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TN PENNED WHITE-TAILED

BUCK FAWNS DURING wm

Thesis for the Degree of M. S.

MICHIGAN STATE UNIVERSITY
EDWARD E. LANGENAU, JR.

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1973

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ABSTRACT

AGGRESSION AND PLAY IN PENNED WHITE-TAILED
BUCK FAWNS DURING WINTER

BY

Edward E. Langenau, Jr.

The aggressive and play behaviors in a group of
three buck fawns, Odocoileus virginianus, being fed ad.
libitum were compared to the behaviors of a trio given
seven successive reductions in feed over a three month
period of winter. The number of fights in the food-
deprived group increased until food was reduced by 25.0 per-
cent and then decreased. Fighting again increases as one
fawn approached death from starvation. As compared to the
control deer, when these fawns fought more, they tended to
.fight more intensely, play less, and fight almost ex-
clusively over food.

Play and aggressive behaviors of the control trio
were also compared to the behaviors of three fawns kept in
a pen which was reduced in size seven successive times.
Fighting increased until maximal levels of confinement, but

then fawns became more tolerant of each other.

Edward E. Langenau, Jr.

It was concluded that the number and intensity of
fights, as well as the amount of play, were related to the
availability of food and space. Additionally, the social
relationships between fawns were adjusted to distribute
stress unequally among group members. Hence, aggressive
behavior is a significant parameter influencing survival

at both individual and population levels.

AGGRESSION AND PLAY IN PENNED WHITE-TAILED

BUCK FAWNS DURING WINTER

BY

Edward E. Langenau, Jr.

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Fisheries and Wildlife

1973

ACKNOWLE DGMENT S

This project was supported by funds from the
Federal Aid to Wildlife Restoration Program, Pittman--
Robertson Project W-ll7-R.

I thank Lyman F. Shippy, foreman of the Porter
Ranch, Houghton Lake Wildlife Research Station, for sharing
his practical experience of the white-tailed deer. The co-
operation of Dr. Jerry T. Duvendeck, John T. Nellist and
Charlie Wyckoff was appreciated.

I thank Dr. George A. Petrides, chairman of my
guidance committee, for helping me explore a small portion
of the frontier where the sciences of animal behavior and
wildlife biology are growing towards each other. I
appreciate the assistance of Dr. Walter H. Conley,
Department of Fisheries and Wildlife, and Carl L. Bennett,
Jr., Michigan Department of Natural Resources, in the
planning of this study.

Dr. Martin Balaban, Department of Zoology, has been
a dynamic guide through the literature and offered valuable
advice in interpretation of results.

I express my appreciation to William G. Youatt of

the Department of Natural Resources. I have been fortunate

ii

to have had the opportunity to work with a researcher of
his caliber and professional bearing.
Most of all, I thank my wife, Di and son, Erik, for

their many scarifices.

iii

LIST OF TABLES .
LIST OF FIGURES.
INTRODUCTION. .
METHODS . . .
RESULTS . . .

Control Trio .

Space-Limited Trio
Food-Limited Trio

TABLE

OF

CONTENTS

Aggressive, Submissive and Play Postures.

DISCUSSION . .

Control Trio .

Space-Limited Trio .

Food-Limited Trio
Aggressive, Submissive and Play Postures.

CONCLUSION . .

LITERATURE CITED

iv

Page

Table

1.

LIST OF TABLES

Treatment data for trios of male white-tailed
deer fawns subjected to food or space
shorages . . . . . . . . . . . .

Mean numbers of aggressive encounters per
hour of observation during successive
12-day periOdS o o o o o o o o o o

Intensities of aggressive encounters:
Percentages of encounters terminated by
non-threat displays . . . . . . . .

Mean number of play encounters per hour of
observation during successive 12-day
periOds I O O O O O O O O O O 0

Mean number of aggressive encounters over
food between pairs of individuals per hour
of observation . . . . . . . . . .

Weight changes of individuals and groups as
a function of time, treatment and social
rank . . . . . . . . . . . . .

