Behaviourat Processes, Elsevier GROOMING EVIDENCE
12 (1986) 227-236
227
IN THE VEERY AND THE AMERICAN FOR A SIMPLE TIMING HIERARCHY
KAREN K. HATCH,
LOUIS LEFEBVRE,
ROBIN:
and R.E. LEMON
Department of Biology, McGill University, 1205 a". Docteur Penfield, Montr&l H3A 1Bl Qui?bec (Canada) 7 August
(Accepted
1985)
ABSTRACT Hatch, K.K., Lefebvre, L., and Lemon, R.E. 1986. Grooming in the veer-y and the American robin: evidence for a simple timing hierarchy. Rehav. Processes 12: 227-236. Grooming behaviours in the veery (Catharus fuscescens) and the American robin (Turdus migratorius) cluster into four hierarchical groups based on function and anatomy: (1) non-preening, (2) upper body and wing preening, (3) lower body cleaning, and (4) tail preening in the veery; (1) non-preening, (2) body preening, (3) wing preening and (4) tail preening in the robin. The frequency distributions of the number of consecutive acts per cluster and the number of cluster visits per bout approximate geometric distributions in both species. These results provide evidence for the generality of the timing hierarchy model.
INTRODUCTION In a study of cricket grooming, sequential
structure
and the timing
in terms of hierarchical cluster
analysis
Teleogryllus grooming
(Wiepkema,
oceanicus
of events performed
equivalent
timing modeL
interruption behavioural
to
and
hierarchy
American
added
generality
of
birds:
migratorius,
for
the
of the hypothesis
test the validity the
Catharus
two members
cally, we evaluate
whether
geometric
of the
thrush
grooming
acts
and Young
from
random
controlling
the
1981). apply
this
of a more
family
of
species,
support
model
to
a
the
for the
level (preening)
to question.
and
hypothesis
complex
however,
timing
timing hierarchy fuscescens
for
the discrete
and Fagen results
systems
In kestrels,
is thus open
of the simple
veery
(1978)
since an extra hierarchical
posteriori
of the series
as well as the number
distribution,
the
to
behaviour
(Falco sparverius).
was unclear, a
attempted
to the grooming
kestrel
hypothesis
between
in
level categories:
The length
distribution
(but see also Getty, (1982)
form of
events
bout could then be accounted
Slater
of
type
a syntactic grooming
into two higher
on the geometric
competition
Joly
1976)
level category
exponential.
that both the
could be understood
Using
regions.
in a grooming
based
this
categories
Lefebvre
be
that
due
1976).
Dawkins,
each higher
of a negative
suggest
(1978)
1961;
and posterior
within
(1981) proposed
of this behaviour
(Dawkins,
could be regrouped
to the two regions
by a simple
timing
rules
in the anterior
of visits
Lefebvre
work.
had to The
In this paper, we
model on two other species the
American
(Turdidae).
in these species
robin More
Turdus specifi-
can be clustered
0376-6357/86/$03.50 0 1986 ElsevierSciencePublishersB.V. (BiomedicalDivision)
228
into
higher
level
acts per cluster
and
categories
and clusters
whether
the
frequency
per bout fit the geometric
distributions
of
model.
METHODS Four veeries and four robins were captured as nestlings near the Huntsman Marine Laboratory, St. Andrews N.B., and hand-reared at McGill University. They were kept in individual 76 x 51 x 104 cm cages, in natural lighting conditions and given ad libitum access to food, drinking water and a bathing dish. Observations on spontaneous grooming sequences performed in the home-cage were started at 9 mo of age for the veeries and 4.5 mo for the robins. Each veery was observed for 9 h and each robin for 15 h, in 1 to 2 h sessions, All birds were dry when observed, with a minimum of 1 h separating the beginning of an observation session from the end of a bathing episode. Grooming movements were recorded on a Datamyte 900 electronic event recorder. Time of occurrence, length of the pause between acts and first-order transitions (excluding auto-transitions) were calculated for each grooming category. A total of 3686 acts were recorded for the robins and 4081 for the veeries. Seventeen categories were used to describe grooming in robins and 18 in veeries, based on catalogues used in previous studies of birds (van Rhijn, and Joly, The 1977; Lefebvre 1982). categories common to both species include preening of the neck (NE), breast (IW), outer wing coverts (WC), (BR), back (BA), inside of the wing primaries from under the wing (PR), cloaca1 region from the front (CL), rump (RU) and tail (TA), nibbling of the foot and leg (LEG), beak and face wipe on a perch (BW), head scratch (SC), general shaking of the plumage (SH), upward stretching of both wings (DS), and lateral stretching of a involve stretching of the single wing (SS; this category may also ipsilateral leg). Categories specific to robins are preening of the lower layer of wing coverts (LC) and head shake (HSH), while the veery catalogue includes stretching upwards on both legs (LS), preening of the secondaries These of the wing (SE) and rapid flicking movements of the wing (FL). were defined following 7 h of preliminary species-typical categories observations; only characteristic movements which occurred often in one species were included in the species and not at all in the other In both species, the catalogues species-typical part of the catalogue. represent an exhaustive sample of all mutually exclusive, morphologically and functionally discrete categories of grooming activity observed.
