Fear responses in domestic chicks as a function of the social environment

fiocessee, 8 (1983) 309-325 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands

309

Behauioural

FEAR RESPONSES

R.

IN DOMESTIC CHICKS AS A FUNCTION OF THE SOCIAL

ENVIRONMENT

BRYAN JONES

Agricultural EH25

Research

9PS,

Council’s

Poultry

Research

Centre,

Roslin,

Midlothian

Scotland.

18 February

(Accepted

1983)

AB8TRACT 1983. Jones R.B., environment.

Fear Behav.

responses processes,

in

domestic 8: 309-325.

chicks

as

a function

of

the

social

The open field or novel environment has been used to assess fear in many species but its validity for the domestic fowl has recently been questioned. involved manipulation Based primarily on experiments which of the social environment Gallup and Suarez proposed that, contrary to an emotionality or fear interpretation, “open-field behaviour in chickens represents a compromise between opposing tendencies to reinstate contact with conspecifics and to minimize detection in the face of possible predation”. Predictions which can be made from the Gallup and Suarez model and from the fear hypothesis were tested by examining the effects of manipulating the social environment, during rearing and testing, on the open-f ie Id, hole-in-the-wall box tonic and immobility responses of domestic chicks. inconsistent with The results were predictions made from the Gallup and Suarez model but they conformed to the fear hypothesis. Furthermore, they were consistent with the majority of findings reported in the literature. Thus, while the opposing tendencies of reinstatement and predator evasion are, almost undoubtedly, important in many situations there remains considerable evidence for the role of fear in regulating the responses of domestic chicks to novel environments such as the open field. The two interpretations should not be considered mutually incompatible.

The

open

primarily is

a

field

to

or

(1981)

who

or

concept

define

to

fear

perceived

in

immediate

or

Rather

than

adopting

a

often

turn

previous term

the out

use to

of be

anything

(see

Candland,

synonymous

with

that

0 1983

of

behavioural of

greater an

fear

to

specific

specific,

it

1971;

is

Archer,

1973;

to

damage

Publishers

B.V.

regarded Gray,

Fear

Jones

et

al.

psychophysiological protect

(Salzen,

(Archer,

identifiable

emotionality.

Elsevier Science

by

functions

approach

studies,

species.

detail

adaptive

behaviour

unpopular

but

in variety

physicochemical

generally term

as

fear

used

a wide in

terms All

potential

the

often in

discussed

general

usage

0376+3357/83/$03.00

is

danger.

from

is

emotionality

and

animal

restricting

environment

fear

controversial

response

novel

estimate

1979) sources,

in 1979)

line as

the 1979).

with a

and which much

blanket

310 There method

is of

Cummins,

considerable

assessing

1976; Royce,

ducklings 1980).

has

data with

tendencies, important

1981a)

is strong

could,

to

describe was

that

1982)

Gallup could

two

was

observer

proximity

reduce

that

ducklings

simply

distress

call

hypothesis,

and

remained

influence

functions

(shock

of

not

in

adaptive

fact,

been

stimuli

(Faure

conditioned

aversive

(Ivinskis

from

that 1970),

longer when

their model

where

from the fear hypothesis

experiments

et

mutually

study.

immobile

as an additional

and fifth

in

fear hypothesis

if it is postulated

and

only

but also

Gallup, testing.

considered

stimulation

silent

between

and

or fear interpretation

and

However,

intensity

and, hence,

fear-eliciting

which

involved

of the reinstatement

the the

where

stimulus.

manipulation

tendency

were not,

the fear hypothesis.

predicted

the tendency

that

to reinstate

response

prediction

domestic

two,

be predicted

fourth

with

This

the

chicks

could

Suarez

(Suarez

in the present

experiments. to

a predatory

the predominant

pair-tested

five

related

of

certainly,

hypothesis

be

only

results

environment

birds.

not

to

opposing

or startling

fear

the

of their

and

is examined

Suarez

has,

to novel

should

almost

the

It

dismissed.

interpretations

and

These

of open-field

that

or

a compromise

environment

felt

the

Gallup, of their

correspondence

1975;

that an emotionality

in view

consistent

the

(1980) conceded

finding

exerted

tested

the

their

observer

evasion

unjustifiably

and much

conspecifics

are,

novel

using

observer

Gallup

a was

chicks

for

of the social

to

concern

interpreted

of

third

however,

but

and

represents

overtones

of domestic

is positively

The results

reactions

This proposition

stimulation),

their

the

for chickens

on the emotionality

with

(Faure,

be adequately

6 Suarez

account

indeed

a

and

to an emotionality

to chickens,

immobility

as

Walsh

predation".

the responses

though

incompatible.

only

for the predatory

welcome be

contact

field

1973;

Suarez

based

in chickens

situations,

tonic

evidence

terms

generally

would

many

1980;

contrary

possible

of

open

to reconcile

behaviour

reinstate

face specific

and

consequently,

proposed

fear

in

Suarez,

that,

behaviour

to

the not

behaviour

attempt

al.,

are

factors

ethological

can

tendencies

which

open-field

proposed

the

Archer,

its validity

it difficult

of open-field

"open-field

in

and

found

of

llse

1971;

recently,

(Gallup

(1980)

the

(Gray,

and, more

They > therefore,

detection

over

rodents

questioned

& Suarez

opposing

minimize

An

1977)

interpretation,

between

in

an interpretation

hypothesis. fear

been

Gallup

controversy

fear

chicks

presence

social

of

contact,

familiar

conspecifics

thereby making

to the open field in group-reared, was

supported

(Gallup

and

Gallup,

1980)

to

ambulate

than

would predict

the

the opposite

and showed those results.

by their Suarez,

1980)

longer tested

findings

that trio- and

and

latencies

individually.

