Lecture 2: Population Ecology Flashcards
Population
Group of individuals of the same species living in the same area
- Have similar resources
- Interact and breed
What are different methods used to measure population size?
- Census
- Counting number of nests, burrows, etc
- Catch per unit effort
- Mark-recapture methods
How does mark-recapture work?
A subset is captured and released, then another sample is captured after a period of time and the number of marked individuals is counted to estimate the population size
What are the population growth models?
Exponential and logistic
Why does population growth slow down?
- Resources become limited
- Food and space become limited
- Competition for food
Intra-specific competition
Competition for resources among individuals of the same species
What is carrying capacity?
The number of individuals in a population that an environment can support
- when the birth rate is equal to the death rate
What is maximum sustainable yield?
The highest yield a population can support in the long-term, given that environmental conditions do not change much
What is life history?
Traits that affect an organism’s schedule of reproduction and survival
What are the three main variables of life history?
- Age of first reproduction
- How often an organism reproduces
- How many offspring produced per reproductive episode
Semelparity
One-time reproducer
Iteroparity
Reproduces many times
R-Strategists
- Maximize number of offspring
- Smaller offspring and no parental care
- Prefer physically harsh and unpredictable environments
- Invading and colonizing species
K-Strategists
- Maximize offspring survival
- Larger offspring and more parental care
- Prefer competitive and predictive environments
- Strong competitors
Does the number of K or R strategists tend to increase over time?
K-Strategists
