Lecture 9

Question 1

Define anthropomorphism

Answer 1

assigning human emotions and feeling to animals that don’t run with our spectrum of visual and emotional cues.

Question 2

What are some species in the animal kingdom that suffer limited predatory threat?

Answer 2

elephants
gorillas
lions
whales

Question 3

Predation is almost ________

Answer 3

universal

Question 4

among group living species, some individuals may produce what?

Answer 4

vocalizations or other warning sounds to alert the conspecifics in the area to a potential threat (produce a predictable change in behavior among group)

Question 5

Describe reciprocal altruism?

Answer 5

consistent groupings
individual recognition
Some form of cost/benefit assessment

Question 6

What are some functional hypotheses of alarm calling?

Answer 6

individual selection

kin selection

Question 7

Describe individual selection

Answer 7

Manipulate action of conspecifics

• -facilitate group formation and cohesion
• -silence group members to decrease predator detection
• -reduce chance of future attack

Question 8

Benefits to individual selection hypothesis?

Answer 8

Alarm signals represent a form of mate investment

• -invite predator pursuit
• -deter predator pursuit
• -confuse predator orientation when alone

Question 9

Describe the kin selection hypthesis?

Answer 9

warn kin of varying degrees of relatedness

to defend offspring

Question 10

what’s the difference between vocalizations used to attract mates and alarm calls?

Answer 10

vocalizations for mates are easy to locate and are low frequency and have clear start and stop points to help with localization.
–alarm calls need to be difficult to locate

Question 11

What are some factors that influence the detectability of alarm calls?

Answer 11

Amplitude of the signal at the sound source
 2. Attenuation characteristics of the environment
 3. Signal-to-noise ratio at the perceiver
 4. Discrimination ability of the perceiver against the background noise
 5. Auditory sensitivity of the perceiver

Question 12

why should production capabilities of the sender and perception capabilities of the receivers matter?

Answer 12

Conspecifics must be able to avoid predation

 Predators must be confused or challenged by the same signal

Question 13

__________ noise is easier to localize than __________ noise

Answer 13

broadband, narrowband (pure tones are difficult to localize)

Question 14

what kinds of calls are more readily localized?

Answer 14

frequency modulated calls (like sage grouse stridulation)

Question 15

how does environment impose its own effects on signal structure:

Answer 15

most alarm calls under lab conditions (in the absence of broadband noise) appear to be frequency-modulated

Question 16

the composition of similar species (sympatric species) in a given area should what?

Answer 16

should create a situation where alarm calls overlap; calls should be understood across species boundaries

Question 17

why should alarm calls show distinct overlap

Answer 17

Since environmental pressures are similar and sound producing equipment is similar;

Question 18

What did marler observe about alarm calls.

Answer 18

Single, brief duration “seeet” call  Low amplitude
 High frequency (narrowband)
 Gradual onset

Question 19

marler found that alarm calls in birds causes what?

Answer 19

others to seek cover. Alarm calls in different bird species have similar structure:

Question 20

unlike alarm calls, mobbing calls are made of what?

Answer 20

Repeated series of loud “chuck” calls
 Wide range of frequencies (broadband)
 Sudden sharp onset and offset

Question 21

when does mobbing behavior occur?

Answer 21

when predators perch in an area and the threatened species work together to drive away the intruder

Question 22

what did molar suggest about alarm calls?

Answer 22

shaped by strong selection pressures. Alarm calls reveal a clear trade-off between detectability and localizability

Question 23

What kinds of sounds are hard to localize?

Answer 23

narrow band of frequencies and gradual onsets and offsets are hard to localize

Question 24

What are the 5 points of Marler’s hypothesis?

Answer 24

1. Small animals are better at detecting high frequencies than larger animals (e.g., predators)
    2. Sounds with gradual onsets and offsets are hard to localize
    3. Narrowband sounds are harder to localize than broadband
    4. High frequencies are linked to fear rather than attack
    5. Mobbing calls are repeated in a loud voice to attract others

Question 25

________ _______ are linked to fear rather than attack.

Answer 25

high frequencies

Question 26

What is the best course of action for alarm calling?

Answer 26

Use brief, high-frequency sounds without sharp onsets to avoid localization  Use longer, more intense, broadband sounds to attract attention

Question 27

what does alarm call detection depend on?

Answer 27

1. Amplitude of signal at the source
    2. Attenuation characteristics of environment
    3. Signal-to-noise ratio at the receiver
    4. Sensitivity and discrimination ability of the receiver