Chpt 51: (13) Ecology Flashcards
Survivorship curve
shows on a graph the proportion of individuals still alive by age group
What S represents in mark-n-capture calculations
of captured and tagged individuals
Density INdependent population effects
result in birth and death rates that DO NOT vary as a function of population size
exp. hurricanes, droughts
Exponential population growth (model)
1 or 2 types of population growth (models)
population grows increasingly rapidly like weeds, exponentially, with no limiting factors to slow it down.
Represents max possible growth rate (because it’s based solely on birth & death rates and doesn’t account for resource or environmental limitations)
Per capita birth rate (little b) definition
Rate that can be applied to population regardless of its size
Represents the number of offspring produced by the avg member of a population per unit time
Type I survival curve
that would be shown on a survivorship graph
1 of 3 types of survivorship graph curves
Involves flat/steady survivorship throughout life, with steep/dramatic increase in deaths happening in old age (usually in org. that have few offspring)
exp from class: elephants
Death rate (big D) definition
Number of deaths in a population at a given time
What n represents in mark-n-capture calculations
number of individuals who were caught the second time, but not the first time
Density dependent population effects
result in birth and death rates that vary as a function of population size
esp. too little food
What little b represents (in population ecology)
Birth rate (specifically meant to represent the avg # of births per individual)
Number of births/total population
Type II survival curve
that would be shown on a survivorship graph
1 of 3 types of survivorship graph curves
Involves a linear likelihood of death at all stages of life (like a hypoteneous);
Carrying capacity (K) definition
max population size that a given environment can sustain
Ecology
the study of how organisms interact with each other and with their abiotic & biotic environment
What x represents in mark-n-capture calculations
of REcaptured an tagged individuals
3 types of survival curves (that would be shown on a survivorship graph)
- Type I
- Type II
- Type III
Formula for calculating patterns of population GROWTH
(Little b-little d)(N)
(Birth RATE - death RATE)(number of individuals in a population)
This is not the same as calculating how many individuals there are at particular instant in time!!!
4 main parts of mark-recapture
- Catch
- Mark
- Release
- Catch again, and calculated the ratio of re-captured to newly captured
Re-captured to newly recaptured is supposed to give you a sense of the total population size.
Birth rate (big B) definition
Number of births in a population at a given time
Mark and recapture method is a type of
Measurement for population size
When you can represent population size in terms of N
When N is meant to represent the number of individuals in a SINGLE population.
Cannot be applied to multiple populations because it is based on exact numbers, not proportions or rates
3 levels of ecology
- population ecology
- community ecology
- global ecology
Survivorship
the proportion of individuals that live to a certain age
Per capita death rate (little d) definition
Rate that can be applied to population regardless of its size
Represents the represents the expected death rate per unit time
Population ecology according to Dr. C
Study of population sizes and why/how they change over time