summary (oscines): (2) birds must practice (sub-, plastic, and...

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