RESULTS As a first step, bouts divided events the
into
hierarchical
separated
frequency
recorded
can
used
to
of
time
define
distributions
are shown in Fig.
distributions
are unimodal
combined
data
distributions
Since
the
bout
1 for robins out
with
all
are similar
4
birds
are
before series
or by alternative between
all
separation
of related behaviours,
grooming
acts These
and Fig. 2 for veeries. at around
Although of
they can be
criterion.
15 sec.
all acts separated
to be in the same bout. from
bouts
intervals
and flatten
can be used as the bout criterion, set considered
must be defined
from other series by pauses
distribution be
of grooming components.
each
by less than 15
Figs. 1 and 2 present species,
in all cases and can be lumped.
Both
This value
the
the
individual
229
ROBINS
3
12
6
15
15
21
24
INTERVAL
Fig. 1.
Frequency
distribution
2,
30
33
LENGTH
35
30
42
45
45
5,
54
57
SD+
(SECONDS)
of inter-act
interval
lengths
in robins.
VEERES
3
6
3
12
15
15
2,
24
INTERVAL
Fig. 2.
Frequency
distribution
27
30
LENGTH
33
36
32
42
45
48
51
54
57
ED+
(SECONDS)
of inter-act
interval
lengths in veeries.
230
step, first-order
As a second between
all acts occurring
veeries
provided
assessment
of
frequencies
from
transition
0.60
to 0.69
were
robins
the
the
of
Transition
yield
the
highest category
veeries
threshold
for
entry
very Joly,
=
be
correlated from When
frequencies
above,
p
12 (1986) 227-236
227
IN THE VEERY AND THE AMERICAN FOR A SIMPLE TIMING HIERARCHY
KAREN K. HATCH,
LOUIS LEFEBVRE,
ROBIN:
and R.E. LEMON
Department of Biology, McGill University, 1205 a". Docteur Penfield, Montr&l H3A 1Bl Qui?bec (Canada) 7 August
(Accepted
1985)
ABSTRACT Hatch, K.K., Lefebvre, L., and Lemon, R.E. 1986. Grooming in the veer-y and the American robin: evidence for a simple timing hierarchy. Rehav. Processes 12: 227-236. Grooming behaviours in the veery (Catharus fuscescens) and the American robin (Turdus migratorius) cluster into four hierarchical groups based on function and anatomy: (1) non-preening, (2) upper body and wing preening, (3) lower body cleaning, and (4) tail preening in the veery; (1) non-preening, (2) body preening, (3) wing preening and (4) tail preening in the robin. The frequency distributions of the number of consecutive acts per cluster and the number of cluster visits per bout approximate geometric distributions in both species. These results provide evidence for the generality of the timing hierarchy model.
INTRODUCTION In a study of cricket grooming, sequential
structure
and the timing
in terms of hierarchical cluster
analysis
Teleogryllus grooming
(Wiepkema,
oceanicus
of events performed
equivalent
timing modeL
interruption behavioural
to
and
hierarchy
American
added
generality
of
birds:
migratorius,
for
the
of the hypothesis
test the validity the
Catharus
two members
cally, we evaluate
whether
geometric
of the
thrush
grooming
acts
and Young
from
random
controlling
the
1981). apply
this
of a more
family
of
species,
support
model
to
a
the
for the
level (preening)
to question.
and
hypothesis
complex
however,
timing
timing hierarchy fuscescens
for
the discrete
and Fagen results
systems
In kestrels,
is thus open
of the simple
veery
(1978)
since an extra hierarchical
posteriori
of the series
as well as the number
distribution,
the
to
behaviour
(Falco sparverius).
was unclear, a
attempted
to the grooming
kestrel
hypothesis
between
in
level categories:
The length
distribution
(but see also Getty, (1982)
form of
events
bout could then be accounted
Slater
of
type
a syntactic grooming
into two higher
on the geometric
competition
Joly
1976)
level category
exponential.
that both the
could be understood
Using
regions.
in a grooming
based
this
categories
Lefebvre
be
that
due
1976).
