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38 Cards in this Set
- Front
- Back
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What is a population and what is it defined by |
- A group of individuals of a single species loving in the same general area - size and density |
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Density and it's importance |
Number of individuals per unit area or volume |
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Dispersion and it's importance |
Pattern of spacing among individuals within the boundaries of the population |
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What are the 3 types of dispersion |
Clumped, uniform and random |
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Explain clumped dispersion |
Happens when resource availability is clumped |
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Explain uniform dispersion |
- Territory is a strong influence (personal space) - all lined up perfectly |
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Explain random spacing |
When there is no strong attraction or repulsion (don't care) |
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Explain the sampling method |
- divide the environment into sections - count how many r in one section then multiply it by the # of sections - best used with uniform dispersion |
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What 2 ways can you use to find the size of a population |
Sampling and mark and recapture |
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How do you do the mark and recapture method |
1. Capture, tag, and release q random sample of individuals in a population 2.let then mix back with population 3. Capture second sample and note how many are marked 4. Use equation to figure out the size |
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What equation do you use for the mark and recapture method |
N= sn/x N= Pop. estimate s= total # captured n= number marked x= total # captured with mark |
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What effects population size |
Births and immigration add to pop. Deaths and emigration take away form pop. |
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What is a life table |
- An age-specific summary of the survival pattern of a population. - Follows the fate of individuals the same age |
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What are the 3 types of survivorship curves |
Type 1- high, type 2- straight and type 3- low |
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Type 1 survivorship curves |
Huge parental care, less babies(1-2), most survive to adulthood ex: humans |
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Type 2 survivorship curves |
Few babies(5-10), moderate parental care, some die young and some survive Ex: robins |
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Type 3 survivorship curve |
No parental care, many die in infancy, thousands of babies Ex: sea turtles |
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Explain reproductive rates |
- Age specific - describes reproductive rates of a population - concentrate on females |
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Exponential model of population growth |
- population growth of an idealized situation - j-curve - helps to understand conditions that facilitate growth and the capacity of species to increase |
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Logistic model of population growth |
- s-curve - eventually hits the carrying capacity - more realistic |
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How do you find the per capita rate of increase |
Change is pop. Size = births+immigrants-deaths-emmigration |
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Birth rate |
Average birth rate x population size |
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Death rate |
Average death rate x population size |
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What are the 3 equations for population growth rate |
- ∆N/∆t= B-D - ∆N/∆t=rN - ∆N/∆t= bN-mN |
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How else can births be expressed mathematically |
B=bM (per capita birth rate times population size.) |
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How else can deaths be expressed mathematically |
D=mN |
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How do u find the per capita rate of increase (r) |
r=b-m |
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What is zero population growth |
When the birth rate equals the death rate (r=0) - population stays the same |
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What is semelparity (big Bang) reproduction |
- Reproduce once then die (salmon) - common in unpredictable environments |
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What is iteroparity (repeated reproduction) |
- Produce offspring repeatedly - common in dependable environments |
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What are 2 strategies to deal with trade-offs between survival and reproduction |
R-stratagies and k-stratagies |
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R-STRATAGIES |
Many young, little to no parenting, rapid maturation, small young, reproduce once |
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K-STRATAGIES |
Few young, intensive parenting, slow maturation, large young , reproduce many times |
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Density independant |
Factors not depend on density (floods) |
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Density independant |
- Factors that change with the density (disease, territory, predators) - When density increases death rates increase and birth rates decreases |
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Population dynamics |
- Interactions between the living and nonliving factors that change the population size. - constant fluctuations |
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Metapopulations |
Groups of populations linked by immigration and emigration |
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Age structure |
- relative number of individuals at each age - helps factor in present and future growth trends |
