6/18/18

1

Exotic and Invasive Species

Which of the following species is native to North America?

House Mouse Dandelion

6/18/18

2

Honeybee

Pigeon (Rock Dove)

Starling

Which of the following species is native to North America?

None of these species are native to

North America.

6/18/18

3

Communities can be disrupted by exotic species.

Communities can be disrupted by exotic species.

•  species introduced by humans to communities in which they were not previously found.

Communities can be disrupted by exotic species.

•  species introduced by humans to communities in which they were not previously found.

•  introduction can be intentional or unintentional.

Communities can be disrupted by exotic species.

•  have affected virtually all communities, but especially problematic in disrupted habitats.

6/18/18

4

Communities can be disrupted by exotic species.

•  have affected virtually all communities, but especially problematic in disrupted habitats.

•  exotics often invasive.

European Starling – Introduced Species

William Shakespeare’s Birds Central Park NYC, 1896

Spread of the

Starling

1896

6/18/18

5

Spread of the

Starling

1904

Spread of the

Starling

1908

Spread of the

Starling

1910

Spread of the

Starling

1912

6/18/18

6

Spread of the

Starling

1916

Spread of the

Starling

1918

Spread of the

Starling

1920

Spread of the

Starling

1922

6/18/18

7

Spread of the

Starling

1924

Spread of the

Starling

1926

Starling – Current Distribution Great Lakes

6/18/18

8

Great Lakes – Rate of Invasions

Woolly Adelgid – Invasive Species

32

6/18/18

9

33

Honeysuckle – Invasive Species

Cost of Invasives •  More than 4,500 foreign species have

gained a permanent foothold or taken root in the U.S. during the past century.

•  Invasive species contribute to the decline of 46% of the imperiled or endangered species in the U.S.

•  Invasive species are estimated to cost a total of $137 billion annually in losses to agriculture, forestry, fisheries and the maintenance of open waterways in the U.S.

Characteristics of Invasives

6/18/18

10

Characteristics of Invasives

•  Rapid Population Growth.

Characteristics of Invasives

•  Rapid Population Growth. •  Displace or Kill Native Species.

Characteristics of Invasives

•  Rapid Population Growth. •  Displace or Kill Native Species. •  No natural population regulation.

– No predators. – No pathogens.

Characteristics of Invasives

•  Rapid Population Growth. •  Displace or Kill Native Species. •  No natural population regulation.

– No predators. – No pathogens.

•  High Dispersal Rates.

6/18/18

11

Communities can be disrupted by exotic species.

•  have affected virtually all communities, but especially problematic in disrupted habitats.

•  exotics often invasive •  native species affected negatively.

Communities can be disrupted by exotic species.

•  have affected virtually all communities, but especially problematic in disrupted habitats.

•  exotics often invasive . •  native species affected negatively. •  at least 30,000 exotic species in U.S. alone.

Exotic species, example

•  Hawaiian land snails – before human contact, more than 1000 species.

Exotic species, example

•  Hawaiian land snails. – before human contact, more than 1000 species.

•  compare to 719 in all of U.S. and Canada.

6/18/18

12

Exotic species, example

•  Hawaiian land snails. – before human contact, more than 1000 species .

•  compare to 719 in all of U.S. and Canada. – just after European arrival, ~930 species.

Exotic species, example

•  Hawaiian land snails. – before human contact, more than 1000 species.

•  compare to 719 in all of U.S. and Canada. – just after European arrival, ~930 species. – 1950s, ~500 species.

Hawaiian snails

•  1950s — Giant African snails. – imported for food.

6/18/18

13

Hawaiian snails

•  1950s — Giant African snails. – imported for food. – escaped, became agricultural pest. – tried to control with poison, didn’t work.

Hawaiian snails

•  1950s — Giant African snails. – imported for food. – escaped, became agricultural pest. – tried to control with poison, didn’t work.

•  imported carnivorous Rosy Wolfsnails.

Hawaiian snails

•  1950s — Giant African snails. – imported for food. – escaped, became agricultural pest. – tried to control with poison, didn’t work.

•  imported carnivorous Rosy Wolfsnails. – didn’t eat Giant African snails. – did eat native snails.

6/18/18

14

Hawaiian snails •  1950s — Giant African snails.

– imported for food. – escaped, became agricultural pest. – tried to control with poison, didn’t work.

