summary (oscines): (2) birds must practice (sub-, plastic, and...
TRANSCRIPT
Summary (Oscines):
(2) Birds must practice (sub-, plastic, and ………………………………………… (3) crystallized song) Trimmed, cut, and frozen
If not, song performance isgreatly distorted
(1) Bird must have a tutor during the sensitive period
Dependent care
Independent Juveniles
MaturingAdult
Crude template
Template matchedto song heard
Exact template
Own species song heard
MEMORIZATIONPHASE
Song matched to template
Hears own song
Song output
Testosterone
MOTOR PHASE
Day length increases
Gonad sizeincreases
AUDITORY TEMPLATE MODEL
I
III
II
Requires Tutor
Requires hearing yourself
This is a (brief) window of crystallization
Forgetting or culling
Brown-headed cowbirds
Brood parasites
HOW DO THEY LEARN THEIR SONGS?
Action-based Learning
• Eastern and Southern sub-spp
• when transplanted chicks raised by the ‘other’ sub-spp they learn that sub-spp songs
• males respond to female wing-flicks by repeating songs more when females respond this way
Indirect pathway between HVC and RA – recursive loop
HVA=Higher vocal centerRA=Robust nucleus of the Arcopallium
Anterior Vocal pathway(learning)
PosteriorVocal pathway(production)
Many of the nuclei have neurons that recognizespecific sounds in complex song
Summary:
• Some neurons are specific to individual syllables (higher firing rate) • Gene induction higher for species-specific songs, and in some case novelty • “ “ for so-called “sexy” songs (canaries) • The feedback loop, singing behavior itself (feedback?) increase neuron production
Vocal fighting and vocal flirting
Males sing differently to males and females
Two studies how that femalesprospect for males based on song
Pied flycatcher
Great reed warbler
# fe
mal
es c
augh
t10
5
So what are females looking for in song or singing that indicates a good male?
Specific song structures:
- Sexy song in canaries (sensory bias or signals precise vocal coordination?) - Potent songs in cowbirds: males punish rivals singing potent songs, thus it
indicates the # fights won and lost (like isolated males)
- Swamp sparrows and limitsto vocal performance
Song frequency (over time):
- Song frequency is correlated to males nest defense and feeding the young (parental care)
WHY? What does it indicate?
Song
s pe
r 5 m
in
Num
ber o
f bird
s pa
ired
first
- In pied flycatchers suppl. feeding increases singing 2-fold) and results in faster pairingbetween males and females
Song repertoires:
- Females show preferences for males with larger repertoires (song or syllable)
Repertoire size
Mea
n #
disp
lays
Song repertoires:
Yea
rs o
n t
erri
tory
- Older birds (open-ended learners) sing more songs- Or song repertoire correlates with survivorship (close-ended learners)
Song Sparrow
Repertoire size
Mea
n #
disp
lays
Life
time
rep
succ
ess
- Males with larger repertoires have higher LRS
- And females prefer them
- But it would nice to this in offspring…
Pairi
ng d
ate
Mea
n #
disp
lays
Repertoire size
Gen
etic
offsp
ring
surv
ival
Repertoire size
Male canaries affected with malaria• lower repertoire size• smaller HVC
But also in response to nutritional stress in:song sparrows, canaries, and starlings
Song familiarity (local song structure):
-Female song sparrows prefer the local dialect over ‘foreign’ dialect
…this sets up a performance index…
Many notes; high accuracy
Few notes; poor accuracy
Intermediate
Vocal fighting and vocal flirting
Males sing differently to males and females
Yasukawa’s experiment (1981) - Mute males via removinga portion of the hypoglossalnerve
Krebs’ Experiment (1977)- Remove males- Monitor settlement
songs per min Neighbor
stranger
- Muted males creates more territory intrusions
- Experimental playbacks delays territorial settlement in the absence of males
- There is a level of sophistication males recognize neighbors from strangers and have different responses relative to their position in space with respect to territory intrusion
Songs to advertise territory ownership and aggression to other males – 3 examples
Track 38 (Kroodsma)
#1 Song (Type) Matching
Counter singingMarsh Wrens
Repertoire MatchingBeecher’s Studies on the song sparrow
A
N
B
EH
JL
K
OP
U V W
X
T
S
RQG
CIDF
Bird 1
Bird 3
Bird 4
Bird 2
(1) Match song exactly Type Matching
(2) Match with another shared song Repertoire Matching
(3) Sing a unshared song
TypeMatch
RepertoireMatch
Unshared
- Neighbors tend to repertoire match more than expected by chance
- Neighbors type-match early and repertoire match later in the season
Song functions to communicate to territory ownership in very sophisticated ways