 Box 3730, Pago Pago, American Samoa American Samoa Community College Community and Natural Resources Division Box 5319, Pago Pago, American Samoa NATURAL HISTORY GUIDE Preface & Acknowledgments This booklet is the collected writings of 30 authors whose first-hand knowledge of American Samoan resources is a distinguishing feature of the articles. Their contributions are greatly appreciated. Tavita Togia deserves special recognition as contributing photographer. He generously provided over 50 exceptional photos. Dick Watling granted permission to reproduce the excellent illustrations from his books “Birds of Fiji, Tonga and Samoa” and “Birds of Fiji and Western Polynesia” (Pacificbirds.com). NOAA websites were a source of remarkable imagery. Other individuals, organizations, and publishers kindly allowed their illustrations to be reprinted in this volume; their credits are listed in Appendix 3. Matt Le'i (Program Director, OCIA, DOE), Joshua Seamon (DMWR), Taito Faleselau Tuilagi (NPS), Larry Basch (NPS), Tavita Togia (NPS), Rise Hart (RCUH) and many others provided assistance or suggestions throughout the text. Dr. George Zug (Smithsonian Inst.) provided an updated list of reptiles. Lelei Peau (DOC) spearheaded the effort to translate the Guide into the Samoan language. Support to DMWR was provided by the Federal Aid in Sport Fish and Wildlife Restoration Acts. Support to ASCC was provided, in part, by a USDA Cooperative State Research, Education, and Extension Service grant. Printing was made possible by funds from NPS, the Pacific Cooperative Studies Unit at the University of Hawaii, and the American Samoa Coral Reef Advisory Group. The use of English, Samoan and scientific names varies among chapters, so the reader is referred to cross- referenced lists in the species checklists in Chapters 33, 34, 56 and Appendix 2. Acronyms used above: ASCC (A. Samoa Community College), DOC (AS Dept. Commerce), DOE (AS Dept. Education), DMWR (AS Dept. Marine & Wildlife Resources), NOAA (National Oceanic Atmospheric Administration), NPS (National Park Service), OCIA (Office of Curriculum, Instruction & Accountability), RCUH (Research Coop., Univ. Hawaii), USDA (US Dept. Agriculture). 2 NATURAL HISTORY GUIDE GENERAL TOPICS 1. Local facts and maps……….........… 5 2. Seasons and weather.……….….….. 7 3. Cyclones……………………………… 9 4. Volcano we live on…………………... 11 5. Biodiversity……………...…….…...… 13 6. Status of local species……..……….. 15 7. Environmental overview…………….. 17 8. Early Samoans………………………. 19 9. Southern night sky…………….......... 21 MARINE ENVIRONMENT TERRESTRIAL ENVIRONMENT 10. Our ocean….….………………......... 22 34. Mammal, reptile checklist................. 60 11. Ocean currents……………………… 24 35. Flying foxes (fruit bats)….….…..…… 61 12. What is coral……...…………………. 25 36. Vegetation……..…………………….. 64 13. Coral reefs…………...……..…….…. 28 37. Banyan trees…………...……........... 66 14. Coral bleaching………..……………. 30 38. Wildlife foods……….….…..………… 68 15. Palolo swarming....…..…................. 32 39. Streams: general...…..……………… 71 16. Giant clams………...….…………….. 34 40. Stream fish, shrimps, snails……….. 72 17. Crown-of-thorns starfish……………. 35 41. Stream species posters…………….. 74 18. Octopus………………………….…… 36 42. Snakes…………..…….…................. 77 19. Sharks………………...…………….… 37 43. Skinks and geckos……………......... 79 20. Surgeonfish: alogo…..…………….... 38 44. Land crabs………...…..……...……… 81 21. Surgeonfish: manini, pone………..… 40 45. Land snails…………………………… 83 22. Traditional enu fishing….…………… 42 46. Insects……..….……………………... 85 23. Atule fishing….…..………………….. 43 47. Dragonflies, damselflies……………. 86 24. Small reef fish……………………….. 45 48. Household bugs……………………... 87 25. Old reef fish………………….………. 46 49. Mosquitoes, filariasis, dengue.......... 89 26. Tuna and the canneries…………….. 48 50. Fungus……………………………….. 91 27. Pelagic fish…………………………... 49 51. Soil community………………………. 93 28. Sea turtles…..……………………….. 50 29. Sea turtle hatchlings………………… 52 INTRODUCED PEST SPECIES 30. Sea turtle identification key………… 54 52. Plant and animal pests…...………… 94 31. Humpback whales….…………......... 55 53. Toads…….…………………………… 96 32. Dolphins and small whales….…….. 57 54. Forest invaders……..……………….. 97 33. Mammal, reptile checklist…….......... 59 55. Agriculture pests……...…….………. 99 BIRDS 56. Bird checklist…………...................... 101 57. Pacific Pigeon…………...….……….. 