•  Imported carnivorous Rosy . – Did eat native snails.

•  now, 75% native species extinct, almost all others endangered.

Exotic species, zebra mussel

•  Native to Black Sea and Caspian Sea.

Exotic species, zebra mussel

•  Native to Black Sea and Caspian Sea. •  1985 – ship discharged ballast (fresh water) in Lake St. Clair.

6/18/18

15

Exotic species, zebra mussel

•  Native to Black Sea and Caspian Sea. •  1985 – ship discharged ballast (fresh water) in Lake St. Clair.

•  Zebra mussels now in: –  all Great Lakes. –  Mississippi and Ohio drainages. –  increasing number of other eastern waterways.

Exotic species, zebra mussel

•  Native to Black Sea and Caspian Sea. •  1985 – ship discharged ballast (fresh water) in Lake St. Clair.

•  Zebra mussels now in: –  all Great Lakes. –  Mississippi and Ohio drainages. –  increasing number of other eastern waterways. –  catastrophic decline of native mussel species.

Exotic species, zebra mussel

•  Native to Black Sea and Caspian Sea. •  1985 – ship discharged ballast (fresh water) in Lake St. Clair.

•  Zebra mussels now in: –  all Great Lakes. –  Mississippi and Ohio drainages. –  increasing number of other eastern waterways. –  catastrophic decline of native mussel species. –  encrustation troublesome to humans.

6/18/18

16

Why are exotics such strong competitors?

•  Study of European plant (473) and animal (26) species that have invaded U.S.

Why are exotics such strong competitors?

•  Study of European plant (473) and animal (26) species that have invaded U.S.

•  Compared parasites in both locales.

Why are exotics such strong competitors?

•  Study of European plant (473) and animal (26) species that have invaded U.S.

•  Compared parasites in both locales. – 84% drop in fungal infections (plants). – 24% drop in viral infections. – Overall 77% lower disease rate.

6/14/18

1

Current Threats to Biodiversity

6/14/18

2

Threats by Taxonomic Group The Sixth Great Extinction

Human caused contemporary extinctions.

The Sixth Extinction •  Currently extinction rates are greater than

speciation rates. •  Current anthropogenic extinction rate greater than

natural background rate. –  Natural background rate 0.0001% – 0.00001% of

species per year. –  Current rate for Birds and Mammals 0.01%.

•  99% of modern extinctions are linked to human causes.

•  Current extinction rates comparable to rates during previous historic mass extinctions.

6/14/18

3

6/14/18

4

Survey of Threats to Biodiversity

Habitat Impacts

Habitat Impacts

Direct Loss Fragmentation Effects

Direct Loss Direct Loss

Organism’s have evolved to do best in particular habitats.

Mortality rates are higher and fertility rates are lower in less

preferred and unsuitable habitat.

6/14/18

5

Natural Vegetation •  US – 42%.

–  East and Midwest less then 25%. •  Europe – 15%. •  Thailand, India, and Vietnam – 50%. •  Mediterranean – 10% forest left.

US causes •  Agriculture 38%. •  Commercial Development 35%. •  Water Projects 30%. •  Outdoor recreation 27%. •  Livestock grazing 22%. •  Pollution 20%. •  Infrastructure and roads 17%. •  Disruption of fire ecology 13%. •  Logging 12%.

6/14/18

6

Habitats Lost

•  Tropical Forest. –  Madagascar 13% left. –  Rest of world varies from 90% to 5% left.

Habitats Lost

•  Tropical Forest. –  Madagascar 13% left. –  Rest of world varies from 90% to 5% left.

•  Grassland – US 97% lost. •  Wetlands – US 50% lost.

Habitats Lost

•  Tropical Forest. –  Madagascar 13% left. –  Rest of world varies from 90% to 5% left.

•  Grassland – US 97% lost. •  Wetlands – US 50% lost. •  Coral Reefs – 20% lost and at least 20%

degraded. Estimate that up to 95% may be lost by 2100.

6/14/18

7

Habitat Fragmentation

Breaking larger contiguous blocks of habitat into smaller

isolated island of habitat.

Fragments tend to have higher extinction rates.