Inactivity

predator

group-

pair-tested to

peep The

and silence

or fear

311

following

placement

positively Faure

related 1975;

,

expected

the

reared

feeding

fear

or

of

food

was

measured.

and

Suarez

provide

No (1980),

an

in

intrinsic

logical

dark

chicks

tested

result.

pairs

to

has

been

and

walked

and

Hara,

above

reported more

Tonic

immobility

by

It

(1977)

tested

the

of in

consistent

field),

lib

were,

behaviour

patterns

used

would

sooner to

by

Gallup would

predict

that

when

placed

light

than

predict

in

the

Experiment

vocalisation exposed and with

chicks their

to

Suarez, a

fear

in

a

would

opposite 2

using

a

1978).

ambulation

the

open

1980).

field

However,

sooner

it

and

peeped

counterparts

The wet-e,

and

interpretation,

ambulated

group-reared

behav iour

unlearned

response state

regarded

for views duration

tendency to

in show

1967; its

effects

(Fujita

of

therefore,

as

and chicks longer

group-

or

examined

in

hypothesis

would

tested

individually

Experiment

4.

1977;

Thompson

important

imprinted

with

individually

predict

the would

companions.

et

a

al.,

fear

is

and

reverse

These

of

1981)

and

reviewed for

evasion

tested

alone

group-reared

experience

and

chain

condition

predator

than

and

(Nash in

antecedent If

immobility

restraint

responsiveness

relationship an

reared tonic

physical

reaction

susceptibility.

fear

from

t-educed

by

terminal

Gallup

chicks separation

the

positive

fear

induced of

as

(Ratner,

who

expected

group-reared distress

is

response

predominant

However,

an

evidence

manipulating

be

(Gallup

catatonic-like

responses

Gallup

the

a

1976).

substantial

would

of

ad

differences

would

longer

individually

ie Id

open

of

model

examined

Wood-Gush,

open-f

is

by

anti-predator the

on

following

model.

peep

when

than

the

exposure

tendencies

field

and

Suarez

separation responses

1979).

show

and

in

be

3.

characterised Gallup,

open

Murphy

individual-rearing Experiment

chicks

both

procedures

hypothesis

(Jones,

should

pairs,

their

would

individually-housed

the

1971;

of

therefore,

test

in

1973;

individually

open-field

methodological

and

fear

tested

range the

subsequent

the

prediction

that in

that

birds

reinstatement

the

mimic

felt

upon

isolation

wider

generality

Gallup

wet-e,

group-reared

diminished

contrary

the

box

in

than

to

was the

whereas

predictions

housed

latencies due

in

hole-in-the-wall

Birds

it of

and

or

a

to

those

al.,

as

therefore,

decrease

feeding

and

made

group-reared environment

The

modified

wet-e

to

individually-tested,

1

would,

The

field.

stimulate

regarded et

birds

would

open

are

Montevecchi

than

individually

(to

fact,

extension

nova 1,

tested

measure

1969;

companions the

Experiment

attempts

environment

Nagy,

sooner

of

deprivation

novel

Group-tested

familiar

and

in

and

1978).

value

groups

or

ambulate

and

examined

therefore,

(Candland b;

novelty

in

field

open

1977a;

presence

and

chicks

an

vocalise

the

distress

to

Jones,

to

because

A

in

they birds.

finding the

was

because additional

predictions

were

312 There and

are

Faure,

sex

differences

1981a)

domestic

and

fowl.

in

tonic

Femalr

the

open-fie

immobility

chicks

only

Id

behaviour

reactions

were,

(Jones,

(Jones

therefore,

and

used

in

1977~;

Faure,

the

Jones

1981b)

present

of

study.

EXPERKHENT 1 Uethods Five

batches

commercial Brown

(Rhode

were of

Ross ten

The

Island

experiment),

until 17.00

h

to

testing The

21 h. The

Food

field

home

companions

the

two once

it

10

min

the

and

of

some

preens. indices

of Suarez’s

of

area is,

(Archer,

1979;

latency

these

the

fact,

Clayton to

measures

the

;

first

open

of

to Jones

and

as

the

field

disagrees

chkLdi-terised and

Andrew,

step.

by 1979;

Following

useful,

with

Jones,

1980)

testing

each

chick

the a”Y

distress

call

swallowing)

and

feeding

though

Gallup

to

leave usage.

previous

was

and not

and

indirect,

1980).

is

and

jumps

latency

and

in hear

and

Black,

most

picked

observation,

immobility

complete

was

environment,

1977a; freezing

was

placed

or

eye-closure

be

to

chick

not

by direct

thought

Jones,

and

the

litter,

assigned

chick

peep

of

each

could

the

box. were

wood

randomly

(pecking

at

home

separation

room

first

lying,

a maximum

the

clean

each

feeding

pecks

to

illumination

and

another

the

until

steps, are

were

companions

till

and

h on

deprived

deprivation

h

to

room,

recorded,

sitting,

definition

of in

latencies

peeps,

1975

into box

food

and

pair-testing,

patterns

step

freezing,

(Faure, (1980)

Freezing

the

first

of

box

17.00

were

h.

condition

home

behaviour

defaecations,

fear

delineated

with

the

durations

numbers

home

drprivation

from

16

involved

Subjects or

the and

food

of of

dimensions

a different

jar.

Its

were

and

its

18.00

however,

of food

food

period

temperature

individual-testing

The

period

The

groups

x height).

and

3 groups

a minimum

to

as

individual

field.

made.

1952)

(Collias,

the

5 m from open

the

vocalisations

began,

In

of

similar

to

when

remaining

04.00

such

water

deprived

8.

Testing,

a

age

in

duration

heaters

of

from

of

exposure

namely

carried of

a

of

day

from box

features

and

absence

only.

UP gently, centre

on varied

environment.

conditions,

the

field

wooden

other

its

tested

the

and

were

testing

the

Ross

3 batches

housed

x breadth

for

from

were

remaining

dull-emitter day

obtained

batches

were

x 300 mm (length

sixth

groups

extended a

the

chicks

(unchanged

Similarly

open

was

the

and

over

the

to

of

six

two

whereas

overhead the

were

first

The

litter,

by

7.

7 until

in

The

White)

680 x 380

until

the day

from

silence one

day

provided

similar

of on

photoperiod

open

was

chick

on

Island

wood

libitum

Three

Cram

uf

with

chicks

female

2 weeks.

derivation).

providrd

ad

testing

Prior

Rhode

measuring

was

supplied

began.

6

x

of

Leghorn

covered

warmth

were

regimes

Red

boxes

were

newly-hatched

intervals

(White

6 wooden

floors

day

sixty at

White

in

water

of

breeders

silence

synonymous

marked

on

a

313

the

head

used

with

and

a

felt-tip

their

pen

and

observations

returned

did

not

to

differ

its

home

box.