Page

10

13

23

LIST OF FIGURES

Figure Page

1. Mean number of aggressive encounters per hour
of observation during successive 12-day
periods . . . . . . . . . . . . . 12

2. Lip curl was seen in some aggressive
encounters . . . . . . . . . . . . 15

3. Some strikes occurred in which contact with
the opponent was made during an upward
sweep of the forefoot . . . . . . . . 15

4. The rush, an adult buck aggressive posture,
was displayed by fawns only during play . . 18

5. Driving, an adult buck courtship posture,
was displayed by fawns only during play . . 19

6. Gamboling appeared to be the only play

posture not used in any other biological
context 0 O O O O O O O O O O O O 19

vi

INTRODUCTION

White-tailed deer, Odocoileus virginianus, are
stressed by shortages of food and space during winter.
Bartlett (1950) estimated that the winter range of the
Michigan white-tailed deer is 10-15 percent of the area of
the summer range. This concentration of deer in specific
habitat types often results in depletion of the winter food
supply and in a significant number of deaths from star-
vation. Additionally, concentrating deer select wintering
areas primarily on the basis of the cover value of the site
and only secondarily on the amount of food present (Webb,
1948). As Allen (1948) summarized this phenomenon, "they
keep coming back to the same swamp each winter until it's
clean and then leave their bones among the cedars."

The social behaviors of wintering deer may be
adjusted to meet the demands of these severe conditions.
Intense social intolerance has been found in free-ranging
deer during winter (Kabat, Collias and Guettinger, 1953)
and in penned deer during winter (Robinson, 1962). Ozoga
(1972) observed deer competing for food at white cedar

(Thuja occidentalis) cuttings. He used the number of

conflicts per hour of observation as an index to the
frequency of aggression and defined the intensity of
aggression as the percentage of conflicts which were
terminated by non-threat postures. Among deer feeding at
these winter cuttings, he observed that the frequency of
aggression increased while the intensity of conflict
decreased from February to April.

The purpose of the present study was to determine
how habitat features of spatial restriction and low food
availability influence the change in play and aggressive
behaviors over winter. The experimental null hypothesis
was that changes in the amount of food or space would cause
no changes in aggression or play. The philosophical
hypothesis underlying this question is that severe winter
conditions induce changes in social behavior which have

survival value.

METHODS

Nine buck fawns, born and maintained in captivity,
were weighed and grouped in three trios on October 25, 1972.
Each trio was placed in a pen, 30px 60 feet. Colored ear
tags were attached to some deer, permitting visual recog-
nition of individuals at a distance. A pre-treatment
period of one month allowed the fawns to adjust to the new
physical and social environment and to the presence of an
observer during evening feedings. Eight treatment periods
were scheduled, each 12 days long (Table 1).

Pen A was maintained as a control, with no alter-
ation in food or space. Trio B was fed ad libitum but was
kept in a pen which was reduced in size seven times. The
rear wall of pen B was moved forward 5 feet at each 12-day
interval, permitting gradual space reduction. Food was
systematically reduced for the trio in pen C only. Food
was reduced on the first day in each of periods 2-8 by the
same percentages that space was reduced in pen B (Table 1).
This reduction was based on the average daily amount of

feed consumed by the control trio in pen A during the final

Table 1.--Treatment data for trios of male white-tailed deer fawns
subjected to food or space shortages.

 

 

 

Treatment Space Feed
Period Pen B Pen C Percentage
Number Dates (Square Feet) (gms./day) Reduction
1 Nov. 30-Dec. 11 1800 4515* 0
2 Dec. 12-Dec. 23 1650 4240 8.3
3 Dec. 27-Jan. 7 1500 3867 16.7
4 Jan. 8-Jan. 19 1350 3246 25.0
5 Jan. 20-Jan. 31 1200 2800 33.3
6 Feb. 1-Feb. 12 1050 2263 41.6
7 Feb. 13-Feb. 25 900 2164 50.8
8 Feb. 26-Mar. 9 750 1227 58.3
*g libitum.
six days of the preceeding treatment period. Commercial

deer feed (Andersons'--Maumee, Ohio) was used.

Behavioral patterns of each trio were observed for

30 minutes a day from behind a 4 x 8 feet canvas shield
which had a small rectangle
measured amount of feed was
zero minute of observation.
made on a rotating schedule

the order of observation or

time of day.

cut out to permit viewing.

Observations of trios were
to reduce differences due to

Observation

.A

introduced to the group at the

periods were adjusted during winter so that observation of

the last group ended approximately a half-hour before

sunset. Food was left in the pen until observation-time

the following day, when any remaining feed was removed and
weighed.