Habitat Fragmentation

Cadiz Township Green County

Wisconsin

1831 – 1950

Fragmentation – Warwickshire England

6/14/18

8

Fragmentation Effects – I

•  Increasingly Smaller Patches. •  Increasingly Isolated Patches. •  Changes in Patch Habitat Quality.

–  Increased Edge Habitat. –  Changes do to intensive human use. –  Greater penetration of Invasive Species.

Patch and Matrix

Patch Characteristics and Conservation Biology

•  Size. •  Number. •  Position. •  Edges. •  Corridors. •  Networks of Patches and Corridors.

Patch Size

6/14/18

9

Local Extinction Probability Habitat Quality as an Extinction Factors

Large Patch Benefit – Habitat Diversity

Number of Patches

6/14/18

10

Habitat Loss

Patch Isolation

Isolation and Extinction

Edges

6/14/18

11

Large Patch Benefits – More Interior Habitat Interior Habitat and Species

Change in Edge/Interior Ratio Loss of total vs. Interior Habitat

6/14/18

12

Interior Habitat Species – Area Sensitive Species

•  Require large patches of habitat. •  Avoid the edges of habitat. •  Are sensitive to edge effects.

45 Northern Goshawk

Area sensitive species need interior forest

Edge effects – Why do they effect forest interior species?

48

6/14/18

13

Edge effects as a function of distance from the edge.

49

Edge effects on microclimate

50

Edge Effects

Edge effects on vegetation

52

6/14/18

14

Edge Effects

Edge effects on animals

54

Edge Effects Edge Effects

•  Changes in Microclimate. •  Changes in Plant Community. •  Changes in Animal Community. •  Invasion of Interior by Edge Species.

–  Brown-headed Cowbird. –  Invasive Plants.

6/14/18

15

Brown-headed Cowbird Habitat Fragmentation Effects II

•  Limits to dispersal and colonization. •  Restricted access to food and mates. •  Disruption of interspecific interactions.

6/12/18

1

Extinctions – History Historical Mass Extinctions

443 mya 364 mya

251 mya 206 mya

65 mya

Major Mass Extinctions

443 mya 364 mya

251 mya 206 mya

65 mya

Major Mass Extinctions

6/12/18

2

The Five Great Extinctions Ordovician

1- End of Ordovician •  When: 450 to 440 mya, two pulses. •  Duration: 10 million years. •  Context: All life marine, very warm period. •  Results: Marine Species – 60 to 85%. •  Cause: Increased CO2 sequestration.

Drop in sea level caused by global cooling. This resulted in rapid loss of habitats and rapid change in ocean temperatures. Then rapid warming at end of ice age.

The Five Great Extinctions

6/12/18

3

Devonian 2 – Late Devonian

•  When: 364 mya. •  Duration: 3< million years. •  Context: Fish, plants, insects, amphibians. •  Result: Mostly marine Species, 57 to 83%. •  Cause: global cooling, loss of oxygen in

water and decline of CO2. – Impact. – Plants.

The Five Great Extinctions Permian

6/12/18

4

3 – End of Permian •  When: 251 to 261 mya, two pulses. •  Duration: 10 million years. •  Context: Major diversification of marine

and terrestrial life. •  Result: Marine Species 95% and 70%

terrestrial vertebrates, and 83% of insects. •  Cause: global climate and sea level fluctuations.

–  Impact. –  Volcanism, cooling and acidification followed

by abrupt warming. –  Methane hydrate gasification – warming and

acidification.

The Five Great Extinctions

Triassic 4 – End of Triassic •  When: 200 mya. •  Duration: 3 – 4 million years. •  Context: Diversity of reptiles and

amphibians. •  Result: Marine Species 53-80%, majority of

reptiles and amphibians. 50% of all life. •  Cause:

– Impact. – Severe volcanic activity. – Global warming.

6/12/18

5

17

The Door to Dinosaur Diversification The Five Great Extinctions

Cretaceous

Age of the Dinosaurs

Cretaceous

6/12/18

6

5 – Late Cretaceous

•  When: 65 mya. •  Duration: <1million years. •  Context: Peak of Dinosaur diversity. •  Result: Marine Species – 47-76%,

extinction of Dinosaurs. •  Cause:

– Impact. – Severe volcanic activity.

The Alverez Iridium anomaly

Around the world is a thin band of clay at the Cretaceous-Tertiary (KT) boundary.

This band is highly enriched for Iridium (Ir).

