L4 - Birdsong

Question 1

What class are birds?

Answer 1

Aves

Question 2

How many orders, families, genera and species of bird are there?

Answer 2

28 orders, 163 families, 2000 genera, ~9000 species

Question 3

How many species of birds are songbirds?

Answer 3

~4000 (about 50%)

Question 4

What is the difference between a bird song and bird call?

Answer 4

Call: usually a short and simple vocalization that signals flight or danger and is produced throughout the year
Song: tends to be a long and complex vocalization produced during a breeding season

Question 5

What is it called when an individual bird can sing more than one version of a song type?

Answer 5

A repertoire

Question 6

What are the structural parts which make up a birdsong?

Answer 6

Notes/elements:
- Continuous mark on the spectrogram
- Simple continuous narrow frequency band
- Complex frequency and amplitude
Syllables:
- Composed of two or more notes clustered together
Phrase:
- Two or more syllables grouped together
- Could also be series of single notes/syllables
Syntax:
- Specific timing and ordering of notes, syllables and phrases

Question 7

What is interesting about White-Crowned sparrow’s song?

Answer 7

They have dialects, can tell where a bird lives from it’s song

Question 8

Which sex sings and why?

Answer 8

Depends on who competes to breed – usually males, sometimes both sexes duet

Question 9

What selective pressures have driven evolution of birdsong?

Answer 9

Twin selective pressures have driven the evolution of song – female choice and male-male competition

Question 10

In Barn Swallows, what does the length and frequency of the “rattle” part of their song correlate with?

Answer 10

Longer rattle - higher testosterone levels (therefore breeding success)
Higher frequency - healthier bird

Question 11

What information is in a song?

Answer 11

• Presence of potential mate
• Individual identity
• Where he was born & raised
• Where is physically located at the time
• Whether or not he owns a territory
• His willingness to breed
• Condition
• Early environmental experience
• “Quality”

Question 12

What does conspecific mean?

Answer 12

Within the same species

Question 13

What does heterospecific mean?

Answer 13

Within different species

Question 14

What did William Thorpe discover about chaffinch’s birdsong?

Answer 14

• Young males in isolation learn song by playing ‘tutor’ tapes of the conspecific song
• In absence of recorded song, develop abnormal song
• If recorded song is given after sexual maturity, chaffinch still develop abnormal song
• Showing innate predisposition to learn songs of conspecifics

Question 15

What is the subsong?

Answer 15

Stage in song development when young birds produce rambling sounds variable in timing and pattern

Question 16

What is plastic song?

Answer 16

Stage in song development - as birds grow older, assume posture produce sounds in discrete clusters & aspects of the temporal patterning of the adult song is detectable. First evidence of imitation & characterization of adult species-specific song. First stage at which rehearsal of previously learned songs begins

Question 17

What is crystallised song?

Answer 17

Stage in song development when full song expressed with normal variations in volume, duration, syllabic structure, etc.

Question 18

What are the three stages of song development?

Answer 18

Subsong, plastic song, crystallised song

Question 19

What are the three song learning phases?

Answer 19

Sensory phase, sensorimotor phase, transition to crystallised song phase

Question 20

Describe the sensory phase of song learning?

Answer 20

It is when auditory experience occurs. Must hear their normal species song from other adult birds. During this phase commits song to memory, but may not sing at this time. This is a critical/sensitive period in which auditory experience must occur

Question 21

Describe the sensorimotor phase of song learning?

Answer 21

It is when vocal practice begins
Includes both the subsong and plastic song stages

Question 22

What are the three categories birds fall in for learning a song? (to do with when they learn)

Answer 22

Seasonal closed learners
Age-limited learners
Open-ended learners

Question 23

Two species of swamp sparrow overlap in territory - what happens to their birdsong as they get closer to crystallisation?

Answer 23

Initially their birdsong contains notes from both species but as they get closer to crystallisation the birdsong becomes species specific

Question 24

Name the factors which go into a bird correctly learning their species birdsong

Answer 24

• Innate (genetic) factor
• Trained factor
• Social (interaction) factor

Question 25

Which hormone has a negative correlation with the learning of new syllables?

Answer 25

Testosterone

Question 26

What three parts of the brain are used in song production and make up the song production nuclei?

Answer 26

• Higher Vocal Centre (HVc)
• Robust nucleus of the archistriatum (RA)
• The tracheosyringeal portion of the hypoglossal nucleus (nXIIts)

Question 27

What three parts of the brain are used in song learning? And which pathway is this?

Answer 27

• Area X
• Medial portion of the dorsolateral thalamus (DLM)
• Lateral portion of the magnocellular nucleus of the anterior neostriatum (LMAN)
• Anterior forebrain pathway

Question 28

What is laterality?

Answer 28

When one side of the brain is (most) responsible for an action, behaviour or learning etc

Question 29

Is there any laterality in birdsong? What is the evidence?

Answer 29

Yes
- When right side of brain was lesioned (lesion in HVc) the birdsong was very similar
- When the left side of the brain was lesioned (lesion in HVc)the new birdsong showed no resemblance of the original

Question 30

What effect does the time of the year have on the size of the HVc and RA?

Answer 30

HVc and RA are 99% and 76% larger respectively in spring (singing vigorously) than in autumn

Question 31

What effect does injecting females with testosterone have?

Answer 31

They will sing and have increased volume of HVc and RA

Question 32

What is the relationship between size of HVc and sex bias in singing?

Answer 32

The bigger the HVc in a species of bird the higher the sex bias in singing

Question 33

How many times did birdsong evolve?

Answer 33

2 or 3

Question 34

Does injecting non-songbirds with testosterone cause them to start singing? And why?

Answer 34

No - because non-songbirds do not have the brain circuitry to be able to sing