Two

significantly

observers

were

(Mann-Whitney

U test,

two-tailed). In the

the

pair-testing

same

open

box

home

field. Each

were

5 pairs

individuals

described

and

5

White

birds

size

of

were

30

The

in

mean

of

square. individually

than

versus

those

the

from

together

in

the

amounts

two

chicks

of

and

the

each

of

ad

lib

the

7th

batches

of

individual-ad

variability

and

feeding

days

of

Brown

20

paired-ad

Three high,

5 pairs

Ross

lib,

was

8th

and

thus

and

chicks

were

lib,

batches

20

of

affording

5

Ross

a sample

conditions.

that of

of

paired-food-deprived.

pair

were

used

the

Mann-Whitney -

with

on

Two

20

20

four

responses

The

of

each

placed equivalent

one

following

because the

method the

food

of

scores

conservative examined

of

tested

were

simultaneously

above.

deprivation.

and

each

assigned

performed

sizes

individual-food-deprived

they

taken

approximately

individuals

food

sample

were

before

randomly

randomly

following

affording

marked

chicks

received

was

as

were

two

was

observer

tests

i.e.

used

one chicks

performed

Twenty age,

and

Both

handling. tests

condition,

by

analysis. and

chick

test

pair-tested

for

Gallup

first

U

maintained

used

to

&

birds, an ad

Table

I

lib

Suarez

vocalise

(two-tailed)

on

This

the

two

(1980)

and

was

for

and

2

a

more

who

move

used

lines

was

only

out

of

a

comparing birds

5

deprived

regime.

Results The Ross

results

White

regimes

are

birds

shown (RW).

ambulated

in

and

peeped

individually

though

some

Significantly

less

freezing

conditions

other

significant

birds

regime

feeding

individually.

though

this

at

environment

than

trend

individually-tested

deprived

pairbut

a

to and

RW birds.

were

in

shown lib

chicks

(RB)

lines

and

the

open

pairs

and

and

time

individually-tested

and

chicks

shown

in

less the

than

differed

tested

in

all

behaviour

rarely

resulted open

test

though

field

rarely differed

maintained

on in

an

Preening more

than

those ones

and

frequently

significantly

ad

paired

individually-tested

RB birds.

significantly

jumping

the

those

passive

generally in

longer

peeped only

but

chicks

regime

for

feeding

significance.

similar feeding

II

both

isolates

a

spent

Table

reach

other

showed

and from

than

to

than

Browns

losure),

feed

field

failed

by

Ross

eye-c

significant generally

birds

both

comparisons

sooner

Paired was

Brown

of

food-deprivation

significantly

tested

the

ad and

Latency

between

feeding

the was

the

Ross

chicks sooner

of

lying

trend.

significantly lib

than

(sitting,

patterns,

for

Pair-tested

pecking by

only

pairs in

the

I.

feeding

or

(s)

of

+ 5 5 T 5 T 5 7 5 T 5 5 T 0

26.4 14.9 15.3 4.1 13.4 4.1 2.4 1.3 0.2 59.2 13.0 0.7 0.7 0.5

1.3 11.2 458.1 45.9 0.6 242.5 98.1 13.6

43.5 1.7 19.0

(x)

+ 8.5 5 0.7 T 7.2 0 + 0.9 5 1.7 5 42.1 5 14.4 5 0.1 I 24.2 7 8.5 I 2.3 Ti 0.2 -+

ad

lib

Paired-

N.S. N.S. CO.05 N.S. N.S. <0.02 N.S. <0.002 N.S. CO.002 N.S.
N.S.

N.S.

P

Brown

chicks

10.6 37.1 516.0 31.6 0.8 368.4 49.3 0.8 1.0 0.1

212.8 20.7 104.3

+ T 5 0 + 5 r 5 T 5 5 T 5 z

Deprived

Individual-

tested

analysis by the Mann-Whitney U test (two-tailed) and birds under each feeding regime. summing the mean scores of each pair; (s) = seconds;

76.2 21.2 30.7 4.7 35.4 17.3 597.6 1.3 1.0 497.1 69.8 0.9 1.0

Individualad lib

Ross

= 20).

8-day-old

+ SEM (n

7 and

- means

group-reared

deprivation

P values are derived from individual and pair-tested (x) = means derived after

Lying (s) Eye closure (s) Peep latency (s) Latency to feed Feeding (s) Defaecation (no) Peeps (no) Steps (no) Pecks (no) Jumps (no) Preens (no)

food

responses

Latency to first step (s) Freezing (s) Sitting (s)

lib

Open-field

Table

(no)

refer

3.7 13.7 31.2 11.7 0.2 47.2 9.5 0.7 0.5 0.1

47.9 12.5 39.2

in

N.S.

comparisons

43.4 1.6 25.1 2.7 3.0 9.6 373.3 109.6 0.3 198.5 96.8 24.2 0.1 0.6

+ + 5 7 T 5 5 5 5 5 5 5 5 5

(x)

= not

P

significant.

CO.002 <0.02 N.S. N.S. <0.05 <0.05 N.S. CO.05 N.S. CO.02 <0.002 CO.002 N.S. <0.002

following

between

9.4 1.0 11.8 2.7 2.0 1.7 52.1 25.8 0.1 32.4 10.0 10.1 0.1 0.1

pairs

Deprived

Paired-

or

= number;

to

individuaily

ad

1.9 0.1

0.7 214.5 76.4

331.3 41.1 142.7 53.9 94.3 108.7 600.0

+ 46.2 T 7.2 5 25.9 7 19.0 5 20.5 5 31.8 5 0.0 0 + 0.2 5 36.1 7 21.1 ii + 1.1 5 0.1 160.6 8.3 123.8 34.9 60.5 30.9 556.9 17.5 0.4 201.7 57.7 11.1 0.1 0.4

+ T 5 T T T T T T 5 7 5 T 5 -

20.7 2.4 21.3 10.2 13.8 7.0 18.3 7.8 0.1 16.3 18.4 7.8 0.1 0.1

Paired -ad lib (x)

<0.04 <0.0002 N.S. N.S. N.S. <0.004 N.S. N.S. N.S. N.S. N.S. <0.0004 N.S. N.S.

