Population Ecology Flashcards
(93 cards)
what is population ecology?
the study of intraspecific interactions
what are intraspecific interactions?
“intra” - within
organisms interacting with members of the same species in relation to environment
how both biotic and abiotic factors affect density, distribution, size, and age structure
what is density?
of individuals per unit area or volume
what is dipersion?
pattern of spacing among individuals within the population
what are two ways population ecologists measure density?
count individuals
quadrant sampling
what is count individuals?
count nests, burrows, tracks, or scat
what is quadrant sampling?
count number of oak trees in several randomly located 100m x 100m plots in Troy and calculate an average for the city
how can you create a more accurate representation with quadrant sampling?
increase sample size
what is the mark-recapture method? what is it also known as?
capture-recapture method
taking a sample of a population, marking those individuals and releasing them back into the population. after the individuals have mixed freely with unmarked individuals, take new samples and record marked to unmarked individual ratio
how to calculate ratio of marked to unmarked individuals?
1st catch x 2nd catch total
____________________
number of recaptures in 2nd catch
what increases population density?
birth/natality/fecundity
immigration
what decreases population density?
death/mortality
emmigration
what are the 3 types of dispersion? give examples
clumped - most common (seastars)
uniform - most rare (penguins)
random (dandelions)
what is a demography?
studies vital statistics of populations and how they change over time
what are life tables?
age specific summaries of the survival pattern of a population which tracks cohorts from birth to death
at are cohorts
individuals of the same age
what is a survivorship curve?
data from a life table put into a graph
what is a reproductive table?
based on female cohorts producing offspring from birth to death
hoe many days on average are many female squirrel species fertile each year?
few hours/1-3 days
what cycle do squirrels and most other mammals have that reabsorbs the endometrial lining when not pregnant? humans?
estrous cycle; menstrual cycle
most mammals have a bone in the penis to aid in copulation, what is called?
baculum
what is generation time?
the amount of time between the birth of an individual and the birth of their progeny (offspring)
how long are generation times for small organisms?
short
how to some bacteria divide?
asexually by binary fission every 20 minutes