• Tinbergen’s four ‚questions’ for investigating behavior• Mechanism

• Ontogeny

• Function

• Evolution

Topic for today

Socio-cognitive abilities of dogs – mainstream research direction is bottom-up

It starts with a comparative question: „Do dogs have the capacity of…, such as the humans/apes…?” e. g.

Following visual cuesLearning from demonstratorsAttribute false beliefs to others, etc.

Studies on vocal behavior however are usually based on observationsof commonly occuring phenomena, similarly to some other examples,like

Attachment behavior, empathy, ‚guilt’ etc.

Vocal behavior of dogs provides a unique chance for ethologists tostudy natural dog behavior and its possible functions, as well as an exciting opportunity for building theories about the course of evolution during the domestication process

Describing the abundance of canine vocalizationsEarly, but throughout efforts (Cohen and Fox, 1976)

Recurrent problems with naming the categoriesBetween-language correspondanceA new (acoustics-based) categorization would be necessary

Are there dog-specificvocalizations?

*

*= woof woof in Hungarian

Compared to the closestrelative(wolves – Feddersen-Petersen, 2000)

Different acoustics? (yes and no)Different contexts? (yes and no)

WHY?Function?Evolution?

Answer may shed light to

events during domestication

Cohen & Fox,

1976

meow

gru

nt

wh

ine

yelp

scre

am yip

ho

wl

co

o

gro

wl

co

ugh

bark

clic

k

too

th

snap

pan

t

Greeting F WD WC

D

D F C WD R WD - D - - F

Play

initiation

- - D D - - - - - - D - WK FD

Submission F - WC

D

D W

CD

- - - - - - - - -

Defense - - WC

D

K CF

W

- W - WC

DF

WC

DF

WD F WC

D

-

Threat - - - - - - - - WC

DF

WC

DF

WC

DF

F WC

D

-

Contact

seeking

nF DF n, D

W C

nW

nC D

F C - F - - D - - -

Pain/ distress n - n, D

WC

F

nW

nC D

n, D

W C

F

- - - D - D - - -

Loneliness - - n, D

WC

D - - W C

D

F - - D - - -

Group

vocalization

- - n, D

W C

- - C W C

D

- W

C D

- - - - -

Predominantly dog-specific occurrence

Abundant (easy to experience/collect)

Large acoustic variability, and different from the wolves’ bark

The role of barks in dog-dog communication

Early ‚non-communicative’ theoriesHypertrophyExcitementNeoteny

Mobbing theory (Lord et al., 2009)

Acoustic similarities (bark = mobbingsignal)

Bark contexts are only partly overlappingwith the opportunity to mob (unlikebarking alone, joint action with owneretc.)

Cohen and Fox, 1976

Coppinger and Feinstein, 1991

Back to the basics – reliable acousticfeatures are needed for possiblecategories of informationIdentity, affective state, context, etc.

Early analyses (few parameters, related tomostly context and affective state)Yin, 2002; Pongrácz et al., 2005)

Machine learning approaches (manyparameters, also about identity, sex, age of the dog)(Molnár et al., 2008; Larrañaga et al., 2013 – Anim. Cogn.)

The acoustic basis is given

for information transfer

between dogs

Habituation-dishabituation paradigmDogs show evidence of ‚hearing the difference’

BUT the circumstances were far from being realisticWhat about the natural behavior?

IDENTITY, CONTEXT

Maros et al., 2008 –

Appl. Anim. Behav. Sci.

Molnár et al., 2009 –

Behav. Proc.

The effects of context (affectivestate) and identity were tested

Territorial (‚stranger’) barks elicitstrong reaction

Distress (‚alone’) barks do notFamiliarity of the caller also counts

PARTICULAR types of barks

elicit appropriate response

from the receiver dog

OTHER barks (‚alone’) elicit

no response

These latter are ‚new’

compared to the wolf barks

If they are communicative

signals, who is the

AUDIENCE?

Pongrácz et al., 2014 – Appl. Anim. Behav. Sci.

