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Lecture 56
Hawaii’sBiodiversity
Environmental Diversity
Extremely wide range of habitats
temperature
moisture
soils
vegetation
Environmental Diversity
Cold & Dry
Cool & Dry
Warm & Wet
Hot & WetHot & Very Dry
Warm & Very Dry
Warm & Dry trades
inversion
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.
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
Hawaii’s Flowering PlantsHawaii’s Flowering Plants
Long Distance Dispersal Wind, Water, & Wings Theory
The original colonist plants arrives in the following ways:
water 23%
wind 2%
birds 75%
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
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.
Adenophorus periens
• 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 Metrosideros polymorpha
Insects.
• Passive flight and small body size of insects accounts for their dispersal to the island.
Yellow-faced beeNesoprosopis
pollinates
• Embedded in mud on feet or other parts of birds
• Sticky substances
• Mechanical devices (barbs, hooks, bristles)
Pacific golden plover
• 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
migrationmigrationmigrationmigration
Flowering Plant Dispersal by Birds
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
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
Amphidromous- migrate to and from the sea but do not use the ocean for reproduction
Anchialine pond
Immigration Rates
number rate (1 every …)flowering plants 272 110 thousand yearsinsects 275 110 thousand yearsland snails 25 1.2 million yearsland birds 15 2 million yearsmammals 1 30 million years
Biodiversity
Number of species
Native (got here “naturally”
or evolved here)
Endemic (found only here)
Alien (exotic, human introduction)
NATIVE
Occurring naturally in a given geographic area; not introduced
as a consequence of human activities
Turkey fish
ENDEMIC
Occurring exclusively in a given geographic area, having
originated in that area through natural means.
Hawaiian Cleaner Wrasse
Hawaiian Honeycreepers
Hawaiian Crickets
Pueo
Hawaiian Hawk (Io)
Hoary Bat (Opeapea)
Hawaiian Monk Seal
Unusual Insects & their Relatives
Happy Face Spider
Tree Snails
Nene
Ohia Lehua
Hapu Ferns
Percent Endemism in the Hawaiian Islands
Marine Algae
Ferns & Fern Allies
Mosses
Flowering Plants
Terrestrial Mollusks
Marine Mollusks
Insects
Mammals
Birds
Plant or AnimalGroup
?
ca. 25
114
225
ca. 270
24 - 34
?
230 - 255
2
EstimatedNo. of
Colonists
420
ca. 135
145
233
ca. 1000
ca. 1000
ca. 1000
5,000
2
EstimatedNo. ofNative
Species
13
81
70
46
91
99
30 - 45
99
100
%EndemicSpecies
Endemic and Native Wildlife of the Hawaiian Islands
EXOTIC
Introduced to a given geographic area as a
consequence of human activities.
Anemone fish
Speciation
Flowering PlantsFlowering Plants
9% of immigrants
adaptive radiationadaptive radiationnew species
migrant species
Results of Speciation
colonists species radiationflowering plants 270-280 956 91insects 233-254 3,722 81land snails 23-24 1,064 294land birds 15 70 42
radiation = maximum species from 1 colonizing species
Gaps in Speciation
Metrosideros polymorpha (ohia)
1 tree species dominates
Fills many ecological roles
Ordinarily, there would be many species
Metrosideros polymorpha
Honeycreepers
No woodpeckers (recently introduced?)
No hummingbirds
Gaps in Speciation
No native large herbivores
Plants with:
No thorns (berries)
No stingers (nettles)
No chemical defenses (mint)
Gaps in Speciation
How do they arrive?
Dispersal Methods:• Rafting• Hitchhiking• Currents • Storms• Migrating Islands
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
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
Polynesian Voyagers to Hawaii
taro
breadfruit
kava
yam
Ahupua’a
1. Upland2. Plains3. Ocean
Ranges from the tip of the mtn to the reef area
Slash & burn agriculture (swidden)
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
European Contact
Large herbivores introduced
Native plants are “ice cream”
Animals multiplied rapidly
Introduced Feral Mammals
Goats
1.5 million skins 1844-1900
Cattle on Oahu
Wandered Honolulu streets
On all land but residential, agricultural or dense forest
MongooseBrought in to help control rat population in sugar cane fields
• Rat nocturnal• Mongoose diurnal
Mongoose, dogs, and cats are the nene’s main predator
Caribbean frogCaribbean frogcoqui
coqui
coqui
coqui
coqui
coquicoqui
Feral pigsFeral pigsOriginally introduced by Polynesian voyagers from the Marquesas Islands ca. 400 AD
Two Piranhas were caught in Lake Wilson in 1992-93. There may be more. We don’t know.
PiranhasPiranhas
Jackson’s Chameleon Jackson’s Chameleon
Brahminy “Hawaiian” Blind SnakeBrahminy “Hawaiian” Blind Snake
• Introduced 1930’s• Eats ants and beetles• Parthogenic• Not a threat
Introduced SpeciesIntroduced SpeciesAcanthophora, Eucheuma, & Gracillaria
Super Sucker to the Rescue!Super Sucker to the Rescue!
