Antipredator behaviour

Question 1

Species evolve adaptions to block what?

Answer 1

-detection
-attack
-capture
-consumption

Question 2

Examples of species that avoid detection by foraging at night

Answer 2

1. Banner-tailed kangaroo rats
2. Jamaican fruit bats

Question 3

What is cryptic behaviour and what animal is it seen in?

Answer 3

It is when an animal chooses a background that matches itself
- Seen in peppered moth: camouflaged on lichen

Question 4

What adaptions are used to make attack less likely?

Answer 4

• Chemical defences
• Warning colouration
• Batesian mimicry
• Associating with a protected species
• Advertising unprofitability to deter pursuit

Question 5

What are some examples of chemical defences?

Answer 5

Sprays
Injections
Toxins
Sticky secretions

Question 6

What is aposematism?

Answer 6

When animals are poisonous and advertise it by warning colouration

Question 7

What is mullerian mimicry?

Answer 7

When a poisonous species has the same warning colouration of another poisonous species e.g wasp & cinnabar moth caterpillar

Question 8

What is batesian mimicry?

Answer 8

When a harmless species resembles a poisonous species e.g. Tephritid fly resembles jumping spider

Question 8

What is batesian mimicry?

Answer 8

When a harmless species resembles a poisonous species e.g. Tephritid fly resembles jumping spider

Question 9

An example of an animal that associates with a protected species

Answer 9

anemone hermit crabs use anemones for defence

Question 10

How do animals advertise unprofitability?

Answer 10

Stotting

Question 11

What are the alternative hypotheses to explain stotting?

Answer 11

1. As a signal to other gazelles
   - Alarm signal
   - Group formation-flee together
2. Signal to predator
   - Advertisement for unprofitability

Question 12

What were the observations of the alternative hypotheses for stotting?

Answer 12

-Solitary gazelles stott
- Turn white rump to predator
- Predators more likely to abandon hunt when gazelle stots

Observations support the pursuit-deterrence hypothesis

Question 13

How do animals adapt to make capture less likely?

Answer 13

• Startling predators e.g. sudden flashing of eyespots
• Rapid escape flight
• Group vigilance

Question 14

How does a Bombardier beetle make a last ditch attempt to escape?

Answer 14

Creates an explosion (noxious spray) to deter predators

Question 15

Describe the noxious gas ejected by the Bombardier beetle

Answer 15

• Explosive gas (100 degrees celcius)
  -Made up of hydrogen peroxide & hydroquinones mixed with enzymes

Question 16

How do animals misdirect a consumer?

Answer 16

Regenerate their tail if it is lost

Question 17

False head deflects outcome in cabbage white butterflies

Answer 17

Butterflies with false heads added escape more often than those without

Question 18

How do animals attract competing consumers?

Answer 18

• Fear screams
• Release of fear chemicals into water

Example: Pike take longer to handle minnow when competitor present

Question 19

What are the possible explanations for fear screams?

Answer 19

• pain (not adaptive)
• warning (but not easy to locate, and ignored by
  others)
• call parents (but adults as likely to scream)
• alarm predator (maybe?)
• call competing predators

Question 20

What observation was seen in recording starling fear screams?

Answer 20

recording of starling fear scream attracted foxes, cats and hawks, supporting the hypothesis that fear screams attract competing predators

Question 21

Why are prey always one step ahead in the arms race?

Answer 21

• Have a shorter generation time
• Life –dinner principle (Dawkins & Krebs) fox runs for his dinner, rabbit for his life!

Question 22

Examples of predator adaptations and counter-adaptations by prey

Answer 22

See Antipredation lecture notes slide 32

Question 23

What is an evolutionary arms race?

Answer 23

-Natural selection results in predators with increased efficiency in finding and capturing prey
-The selection for prey’s ability to avoid
detection and capture
-Each improvement in the predator will put pressure on the prey to evolve counter-adaptations, and vice versa

Question 24

How have adaptions of crypsis and visual acuity evolved in prey?

Answer 24

Blend in with background resulting in increased survival of those that blended in -Better cryptic colour/behaviour selected in prey

Question 25

What is the predator adaption to crypsis and vision acuiity?

Answer 25

Prey harder to find- selection for better vision/search image formation in predator

Question 26

What selections have evolved for predators?

Answer 26

-selection on predator for better vision and ability to form a search image -selection on prey to improve crypsis, also polymorphism (e.g. underwing moths)

Question 27

What are the defences used by underwing moths against predation by jays?

Answer 27

-Forewing: crypsis to avoid detection -Hind wings: startle to avoid capture Jays detect fewer moths on cryptic background

Question 28

What is the result of variation in colour of the hind and fore wings in underwing moths?

Answer 28

Hinders learning by the predator and helps the moths to escape

Question 29

What occurs as a result of polymorphism in crypsis?

Answer 29

it impedes formation of a search image by predator

Question 30

What occurs as a result in variation in startle?

Answer 30

colour impedes learning (habituation)

Question 31

An example of a species that shows polymorphism?

Answer 31

The forewings of Catacola are polymorphic- different varieties within one population - Helps avoid detection by interfering with formation of a search image

Question 32

Describe the experiment to show variation in startle colour impedes learning

Answer 32

- Hind wings startle jays - Jays habituate to a particular pattern after repeated presentations - But still startled by a different hind wing pattern

Question 33

What is habituation?

Answer 33

A stimulus-specific decline in response to a repeated stimulus not associated with reward or punishment

Question 34

How do forewings effect the relationship between underwing moths and jays?

Answer 34

- Forewings reduce detection (on appropriate background) - Detection improves with experience: jays form search image - Polymorphism in moths interferes with search image formation

Question 35

How do hind wings effect the relationship between underwing moths and jays?

Answer 35

Jays habituate to hindwings – but habituation is pattern-specific Adaptive for hindwing patterns of sympatric species to differ markedly

Question 36

Trade-off between crypsis and conspicuousness in guppies showed what?

Answer 36

- Male guppies more brightly coloured than females - Brighter male guppies, with more spots have mating advantage (sexual selection for spots

Question 37

What species show trade-off between crypsis and mating success?

Answer 37

Distinctive colours lost after breeding season -Mallard: drakes in mating season

Question 38

What was seen in an experiment performed using guppies?

Answer 38

- Male guppies from streams with higher predation pressure have fewer, smaller spots (selection against spots) - Guppies without predators (“k”) evolved to be brighter over 20 months (sexual selection for spots)