ChemicalWith little to no relevance for humans…

VisualDogs understand a variety of human visual cues

(Lakatos et al., 2009)Humans have to learn the body language of dogs

(sometimes difficult)Misunderstanding can be fatal (small children / aggressive face expressions of dogs – Meints et al.. 2010)

Humans understand ‘humanized’ visual cues, like gaze alternation (Miklósi et al., 2000)

AcousticDogs are usually very vocal, but do we understand

them? ??

Selection pressure alone is not an explanation itobviously did not work in the case of chemical and most of the visual signals

‚Universal’ channel for (even interspecific) communication?

Two main explanatory hypothesesEvolution structural-motivational (Morton, 1977)Mechanism source-filter (Taylor and Reby, 2010)

General approach – playback studieswith large amount of standardizedsound recordings (from Mudi dogs)

CONTEXTSStranger at the gateSchutzhund trainingLeft aloneBefore walk‚Asking’ for ballPlay

Tasks for the participantsContextual recognitionRating of EMOTIONSAggressiveness, Fear, Despair, Happiness, Playfulness

0

5

10

15

20

25

30

35

40

45

50

Mudi-owners Dog-owners Non-owners

rec

og

niz

ed

sit

uati

on

s (

% +

SE

)

chance level=16.7%

***: P<0.001

*** *** ***

Adults with different amount of experience with dogs

High overall success rate of context recognition

No effect of experience (Pongrácz et al., 2005 – J. Comp.

Psychol.)

Sighted and sightless adults (visual experience varies)

High overall success rate of context recognition

No effect of sightedness (Molnár et al., 2010 – Q. J. Exp. Psychol.)

0

5

10

15

20

25

30

35

40

45

Sightless from birth Sightless with visual

experiment

Sighted

co

rre

ctl

y c

ate

go

rize

d s

itu

ati

on

s (

%)

chance level: 17%

*** *** ***

Children with different extent of dog-experience

Only three contexts, success rate mostly above chance level

No effect of experience, general effect of age (Pongrácz et al.,

2011 – Appl. Anim. Behav. Sci.)

0

10

20

30

40

50

60

70

80

90

100

6 years

old

8 years

old

10

years

old

adults

corr

ectly

cat

ego

rize

d s

ituat

ion

(%+S

E)

dog yes

dog no* NS * *** *** *** *** ***

Experience had only minimal effect

Overall recognition rate is well above chance level

Strong effect of context on recognition accuracy

0

10

20

30

40

50

60

70

Stranger Schutzh. Walk Alone Ball Play

reco

gn

ized

sit

uati

on

s (

% +

SE

)

a ac bc ac bc c

chance

level=16.7%

Pongrácz et al., 2005 – J. Comp. Psychol.

What could be the reason?

Pongrácz et al., 2006

Silva et al., submitted

Repeated study on

Hungarian and

Portuguese samples.

Affective state of dogs in particular contexts was rated ratheruniformly across the sample‚stranger’, ‚Schutzhund’‚alone’‚play’

These contexts were easier to recognize contextually as well

Emotional assessment Contextual recognition

(unconscious) (conscious)

Wolf-like ancestor

• Barks encode• Aggression

(defensive/offensive)

• Other affective statesare being encoded by• Howling

• Growls

• Whining, etc.

Dogs

• Barks encode• Aggression

(defensive/offensive)• Fear• Frustration• General excitement (?)• Happiness / positive

affective state

• Other types of vocalization remain intact, or become more rare(e.g. howling)

What kind of selective pressure?

Human environment is of crucial importance

Protection (i.e. passive tolerance) against thenegative consequences of being loud (both thepredators and shortage of prey)

Preference for particular functions of barking(alarm, hunting, herding)

Some forms of barks were retained (aggression)Some new forms turned to be useful (fear/separation)Some new forms were tolerated (playfulness)

But see the new challenge!

