Lecture 17

Question 1

To maximize conspicuousness, what do tropical birds use?

Answer 1

patches of red that stand out

against green backgrounds

Question 2

Vertical jumping displays are what?

Answer 2

against horizontal backgrounds are conspicuous.

Question 3

Aposematic coloring

Answer 3

used to describe colours and / or patterns that act as a warning to predators that a potential prey species is unpalatable, toxic or dangerous.

Question 4

What are some species that are both conspicuous and unpalatable to predators?

Answer 4

Arthropods and salamanders.

Question 5

Species like arthropods tend to form large aggregates to maximize what?

Answer 5

Maximizing saliency

thereby reducing predation

Question 6

Evolutionary advantage to prey species of

being easily identifiable confers what benefit?

Answer 6

Beneficial for predators to be able to recognize

unpalatable prey

Question 7

Predators need to learn to avoid aposematic prey, give an example?

Answer 7

Naïve blue jays will readily eat viceroy butterflies
until they eat a monarch, then they avoid both
species

Question 8

What is a signal?

Answer 8

A perceivable behavior or feature that
has evolved and acquired a specific
characteristic of conveying information about
the signaler or the signaler’s environment

Question 9

what is a cue?

Answer 9

– A regularity or pattern that is either
permanently ‘ON’ or is ‘ON’ or ‘Off’ depending
on specific conditions
 …  Cues benefit the receiver exclusively
 Ex. Mosquitos fly against CO2 streams to locate
mammals to bite

Question 10

Aposematic colors as cues?

Answer 10

Warning signals are permanently “ON” and

associated costs are paid early in development

Question 11

 Lygaeid bug (Lygaeus equestris) has two _____

morphs

Answer 11

color (both morphs are equally umpalatable)

Question 12

Researchers place T. guttata and P. majors in a

ring with both color morphs of lygaeid bug. What did they find?

Answer 12

Birds that were wild-caught rejected prey more
often than hand-reared individuals
 Some prey were rejected after handling
whereas other prey were avoided (never
handled)

Question 13

Predator avoidance was a combination of …?

Answer 13

indirect effect of coloration

influenced by predator’s experience.

Question 14

Sandre found that aposematic signal efficacy might be linked to?

Answer 14

Distinctiveness from undefended prey or
background
 Predator’s ability to remember previous encounters

Question 15

Variation in some predator species can change

selection pressures on coloring. How?

Answer 15

Individual ability to overcome prey defense or toxicity

 Individual differences in the unspecific motivation to feed (appetite/hunger)

Question 16

Describe the Sandre study

Answer 16

 P. major were used as predators
 Wild-caught and housed for 4 days prior to testing
Boiled meal worm (T. molitor) larvae were
painted based on different color morphs of
lepidoptera (O. antiqua)  …  Two yellow spots, two black spots
 Four brown spots

Question 17

Mealworms were presented on a white plate. What was done to them prior to presentation?

Answer 17

All mealworms were injected with chloroquine
phosphate to make them distasteful and mildly
toxic

Question 18

What were the findings of the Sandre study?

Answer 18

Birds hesitated longer in attacking the yellowyellow
morphs than the brown morphs
No difference between yellow-black morph and
yellow-yellow
Attack delay increased with each training trial but there was no difference in learning rate between the different prey color morphs
 Birds appeared to learn to avoid the prey

Question 19

Appetite of the birds significantly impacted the

attack delay. Why?

Answer 19

There was a negative correlation between hunger
and attack delay (hungrier birds attacked
mealworms faster)

Question 20

The birds showed equal rates and ________ _ ________ for all color morphs

Answer 20

effectiveness of learning

Question 21

Birds learned to avoid all mealworms with

_________ _____

Answer 21

painted dots

generalized their avoidance easily

Question 22

What did Gagliardo study?

Answer 22

Studied the impact of gregariousness on prey

avoidance

Question 23

_______ _______ appears to have evolved

prior to gregariousness

Answer 23

Aposematic coloring

Question 24

What is a primary hypotheses regarding aggregation?

Answer 24

Aggregation naturally ‘dilutes’ predation risk

Question 25

Describe the Gagliardo study?

Answer 25

Domestic chicks (Gallus gallus) were trained to
eat both yellow and green dyed bread crumbs

Question 26

Describe the single treatment in the Gagliardo study.

Answer 26

10 birds received 18 green
palatable and 18 yellow unpalatable (treated
with Quinine and mustard) bread crumbs during testing; crumbs were placed singly in 36 different wells in random order
Extinction presented same number of bread
crumbs but both colors were palatable

Question 27

Describe the aggregated treatment ?

Answer 27

10 birds received the
same number of crumbs but in three
aggregations of six green and three of six
yellow

Question 28

Describe visually aggregated treatment?

Answer 28

9 birds received same arrangements of single crumbs as in single treatment, but below the clear base of the well were six visually similar crumbs, (only ate on, but saw many)

Question 29

Describe visual single treatment?

Answer 29

9 birds were offered a single crumb inside the well with one crumb below the clear base (ate one, only saw one)

Question 30

What were the findings.

Answer 30

Ate more crumbs in the single condition.

Unpalatable prey suffer higher predation if arranged solitarily.

Question 31

________ ________ is not a function of number of

prey eaten in rapid succession

Answer 31

Taste Deterrence (Aggregate conditions showed no difference in
consumption rate)

Question 32

When did birds eat more newly palatable crumbs?

Answer 32

single treatment extinction phase (Extinction rates would occur more quickly for nongrouped
prey)

Question 33

Which birds took longer to learn?

Answer 33

Birds in the single treatment condition took
longer to learn to avoid the non-palatable
crumbs
There were no significant differences between
the remaining three groups

Question 34

What may be the mechanism when deciding if a prey is noxious?

Answer 34

Being able to see prey coloration as the noxious
stimulus is perceived during ingestion may be
the mechanism by which discriminative aversion learning is enhanced
This may support such associated characteristics as larger size, resilience to
ingestion, or expendable parts

Question 35

Describe the handicap principle

Answer 35

Inducing a disadvantage to the bearer to signal the

ability to overcome the challenge