2: Predation Flashcards
Define competition
(-/-) → interaction is detrimental to both species
Define predation
(+/-) → Interaction beneficial to one species and detrimental to the other
Define mutualism
(+/+) → interaction benefits both species
Define commensalism
(+/0) → One species benefits from the interaction, the other is unaffected
Describe how a grazer could perhaps be considered a predator
→ from a species interaction perspective
- Many kill targets at a time
- Parts of target is consumed
Describe the targets of a true predator
- Kill target
- Generally one target at a time (but many over a lifetime)
- All of target consumed (generally)
What are some predator traits?
Mobility
Camouflage
Trickery
Morphology
What are some predator behavior strategies?
Sit & wait
Sit & dangle
Sit & pursue
Pursue
Stalk
What are some predator domains?
Timing (e.g nocturnal)
Spatial location
What are some predator modes?
Individual
Group
What are some prey traits?
Mobility
Camo
Aposematism (warning colours)
Mimicry
Trickery
Defensive structures
Autotomy (lizards drop tails)
Chemical defence
What are some prey domain shifts?
Timing
Spatial location
What are some prey behaviors?
Warning signals
Playing dead
Startling / distraction
Describe how prey can be safer in numbers
Dilution effect
Predator confusion
Predator satiation
Improved vigilance
What are prey inducible defences
Defence structures that are induced by the presence of predators
Describe Daphnia’s inducible defences
Heads become larger
Spines in pulex
Plastic morphogenesis, triggered by external chemical cues
+ 50% survival
Describe the study that shows predation can decrease biodiversity
Addicott (1974) → mosquito larvae and protists
Mosquitos had a preference for weaker species
Describe the study that shows predators can increase biodiversity?
Paine (1966) → starfish predator removed, mussels number increase unchecked
Keystone species removed = community ceases to exist
Describe the study that shows predation can alter rank and relative abundance without affecting biodiversity
Morin (1983) → Newts and tadpoles
Predator preference alters rank of species in community
Describe the study that shows that predators can change competitive dominance & context matters
Lubchenco (1978) → periwinkles and macroalgae
Periwinkles feed on dominant competitor = increases biodiversity, to a point