‚Nuisance barks’

‘Theory of communicative relevance of auditory nuisance’

Particular signal-structures evolved for intenseattention elicitingBaby cries (artificial version: siren)

Natural response: interventionDog barks do the sameWhen intervention is impossible…

STRESS ANNOYANCE

High pitched barks are the most annoyingAttention eliciting (baby cry, cat meow, sirens)No habituationTypical to dogs in trouble, separation

Fast, harsh, deep barks are very annoyingAggressive vocalizations‘Original’ function of barks – similarity to wolvesFight, flee, or intervene

‚Works’, because of the NEW FUNCTION of barks

‚Works’, because of the OLD FUNCTION of barks

Growls – apparently no ‚new function’ in the human

environment

Agonistic interactions

Play

Commonly encountered in dog-dog and dog-human

interactions

Testing of the information content of growls

Step 1: intraspecific relations

Step 2: dog-human communication

Playful vs. two types of agonistic growls

Test situation matches with only one of the

contexts

Dogs gave up only when a

‚food guarding’ growl was

played back

Discrimination

between agonistic and

playful growls?

Discrimination

between two types of

agonistic growls?

Recognition of the

food guarding growls?

functional referentiality?

Faragó et al., 2010, Animal Behaviour

2

7

31

3

4

9

2

5

0123456789

101112

FG TS PL

Type of growl playback

leave

eat

take

‚Human version’ of the

aforementioned study

Choose the correct context

Rate the affective state

Each context was recognized

above chance level

Emotional rating congruent with

context

Food guarding growls were the

most ‚aggressive’ for HUMANS

Maybe for dogs, too?

(Faragó et al., subm.)

Formant dispersion of play and

food guarding growls from the

same dog show interesting

difference

Formant dispersion – connected

to the size of the vocal apparatus

indirectly to body size

Do dogs ‚manipulate’ the

indexical information about

themselves?

A A

B950

1000

1050

1100

1150

FG TS PL

Formant dispersion

Play growl

Food guarding growl

Faragó et al., 2010, PLoS ONE Bálint et al., 2013, Appl . Anim. Behav. Sci.

Food-guarding growls

Dogs look at the

‚matching’

size DOG picture

Playful growls

Dogs look at the

‚bigger’

size DOG picture

+ sound playback

The honesty of agonistic growls may originate from theclose-distance circumstances of these vocalizations, where cheating would be difficult due to the instant visual reference

Exaggerated size information encoded in play-growlsmay serve to sustain playful context due to theobvious discrepancy between the acoustic and visualinformation

What about indexical signaling towards humans?

Taylor et al. (2008) found in play-back studies that

humans are sensitive to the size-component of dog growls

Would dogs use ‚honest’ signals in an agonistic encounter

also towards HUMANS?

‚Threatening stranger’

experiment

Various human

participants of ‚small’

and ‚large’ body size

Male

Female

Multi-parameter

acoustic analysis of the

elicited growls

Dog growls with lower

fundamental frequency and lower

formant dispersion at

MEN

Experience counts, the effect is

the strongest if the dogs lived in

MIXED-GENDER families

First time evidence was found

that dogs modify vocal indexical

information as a function of

different

AGONISTIC encounters

Bálint, Faragó, Miklósi, Pongrácz (2016) in press Anim. Cogn.

moan

whine growl

whimper

snarl woofyelp

Fear, pain

Play

Warning, defense

Frustration, anxiousness

Tonal sounds Atonal sounds

bark

Repetitiveness grows

Tonal barks

High pitched barks

Recruiting effect;

Long distance communication

Non-aggressive

inner states encoded

Long distance

non-aggressive communication

Hypothesized receivers:

HUMANS

Growls convey an abundance of information to other DOGS

Growls are also understandable for HUMANS

inner state ? context(indexical features) body size

Growls were found suitable for

dynamic apparent size communication

Voluntary control???Learning???

Effect on the receiver???

Evolution

Did breed-selection affect vocal behavior?

Ontogeny

How does the social environment affect the

emergence of particular vocalization types?

Mechanism

Are there specific acoustic ‚fingerprints’ of

conditions such as separation-related disorder?

(see the lecture of Faragó onWednesday morning)

Function

What type of information do particular types of

vocalizations convey to humans and dogs?