24

6/12/18

7

Iridium A rare-earth element. Rare in earth’s crust. Common in meteorites. Can be extruded by volcanoes.

What was the source? Extra-terrestrial impact vs. volcanoes.

Comet/asteroid impact. Massive series of volcanic eruptions.

Impact rather than volcanic origin Microtektites

very small glass spheres caused by very high velocity impact (impact, not volcanic) . Strewn fields worldwide.

Microtektites

6/12/18

8

Impact rather than Volcanic origin suggested Microtektites

Very small glass spheres caused by very high velocity. impact (impact, Not volcanic). strewn fields worldwide.

Shock quartz Quartz grain with multiple sets of shock lamellae, impact, not volcanic.

Presence of both at Ir anomaly layer strongly supports impact

over volcanic origin of Ir.

Shock quartz

Where was the crater?

North American marine site suggested. Distribution of microtektite strewn fields.

greater abundance and larger grain size of shocked minerals in North American.

Crater appears to be underwater, just off the Yucatan peninsula.

6/12/18

9

Extinctions are a natural process.

Why the concern today?

Major Extinctions Processes •  Rapid and intense environmental change.

– Temperature, rainfall, amount sunlight, etc. – Change in CO2 and pH in oceans.

•  Rapid loss of habitat. – Direct destruction. – Loss of plants that could not withstand environmental

changes. •  Rapid declines in populations. •  Secondary extinctions based on biotic

interactions. – Predator – prey. – Plant – pollinator. – Etc.

What happens after an extinction?

Recovery

•  Some species survive and may proliferate rapidly.

•  Slowly new species arise and in some cases explosive adaptive radiations generate new groups.

•  This process takes 10 of millions of years.

6/12/18

10

Why are Big and Fierce Animals So

Rare?

The Pleistocene Extinctions Megafauna are animals which weigh more than 100 lbs. North America lost thirty-three genera of megafauna. 70 species or 95% of the megafauna. Worldwide lost 200 genera, most of which were megafauna.

Worldwide Loss of Megafauna during Pleistocene

American Lion Close relative of African Lion

6/12/18

11

Saber-toothed Tiger Ambush predator

Dire wolf Larger teeth shorter limbs than Timber Wolf Hyena like lifestyle

Short-faced Bear 1,800 lbs, 5 feet at shoulder

Herbivores lost from America, Europe and Australia

All herbivores > 1000 kg

75% of herbivores 100-1000 kg

41% of herbivores 5-100 kg

< 2% of herbivores < 5kg

1 kg = 2.2 pounds

6/12/18

12

Ground Sloths 3,500 lbs and 6 feet tall

North American Camel Related to Llama

Tapir Related to Horses

American Mastodon Browser – Twigs, Leaves 4 to 6 tons, 8-10 ft at shoulder

6/12/18

13

Mammoth Grass eater, 10,000 lbs, 10 feet tall

What caused extinction?

What caused extinction?

Climate Change, Overkill, Disease or all of the above?

Environmental Changes

Climate Change

6/12/18

14

Land Cover 18,000 yrs bfp

Land Cover 13,000 yrs bfp

Land Cover 11,000 yrs bfp

Land Cover 8,000 yrs bfp

6/12/18

15

Land Cover Present

Environmental Changes •  Eliminate food sources. •  Disrupt birth schedules. •  Expose animals to environmental

conditions they are not adapted to.

Changing Ice Volume Arrival of Homo sapiens

6/12/18

16

Stone Tipped Spears Worldwide Loss of Megafauna during Pleistocene

Human Migration Corridor

6/12/18

17

Pleistocene extinction episodes

Overkill?

Second Order Overkill

New Zealand – about 800 years ago Maori – Arrive 1000 years ago

6/12/18

18

Moa – Flightless Birds Madagascar – about 1500 years ago

Polynesians Arrive Giant Elephant Bird

6/12/18

19

Extinct Lemurs

6/12/18

1

Extinctions Extinctions

Theory

Historical Extinctions Contemporary Extinctions

2

Extinctions – Theory How long do species survive?

First, what about chronospecies?

6/12/18

2

Evolutionary change within a species.

Chronospecies

How long do species survive?

First, what about chronospecies?

Species survival can be misleading if your looking at fossil record.

Species survival can be misleading if your looking at fossil record. So instead ask: How long does a clade survive?