Mangroves in Hawaii (transplanted in 1902)
Brown Tree Snake, Guam
Upside-down JellyfishUpside-down Jellyfish
Snowflake CoralSnowflake Coral
Samoan CrabSamoan Crab
7 lbs 7 oz, 0/27/09 windward side
Blue stripped snapper
Forest Recovery
1903 = First forest reserve
Goal: water conservation
For the welfare and development of agriculture
Include all non-agricultural lands
1,057 plant species introduced
‘50s: Koa forests burned to plant alien pine trees
‘60s: Ohia forest defoliated by military
‘70s: Bulldozed ohia for alien tree plantations
‘80s: Burn ohia for “bio-power”
Forest Recovery
Volcanoes National Park
Created 1916; expanded 1927
Cattle grazing for 100 years
Cattle eat koa; park concerned
Complaints in ‘30s; no action
Grazing ended in 1938
Cattle out in 1940
WW II: Grazing again (‘42-’48)
Volcanoes National Park
1927: goat control started
5 years: 17,000 goats removed
1938: 5,000 goats removed
Goat proof fence: 70 sq. mi. area
25 years: 25,000 removed
Finally: Park is goat-free
Hawaii’s Extinction Crisis
Birds and PlantsBirds and Plants
Hawaii as % of US
land area 0.2%native species 14%endangered 28%extinct 73%
Human Impacts
4,000 - 6,000 alien plants
About 1,000 naturalized(reproducing naturally)
Introductions cause:
CompetitionHarbor diseasesDeplete resources
Factors Reducing Habitat
Crop lands
Cattle grazing
Feral animals (cattle, pigs, goats, sheep, deer)
Urbanization
1500 years ago1500 years ago
dry forestshrublandgrassland
dry forestshrublandgrassland
mesic forestshrubland
mesic forestshrubland wet forestwet forest
19911991
developed landsand non-nativevegetation
developed landsand non-nativevegetation
Solutions?• Conservation• Mechanical (physical removal)• Chemical (pesticides, herbicides)• Biological (natural predator)• Legislation• Education• Prevention• Ballast water:
* UV light* chemicals* dump water far from port
Conservation Protection
National Parks
Nature Conservancy Preserves
State Natural Areas Reserves
State Parks
Alien Animal Control
> $40,000/mile to fence
Haleakala NP = $5 million
Hard to eradicate animals
Animal control not popular
PETA: snares are “in-humane”
Few pigs survive > 24 hours
Pigs learn how to evade dogs and hunters
Hunting doesn’t always kill
Dog injury (prohibited?)
Pig Control: the Controversy
Lots of misinformation
Who speaks for the native vegetation, insects, birds?
Pig Control
Introduced grasses a problem
Fountain grass in Kona area
After fires, fire-adapted species become abundant
Helicopters = $700/hour
Fire
Fountain grassFountain grass
Introduces weeds
Clean boots before hiking
Activities breaking vegetation
Creates a path (water, erosion)
10-20 people/month= major disturbance
Human Activity
Specific diseases or pests for weeds
Lantana:
Introduced ~170 years ago
Mynah birds spread seeds
1900: was a major pest
22 insects introduced; 12 established
Biological Control
Lantana camara
Rigorous testing before introduction
No viruses; highly specific
1st on mainland; repeated here
Takes 7 to 8 years
Must learn to rear control
About 50% success
Biological Control
Biological Control
About $500,000/year
Hard to get $ for herbicides;easy for biological control
Public Attitudes
“Goat eradication program”
Negative public reaction
“Native ecosystem restoration program”
Positive public reaction
“Exotic”
“Alien”
Introduced SpeciesYellow ginger
1. What are the two ways in which plants and birds are able to travel the long-oceanic distance to the Hawaiian islands by drifting through the air?
2. How can plants and animals be dispersed to the Hawaiian islands by attachment to birds?
3. What accounts for the largest means of seed dispersal to the Hawaiian islands than any other mechanism?
4. What adaptations must a plant or seed have for dispersal by flotation in seawater?
5. What advantage does “rafting” play in dispersal?
Inquiry
6. Two of the major environmental factors influencing Hawai`i's habitat diversity are:
7. The most likely way that flowering plant species arrived in Hawai`i was by:
8. If a species is referred to as being endemic to Hawai`i, you can assume that it:
9. The main reason that Hawai`i's native species don't have thorns, stingers or chemical defenses is that they:
Inquiry
10. The removal of cattle from Oahu's forests was important to:
11. There are about _____ native flowering plant species in Hawai`i and _____ introduced ones that are now naturalized.
12. The control of pigs in Hawai`i's forests is: Biological control in Hawai`i has been:
Inquiry
Inquiry13. What class of vertebrates did not arrive to Hawaii
by natural means?14. Compare a generalist exotic species to a specialist.15. What 2 species have impacted the great lakes and
how did they arrive?16. Why are pigs such a problem?
Endemic, Native or Exotic?A B C D E
F G
Carnivorous caterpillar
Cane toadMushroom coralGreen turtle
Bottlenose dolphin
Blue stripped snapper