Hawaiis Biodiversity

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Lecture 38
HawaiisBiodiversity
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Environmental Diversity
Extremely wide range of habitats
temperature
moisture
soils
vegetation
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Environmental Diversity
Cold Dry
Cool Dry
inversion
trades
Warm Dry
Warm Wet
Warm Very Dry
Hot Wet
Hot Very Dry
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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.   

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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

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Dispersal to the Hawaiian Islands

• Questions 
• 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?
• How can plants and animals be dispersed to the
  Hawaiian islands by attachment to birds?
• What accounts for the largest means of seed
  dispersal to the Hawaiian islands than any other
  mechanism?
• What adaptations must a plant or seed have for
  dispersal by flotation in seawater?
• What advantage does rafting play in dispersal?

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Long Distance Dispersal Wind, Water, Wings
Theory The original colonist plants arrives in
the following ways
Hawaiis Flowering Plants
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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
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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.

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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
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Drifting in Air

• Insects.
• Passive flight and small body size of insects
  accounts for their dispersal to the island.

pollinates
Yellow-faced bee Nesoprosopis
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Flowering Plant Dispersal by Birds
migration
migration
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Drifting in Air

• Birds
• Travel through active flight such as migratory
  birds, marine birds, shore birds and waterfowl.
• Land birds underrepresented. 
• Air currents are a major factor
• Northern Hemisphere jet stream.

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Attached to Birds

• Estimated 12.8 of the hypothetical original
  flowers arrived this way
• Attachment
• Embedded in mud on feet or other parts of birds
• Sticky substances
• Mechanical devices (barbs, hooks, bristles)

Pacific golden plover
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Fruits Eaten by Birds

• Most effective means of seed dispersal to the
  Hawaiian Islands.
• Fruit-eating birds ate the seeds, carried them
  internally, and excreted them on islands.
• Accounts for dispersal of an estimated 39 of the
  255 hypothetical original plants.

Tetraplasandra flynii Has hairy gray fruits
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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
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Biodiversity
Number of species
Native (got here naturally or evolved
here) Endemic (found only here) Alien (exotic,
human introduction)
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NATIVE Occurring naturally in a given
geographic area not introduced as a consequence
of human activities
Turkey fish
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ENDEMIC Occurring exclusively in a given
geographic area, having originated in that area
through natural means.
Hawaiian Cleaner Wrasse
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Hawaiian Honeycreepers
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Hawaiian Crickets
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Happyface Spiders
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Tree Snails
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Nene
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Ohia Lehua
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Hapu Ferns
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Percent Endemism in the Hawaiian Islands
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EXOTIC Introduced to a given geographic area
as a consequence of human activities.
Anemone fish
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Speciation
adaptive radiation
new species
migrant species
9 of immigrants
Flowering Plants
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Results of Speciation
colonists species radiation flowering
plants 270-280 956 91 insects 233-254 3,722 81 lan
d snails 23-24 1,064 294 land birds 15 70 42
radiation maximum species from 1 colonizing
species
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Gaps in Speciation
Metrosideros polymorpha (ohia) 1 tree species
dominates Fills many ecological roles
Ordinarily, there would be many species
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Metrosideros polymorpha
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Gaps in Speciation
Honeycreepers No woodpeckers (recently
introduced?) No hummingbirds
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Gaps in Speciation
No native large herbivores Plants with No thorns
(berries) No stingers (nettles) No chemical
defenses (mint)
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What are some ways that animals arrive at
their new location?
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How do they arrive?

• Dispersal Methods
• Rafting
• Hitchhiking
• Currents
• Storms
• Migrating Islands

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WHY SOME INTRODUCTIONS SUCCEED AND SOME DONT?

