Predator-prey coevolution and dynamics Flashcards
List six different types of inter-specific interaction
1) Competition
2) Mutualism
3) Commensalism
4) Antagonism
5) Neutralism
6) Amensalism
Define Competition
An interaction in which both organisms or species are harmed
Define Antagonism
An association between organisms in which one benefits at the expense of the other
Define mutualism
a relationship between two organisms of different species in which both parties benefit
Define commensalism
When one organism benefits from another without affecting it
Define amensalism
A relationship between organisms of different species in which one organism is inhibited or destroyed while the other organism remains unaffected
Neutralism
A relationship between two organisms that do not affect each other
Most predators are limited by what?
Gape limitation
How can smaller predators eat prey larger than themselves?
Through pack hunting
How can plants defend themselves from herbivores?
They have morphological and chemical defence strategies
Most plant material is not consumed directly. Where does it go?
More than 90% enters the detrital pool, giving rise to the ‘brown’ energy pathway
What is a parasitoid?
A consumer that lives inside a living resource that gets killed at the point fo hatching of the consumer
What is a parasite?
A consumer that eats part of a living resource without necessarily killing it
What is prey switching?
When the predator focuses disproportionately on the most abundant species and as that prey becomes increasingly scarce, it switches to the other victim species
How does preferential predation on dominant competitors mediate coexistence?
It releases niche space for resident inferior competitors and potential new colonists
Who conducted the starfish removal experiment and when? What did this demonstrate?
Paine in 1966. It demonstrated that some species have a disproportionately large effect on its environment relative to its abundance
What happened when Paine removed the predatory starfish?
It resulted in a reduction of species from 15 to 8 species (Paine, 1966)
Define coevolution
When two separate lineages mutually influence each other’s evolution
Give some examples of coevolution
1) Mimicry (too look toxic when you’re not)
2) defenses –> evolutionary arms race between prey and predator
3) Camouflage
Give a specific example of coevolution to do with predators and prey
Relative brain size has increased in predators and prey through the Cenozoic
What is the Red Queen hypothesis?
A hypothesis that proposes that organisms must constantly adapt, evolve and proliferate to survive while pitted against ever-evolving opposing organisms in a changing environment
What are predator-prey oscillations characterised by?
1) Frequency
2) Amplitude
3) Phase shift between prey and predator oscillation
If predators are common then prey density ________
Declines
If predators are scarce then __________ increases
Prey density increases
What is a type 1 functional response?
The number of prey eaten depends only on the prey density, there is no saturation at higher densities
Give some real world examples of type 1 functional response
Filter feeders and net building spiders
What is the asymptotic type 2 functional response?
Number of prey eaten increases with increasing prey densities and saturates at high prey densities
The percentage of eaten prey decreases with increasing prey density
Common functional response for predators
What is the sigmoid type 3 functional response?
Sigmoid shape of functional response is caused by:
- Refuges
- Learning
- Prey switching
Prey refuges protect a subpopulation of prey at low prey densities
At high prey densities, the same maximum feeding rates as in type 2 functional responses can be reached