P

284.8 29.4 149.5 39.4 81.3 109.5 595.4 3.7 0.4 225.4 56.9 0.3 1.7 + 5 5 T 5 T T 5 T 5 T 5 T 0

42.1 5.9 31.8 15.3 20.8 35.8 4.6 3.7 0.1 35.7 14.9 0.3 0.7

Individual deprived

200.5 14.9 110.2 29.8 32.2 60.9 512.8 63.7 0.2 151.0 46.4 1.7 0.1 0.1

+ T T T T 5 5 T 5 T 7 T 5 T -

Paired deprived

33.7 4.9 25.2 11.2 8.5 17.2 26.1 18.6 0.1 20.9 9.4 0.7 0.1 0.1

(x)

N.S. <0.02 N.S. N.S. N.S. N.S. <0.04 CO.04 N.S. N.S. N.S.
P

or in pairs following ad

P values are derived from analysis by the Mann-Whitney U test (two-tailed) and refer to comparisons between individual and pair-tested birds under each feeding regime. (x) = means derived after summing the mean scores of each pair; (s) = seconds; (no) = number; N.S. = not significant.

Latency to first step (s) Freezing (s) Sitting (s) Lying (s) Eye-closure (s) Peep latency (s) Latency to feed (s) Feeding (s) Defaecation (no) Peeps (no) Steps (no) Pecks (no) Jumps (no) Preens (no)

Individualad lib

Open-field responses of group-reared 7 and &day-old Ross White chicks tested individually lib feeding or food deprivation - means + SEM (n = 30).

Table II.

Significance Table

III.

levels

RW

of

chicks

strain

comparisons

generally

showed

peeps and pecks at the environment Table

in each

lower

situation

levels

of

are

activity

shown and

in

fewer

than RB birds.

III.

Significance levels of the differences between the open-field responses of 7- and 8-day-old Ross Brow" and Ross White chicks tested individually or in pairs following ad lib feeding or food deprivation.

Latency to first step Freezing Sitting Lying Eye closure Peep latency Latency to feed Feeding Defaecation Peeps steps Pecks Jumps Preens

Individual - ad lib

Paired ad lib

Individual - deprived

Paired deprived

<0.0002
<0.00006 CO.04 <0.0001 <0.006 <0.00006 N.S. N.S. N.S. N.S. N.S. <0.00006 N.S. N.S. N.S.

N.S. CO.02 N.S. N.S. N.S. N.S. N.S. N.S. N.S. CO.01 N.S. N.S. N.S. N.S.

<0.0002 <0.004 CO.01 N.S. <0.006 CO.02 N.S. N.S. N.S. N.S. <0.0004 <0.00006 N.S. <0.0002

P values are derived from analysis N.S. = not significant. Pair-tested (p
than

no

(p
RW

chicks

their

ad

significant

deprived lib

chicks

showed

of

food

counterparts

differences.

than those maintained

than their deprived

by the Mann-Whitney

defaecated

but

Deprived

the

a significantly

lower

significantly

more

individually-tested

RB pairs

on a" ad lib regime

counterparts.

U test (two-tailed).

birds

fed significantly

more

and ad lib, individually-

(p
latency

to the first step

There were no other differences.

JCXPERIMENT 2 I¶ethods

A number selected The

of

and

RB

and

tested

apparatus

RW

of

by a wooden

uncovered

by a guillotine

was

cover whereas

placed

in

individually

birds

to

door.

the other separate,

period the

two

partition

or in pairs

acclimatisation the

a

used

in the

in a hole-in-the-wall

consisted

separated

wooden

chicks

300 x

box

200 mm

containing

lighted

and

latency

300 mm

deep

that could

be

the start box, had an opaque

chicks

lid.

The apparatus placed

were

either

the lid was closed and a 2 min

the door was raised to peep

randomly

at 9 d of age.

compartments

had a wire-mesh

in the dark start box,

The

1979)

were

a 100 x 100 mm hole

room

before

experiment

(Jones,

wooden

One compartment, compartment

was allowed

light.

first

(distress

thereby

call)

was

exposing measured

317 before

and after the door was raised. a maximum

was raised,

peeping within

If no peeping

latency of 120 s was afforded

5 min of raising

the door resulted

occurred

before

the door

whereas

the absence

in maximum

latencies

of of

300 s being scored. Comparisons

of lines and paired versus

using the Mann-Whitney

individually-tested

chicks were made

U test (two-tailed).

Results

They are shown in Table significantly tested

sooner

before

individually.

(p
IV.

chicks of both

and after the door was raised

Similarly,

in every situation) Table

Pair-tested

RB

lines peeped than did those

chicks peeped significantly

sooner

than did the RW birds.

IV.

The latencies to peep shown by individually- and pair-tested birds of two strains in a hole-in-the-wall box (means + SEM) Peep latency (s) Door closed Door open Ross Brown Individual (n = 15) Paired (n = 15)

43.7 + 8.0 16.3 5 - 3.0

179.8 + 47.9 28.9 5 6.7

Ross White Individual (n = 20) Paired (n = 20)

94.8 + 8.4 ** 44.5 5 8.4

416.8 + 53.1 * 187.1 5 - 50.9

*

*p
3

ne thods Thirty line

newly-hatched

(derived

allowing either

340

x

individual

rearing

individually

or

by hardboard 170

x

300

on the floors, the

thus in visual At

7

previously

d

of

birds

Food

was provided

age

described

each and

jumping

hatch.

housing

its

The

were

chicks

and

water

were

by dull-emitter out.

The

tested

responses

were

consisted

own

used

were

'T' thus

housed

of wooden

each measuring

types of rearing

was

Centre's

cross)

one of 8 and one of 7, in the wooden

but not auditory chick

Research

Sussex

into four compartments

Both

from

Light

Individual

deep.

and tactile,

x

from

in two groups,

hoppers.

warmth

of the Poultry

Red

virtually

described. walls

mm

70 x 50 mm plastic

prevented

Island

a Rhode

home boxes previously divided

female chicks

from

provided

in semi-circular

box contained heaters

boxes

approximately

wood

litter

and wire-mesh

individually-housed

lids

chicks

were

open

field

isolation. individually recorded

in

over

the

a 10 min

period.