6/12/18

3

Taxonomic Categories Clade – any group of related organisms at a level above species.

Dinosaur Clades at the Level of Order

Velociraptor

6/12/18

4

Tyrannosaurus How long does a clade survive?

Time

Clade Extinction Rate – Exponential Decay

C ha

nc e

of g

oi ng

e xt

in ct

Clade survival Plants 1 to 10 million years

6/12/18

5

Clade survival Mammals 0.5 to 5 million years

Extinction Risk Factors

•  Narrow geographic range.

18

Golden Lion Tamarin Extinction Risk Factors

•  Narrow geographic range. •  One or few populations.

20

6/12/18

6

Puerto Rican Parrot Extinction Risk Factors

•  Narrow geographic range. •  One or few populations. •  Small population size.

22

Kakapo Extinction Risk Factors

•  Narrow geographic range. •  One or few populations. •  Small population size. •  Island Habitat.

24

6/12/18

7

Socotra Dragon Tree Extinction Risk Factors

•  Narrow geographic range. •  One or few populations. •  Small population size. •  Island Habitat. •  Hunting or harvesting by people.

26

Rhinoceros Extinction Risk Factors

•  Narrow geographic range. •  One or few populations. •  Small population size. •  Island Habitat. •  Hunting or harvesting by people. •  Chapter 5 in your textbook lists several

other lesser factors. 28

6/12/18

8

Theory of Island Biogeography

•  Predicts dynamic equilibrium of species on any particular island based on: – Size of Island.

Montserrat 102 sq km

Jamaica 10,991 sq km

Which one has more species?

Why?

6/12/18

9

Island size and biodiversity

•  Larger islands tend to have more types of habitats.

•  Larger islands tend to have a greater amount of area in any given habitat.

•  Larger area of habitat can support larger population.

•  Larger population are less likely to go extinct.

33

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Demographic Stochasticity

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

6/12/18

10

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Threshold

Time

Population Size and Extinction

P op

ul at

io n

S iz

e

Population Extinct

6/12/18

11

What’s the real world pattern?

41

Island size – Caribbean Islands and Number of Animal Species

Exponential Increase

Theory of Island Biogeography

•  Predicts dynamic equilibrium of species on any particular island based on: – Size of Island. – Distance from mainland source of species.

Pacific Islands Decreasing Diversity from Mainland

6/12/18

12

Number of species on Island determined by Immigration Rate Extinction Rate

Number of species on Island determined by Immigration Rate : Species Added Extinction Rate : Species Subtracted

6/12/18

13

Habitat Fragmentation creates habitat islands that are smaller and more isolated than the larger landscape they came from.

Habitat Fragmentation creates habitat islands that are smaller and more isolated than the larger landscape they came from.

Predict fragmented landscapes will lose species.

6/12/18

14

Theory of Island Biogeography

•  Predicts dynamic equilibrium of species on any particular island based on: – Size of Island. – Distance from mainland source of species. – Particular group of organisms.

Theory of Island Biogeography

•  Predicts dynamic equilibrium of species on any particular island based on: – Size of Island. – Distance from mainland source of species. – Particular group of organisms.

•  Method of dispersal (flying, swimming, wind borne, etc.).

•  Position on food web and energy pyramid.

Energy Pyramid

Apex Predator

6/12/18

15

Confirmation of Theory Florida Keys Experiment What do theories about

islands have to do with current extinctions?

59

Fragmented habitats are like islands. Biological Dynamics of Forest Fragments Project

6/12/18

16

MCS or BDFFP

•  Small islands (fragments) decreased faster.

MCS or BDFFP

•  Small islands (fragments) decreased faster.

•  First order create second order.

MCS or BDFFP

•  Small islands (fragments) decreased faster.

•  First order create second order. •  Smaller populations go extinct faster.

6/12/18

17

Effective Population Size Effective Population Size

Bottlenecks Genetic Drift Inbreeding Depression

Bottleneck – Founder Effect

6/12/18

18

Bottleneck – Founder Effect Bottleneck – Founder Effect

Genetic Drift

By chance, in small populations some genes become more

prevalent or less prevalent. This reduces genetic diversity.

This can result in lower survival

and reproductive output of resulting young.

6/12/18

19

Inbreeding Depression

In small population high l