Embed Size (px)
Citation preview
Warm up game: 1st example:
Time (s)
Fre
qu
en
cy (
kH
z)
0 10
0
1
Warm up game: 2nd example:
Time (s)
Fre
qu
en
cy (
kH
z)
0 4
0
5
Warm up game: 3rd example:
Time (s)
Fre
qu
en
cy (
kH
z)
0 4
0
5
From bird song to pig squeals: animal signals as a
window into animal welfare
Animal signals and communication, NOVA course January 2010
How do animals view their world?
Animal Welfare
Affective states
Basic health &
functioningNatural living
Vocalizations and Welfare Assessment
1) Indicators of functional states (e.g. calf
response to separation):
- Theory, validation, application
Vocalizations and Welfare Assessment
1) Indicators of functional states (e.g. calf
response to separation):
- Theory, validation, application
2) Indicators of subjective states
(e.g. piglet response to
castration):
- Theory, validation, application
Do signals reflect the animal's state?
“begging” calls
“distress” calls
“alarm” calls
Signals can be uninformative or
misinformative:
- Absence of signal
e.g. calling in response to pain, predator
- Presence of signal
e.g. food calls, alarm calls
Honest signalling: Type I
Signalling quality: condition and
signalling positively correlated
- Signalling entails a cost
- High quality individuals pay a
lower cost to produce a given
signal
Honest signalling: Type I
Signalling quality: condition and
signalling positively correlated
- Signalling entails a cost
- High quality individuals pay a
lower cost to produce a given
signal
Honest signalling: Type II
Signalling need: need and signalling positively
correlated
- Listeners derive a benefit by responding
- Signallers vary in need for the response
- Signalling entails a cost
e.g. calling by dairy calves?
Time (ms)
Fre
qu
en
cy
(k
Hz)
Calf vocal response to separation
0
5
10
15
Peak HR Ear mvmt Head mvmt
Noise
CallChange
Marchant et al., 2000
Cow response to calf calls
Time (ms)
Fre
qu
en
cy (
kH
z)
Cow vocal response to separation
Peak HR Ear mvmt Head mvmt
Noise
CallChange
Marchant et al., 2000
0
5
10
Calf response to cow calls
0
5
10
15
Peak HR Ear mvmt Head mvmt
Other
Mother
Marchant et al., 2000
Change
Calf response to cow calls
Late separation results in improved
weight gains for calves
40
50
60
70
kg
1 14 28
Calf age (days)
Body weight
Separation at 1 day
Separation at 14 days
0
Flower & Weary, 2001: AABS 70, 275-284
Calves drink more milk when given
the chance
0
2
4
6
8
10
12
kg / d
0 7 14 21 28 35Calf age (days)
Milk consumed
Ad libConventional
0
50
100
150
Min / d
Ad libitum 4 L / d
Time in feeder
0
10
20
30
40
No.
Ad libitum 4 L / d
Visits to feeder
Unrewarded
Rewarded
De Paula Vieira et al., 2008
Thomas et al., 2001: AABS 74, 165-173
0
2
4
6
8
10Calls / 4 h
Time of day (4-h intervals)
Control
10 -14
14 -18
18 -22
22 -02
02 -06
06 -10
Vocal response
peaks many
hours after
separation
0
2
4
6
8
10
Time of day (4-h intervals)
Extra milk
Control
10 -14
14 -18
18 -22
22 -02
02 -06
06 -10
Thomas et al., 2001: AABS 74, 165-173
Calls / 4 h
This vocal response
is virtually eliminated
when feeding more
milk
Listeners derive benefit by response 4
Signallers vary in need for response4
Signalling entails a cost ?
Signallers in greater need signal more4
Calf vocal response to separation
Warm up game: 3rd example:
Time (s)
Fre
qu
en
cy (
kH
z)
0 15
0
1
Sow response to piglet calls
Moves/minCalls/min Time (s)
0
6
12
B D A0
10
20
B D A0
3
6
B D A
Sow response to piglet calls
0
4
8Moves/min
D A0
10
20Calls/min
D A
LowHigh
0
25
50Time (s)
D A
Vocalizations and Welfare Assessment
1) Indicators of functional states (e.g. calf
response to separation)
2) Indicators of subjective states
(e.g. piglet response to castration)
Evaluating emotions like pain in animals is
one of the most important challenges in
animal welfare science
“Because subjective phenomena cannot
be observed objectively in animals, it is idle
to claim or deny their existence”
Tinbergen, 1951, p. 4
“develop and implement a definition of pain
that applies not only to those individuals
whose communicative skills conform to the
expectations and capabilities of the
investigators”
Anand & Craig (1996, pg. 5)
Pain assessment in non-verbal patients
“Since subjective experiences are known
only to those experiencing them, the only
way we can infer their existence in any other
being, human or non-human, is by
analogy….”
