Lecture 56

1. Lecture 56 Hawaii’sBiodiversity

2. Environmental Diversity Extremely wide range of habitats temperature moisture soils vegetation

3. Environmental Diversity Cold & Dry Cool & Dry inversion trades Warm & Dry Warm & Wet Warm & Very Dry Hot & Very Dry Hot & Wet

7. Dispersal to the Hawaiian Islands • Facts: • 2,500 miles of ocean separate North America from the Hawaiian Islands. • 3,500 miles of ocean between the small Marianas Islands and the Hawaiian chain. • The Hawaiian chain has never been connected to a land mass. 

8. Dispersal to the Hawaiian Islands • How then, did plants and animals cross the large oceanic distance to arrive on the Hawaiian islands? • Transportation through the air • Attached to Birds • Fruits eaten by Birds • Drifting in Seawater

9. water 23% wind 2% birds 75% Long Distance Dispersal Wind, Water, & Wings Theory The original colonist plants arrives in the following ways: Hawaii’s Flowering Plants

10. Drifting in Seawater • 14.3% of native flowering plants adapted to oceanic drift. • Adaptations for dispersal in seawater: • Seeds or fruits capable of floating. • Seeds or plant parts must be able to resist seawater for weeks. • Must arrive alive on beach and be able to grow there. Pandanus tectorius

11. Adenophorus periens Drifting in Air • Includes plants that reproduce by means of spores such as ferns, mosses, algae, and lichen • Spore size: • Spores so small that a line of a thousand of them end-to-end would be an inch long. • Fern spores would be more successful at reaching Hawaiian island then seeds of flowering plants.

12. Metrosideros polymorpha Drifting in Air • 1.4% of the 255 hypothetical original flowering plants were dispersed by air flotation • Ohia lehua tree has seeds small enough to suggest dispersal through the air. 1st to appear after a lava flow

13. Drifting in Air • Insects. • Passive flight and small body size of insects accounts for their dispersal to the island. pollinates Yellow-faced bee Nesoprosopis

14. Attached to Birds • Embedded in mud on feet or other parts of birds • Sticky substances • Mechanical devices (barbs, hooks, bristles) Pacific golden plover

15. Fruits Eaten by Birds • Most effective means of seed dispersal to the Hawaiian Islands. • Accounts for dispersal of an estimated 39% of the 255 hypothetical original plants. Tetraplasandra flynii Has hairy gray fruits

16. Flowering Plant Dispersal by Birds migration migration

17. Bird & Insect Dispersal • Birds • Travel through active flight such as migratory birds, marine birds, shore birds and waterfowl. • Land birds underrepresented. • Insects • Passive flight and small size • Storms • Air currents • Migration

18. Fish and Marine Invert Dispersal • Fish • Freshwater fish, gobie family (diadromous or amphidromous)) • Drift as larvae (long-lasting stage) • Marine inverts • Drift as larva Ocean currents and gyre Most from Northwest Pacific Islands act as stepping stones

19. O'opu Amphidromous- migrate to and from the sea but do not use the ocean for reproduction

20. Brackish Water Invert Anchialine pond

21. Immigration Rates number rate (1 every …) flowering plants 272 110 thousand years insects 275 110 thousand years land snails 25 1.2 million years land birds 15 2 million years mammals 1 30 million years

22. Biodiversity Number of species • Native (got here “naturally” or evolved here) • Endemic (found only here) • Alien (exotic, human introduction)

23. NATIVE Occurring naturally in a given geographic area; not introduced as a consequence of human activities Turkey fish

24. ENDEMIC Occurring exclusively in a given geographic area, having originated in that area through natural means. Hawaiian Cleaner Wrasse

25. Hawaiian Honeycreepers

26. Hawaiian Crickets

27. Pueo

28. Hawaiian Hawk (Io)

29. Hoary Bat (Opeapea)

30. Hawaiian Monk Seal

31. Unusual Insects & their Relatives Happy Face Spider

32. Tree Snails

33. Nene

34. Ohia Lehua

35. Hapu Ferns

36. Percent Endemism in the Hawaiian Islands

37. EXOTIC Introduced to a given geographic area as a consequence of human activities. Anemone fish

38. Speciation adaptive radiation new species migrant species 9% of immigrants Flowering Plants

39. Results of Speciation colonists species radiation flowering plants 270-280 956 91 insects 233-254 3,722 81 land snails 23-24 1,064 294 land birds 15 70 42 radiation = maximum species from 1 colonizing species

40. Gaps in Speciation • Metrosideros polymorpha (ohia) • 1 tree species dominates • Fills many ecological roles Ordinarily, there would be many species

41. Metrosideros polymorpha

42. Gaps in Speciation • Honeycreepers • No woodpeckers (recently introduced?) • No hummingbirds

43. Gaps in Speciation • No native large herbivores • Plants with: • No thorns (berries) • No stingers (nettles) • No chemical defenses (mint)

44. What are some ways that animals arrive at their new location?

45. How do they arrive? • Dispersal Methods: • Rafting • Hitchhiking • Currents • Storms • Migrating Islands

46. Invasive Species Pathways Purposeful introduction via legal and illegal means; Unintentional introduction • Aircraft and cargo ship hulls • Ballast water and ship cargo • Hand-carry/luggage • Agriculture experiment stations • Mail • Forestry activities • Horticulture trade • Aquaculture • Pet trade • Botanical gardens

47. WHY SOME INTRODUCTIONS SUCCEED AND SOME DON’T? • Disadvantages due to new environmental conditions: • Foraging & predator avoidance strategies may be different • Small #’s of orgs introduced may go extinct • Advantages: • Generalist vs specialist species

48. Polynesian Voyagers to Hawaii yam breadfruit taro kava

49. Ahupua’a Ranges from the tip of the mtn to the reef area • Upland • Plains • Ocean Slash & burn agriculture (swidden)

50. Hawaii Bird Biodiversity Crisis • Half of Hawaii’s native birds went extinct soon after the Polynesians arrived • Half of the remaining species of birds went extinct soon after Captain James Cook arrived