103 58. Many-colored Fruit Dove….….......... 105 59. Honeyeaters……………...…..……… 107 60. Starlings…………………..…............. 109 61. Swiftlet (and sheath-tailed bat).……. 111 62. Rails……………...…………………… 113 63. Cuckoo…………...…………………… 115 64. Owl…………………..………………… 116 65. Wetland birds……….......…………… 117 66. Shorebirds………………................... 119 67. Seabirds………………....…………… 121 68. Special birds of Manu'a…....……….. 124 69. Christmas bird count………………… 126 Appendix 1. Noteworthy environmental events by year... 127 Appendix 2. Index of plant names used in text….…….…. 128 Appendix 3. Figure credits…….………………………..….. 129 3 NATURAL HISTORY GUIDE Land area Marinea Island Highest Island km2 mi2 km2 type Pt. (m) Populationb American Samoa Tutuila 136.2 52.6 volcanic 652 55,400 Ta'u 45.5 17.6 volcanic 965 873 Ofu 7.3 2.8 volcanic 494 494 Olosega 5.4 2.0 volcanic 639 216 Swains 3.6 1.4 atoll 5 37 Aunu'u 1.5 0.6 volcanic 88 476 Rose 0.1 0.1 atoll 5 0 Totals 199.6 77.1 304,300 57,496 Samoa Savai'i 1718 663 volcanic 1858 41,826 Upolu 1125 434 volcanic 1100 131,279 Manono 3 1.2 volcanic 107 955 Apolima 1 0.4 volcanic 168 80 Totals 2847 1099 120,000 174,140 a EEZ (Exclusive Economic Zone). b Census years: 2000 (American Samoa), 2001 (Samoa). 4 NATURAL HISTORY GUIDE 1. Local facts and maps Samoan Archipelago. This remote chain of 13 islands (9 inhabited) and two atolls is located 140 south of the equator near the International Date Line. It is divided into two political entities, the US Territory of American Samoa and the neighboring independent country of Samoa, formerly known as Western Samoa. The land area of (western) Samoa is approximately 15 times larger than the land area of American Samoa. Territory of American Samoa. The total land area of 76 mi2 (197 km2) includes five volcanic islands (Tutuila, Aunu'u, Ofu, Olosega, Ta'u) and two distant atolls (Rose, Swains). When marine waters out to 200 mi are included, the Territory is 117,500 mi2 (nearly the size of the state of Oregon). Population. Polynesians arrived here about 3,000 years ago. The current population (69,000 in 2009) is 80,000 growing about 1.5 % per year, which equates to an addition of more than 1,000 babies and/or immigrants 60,000 per year. The median age is 21 years, so continued growth is expected. Most people (96 %) live on Tutuila 40,000 Island. The ethnic composition is Samoan (88.2 %), People Tongan (2.8 %), Asian (2.8 %), Caucasian (1.0 %), and 20,000 mixed or other (5.2 %). There is a sizeable demographic shift as (western) Samoans migrate into 0 American Samoa and American Samoans migrate to 1900 1950 2000 the United States. About half of the people currently living in American Samoa were not born there. Over 128,000 Samoans live outside the territory. Topography. The main islands are steep volcanic mountains that emerge from the ocean floor 2-3 miles below the sea surface. Peak elevations are 2,142 feet on Tutuila Island (Matafao Peak) and 3,170 feet on Ta'u Island (Lata Mountain). Climate. Hot, humid and rainy year-round, but there is a long, wet summer season (October - May) and a slightly cooler and drier season (June - September). Total rainfall is 125 inches at the Tafuna airport and 200+ inches in mountainous areas. Ocean. Nearshore waters are usually warm (82-860 F, 28-300 C) and clear (60-90 ft visibility). Fringing coral reefs surround the islands. Tropical cyclones (hurricanes). While very destructive, cyclones are a natural but erratic feature of the environment in this part of the world. The most recent ones have occurred here at intervals of 1-13 years: 1981, 1987, 1990, 1991, 2004, 2005. Not all islands were damaged each time. Native flora and fauna. Most native species are closely related to those in Indonesia, but due to our small size and remote location in the Pacific Ocean, the diversity of terrestrial species here is low: 343 flowering plants, 135 ferns, 25 resident or migratory land and water birds, 20 resident seabirds, 3 mammals (all bats), 3 skinks, 1 gecko, 2 sea turtles, and other occasional visitors. In contrast, the diversity of marine species here is high: 961 coral reef fishes, over 250 corals, and several whales and dolphins. Insects and other invertebrate species here are not well known. Endemic species. Species found only in the Samoan Archipelago include one bird (the Samoan starling), one stream fish, several land snails, and about 30% of local