Exotic species, food webs, & ecosystems and Horned Lizards, conservation, & biodiversity

Continental Drifts are also known as?

Plate Tectonics

Land mass of continents 225 million years ago

Pangea

When did Pangea split to create the continents

65 million years ago

Communities coevolved for over

65 million years

Coevolution

Reciprocal evolutionary change that occurs between pairs of species or among groups of species as they interact after one another

Coevolution can range from

Mutualistic to antagonistic

Mutualistic

Benefits both species

Commensal

One species benefits while the other is neither helped nor harmed

Competitive

Mutually harmful relationship, striving for limited resources

Antagonistic

Benefits one species, harms the other

Food web

Each organism is affected by the presence of all the other organisms

Non-native species

Introduced into communities where they did not evolve

Non-native species are not always damaging to the ecosystem

Africanized honey bee do not damage ecosystems but European honey bees do

How can non-native species become invasive?

If they outcompete native species for resources

Invasive species

When an exotic species begins to exploit an ecosystems resources or species excessively

What do invasive species lead to?

Damage to the ecosystem or food web

How does an exotic species become invasive?

It does not coevolve with the rest of the organisms in the food web; could disrupt predator/prey relationships

Exotic species

Population can grow to where they exploit resources used by native species, resulting in a decline in native species

Feral Hogs

An exotic species that are invasive in the U.S

Exotic species could either…

• Not survive

• Blend into existing ecosystems

• Become invasive

Fire Ants

Arrived in Alabama on a boat from south America

When did fire ants come to the U.S.

The 1930’s

Fire Ants migration

Migrated across the southern U.S because they enjoy warmer/hotter areas

Invasive fire ants

They displace native ant species and prey on round dwelling speies

Fire ants habitat

Inhabit about 10% of the U.S

Fire ants invasion of Texas

They have been moving Westward for decades

Fire ants infestation

They swarm any disturbance (stinging & biting)

Each ant mound…

Has about 250,000 fire ants

Fire ants killing ground dwelling species

Fire ants kill quail eggs and the quails don’t have defenses so their population has declined

Controlling fire ants

Pesticides (temporary solution): It kills and disrupts food webs

Controlling fire ants

Biological controls: Introduces a predator to fire ants, Phorid flies

Lionfish

Were introduced to the ecosystem on purpose when people dumped their fish in the ocean

Distribution of Lionfish

Native to the Indian and Pacific ocean; were later introduced along the east coast of the U.S

Lionfish invasive

They are voracious eaters of other fish, devastate fish communities, and have no native predator

Lionfish hunting

Derbies are held to encourage hunting and eating Lionfish

Lionfish Spines

Can be very painful and swelling could occur and last for hours

Burmese Pythons

Were released in the Florida Everglades in 1990 and have spread throughout South Florida

Burmese Python Pet Trade

Dealers would import them from Southeast Asia by the 10’s of thousands

How did Burmese Pythons get in the wild?

Owners no longer wanted them and dropped them in the Everglades

Burmese Pythons and predators

Constrictors, having backwards facing teeth to prevent their prey from leaving, and can unhinge jaw to swallow prey

Native species have not coevolved with Burmese Pythons

Constrictors have not yet existed in North America for million of year

Burmese pythons as predators

Native wildlife species don’t recognize them as predators

Populations impacted by Burmese Pythons

Rabbits, Possums, Raccoons, and Deer populations have dropped by 99%

What results in high Burmese Python populations

Females reproduce rapidly by producing 30-80 eggs

Sentinel Snakes

Male snakes have transmitters to allow people to track the females

When female Burmese Pythons are located…

They are captured and removed

Python removal

Increased after incentives of payment for python capture

Southern America for Pythons

The Southern states match the climate of the native range in Asia, snakes can survive in Texas and much of California

What is biodiversity?

Biological Diversity

What is biodiversity?

All species that exist within a particular space

How many species are there?

Between 3-22 million

How many species have been describes?

1.8 million species

How long is the Earth’s surface area?

197 million square miles

Why don’t scientists know the exact amount of species?

Species live in deep layers of the ocean, underground, and at the tops of tress, unreachable to scientists

How many mass extinctions have their been?

5

When was the last mass extinction?

66 million years ago

What was the last mass extinction?

An asteroid or comment

The 6th mass extinction

Most biologists think we are in the midst of another mass extinction, the fastest in Earth’s history

Passenger Pigeon’s population

Once constituted 25-40% of the total bird population

Passenger pigeon extinction

They became extinct in part due to overhunting and habitat destruction

Saving endangered species

• Moral obligation

• Aesthetic natural beauty

• Useful to humans

• Ecosystem services

• Threat to human existence

How to protect biodiversity

• Reduce exploitation

• Protect habitats

• Reducing climate change

• Monitoring/reporting species decline

• Protecting endangered species

Reducing exploitation

The International Whaling Commission put a pause on whaling of all species, fish face severe hunting pressure

Protecting habitats

Woodrow Wilson helped preserve National parks in the U.S to preserve its natural and cultural heritage

Reducing climate change

Climate change alters the environment which makes reducing climate change challenging; preserving biodiversity is even harder

Monitoring and reporting species decline

Red list of animals threatened by extinction or already extinct could be extinct within the next several decades

Threatened species

An animal or plant that is likely to become endangered within the foreseeable future

Endangered species Act

Provides protection of critical habitats and a creation of a recovery plan for each species that is endangered

Cost of saving species

It costs millions of dollars

Preserving particular habitats

Takes a lot of work

Captive breeding

May be used to re-establish a species

Prairie Dogs

Billions of Prairie Dogs lived in the Great Plains

Largest colony in the Texas Prairie

25,000 Square Miles

Why ranchers dislike Prairie Dogs

They create holes that injure livestock and make mounds that prevent grass from growing

Effects of Prairie Dog burrowing

Improves soil conditions, provides habitats for some endangered species

Black-footed ferret

Feeds primarily on Prairie Dogs

Burrowing Owls

Lives in abandoned Prairie Dog burrows

Humans infecting Prairie Dogs

Humans infected Prairie Dogs with the Bubonic Plague in the 1800’s

Saving Ferrets

Biologists dust the entry of Prairie Dog tunnels with pesticides to kill fleas which spread the plague

Life cycle of a frog vs. Lizards

Frogs lay eggs in water, lizards do not

Texas Horned Lizard

Flat-bodies lizard that lives on land

History of Texas Horned Lizard

• Adapts to dry living conditions

• Regulates body temperature

• Harvests rain on head

Adaptation of the Texas Horned Lizard

• Sticky tongue suited to eat ants

• Immune to ant bites when feasting

Horned Lizard defenses

• Camouflage

• Horns

• Playing dead

• Blood shooting out of the eye

Horned Lizard natural predators

Snakes, birds, and coyotes

Conversion of prairies and deserts

Urban environments eliminated the natural habitat and prey of the horned lizard

Where are horned lizards NOT found?

The Eastern part of Texas

The Red Imported Fire Ants

Horned Lizards do not eat these

The Red Imported Fire Ants competition

They compete against native ants

Red Fire ants pesticides

They reduces red fire ants but also harvester ant species

Horned Lizards are considered…

A threatened species in the state of Texas

Horned Lizard Laws

It is illegal for anyone to take, possess, transport, or sell horned lizards without a permit

TCU research

Saving horned lizards from extinction