318 Fifteen

individually-reared

results

were

and

analysed

using

the

Table

V.

15

group-reared

Mann-Whitney

chicks

U test

were

tested

and

the

(two-tailed).

Results They sooner

are and

shown

counterparts. and

in

pecked

There

peep

Birds

significantly

latency

were

scores

individually-reared

reared

more also and

at

individually

the

non-significant higher

walked

environment

activity,

than

significantly

their

trends

towards

(walking

and

group-reared lower

freezing

jumping),

in

the

birds.

Table

V.

Open-field responses of 7 day-old tested (GR - IT) and individually (IR - IT) ‘T’ line chicks (means GR Latency to first step Freezing (s) Sitting (s) Peep latency Peeps (no) steps (no) Pecks (no) Jumps (no) preens (no)

(s)

IT

129.4 3.3 32.5 19.9 755.9 214.2 0.9 7.1 0.9

(s)

P values were derived (two-tailed) N.S. = not significant;

group-reared - individually reared - individually tested + SEMI (n = 15).

+ 5 5 5 5 5 5 5 7 -

from

IR -

40.4 1.0 20.9 9.6 61.5 30.9 0.6 2.2 0.6

38.8 0.8 12.4 4.3 731.6 302.4 10.6 20.5 1.4

analysis

(s)

by

= seconds;

IT

+ 5 5 T 5 5 5 + 5 _

P

10.5 0.4 11.4 1.0 73.4 48.1 3.8 8.3 0.5


the

Man-Whitney

U test

(no)

= number.

4

EXPERIMENT He thods Eighteen further

newly-hatched 18

were

identical

to

The

chicks

Each

chick

placed

on

and

restrained, observer

first

left

not

on one

nearby

(TI)

a

hand

lasting

scanning

on

its

at

of

was

not

attained

to

be

susceptible

and the

TI,

body

least

i.e.

and

rearing

10

duration

one

boxes

5 of of

0 TI.

s

the

chick

were If

the

of

a

were

the

righted

bird

15

ions

first

head

postural

itself, the for

showed

s.

induct

or

attempts

was

cloth,

for

till

reflexive

age. It

head, of

afforded

d of

black

number

latency

successive

12 room.

layers

than the

at

separate

The

the

rather until

a

over

bird. s,

examined

in several

and

the

after scores

only with

of

movements

duration

and

individually

The

wet-e

once

covered

sight

TI

movement

housed

nine.

reactions and

table

within

TI

were

of

described.

If

head

females groups

individually

side

attain

the

two

immobility

tested

with

and

measured.

the

tonic

(alert,

changes)

line

in

previously

sat to

movement,

deemed

’

its

The

necessary

those

was

‘T’

reared

were bird

was

latency

to

no

head

319 movements 600

s

and

were

remained

in

allotted

TI

for

individually-reared

chicks

Mann-Whitney

U test

over

the

latency

10 min

and

were

testing

duration.

tested

and

period

maximum

Eighteen

the

results

scores

group-reared

were

of

and

compared

using

18 the

(two-tailed).

Results They

are

attain

shown

TI

first

in

head

Table

movement

group-reared the

in

birds

ceiling

VI.

individually-

of

Table

and than

600

Significantly

than the in

in

more

graup-reared

duration

those

of

reared

TI

inductions

were

chicks. were

The

required

latency

significantly

individually.

Only

to

to

the

longer one

bird

in

reached

s.

VI.

Tonic immobility responses individually tested (GR individually tested (IR (n = 18)

of IT) IT)

GR Inductions (no) Latency to first head movement (s) Tonic immobility (s) P values were (two-tailed).

1.7

12-day-old group and individually ‘T’ line chicks

IT -+

IR 0.3

3.2

+ 4.1 7 - 39.3

12.5 54.7

derived from analysis (no) = number; (s)

by the = seconds.

19.7 156.7

reared reared (means

+ SEMI

IT -+

P 0.4

<0.02

+ 7.1 -5 16.2

<0.02 <0.05

Mann-Whitney

U test

DISCUSS IOll Gallup

and

Suarez

interpretation, compromise and

to

al.

between

minimize

(1982)

startling using to

the

proposed

consistent

(1965)

Long

durations

levels

of

elevated

froze

less,

an

are

of

freezing, and of

Jones, vocalised than

to

possible

the

did

fear 1977a; and those

of

open

with

the

findings

fear long

pecking (Candland 1978). ambulated tested

on

to

by

to

the

Nagy,

sooner individually.

1969;

preened This

and/or

interpreted do

not

Gallup

conform

and

Suarez, however,

are,

inhibitory

vocalise

birds and

et

hypothesis.

environment

Pair-tested

a

Faure

novel

They

a progressively

latencies

and

fear

hand,

results

reported

the

exerts

at

present

as

conspecifics

adequately

differences.

based

that

other fowl

be

emotionality

regarded with

On the

can The

an

be

contact

domestic

field,

methodological

to can

reinstate

hypothesis.

or

contrary

chickens

predators.

responses the

interpretation

concluded

levels

field

made,

preening

1975;

tendencies

emotionality

there

with

Hogan

open

or

though

in

by that

that,

behaviour

including

predictions

(1980)

Faure,

detection

fear

proposed

ie Id

opposing

stimuli, the

(1980)

open-f

and have

been

Hughes of

and

and

equated

and

both

finding

effect.

ambulate

Black,

lines

pecked suggests

low with

1974;

generally more

in that

the the

presence

of

familiar

proposition companions stimuli

in

birds

rather Gallup,

behavioural (Rowe11

proposed

than

reduced

fear in

1977b).

presence

and

than

in

reduction that

of

greater

the

Feeding

only

Kiely,

a

bird

is

are

open

The

chicks

fed

field in

of

an

in

and

than

trios,

trios

it

Suarez has

been

inanimate

cues

by

Abel,

chicks

1971;

the

Jones,

environment

this

in

effect

Collins,

to

(1971)

possibly

twittered,

lib

a

found

reflecting

walked

Gallup fear-potentiated

fear.

