ECOL Predation 1

Question 1

What kind of influence do predators exert on prey communities?

Answer 1

Strong influence on behavior and population size

Question 2

What kind of effects do predators exert on prey in relation to behavior and population size?

Answer 2

Consumptive effects and non-consumptive effects

Question 3

What are consumptive effects?

Answer 3

predators kill prey, consistently limiting the size of prey populations

Question 4

What is an example of consumptive effects?

Answer 4

Researchers introduced non-native prey (spiders) to islands with and without predators (lizards) then tracked population sizes

-with lizards: spider population size barely even went above 0 each year
-without lizards: population size exceeded 0 and varied from year to year

Question 5

What are non-consumptive effects?

Answer 5

when prey population size is limited because of fear of predation, rather than predation itself

Question 6

What changes within fearful prey?

Answer 6

habits
behaviors
timing of activity

Question 7

What does the change of habits, behaviors, and timing of activity lead to?

Answer 7

waste of time and energy

Question 8

Consumptive and non-consumptive effects can drive what?

Answer 8

can drive cycles of predator and prey population sizes

Question 9

What is an example of cycles of predator and prey population sizes?

Answer 9

both lynx and hare populations cycle every 9-10 years with lynx being high at one point and hare being low then as the lynx starts to decrease hare starts to increase then the hare reaches a peak and the lynx begins to increase again and it all goes to a cycle

Question 10

High hare densities allow lynx densities to _____

Answer 10

INCREASE
they now have more food available

Question 11

At high lynx densities, fear of predation reduces ______

Answer 11

MATERNAL PARENTAL CARE TOWARDS OFFSPRING
-physiological response
-causing reduced offspring survival and hare population declines

Question 12

After hare population declines, lynx populations ____

Answer 12

DECLINE
-lynx rely on hare population to survive
-carrying capacity has gone down

Question 13

Reduced lynx density causes ____

Answer 13

HARE FEAR TO BE REDUCED AND REPRODUCTION RATES INCREASE

Question 14

Whether the number of prey will increase or decrease at any moment in time is dependent on…..

Answer 14

the number of predators

Question 15

Whether the number of predators will increase or decrease at any moment in time is dependent on…..

Answer 15

the number of prey

Question 16

Predator isocline

Answer 16

number of prey at which predator population size stays constant

Question 17

Prey isocline

Answer 17

number of predators at which prey population size stays constant