1. Reproductive Strategies & Population Growth

2. Reproduction Strategies
What are some reproductive strategies that animals are using?

3. Reproductive Strategies
Survivorship curve:
helps to describe the reproductive strategies of a species
Is a diagram that shows the number of organisms that survive over time, starting from birth
There are 3 basic patterns:
Type I
Type II
Type III

4. Reproductive Strategies
Type I
Typical for humans and large mammals
Few death of infant offspring and most will survive to old age
Parents care for their young

5. Reproductive Strategies
Type II
Typical of birds, small mammals, and some reptiles
At all points of life these animals have equal chances of living or dying, either from disease or predation

6. Reproductive Strategies
Type III
Typical for invertebrates, fish, amphibians and plants
Large number of offspring or produce many eggs or seeds
Many of the offspring will die from predation, only a few will survive to adulthood

7. Conclusion
Each type of curve represents a different reproductive strategy.
Some organisms have few offspring and most will survive. Other organisms may lay thousands od eggs, only a few will survive to maturity.

8. Population Growth Patterns
Change in a population’s size are determined by 4 factors:
Immigration
Movements of individuals into an area
Birth
Increase the number of individuals
Emigration
Movement of individuals out of an area
Deaths
Decrease the size of a population

9. Population Growth Patterns
The size of a population is always changing.
If there are plenty of resources (Food, Water, etc…) a population grows.
If there are few resources, the population decreases.

10. Population growth
Population growth is based on available resources. There are 2 types of population growths:

13. Ecological Factors that limit population growth
Density- dependent limiting factors
Caused by population density
The number of individuals living in one area
Competition
Predation
Parasitism & disease

14. Ecological Factors that limit population growth
Density-independent limiting factors
Affect the size of the population no matter how many individuals live in the area
Unusual weather
Natural disasters
Human activity