and

pecked

in the

which

Gallup,

Williamson

food it

than

deprivation

would

seem

a hungry

found

as

a

means

in

a novel

for and

but

were

behaviour

are

changes

in

in

not tonic

naive

varying

a sated

of

parallels

findings

of

the

pair

food

19771,

maladaptive

one

each

of

no

(Gallup,

paired

facilitation

open-field

These

report

that

of

deprived

were

a companion

birds

scores

1980). (1972)

the

if

paired

the

were

birds

with

Social

mean

and

(Brown

evidence

the

and

1978)

when

feeding

individually.

phenomenon

using

study

further

between

and

Murphy, fearfulness

together

provides

those

1975;

cease

occurred

increases

with

present

finding,

because

and

and

Indeed,

fearful

the

tested

have

situation

al.,

will

differences

a

to

those

regime

because

or less,

19781,

(Suarez

when

in This

underestimated

ducklings

chicks

Chen,

test

et

environment

consistent

ad

the

correlated

pairs.

may

immobility, habituated

enhanced

than

been

lack on

was

1964)

unexpected

unrelated

1980;

because

at

attributed

Rajecki

negatively

in

fearful

have

found

more,

pecking

higher

group-tested

environment

she

with

be

a novel and

(Tolman,

may

used,

the

1968;

to

(Blosch

less

feeding

that

(Wilson,

placed

removed

results

but

The for

Suarez,

and

Harless more

familiarity

Feeding

the

chick

chicks

peeped

when

considered

1974). to

that

occurs

is

exposed

more and

the

Hogan

social

fear-inducing

familiar

at

1965;

familiarity.

tendencies,

or

pecking

reported

individually

decreases

rate

and

birds

through

and

surprising

This

of

1981).

reported

(Gallup

fear.

to

al.,

latencies

(Tolman,

(1978)

et

companions

activity

reduce presence

environment.

fearfulness peck

social

to the

reactivity

Vogt

somewhat

individually-tested

tested

1963;

fact,

of

served that

adrenocorticoid

individually

in

Brown

field

reports

ambulation

situations

reinstatement at

and

increased

arousal

chicks

of

the

open

from

Hinde,

tested

were,

Similarly,

pairs

and

those

unfamiliar

the

and and

call)

1980)

that

in

support

monkeys (distress

and

more

indirect

reduced

vocalisation

placed

companions

gains

animal

potentially

or

arousal to

be

dangerous

situation. The cage

open

though

f ie Id it

considered

desirable

field

home

obscuring

and

fine

used

still

in

the

present

constituted because

cage differences

may

a induce in

study

a novel high

degree

high

behaviour

was

relatively

environment

levels between

of

similar

(see

discrepency of groups

fear

between and

of

to

Methods).

birds

the This the

inhibition which

home was open thus

would

be

321 apparent

low

at

seems

pertinent

novelty

value

Ross and which

be

an

of is

Gallup

and

peeped

sooner

in

often

with

the

to

for

localized

by that

ambulation

Birds at

literature

hours

and

latency

the

(Fujita fear

and

by

Gallup

hatch

in

of

peeping can

1973;

results,

and

1971;

Murphy

The

two-day

and

Suarez

(1980)

the

present

and

of

contrasts

study

and

significantly towards

1974;

others

lower Given

social

increased Faure,

are

in

the

consistent

isolation isolation

partly

1975;

reported

1978),

with

may

adaptive animal.

reflect

al.,

Wood-Gush,

period

to

counterparts.

silence et

easily

difficult

the

trends

with

are

is

pecked

group-reared

for other

stimulation

considered to

that

functionally

notes it

be

sooner,

Ginsburg

be

alarming

attention

together

argued

On the

would

pairs

peeping

environment

alarm

and

the

the

1978)

inactivity

in

is

statement.

should

their

Jones, chicks

elicit

(1980)

with

draw

;

individually

of

“it

confronted

because

1975

size

non-significant

showed

al.,

may

reinstatement

pair-tested

testing this

Shalter,

Hara,

interpretation.

used after

et

present

of

1977),

However,

Suarez

that

would

over

tested

group

significantly

freezing,

environment,

(Faux-e,

those

ambulation

than

when

fearfulness

Duncan,

that

High-pitched

both

scores

fear

for

when

to

walked

of

means

1968;

because

(Montevecchi 1977a),

a

not

environment peep

loudly

to

and

evidence

predation”.

prior

is

a

novelty.

in

speculated

(Boudreau,

levels

fearfulness

testing

call of

individually

the and

Jones,

(1973)

vocalisation

elevated

with

to

reared

freezing that

chicks

predators

accept

more

al.

no

novel

and

occurrence

Gallup is

provide

a

results,

(1978)

Elevated

to

than

The

1977).

to

finding

reduction

ambulation

threat

whereas

al

et

possible

related present

interpretation.

et

Wood-Gush

silence

These

predominated

exposed

box

a mere

also their

study.

inversely the

and

(Murphy

evasion

were

19801,

they

Montevecchi

present

and

birds.

line.

hybrids

and

inactivity

Brown

hybrids

White

predator

chicks

because

but

medium

hole-in-the-wall

fear

prior cues

maladaptive or

a

Murphy

Ross

light

the

if

Suarez,

(Gaioni

vocalisation predatory

in

considered

the

the

in

factor

unexpected

ducklings

hand,

prevalent

by

It

used

1979).

of

Ross

1982).

field

Black,

levels

did

Faure,

open

and

higher

than

and

in

of

(Jones

light

group-reared

1977a;

in

of

and

types

reported

be retarded

peeping

not

those

(Jones

the

showed

fearfulness

important

consistent

that

environment

to

should

pairs

was

the

often

levels

considerably

reaction

,

beings

fear

generally

at

the

Peeping when

varied

greater

human also

emphasise

similar

comparing indicate

to

chicks

pecks

are

moderate

have

White

fewer

to

prior from

explain

the

to

a

few

above

disagreement. Chicks of

tonic

group-reared

reared immobility,

individually in

counterparts.

were

less

fear-potentiated The

present

susceptible phenomenon finding,

and

showed

(Gallup, together

lower 1977),

with

durations than

Salzen’s

their (1963)

322 of

report

lower

consistent reduced

by

It

be

predatory

effect

though

subsequent

hand

into

to

human

novelty

the

case

only

and

domestic

chicks

1980)

species

generality

present

study,

be

to

due

least

rats

those

by

for by

type

ages

at

of

Suarez In can

but

Suarez

apparatus housing

differed.

may

studies

more intrinsic

also

make

the

ducklings

results

and

of

were

were

interpretation

of

the

unlikely

to

account,

at

younger

than rather

contact

and

durations

of

of

versus

social

such

generality

such

directly

the

and

of

those

experimenter in

not

(Suarez

is

observed

of

the

was

fits

view

may

chicks

However,

measure

expect

presumably

behaviour

In

Variations

difficult.

a

exposure

would

and,

literature,

degree

is of

This

1981b).

the

they

the

one

value

present

(19801, and

and

attendant

pre-test

differences

The

remained

isolation

effect.

also

their in

received

1982).