• 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

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Polynesian Voyagers to Hawaii

• Pigs
• Dogs
• Taro
• Coconut
• Kukui
• Banana
• bread fruit
• Kava
• kudzu
• sweet potato
• yams

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Ahupuaa
Ranges from the tip of the mtn to the reef area

• Upland
• Plains
• Ocean

Slash burn agriculture (swidden)
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European Contact
Large herbivores introduced Native plants are
ice cream Animals multiplied rapidly
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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
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• Mongoose
• Brought in to help control rat population in
  sugar cane fields
• Rat nocturnal
• Mongoose diurnal
• Mongoose, dogs, and cats are the nenes main
  predator

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Caribbean frog
coqui
coqui
coqui
coqui
coqui
coqui
coqui
Citric acid and caffeine
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Feral pigs
Originally introduced by Polynesian voyagers from
the Marquesas Islands ca. 400 AD
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Two Piranhas were caught in Lake Wilson in
1992-93. There may be more. We dont know.
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Jacksons Chameleon
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Introduced Species
Acanthophora, Eucheuma, Gracillaria
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Mangroves in Hawaii (transplanted in 1902)
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Brown Tree Snake, Guam
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Blue stripped snapper



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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
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Forest Recovery
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
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Volcanoes National Park
Created 1916 expanded 1927 Cattle grazing for
100 years Cattle eat koa park concerned Complaint
s in 30s no action Grazing ended in 1938 Cattle
out in 1940 WW II Grazing again (42-48)
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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
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Hawaiis Extinction Crisis
Birds and Plants
Hawaii as of US land area 0.2 native
species 14 endangered 28 extinct 73
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Human Impacts
4,000 - 6,000 alien plants About 1,000
naturalized(reproducing naturally) Introductions
cause Competition Harbor diseases Deplete
resources
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Factors Reducing Habitat
Crop lands Cattle grazing Feral animals (cattle,
pigs, goats, sheep, deer) Urbanization
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mesic forestshrubland
wet forest
dry forest shrubland grassland
1500 years ago
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developed lands and non-nativevegetation
1991
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Solutions?
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• Solutions?
• Conservation
• Mechanical (physical removal)
• Chemical (pesticides, herbicides)
• Biological (natural predator)
• Legislation
• Education
• Prevention
• Ballast water
• UV light
• chemicals
• dump water far from port

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Conservation Protection
National Parks Nature Conservancy Preserves State
Natural Areas Reserves State Parks
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Alien Animal Control
gt 40,000/mile to fence Haleakala NP 5
million Hard to eradicate animals Animal control
not popular
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Pig Control the Controversy
PETA snares are in-humane Few pigs survive gt
24 hours Pigs learn how to evade dogs and
hunters Hunting doesnt always kill Dog injury
(prohibited?)
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Pig Control
Lots of misinformation Who speaks for the native
vegetation, insects, birds?
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Fire
Introduced grasses a problem Fountain grass in
Kona area After fires, fire-adapted species
become abundant Helicopters 700/hour
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Fountain grass
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Human Activity
Introduces weeds Clean boots before
hiking Activities breaking vegetation Creates a
path (water, erosion) 10-20 people/month major
disturbance
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Biological Control
Specific diseases or pests for weeds Lantana Intr
oduced 170 years ago Mynah birds spread
seeds 1900 was a major pest 22 insects
introduced 12 established
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Lantana camara
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Biological Control
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
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Biological Control
About 500,000/year Hard to get for
herbicideseasy for biological control
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Public Attitudes
Goat eradication program Negative public
reaction Native ecosystem restoration
program Positive public reaction
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Yellow ginger
Introduced Species
Exotic
Alien
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Questions
Two of the major environmental factors
influencing Hawaii's habitat diversity are
The most likely way that flowering plant species
arrived in Hawaii was by
If a species is referred to as being endemic to
Hawaii, you can assume that it
The main reason that Hawaii's native species
don't have thorns, stingers or chemical defenses
is that they
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The removal of cattle from Oahu's forests was
important to
There are about _____ native flowering plant
species in Hawaii and _____ introduced ones that
are now naturalized.
The control of pigs in Hawaii's forests is
Biological control in Hawaii has been