Oceanic islands

Oceanic islands

• 1.
  Oceanic Islands Krakatoa St. Helena
• 2.
  Krakatau/ Krakatoa Islands Lampung,Indonesia
• 3.
  Area: 3 mileswide, 5.5 miles long Group of 4 Islands ➔ Anak Krakatoa ➔ Verlaten ➔ Lang ➔ Rakata Lies in Sunda Strait b/w Sumatra and Java Convergence of Indian-Austrailian and eurasian tectonic plates→ high seismic and volcanic activity zone Strait: ➢ A waterway that connects 2 large water bodies ➢ Naturally formed ➢ Narrow but Navigable ➢ Sunda Strait connects Java Sea-Indian Ocean Recent Eruption: April 2020
• 4.
  Earliest Account Its wason large Island with 3 volcanoes and 2 small islands nearby 17 August 1883 larger island blew up → Small part left, remaining covered into ashes. Deadliest Volcanic activity 36000 people died ➢ Thermal Injuries ➢ Tsunamis Changing their profiles : Sinking and Rising→ Some part always remained above Sea water
• 5.
  Fauna Ist Faunal surveywas made in 1908. ➔ 13 Birds sps. ➔ 2 Lizard sps. ➔ 192 Insects sps. ❏ Ants ❏ Flies ❏ Beetles ❏ Dragon flies ❏ Spiders ➔ Plant texas rose to 114
• 6.
  Fauna Next survey wasmade in 1921 3 time as many as animals in 1908 ➔ 2 Mammals sps ● A bat→Lesser short-nosed fruit bat/ Dog Faced fruit bat/ Common fruit bat ● Malayan Field Rat ● House Rat ➔ 29 Birds sps. ➔ 2 earthworm sps. ➔ 500 Arthropods sps. ➔ 7 Gastropods sps.
• 7.
  Fauna Third faunal investigation wasmade in 1933 ➔ 1100 animals sps. ➔ No Amphibians ➔ No large land Mammals ➔ No Endemic species Physical Features ❖ Mixed Forests Dominant ❖ Grassland Disappeared . Ecological Succession: The process of change in the species structure of an ecological community over time
• 8.
  Present Fauna Birds ➔ LesserFrigate Bird ➔ Greater Frigate Bird ➔ Pied Imperial-Pigeon ➔ Pink Necked Pigeon ➔ Sunda Island Cuckoo Dove ➔ Silver rumped Needletail ➔ Silver Backed Needletail ➔ Pacific Swift ➔ Slaty Legged Crake ➔ White breasted waterhen ➔ Greater sandplover ➔ Magpie Robin ➔ Bar Tailed Godwit ➔ Ruddy turnstone ➔ Great knot ➔ Long toed stint ➔ Red necked stint ➔ Sanderling ➔ Gray Tailed Tattler ➔ Sooty Tern ➔ Bridled Tern ➔ Little Tern ➔ Barn owl ➔ House Crow ➔ Roseate Tern ➔ Common Tern ➔ Whiskered Tern ➔ Black Naped Tern ➔ Brahminy Kite ➔ Black eagle ➔ Oriental Hobby ➔ White Bellied Sea Eagle ➔ Pacific reef Egret ➔ Brown capped Woodpecker
• 9.
  Reptiles ➔ Hawksbill seaturtle ➔ Reticulated Python ➔ Paradise Tree snake/ Paradise Flying snake ➔ Brahminy Blind snake ➔ Two banded Monitor ➔ Asian water Monitor ➔ Saltwater Crocodile ➔ Flat tailed house gecko ➔ Many striped Skink ➔ Littoral Whiptail skink ➔ Indo-pacific tree gecko ➔ Tokay Geckos ➔ Mourning gecko/ Common smooth scaled gecko
• 10.
  Saint Helena Island BritishOverseas Territory
• 11.
  Area and Location ➢About 80 sq. miles ➢ Lies in South Atlantic Ocean ➢ 1000 miles away from Africa ➢ One of the most isolated Islands ➢ Darwin visited in 19th century during his scientific voyages. ➢ It has volcanic origin but volcanic activity is nearly extinct.
• 12.
  Climate Climate of St.Helena is ★ Tropical, Mild & Marine ★ Trade Winds blows continuously ★ Center is higher, wetter and is covered with green vegetation, ★ Lower coastal areas are drier and hotter, with little vegetation cover.
• 13.
  Fauna Extremely Poor inanimal fauna No native ❏ Mammals ❏ Reptiles ❏ Amphibians ❏ Freshwater Fishes Chief Inhabitants ➢ Birds ➢ Insects ➢ Land Molluscs ➔ No climatic reason ➔ Mammals and insects seems to flourish when introduced by Humans. ➔ Portuguese brought the goats to island in 1513 and the ravages of these animals destroyed the vegetation.
• 14.
  Fauna Birds Chief Inhabitants ofthis Island 1 native land Bird ➢ National Bird→St. helena Plover→ Wire Bird (wader/shore bird) Extinct Birds ➔ Large st. Helena Petrel ➔ Small St. Helena Petrel ➔ St. helena Swamphen ➔ St. Helena Dove ➔ St. Helena Cuckoo ➔ St. Helena Crake
• 15.
  Birds ➢ Many otherbirds are all introduced species. ➢ Serve specific environmental purposes, or for game, or as caged-birds which escaped into the wild. ➔ Yellow Canary ➔ Cardinal/ Robin/ Red Bird ➔ Java Sparrow ➔ Moorhen ➔ Mynah Bird ➔ Chukar & Rock Patridge ➔ Wilson’s storm Petrel ➔ Fairy Tern ➔ Peaceful dove ➔ Zebra Dove ➔ Pigeon ➔ Waxbill ➔ Ring Necked pheasants ➔ Masked Bobby ➔ Red billed Tropical bird ➔ Cattle Egret
• 16.
  Reptiles ➔ White-crowned snake ➔Eastern Small eyed Snake ➔ Black Bellied swamp snake ➔ Robust velvet gecko ➔ Loggerhead Turtle ➔ Green Turtle ➔ Leatherback Turtle ➔ Seychelles tortoise ➔ Asian House Gecko→ Introduced sp.
• 17.
  Other Fauna ❏ 203sps. of Beetles ❏ 33 sps. of Spiders ❏ 29 sps. of Land Snails ❏ Gray's stream Frog: Introduced sp.