Lecture 14

Question 1

population

Answer 1

a group of individuals of a single species inhabiting a specific area

Question 2

characteristics of populations

Answer 2

1. Density
2. Distribution: size, shape, and location of area occupied
3. Other demographic characteristics (age distributions, sex rations, birth/death rates, immigration/emigration rates, rates of growth)

Question 3

density

Answer 3

the number of individuals per unit area

Question 4

absolute density

Answer 4

the number of individuals of a population per unit area

Question 5

ecological density

Answer 5

the number of individuals of a population per unit area suitable habitat (geographic distribution of species is limited by the physical environment)

Question 6

All species aren’t in all the places because

Answer 6

1. All organisms have limited energy and resources

2. It takes extra energy to survive and reproduce in regions on the edge of their niche

Question 7

dispersal

Answer 7

can alter species distributions and local population densities

Question 8

2 major categories of dispersal

Answer 8

1. immigration

2. emigration

Question 9

migration

Answer 9

not dispersal - it is the seasonal movement of individuals from one location to another, dispersal is the permanent/semi-permanent movement from one population to another

Question 10

predator dispersal in response to variation in prey density

Answer 10

prey density can influence numerical response and functional response

Question 11

drivers of numerical responses

Answer 11

1. Reproduction - time lag between peak prey population and peak predator population
2. Dispersal (aggregative response) - no time lag between peak prey population and peak predator population

Question 12

metapopulations

Answer 12

made up of a group of subpopulations living on patches of habitat connected by an exchange of individuals; only exist when individuals can disperse from one population to another

Question 13

distribution patterns

Answer 13

small-scale: random, regular/even, or clumped

large-scale: tend to be clumped

Question 14

numerical response

Answer 14

change in density of predator populations in response to changes in prey density

Question 15

causes of dispersal

Answer 15

changes in resources, climate change, newly available suitable habitat, etc

Question 16

dispersal and climate

Answer 16

in theory, dispersal will allow species ranges to move along with climate, but only if it climate change is slow enough for them to keep up