Chapter 12

Question 1

3 ways to reduce being found

Answer 1

1. Blending into the environment
2. Being quiet
3. Choosing safe habitats

Question 2

What is Cryptic/Camouflage

Answer 2

avoidance of predators by blending into their surrounding environment

Question 3

Cryptic/Camouflage Can happen two ways…

Answer 3

behavioral changes or natural selection favoring different pigments or patterns of color
ie: Cephalopods” octopi, squid, etc do it behaviorally

Question 4

Experiment about camouflage

Answer 4

Hanlon and colleagues realized lots of predation occurs on cephalopods at night since predators have such good night vision. Use a noninvasive light source to observe the nocturnal behavior of cuttlefish and to test if they used camouflage at night to high from predators.

Question 5

Being Quiet

Answer 5

Remade-Healey examined sound suppression in gulf toadfish

Wondered if toadfish listen for sounds associated with dolphins foraging behavior and then reduce the sounds they produce

Captured toadfish and kept individual males in tanks. The males began to make the noise, and then they were exposed to three different dolphin foraging sounds.

Found no differences in call rate between males before exposure to experimental sounds. Males exposed to pop sounds (key foraging sounds in dolphins) reduced sounds by 50% during and after they were exposed. They eavesdrop on their predators to ensure they are safe.

–Hormonal Analysis: Showed higher levels of cortisols

Question 6

Choosing Safe Habitats

Answer 6

Parrots were tested form the Amazon and Australia.

Found that there was an independent ancestral evolution where some were nesting in trees and some move to nesting in cavities.

Birds who nested in cavities have longer nesting periods

Birds do this to avoid predation especially of their young

Question 7

When encountering predators

Answer 7

Frontal cortex of the brain regulates the effect of stressors in behavior and that area of the brain may alter neurological and endocrinological responses to stressors such as predators
Smith and team exposed mice to two different stressors

1. Odor of predator
2. Immobilized in a device called a Universal Mouse Restrainer

Both predator groups increased the circulation of acetylcholine, serotonin and dopamine within the frontal cortex

Question 8

5 Anti-predator encounter behaviors?

Answer 8

1. Fleeing
2. Approaching as predator to obtain information
3. Feigning death
4. Signaling to the predator
5. Fighting back

Question 9

Flight initiation distance

Answer 9

how close a predator can approach before prey flee

The farther an animal is from their home the sooner they flee from a predator

Animals who are mating/ foraging/ fighting were slower to flee from predators

Animals that had armor reduce preys prediction of risk

Animals who have experience with predator flee at greater distance

Question 10

Treefrog Embros and Snakes

Answer 10

Treefrogs attach eggs to various vegetation and when the eggs hatch, the tadpoles drop into the water. If predation is weak, the egg season is longer.

When unbothered eggs hatched at 6 days.
If there is predation the vibrations of the snake causes the tadpoles to hatch at 4-5 days and swim away

Question 11

Approaching Predators

Answer 11

Allows individuals to gather information about predators and reduces their chances of mortality

Question 12

The Costs and Benefits of Thomson’s Gazelles Approaching a Predator

Answer 12

4 main predators: lions, cheetahs, hyenas, and wild dogs

Rarley approach hyenas and wild dogs because they cannot out run them.

3 Possibilities of benefits:
1. Decreases the risk of predation

2. Allows gaelles to gather info about a potential threat
3. Serves to warn other groups members of the potential danger associated with predator

Cheetahs respond to this by giving up because the element of surprise is gone

Question 13

Feigning Death

Answer 13

Occurs when an individual falls down and remains frozen (tonic immobility)

Question 14

Ohno and Miyatake

Answer 14

Adzuki bean beetle will either fly away or fake death

Hypothesis: there is negative correlation between the intensity of death faking the the ability to fly – those who do one more over the other will be better at it

For faking death: exposed beetles to danger and measured how long they froze

For flying: dropped a beetle through a hale and measure whether they dropped or flew and how far it flew.

Question 15

Signaling to Predators:

Warning Coloration in Monarch Butterflies

Answer 15

Milkweed food contains chemical called cardiac glycosides, which are toxic to birds and are stored In the butterflies. When a bird eats the monarch, the toxins make the predator ill.

Question 16

Signaling to Predators:

Tail Flagging As A Signal

Answer 16

Communicates to predator that an attack is unlikely to be successful

Question 17

Fighting Back:

Chemical defenses in beetles

Answer 17

defend themselves against predators by using a spray that’s acidic.

Question 18

Mobbing

Answer 18

a group of prey join together approach a predator and try to chase it away

Question 19

Fighting Back:

Social Learning and Mobbing in Blackbirds

Answer 19

Experiment: a model and a naive bird in each location. The design was that each bird could see another bird and this bird acted as a predator.
Then there was another bird, which was the real predator. The naive bird could only see the fake predator, and the experienced bird only saw the real predator.

Found that the naive bird mobbed the fake predator after seeing the experienced bird mob. → Cultural transmission allows these birds to figure out which predators to mob

Question 20

Predator and Foraging Trade-offs

Answer 20

Animals that spend time engaged in anti-predator behavior could have been foraging, mating, resting, playing

Question 21

Predator and Foraging Trade-offs Experiment

Answer 21

Lima and Valone: Foraging/Predation in Squirrels:
Alter foraging choice as a result of predation from red tailed hawks.

Eat food where they found them or carry the food to a safer area. The closer the refuge from the predation, the more likely squirrels were to use the shelter when foraging.

Presented 2 types of food: a large cookie and a small cookie. (Used instead of nuts cause they tend to hide the nuts and not eat them.

2 critical pieces of information: the profitability of small food items needed to be greater than large food items – in the absence of predation, squirrels would take smaller food items.

The total handling time with larger food was great enough that optimal foraging models predicted that larger items were eaten in cover.

Hypothesis: when faced with predation, squirrels would find larger food items to bring back to cover ← this was the results