Dawkins, 1990, p. 4
Concepts - the argument by analogy
Evidence:
Neuroanatomy
Neuropharmacology
Behaviour
0
2
4kHz
Lido. Contr.White et al., 1995
Concepts - the argument by analogy
Piglet calls during castration
0
50
100
150
200
250
Obs.
0 1000 2000 3000 4000 5000 6000 7000 8000
Frequency (Hz)
Bimodal distribution with
separation at 1000 Hz
Weary et al., 1998: AABS 56, 161-172
Call rate increases during castration - but
only for calls > 1000 Hz
0.0
0.4
0.8
1.2
Calls < 1 kHz
Control Cast.0.0
0.4
0.8
1.2
Calls > 1 kHz
Control Cast.
Calls / s
Taylor & Weary, 2000: AABS 70, 17-26
0
0.2
0.4
0.6
0.8
1
1 2 3 4 5 6
Stage
Hig
h c
all
s (
ca
lls
/s)
Taylor & Weary, 2000: AABS 70, 17-26
Effect of procedure?
0
0.2
0.4
0.6
0.8
1
1 2 3 4 5 6
Hig
h c
alls (
calls/s
)
Taylor & Weary, 2000: AABS 70, 17-26
Stage
Effect of procedure?
0
0.2
0.4
0.6
0.8
1
1 2 3 4 5 6
Piglets respond most to pulling and cutting of the
spermatic cords, regardless of stage
Hig
h c
alls (
calls/s
)
Taylor & Weary, 2000: AABS 70, 17-26
Stage
Evidence for analogy 4
Understanding the signalling system4
Link between signalling and pain4
Using calls to identify problems4
Piglet vocal response to pain
Use of signals in welfare assessment
is a three part process -
Theory: understanding the signalling system
and why the signals should relate to the state of
interest
Validation: establishing an empirical link
between the signal and the state
Application: using signals to improve conditions
for animals
CO2 euthanasia
Behavioral responses to CO2
0.0
2.0
4.0
6.0
8.0
-105 0 105
Time (s)
Nose to
lid (s /
period)
Air
Carbon dioxide
Niel & Weary, 2006
-5
0
5
10
15
Side changes Rears Escape
behaviours
Vocalizations
Change
from
baseline
Air
Carbon Dioxide
Behavioral responses to CO2
Niel & Weary, 2006
Behavioral responses to CO2
Niel & Weary, 2006
Question – positive welfare
Jaak Panksepp suggests that 50 kHz calls are
indicators of positive affective states in rats:
–What function does he propose for „laughter‟ in rats?
–What is the best evidence this signals positive affect?
–What signaling systems in farm animals (species,
situation, etc.) might be good candidates for study?
Questions – individual differences
•Grandin‟s paper shows that some presumably
aversive events (like electric prodding) result in low
rates of calling. Can we still use these vocal
responses when not every animal vocalizes? Is it
“illogical” to attribute these individual differences to
welfare, as Watts & Stookey suggest?
•How would you design a study (or conduct the
analysis) to account for these individual differences in
responsiveness?
•What individuals might be most suitable for using
vocal responses in welfare assessments?
Signalling illness
Questions – signals of health
•Can vocal (or other?) signals be used to assess
health in farm animals? Which examples are most
promising and why? In his review paper, Manteuffel
suggests that non-linearities in some vocalizations
might be good candidates for health assessments –
do you agree?
Budzynska et al., 2008; Appl. Anim. Behav. Sci. 112: 33–39.
0
50
100
150
200
Calls/calf/ hr
Day and time (h)
Control
Experimental
12 0 12 0 12 0 12 0
Day 0 Day 1 Day 2 Day 3
Questions – make fun of Dan
The paper by Budzynska & Weary uses changes in
vocal responses to assess the effects treatments
designed to improve welfare:
–What assumptions does this study rest upon?
–What are the functions of the calls (and who are they
directed to)?
–Are the conclusions justified?