Gallup,

reported

the

slight

chicks

the

If

little

a

introduction

fear

open-field

Methodological

and

an

of

1980)

disagreement.

to as

Faure,

between

others

s)

may

in

chicks

before

novelty

and

and

disagreement

field

and

methodological

of

the

Gallup

and

model. cone lus ion,

be

made

the

from

the

present Gallup

predator

domestic The

the

evidence chicks two

to

undoubtedly,

that

fear

novel

plays and/or should

inconsistent

model

but

consistent

while

are,

interpretations

are

Suarez are

Thus,

literature.

evasion

results and

they

Furthermore, in

considerable

field.

Suarez,

30

have

model

(Suarez

television

provide

reported

of

and

Gallup

differential

hypothesis.

and

(Gallup

this

isolation-rearing differences

their

with

hours

influencing

differing

that

circuit

open

be

study

be

The

withdrawal.

to

(Jones

differences.

closed

the

of used

mice

group-housed

particularly

factor

present

indeed

contact.

elicited

claimed

together

tested

than

fields

the

strain

partly,

are would

reduction

may

several

environment

were

and

and

imprinting

main

test

open

Suarez

Gallup,

the

the

There

for

the

consequent

experimenter

always

properties

Gallup

individually distress

in

a

(approximately

in

indeed

when

fear-eliciting

of

exposure

result

of

with

incubator

virtually

was

individually

individually-

the

daily to

cage

beings

increased not

short

the

reared

separation

testing.

both

in

unlikely

housed

attendants

amounts

companions

considered

chicks

because

open-field

equivalent

their

birds

their of

familiarity

with

that

onto

overtones

approximately

in

interpretation

rearing.

argued

imprinted

susceptibility

fear

a

individual

could

become

the

response

with

the

with

a major startling be

predictions conform

majority

tendencies in

role

do the

opposing

important

not

with

they

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323

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a review. Archer, J., 1973. Tests for emotionality in rats and mice: Anim. Behav., 21: 205-235. Archer, J., 1979. Behavioural aspects of fear. I": W .Sluckin (Editor), Fear in Animals and Man. Van Nostrand Reinhold Co., New York, NY, pp. 56-85. Blosch, vo" M. and Chen, S-CH., 1978. Die Beeinflussung der Stimmungsubertragung bei Huhnerkuken durch neurotrope Substanzen. Arnzeim Forsch., 28: 1511-1512. Boudreau, G.W., 1968. Alarm sounds and responses of birds and their application in controlling problem species. Living Bird, 7: 27-46. Brow", C.P., 1978. Social facilitation of pecking following differential rearing. Anim. Learn. Behav., 6: 94-97. Brown, C.P. and Kiely, P.C., 1974. The role of early experience and emotionality in social facilitation of pecking in chickens. Anim. Behav., 22: 100-109. Candland, D.K., 1971. The ontogeny of emotional behavior. I": H. Molts (Editor), Ontogeny of Vertebrate Behavior. Academic Press, Inc., New York, NY. pp. 95-169. Candland, D.K. and Nagy, Z.M., 1969. The open field: some comparative data. Ann. N.Y. Acad. Sci., 159: 831-851. Clayton, D.A. and Andrew, R.J., 1979. Phases of inhibition and response during investigation of stimulus change by the domestic chick. Behaviour, 69: 36-56. Collias, N.E., 1952. The development of social behavior in birds. Auk, 69: 127-159. Faure, J.M., 1975. Etude des liaisons entre comportements en open-field et Ann. Genet. Sel. Anim., 7: 197-204. emotivite chez le jeune poussin. Faure, J.M., Jones, R.B. and Bessei, W., 1982. Fear and social motivation as factors in open-field behaviour of the domestic chick: A theoretical consideration. in press. Biol Behav.Fujita, 0. and Hara, M., 1971. Effects of early rearing conditions and age upon open-field behaviour in chicks. Annu. Anim. Psychol., 21: 31-42. Gaioni, S.J., Hoffman, H.S., Klein, S.H. and De Paula, P., 1977. Distress calling as a function of group size in newly hatched ducklings. J. exp. Psychol. Anim. Behav. Proc., 3: 335-342. Gallup, G.G. Jr., 1977. Tonic immobility: The role of fear and predation. Psychol. Rec., 27: 41-61. Gallup, G.G. Jr. and Suarez, S.D., 1980. An ethological analysis of open-field behaviour in chickens. Anim. Behav., 28: 368-378. Gallup, G.G. Jr. and Williamson, G.T., 1972. Effect of food deprivation and a visual cliff on tonic immobility. Psychon. Sci., 29: 301-302. Ginsburg, H.J., Braud, W.G. and Taylor, R.D., 1974. Inhibition of distress vocalization in the open field as a function of heightened fear or arousal Anim. Behav., 22: 745-749. in domestic fowl (Gallus gallus). Weidenfeld and Gray, J.A., 1971. The Psychology of Fear and Stress. Nicolson, London. 256 pp. in male and female rodents: A reply to Gray, J.A., 1979. Emotionality Archer. Br. J. Psychol., 70: 425-440. Harless, M.D. and Collins, T.B., 1971. Open-field behavior in isolate and Psychol. Rep., 29: 787-790. trio chicks of two age groups. Hogan, J.A., 1965. An experimental study of conflict and fear: an analysis of behaviour of young chicks towards a mealworm. Part 1. The behaviour of chicks which do not eat the mealworm. Behaviour, 25-26: 45-95.

