Lecture 9 - DA Flashcards
Define population.
A group of individuals of a single species.
What is the mark-recapture method?
A sample of animals are captured, marked and then released.
Another sample is later captured, and the proportions of marked and unmarked samples are noted.
A formula is used to extrapolate to an estimated total population size.
What is the formula used in the mark-capture method, and what kinds of populations is this method suitable for?
Animals in the 1st sample / total population size = marked animals in 2nd sample / total caught in 2nd sample
Solve for total population size
What are three assumptions made in the mark-recapture method?
Marked and unmarked animals are captured randomly
Marked and unmarked animals have the same mortality
Marked animals are neither lost nor overlooked
What does a survivorship curve show?
Number of survivors (y-axis) per age year (x-axis)
Describe a type 1 survivorship curve, including juvenile survival rate, life length, lifestage where most deaths occur, reproduction speed, and energy amount expended to offspring.
Give an example of an organism in this category.
Juvenile survival is high, most mortality occurs in the older individuals. Long lived, and slow reproduction. Energy is invested into offspring to ensure survival.
Humans are an example.
Describe a type 2 survivorship curve, including juvenile survival rate, life length, lifestage where most deaths occur, reproduction speed.
Give an example of an organism in this category.
Organisms die at equal rates regardless of age. Intermediate lifespan and reproduction rates.
Magpies are an example.
Describe a type 3 survivorship curve, including juvenile survival rate, life length, lifestage where most deaths occur, reproduction speed, and energy amount expended to offspring.
Give an example of an organism in this category.
High rate of death in the lower ages, and very few deaths in the older ages. Short lifespan, with high reproduction rate. Little energy is invested to offspring.
Insects are an example.
What is the tradeoff in life history strategy, and which type of survivorship uses it? Define the principle it is based on.
Make as many offspring as possible, investing little energy into them, and accepting most will die, but few will survive.
Based on the principle of allocation - each organism as a finite amount of energy that can be allocated for various functions.
Found in type 3 survivorships.
What kind of species in type 1 survivorships tend to be? What is characteristic of them?
Equilibrium species.
Long lifespan, large body size, slow development rate, reproduce at an old age, have few large offspring, with extensive parental care and low population growth.
What kind of species in type 3 survivorships tend to be? What is characteristic of them?
Opportunistic species. Short lifespan, small body, rapid development rate, reproduce at a young age, with many small offspring, and little to no parental care.
What formula is used to calculate change of a population size?
N = B - D
N - population size
B - number of births
D - number of deaths
What formula is used for the general model of population growth?
dN/dt = rN
N - population size
d - per capita growth rate
d - per capita death rate
How is per capita growth rate calculated? What happens to growth if r is constant? Can this continue indefinitely? Explain why.
r = b - d
Exponential growth if constant. Cannot continue indefinitely due to limited resources.
Define rmax in population growth modelling.
Every species has a maximum specific growth rate - is the defined intrinsic rate of increase.
