Competition and Predator-prey Models

Question 1

What types of interactions include one species not being affected in any way

Answer 1

-commensalism (+0)
-amensalism (-0) (step on bug)
-neutralism (00)

Question 2

In competitive exclusion, which isoline shows the population that persists

Answer 2

Above isocline

Question 3

Equilibrium in isocline

Answer 3

Intersect= populations both stop growing so DN/Dt=0
-Births=Deaths
-if populations move, they are brought back to equilibrium

Coexisting

Question 4

Unstable equilibrium on isocline

Answer 4

-if pop is moved to a point, it will go extinct

Open circle

Question 5

Complete competitors _____ exist

Answer 5

Cannot

No two species can occupy the same ecological niche

Question 6

Niche

Answer 6

All the environmental conditions and resources required for the existence of a viable population of a certain species

-nesting sites, food, reproductive season, germinations sites, pollination flora, place in food chain

Question 7

Fundamental

Realized

Niche

Answer 7

Focus on abiotic factors

Takes into account biotic interactions more restricted set of conditions

Question 8

Sympatric

Allopatric

Answer 8

2 populations living in same area

2 populations living independently of each other (not together in environment)

Question 9

G. fortis and G. fuliginosa character displacement example

Answer 9

Two finches have beaks with ranges including 9mm when living separately.

When I’m same environment, their beak ranges do not include 9mm.

Too much competition for food size that can be eaten with 9mm beak. So no birds have that type of beak.

Question 10

Looks volterra predator and prey models form a ____

Answer 10

Circle

No stable point, disturbances eventually end up back in the cycle.

As prey goes up, predators go up.
As prey goes down, predators go down

Question 11

What things can also be affecting population instead of competition

Answer 11

Food, weather, solar radiation, parasites, disease

Question 12

Under which conditions does hare population grow massively

Answer 12

Reduce predators
Increase food supply

Question 13

Been weevil and parasitoids wasp example

Answer 13

Was okay eggs in host. Eggs Hatch and the larvae eat host inside out. Time the kill so they are ready to emerge when they are ready.

In graph: parasitoids follows been weevil population density curves

Question 14

Paramecium/ Didinium and immigration

Answer 14

In the absence of refuges and immigration, both prey and predator populations go extinct

Adding a refugee allowed the prey population to persist but the predators still become extinct

Immigration from source populations maintained oscillations in predator- prey populations

Question 15

Intraspecific competition

Interspecific competition

Answer 15

Competition among individuals of the same species

Competition among individuals of different species

Question 16

Renewable resources

Nonrenewable resources

Answer 16

Constantly regenerated (seeds from plants, sunlight)

Not regenerated (space)

Question 17

Liebigs law of minimum

Answer 17

Law stating that a population increases until the supply of the most limiting resource prevents it from increasing further

Question 18

Competitive exclusion principle

Answer 18

The principle that two species cannot coexist indefinitely when they are both limited by the same resource

Question 19

Explorative competition

Answer 19

Competition in which individuals consume and drive down the abundance of a resource to the point that other individuals cannot persist

(Indirect interaction)

Question 20

Interference competition

Answer 20

When competitors do not immediately consume resources but defend them

(Direct interaction)

Ex: ants plug other ants nests with stones to give them a head start

Question 21

Allelopathy

Answer 21

Type of interference where an organism uses chemicals to interfere with their competition

Question 22

Apparent competition

Answer 22

When two species have a negative effect on each other through an enemy, such as a predator, parasite or herbivore

Ex: 2 birds living near each other with a wild parasite. One can tolerant the parasite more, other cannot, one excretes large amounts of parasite that infect the weaker.