Animal Behavior: Survival Strategies

Cost-Benefit Analysis – Behaviors have costs and benefits.

• What are the costs

of the behavior shown?

• What are the benefits

of this behavior?

Cost Benefit Analysis• If the cost is HIGHER than the benefit the

behavior will NOT be found in a population.• If the benefit is HIGHER than the cost this is

the behavior observed in a population

• Example: MOBBING BEHAVIOR = prey animals attack a predator as a group by screaming, kicking/throwing sand, diving and if birdsflapping their wings.*

Meerkat mobbing snake

1. What was the cost of mobbing for the meerkats?

2. What was the benefit of mobbing for the meerkats?

3. Which is greater the cost or the benefit?

4. How do you know?

One Meerkat and Snake

5. If one meerkat comes across a snake, how should it behave? Why?

Black headed gull

• Live in large dense group and build their nests on the ground.

Black Headed Gull

– A potential predator can easily attack the nest and eat eggs and young (and adults).

1. Will MOBBING BEHAVIOR be found in this population?

2. Why or why not? What are the costs? The benefits?

Kittiwakes

• Live in large dense groups. They nest on the edge of cliffs. Their nests are very difficult for predators to reach.

Kittiwakes

– A potential predator, (which is rare) eats eggs and young (and adults).

1. Will MOBBING BEHAVIOR be found in this population?

2. Why or why not? What are the costs? The benefits?

California Ground Squirrels

• Live in large dense groups.

• Make burrows (holes in ground) for nests.

California Ground Squirrel

– A potential predator eats young (and adults).

– Will MOBBING BEHAVIOR be found in this population?

– Why or why not? What are the costs? The benefits

Animal Behavior

• Convergent behavior = similarities in behaviors between two different species.

• Divergent behavior = differences in behaviors between two closely related species.

Survival Strategies

• Do any of these populations show convergent behaviors?

• Do any of these populations show divergent behaviors?

Dilution Effect

• Large groups of animals “dilute” or weaken the chance of any one animal being attacked*.

Insects in action*

Cicadas*• Remain underground

for 17 years.• They all emerge at

the same time.• What is the cost of

emerging at the same time?

• What is the benefit?

Survival Strategies

• Camouflage• Leaf insect - The

female has large leathery forewings that resemble the midrib and veins in a leaf. Females are flightless and so the hindwings have no function.

Camouflage

• Walking sticks*

Camouflage

Camouflage

Camouflage

Conspicuous Markings• Red Eft

when living on land – Toxic

• What are the costs & benefits to this color?

Conspicious Markings?

• Newt (adult red eft!) when living in the water.

• Toxicity?

Conspicuous Markings

• Monarch butterfly – Toxic!

Conspicuous Markings

• Viceroy butterfly.

• Toxic?

Monarch and Viceroy

The viceroy mimics the coloration and patterns of the monarch butterfly.

However, the viceroy butterfly is NOT toxic!

Other

• Regal Horned Lizard*

• Puffer Fish*