324 Hogan, J.A. and Abel, E.L., 1971. Effect of social factors on response to unfamiliar environments in Gallus gallus spadiceus. Anim. Behav., 19: 687-694. Hughes, B.O. and Black, A.J., 1974. The effect of environmental factors on activity, selected behaviour patterns and "fear" of fowls in cages and pens. Br. Poult. Sci., 15: 375-380. Ivinskis, I., 1970. A study of the validity of open-field measures. Aust. J. Psychol., 22: 175-184. Jones, R.B., 1977a. Repeated exposure of the domestic chick to a novel environment: effects on behavioural responses. Behav. Processes, 21: 163-173. Jones, R.B., 1977b. Open-field responses of domestic chicks in the presence or absence of familiar cues. Behav. Processes, 2: 315-323. Jones, R.B., 1977~. Sex and strain differences in the open-field responses of the domestic chick. Appl. Anim. Ethol., 3: 255-261. Jones, R.B., 1978. Activities of chicks in their home cages and in an open field. Br. Poult. Sci., 19: 725-730. Jones, R.B., 1979. The hole-in-the-wall test: its validity as a measure of the 'timidity' aspect of fear in the domestic chick. IRCS Med. Sci., 7: 167. Jones, R.B., 1980. Responses of male and female domestic chicks to a startling stimulus and the effects of a tranquilliser. Behav. Processes, 5: 161-172. Jones, R.B. and Black, A.J., 1979. The behaviour of domestic chicks in their home cages and in an open field: substrate effects. IRCS Med. Sci., 7: 619. Jones, R.B. and Black, A.J., 1980. Feeding behaviour of domestic chicks in a novel environment: effects of food deprivation and sex. Behav. Processes, 5: 173-183. Jones, R.B., Duncan, I.J.H. and Hughes, B.O., 1981. The assessment of fear in Behav. Processes, 6: domestic hens exposed to a looming human stimulus. 121-133. Sex effects on open-field behaviour in Jones, R.B. and Faure, J.M., 1981a. Biol. Behav., 6: 265-272. the domestic chick as a function of age. Jones, R.B. and Faure, J.M., 1981b. Sex and strain comparisons of tonic immobility ("righting time") in the domestic fowl and the effects of Behav. Processes, 6: 47-55. various methods of induction. Jones, R.B. and Faux-e, J.M., 1982. Open-field behaviour of male and female domestic chicks as a function of housing conditions, test situations and Biol. Behav., 7: 17-25. novelty. Montevecchi, W.A., Gallup, G.G. Jr. and Dunlap, W.P., 1973. The peep vocalization in group reared chicks (Gallus domesticus): its relation to fear. Anim. Behav., 21: 116-123. Murphy, L.B., 1978. The practical problems of recognizing and measuring fear and exploration behaviour in the domestic fowl. Anim. Behav., 26: 422-431. Murphy > L.B. and Duncan, I.J.H., 1977. Attempts to modify the responses of 1. The association of human contact domestic fowl towards human beings. with a food reward. Appl. Anim. Ethol. 3: 321-334. Murphy, L.B. and Wood-Gush, D.G.M., 1978. The interpretation of the behaviour Biol. Behav., 3: 39-61. of domestic fowl in strange environments. Nash, R.F. and Gallup, G.G. Jr., 1976. Habituation and tonic immobility in J. Comp. Physiol. Psychol., 90: 870-876. chickens: strain comparisons. Rajecki, D.W., Kidd, R.F., Wilder, D.A. and Jaeger, J., 1975. Social factors in the facilitation of feeding in chickens: effects of imitation, arousal, or disinhibition? J. Pers. Sot. Psychol., 32: 510-518. In: J.E. Gordon Ratner, S.C., 1967. Comparative aspects of hypnosis. Macmillan, New (Editor), Handbook in Clinical and Experimental Hypnosis. York, NY., pp. 550-587. Rowell, T. and Hinde, R.A., 1963. Responses of rhesus monkeys to mildly Anim. Behav., 11: 235-243. stressful situations.

325 Royce, J.R., 1977. On the construct validity of open-field measures. Psychol. Bull., 84: 1098-1106. Salzen, E.A., 1963. Imprinting and the immobility reactions of domestic fowl. Anim. Behav., 11: 66-71. Salzen, E.A., 1979. The ontogeny of fear in animals. In: W. Sluckin, (Editor). Fear in Animals and Man. New York, Van Nostrand Reinhold Co., pp.125-163. Shalter, M.D., 1978. Localization of passerine seet and mobbing calls by goshawks and pygmy owls. Z. Tierpsychol., 46: 260-267. Suarez, S.D. and Gallup, G.G. Jr., 1980. An ethological analysis of open-field behaviour in ducks Anas platyrhynchos. Bird Behav., 2: 93-105. Suarez, S.D. and Gallup, G.G. Jr., 198la. Predatory overtones of open-field testing in chickens. Anim. Learn. Behav., 9: 153-163. Suarez, S.D. and Gallup, G.G. Jr., 1981b. An ethological analysis of open-field behaviour in rats and mice. Learn Motiv., 12: 342-363. Thompson, R.K.R., Foltin, R.W., Boylan, R.J., Sweet, A., Graves, C.A. and Lowitz, C.E., 1981. Tonic immobility in Japanese quail can reduce the probability of sustained attack by cats. Anim. Learn. Behav., 9: 145-149. Tolman, C.W., 1964. Social facilitation of feeding behaviour in the domestic chick. Anim. Behav., 12: 245-251. Tolman, C.W., 1965. Emotional behaviour and social facilitation of feeding in domestic chicks. Anim. Behav., 13: 493-502. Vogt, J.L., Coe, C.L. and Levine, S., 1981. Behavioural and adrenocortocoid responsiveness of squirrel monkeys to a live snake: is flight necessarily stressful? Behav. Neural Biol., 32: 391-405. Walsh, R.N. and Cummings, R.A., 1976. The open-field test: a critical review. Psychol. Bull., 83: 482-504. Wilson, G.F., 1968. Early experience and facilitation of feeding in domestic chicks. J. Camp. Physiol. Psychol., 66: 800-802.