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Published byLeo Collin Brown Modified over 9 years ago
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AVOIDING PREDATION HOW NOT TO BE FOOD
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Avoiding Predation Blue petrelBrown Skua
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Avoiding Predation Petrel courtship calls Attracts skua Petrels detect skua Petrels emit skua territorial call Cease courtship
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Avoiding predation Frog hatching times - Red-eyed tree frog - Agalychnis callidryas
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Avoiding predation Frog hatching times - Red-eyed tree frog - Agalychnis callidryas
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Avoiding predation Frog hatching times - Red-eyed tree frog - Agalychnis callidryas Eggs on underside of leaves Tadpoles hatch and drop into water Wasp & snake predators Fish + insect predators
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Avoiding predation Frog hatching times
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Avoiding predation Frog hatching times If predation is absent -hatch slowly Day 4Day 5Day 6 Proportion hatched Consequence: Tadpole is large enough to avoid fish predation
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Avoiding predation Frog hatching times If predation is strong Hypothesis: Eggs should hatch earlier Age of clutch Proportion hatched Clutches under wasp predation Clutches under no predation
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Avoiding predation Frog hatching rates If predation is strong Hypothesis: Eggs should hatch faster Age of clutch Hatch rate (egg/min) Clutches under wasp predation Clutches under no predation
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Avoiding predation Frog hatching times If predation is strong Hypothesis: Eggs should hatch earlier % hatched Time (days) With snake predator With no predator
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ALARM CALLS - VERVET MONKEYS Look up Group and hide in bushes Stand up and search grass VERVET CALLS
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Avoiding Predation 1. Escape and Freezing Crypsis
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Avoiding Predation 2. Deception
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Avoiding Predation 2. Deception - disruptive colouration Butterfly fish
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Avoiding Predation 3. Toxicity and aposematismPoison arrow frogs
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Avoiding Predation 3. Mimicry - Batesian Look like something distasteful Viceroy Monarch
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Mimicry - Müllerian A number of distasteful animals resemble one another Avoiding Predation
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Avoiding Predation - Group Effects And some of the benefits of being in groups a. Encounter Effect Grouped animals are more difficult to find
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Avoiding Predation - Group Effects And some of the benefits of being in groups b. Dilution Effect 1:91:1000’s
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Groups and Predator Inspection Sometimes prey approach predators -called inspection, harassment, mobbing, boldness Why? 1. Decrease current risk 2. Information gathering about threat 3. Warn other group members
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Groups and Predator Inspection Herds from 500
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Groups and Predator Inspection Probability of group approaching predator Group size 0200400600
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Groups and Predator Inspection Distance cheetah walked away from group (m) Group size 0200400600 4000 3000 2000 1000 0
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Groups and Predator Inspection Stotting Stotting video
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Possible Function 1. Alarm signal 2. Social cohesion 3. Confusion effect 4. Pursuit deterrence Relevant information - isolated animals stott - orient rump to predators - isolated animals stott Groups and Predator Inspection
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Hunt abandoned Chase failed Gazelle killed With stotting Without stotting Groups and Predator Inspection
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Predator/Prey Arms Races Red Queen Hypothesis "Well, in our country," said Alice, still panting a little, "you'd generally get to somewhere else — if you run very fast for a long time, as we've been doing." "A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!" For an evolutionary system, continuing change is needed just so that one species can maintain its fitness relative to the species with which it is co-evolving.
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Predator/Prey Arms Races Red Queen Hypothesis Example: Passiflora and Heliconius Passiflora Heliconius
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Predator/Prey Arms Races Red Queen Hypothesis Example: Passiflora and Heliconius Develops chemical resistance Develops chemical defensesDevelops egg mimicry ?
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Predator/Prey Arms Races Red Queen Hypothesis Example: Passiflora and Heliconius Egg Mimicry Heliconius eggs Passiflora egg mimic
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