Ecology: Ecology: Lectures 14-16Lectures 14-16

PredationPredation

November 2, 2005November 2, 2005

Lotka-Volterra equation:Lotka-Volterra equation:Prey isocline (Prey isocline (ddV/V/ddt = 0)t = 0)

Fig. 15.1aFig. 15.1a

Lotka-Volterra equation:Lotka-Volterra equation:Predator isocline (Predator isocline (ddC/C/ddt = 0)t = 0)

Fig. 15.1bFig. 15.1b

Lotka-Volterra model: with Lotka-Volterra model: with both predator and prey both predator and prey

isoclinesisoclines Fig. 15.1 cFig. 15.1 c

Lotka-Volterra prediction:Lotka-Volterra prediction:Predator-prey flux through Predator-prey flux through

timetime Fig. 15.1 dFig. 15.1 d

Rosenzweig-MacArthur: Rosenzweig-MacArthur: Stable cycleStable cycle

Fig. 15.3 aFig. 15.3 a

Rosenzweig-MacArthur: Rosenzweig-MacArthur: Stable/dampened oscillationsStable/dampened oscillations

Fig. 15.3 bFig. 15.3 b

Rosenzweig-MacArthur: Rosenzweig-MacArthur: Unstable/increasing Unstable/increasing

oscillationsoscillations Fig. 15.3 cFig. 15.3 c

Rosenzweig-MacArthur: Rosenzweig-MacArthur: RefugeRefuge

Fig. 15.3 dFig. 15.3 d

Gause’s predation experiments:Gause’s predation experiments:DidiniumDidinium predation on predation on ParameciumParamecium

Fig. 15.4Fig. 15.4

Huffaker’s experiments: mite Huffaker’s experiments: mite predation and complex environmentspredation and complex environments

Fig. 15.6Fig. 15.6

Functional responses of Functional responses of predator to prey predator to prey concentrationsconcentrations

Type 1 response: Fig. 15.7 aType 1 response: Fig. 15.7 a

Functional responses of Functional responses of predator to prey predator to prey concentrationsconcentrations

Type 2 response: Fig. 15.7 bType 2 response: Fig. 15.7 b

Functional responses of Functional responses of predator to prey predator to prey concentrationsconcentrations

Type 3 response: Fig. 15.7 cType 3 response: Fig. 15.7 c

Prey switchingPrey switching

Fig. 15.10Fig. 15.10

Aggregative responseAggregative response

Fig. 15.12Fig. 15.12

Optimal foraging: bluegill sunfishOptimal foraging: bluegill sunfish

Fig. 15.16

Chemical defense/toxicity/ Chemical defense/toxicity/ warning colorationwarning coloration

Warning colorationWarning coloration

From Campbell et al., Biology

Batesian mimicryBatesian mimicry

Harmless Harmless hawkmoth larvahawkmoth larva resembles the resembles the diamond-shaped head of a diamond-shaped head of a poisonous snakepoisonous snake

From Campbell et al., Biology

Müllerian mimicryMüllerian mimicry

Both the cuckoo wasp and the yellow Both the cuckoo wasp and the yellow jacket deliver toxic stings. jacket deliver toxic stings.

From Campbell et al., Biology

Cryptic colorationCryptic coloration

Poorwill and frogPoorwill and frog

From Campbell et al., Biology

Lynx and hare cyclingLynx and hare cycling

Fig. 16.19Fig. 16.19

Hare and winter vegetation Hare and winter vegetation (“browse”) cycling(“browse”) cycling

Fig. 16.9Fig. 16.9