Reproductive Strategies & Survivorship

Stable Environment

K-strategists• Few offspring• Lots of parental care

Chaotic Environment

r-strategists• Lots of offspring• Very little if any

parental care

Name That Strategy!

r-selected

K-selected

K-selected

r-selected

It’s a Spectrum

Why These Methods?

Survivorship!

Survivorship Curves

• Type I = K-selected species • Type II = In Between • Type III = r-selected species

It’s All About Habits and Habitats• Endangered species tend to be K-selected species.

• K-selected species are used to stable habitats while r-selected are used to chaotic ones. • r-selected is better at rebounding after a habitat

disturbance.

• K-selected • Niche Specialists • Commercial Value

What About Invasive Species?• Invasive species are one of our major concerns.

HIPCO• They have a specific niche, survivorship, and

reproductive strategy that make them invasive.

Use Tribbles to figure out what these characteristics are!

Invasive Species Meet the Cane Toad!

• Introduced to Australia in 1935 as a form of pest control.

Greyback cane beetle was eating all the sugar cane!

• Not all of the details of the situation were considered before introducing them into the environment.

Here’s The Story!• Sugar cane is 6-8 feet tall and the cane beetle likes

to eat at the top of the stalk.Cane toads can’t fly or climb!

• Timing is everything! • Cane beetles are out during the day but cane

toads feed at night. • Don’t follow the same seasons either!

• They are niche generalists and are r-strategists laying 8,000-30,000 eggs per year, and are poisonous to Australian predators.

Who can compete with that??

Be Careful!!