learning objectives 12

Question 1

Define a population.

Answer 1

A group of organisms of the same species living in the same geographic area.

Question 2

What do population ecologists study?

Answer 2

Population distribution, population density, life history, dispersion, and demographics.

Question 3

Why is studying population ecology useful?

Answer 3

It helps understand ecological interactions and assess/reduce human impacts on species.

Question 4

What is population distribution?

Answer 4

The area where a population lives.

Question 5

Name some biotic factors that could limit a species’ distribution

Answer 5

Pressure from humans, predators, amount of food.

Question 6

Name some abiotic factors that could limit a species’ distribution.

Answer 6

Water availability, temperature, air quality, precipitation.

Question 7

Define population density.

Answer 7

The number of individuals per unit area.

Question 8

What are some methods to estimate population size other than mark/recapture?

Answer 8

Counting samples using standardized census methods (plots, transects) and counting proxies like nests, feeding damage, or tracks.

Question 9

Explain the steps in the mark/recapture method.

Answer 9

1. Capture and mark animals.
2. Release them and wait for mixing.
3. Capture or count a second sample.
4. Count how many are marked (recaptured).
5. Calculate the proportion of marked individuals to estimate the total population size.

Question 10

How do you calculate the population size using the mark/recapture method?

Answer 10

Estimate the proportion of marked individuals in the second sample and use it to scale up the total population size.

Question 11

Define life history in population ecology.

Answer 11

The timing of events in an organism’s life, including growth, reproduction, and death.

Question 12

What are the three main types of survivorship curves?

Answer 12

• Type I: High survival in early life, most die in old age (e.g., humans).
• Type II: Constant death rate across age (e.g., birds).
• Type III: High mortality early in life, few survive to adulthood (e.g., oysters).

Question 13

Compare and contrast r-selected vs. k-selected species.

Answer 13

• r-selected: High reproduction, low parental care, small body size (e.g., dandelions).
• K-selected: Low reproduction, high parental care, large body size (e.g., elephants).

Question 14

What are some examples of r-selected species?

Answer 14

Dandelions, bullfrogs.

Question 15

What are some examples of K-selected species?

Answer 15

Elephants, chimpanzees

Question 16

Name a species that is “in-between” r-selected and k-selected.

Answer 16

Sea turtles, meerkats