Dawkins,
each higher
of a negative
suggest
(1978)
1961;
and posterior
within
(1981) proposed
of this behaviour
(Dawkins,
could be regrouped
to the two regions
by a simple
timing
rules
in the anterior
of visits
Lefebvre
work.
had to The
In this paper, we
model on two other species the
American
(Turdidae).
in these species
robin More
Turdus specifi-
can be clustered
0376-6357/86/$03.50 0 1986 ElsevierSciencePublishersB.V. (BiomedicalDivision)
228
into
higher
level
acts per cluster
and
categories
and clusters
whether
the
frequency
per bout fit the geometric
distributions
of
model.
METHODS Four veeries and four robins were captured as nestlings near the Huntsman Marine Laboratory, St. Andrews N.B., and hand-reared at McGill University. They were kept in individual 76 x 51 x 104 cm cages, in natural lighting conditions and given ad libitum access to food, drinking water and a bathing dish. Observations on spontaneous grooming sequences performed in the home-cage were started at 9 mo of age for the veeries and 4.5 mo for the robins. Each veery was observed for 9 h and each robin for 15 h, in 1 to 2 h sessions, All birds were dry when observed, with a minimum of 1 h separating the beginning of an observation session from the end of a bathing episode. Grooming movements were recorded on a Datamyte 900 electronic event recorder. Time of occurrence, length of the pause between acts and first-order transitions (excluding auto-transitions) were calculated for each grooming category. A total of 3686 acts were recorded for the robins and 4081 for the veeries. Seventeen categories were used to describe grooming in robins and 18 in veeries, based on catalogues used in previous studies of birds (van Rhijn, and Joly, The 1977; Lefebvre 1982). categories common to both species include preening of the neck (NE), breast (IW), outer wing coverts (WC), (BR), back (BA), inside of the wing primaries from under the wing (PR), cloaca1 region from the front (CL), rump (RU) and tail (TA), nibbling of the foot and leg (LEG), beak and face wipe on a perch (BW), head scratch (SC), general shaking of the plumage (SH), upward stretching of both wings (DS), and lateral stretching of a involve stretching of the single wing (SS; this category may also ipsilateral leg). Categories specific to robins are preening of the lower layer of wing coverts (LC) and head shake (HSH), while the veery catalogue includes stretching upwards on both legs (LS), preening of the secondaries These of the wing (SE) and rapid flicking movements of the wing (FL). were defined following 7 h of preliminary species-typical categories observations; only characteristic movements which occurred often in one species were included in the species and not at all in the other In both species, the catalogues species-typical part of the catalogue. represent an exhaustive sample of all mutually exclusive, morphologically and functionally discrete categories of grooming activity observed.
RESULTS As a first step, bouts divided events the
into
hierarchical
separated
frequency
recorded
can
used
to
of
time
define
distributions
are shown in Fig.
distributions
are unimodal
combined
data
distributions
Since
the
bout
1 for robins out
with
all
are similar
4
birds
are
before series
or by alternative between
all
separation
of related behaviours,
grooming
acts These
and Fig. 2 for veeries. at around
Although of
they can be
criterion.
15 sec.
all acts separated
to be in the same bout. from
bouts
intervals
and flatten
can be used as the bout criterion, set considered
must be defined
from other series by pauses
distribution be
of grooming components.
each
by less than 15
Figs. 1 and 2 present species,
in all cases and can be lumped.
Both
This value
the
the
individual
229
ROBINS
3
12
6
15
15
21
24
INTERVAL
Fig. 1.
Frequency
distribution
2,
30
33
LENGTH
35
30
42
45
45
5,
54
57
SD+
(SECONDS)
of inter-act
interval
lengths
in robins.
VEERES
3
6
3
12
15
15
2,
24
INTERVAL
Fig. 2.
Frequency
distribution
27
30
LENGTH
33
36
32
42
45
48
51
54
57
ED+
(SECONDS)
of inter-act
interval
lengths in veeries.
230
step, first-order
As a second between
all acts occurring
veeries
provided
assessment
of
frequencies
from
transition
0.60
to 0.69
were
robins
the
the
of
Transition
yield
the
highest category
veeries
threshold
for
entry
very Joly,
=
be
correlated from When
frequencies
above,
p