Aggressive and play interactions between fawns were
recorded for each observation period. Aggression occurred
over food, bedding places and right-of—way when moving.
Some encounters were observed in which the releaser for
aggression could not be objectively defined; these were
lumped as "other" aggressive interactions. The aggressive
postures, which comprised components of a sequence, were
classified according to descriptions given by Thomas,
Robinson and Marburger (1965). These authors described
aggressive display as a series of postures arranged in a
sequence of increasing intensity. If an opponent duplicated
the posture was displayed by the aggressor until the with-
drawal of one deer terminated the sequence. The fawn
sequence in order of increasing intensity was ”ear drop,"
"hard look," "sidle," "strike," and ”flail." Ear drop,
hard look and sidle were used as threats; strike and flail
involved contact by kicking with the forefeet.

The following characteristics of play were used to
differentiate play (including aggressive play) from

aggression:

1. Play elements are derived from other contexts such
as fighting, courtship, or escape situations

(Ewer, 1968).

Elements of play usually do not follow each other

in any fixed order or sequence (Leyhausen, 1965).

Behaviors used in play may appear more exaggerated
and displayed with more exuberance than the

situation requires (Leyhausen, 1965).

Play usually occurs at specific times in the daily

activity cycle (Meyer-Holzapfel, 1956).

Play occurs only at times when no instinctive

pattern is activated (Meyer-Holzapfel, 1956).

Dominance relationships may be reversed during play

(Ewer, 1968).

RESULTS

Control Trio

The control trio was watched for 30 minutes a day
for 96 days, during which time the number of aggressive
conflicts was recorded (Table 2). The mean number of
fights per hour of observation was calculated for each 12-
day treatment period.

Conflicts over food accounted for 67.3 percent of
the encounters. Fighting over food gradually decreased
from 4.8 conflicts per hour of observation during period
one to 0.8 per hour in period 4. As winter progressed,
fighting gradually increased to 3.2 encounters per hour in
the final period. The number of aggressive displays
unrelated to food varied from period to period with no
apparent pattern.

The intensity of aggression was defined as the
percentage of conflict which was terminated by contact
displays. Intensity of conflict (Table 3) in the control
group tended to increase until period 6. It then decreased
sharply in the last two weeks.

The relationship between the amount and severity of

fighting during treatment periods was tested by applying

Table 2.--Mean numbers of aggressive encounters per hour of
observation during successive 12-day periods.

 

 

 

 

Encounters Over Food Other Aggressions
Treatment

Period Trio Trio Trio Trio Trio Trio
A B C A B C

1 4.8 1.3 2.0 0.7 0.0 1.2

2 1.8 1.5 2.2 0.3 0.3 0.5

3 2.7 3.5 5.7 1.8 2.3 0.5

4 0.8 1.7 5.7 1.2 0.3 0.8

5 1.2 2.8 3.0 2.3 2.3 0.8

6 1.2 2.7 1.8 0.7 3.7 0.7

7 1.5 0.8 11.0 0.5 4.7 0.5

8 3.2 2.0 12.0 0.8 0.8 0.0

 

Table 3.--Intensities of aggressive encounters: Percentages
of encounters terminated by non-threat displays.

 

 

Treatment Control Space-Limited Food-Limited
Period Trio A Trio B Trio C
l 58 SO 53
2 62 91 62
3 52 8O 92
4 67 92 8O
5 67 74 88
6 73 55 64
7 58 58 86
8 50 65 95

 

the Spearman rank correlation coefficient. The intensity
and frequency of aggression were negatively correlated
(n=8; r8=-O.74: p<0.025). When the control group fought
more, the conflicts tended to be less severe.

Play encounters (Table 4) most often occurred
toward the end of the 30-minute observation intervals.
Aggressive play, or "mock fighting," was evident in 58.7
percent of the play encounters. No relationship was found
between the amounts of aggressive and non-aggressive play
observed (rs=-0.02; p>0.10). However, the amount of
aggression was positively correlated with both aggressive

play (r8=0.75; p<0.05) and total play (ra=0.76: p<0.025).

Space-Limited Trio

Fighting over food among fawns in the space-reduced
pen increased slightly during the study from 1.3 to 2.0
conflicts per hour of observation (Table 2). However, a
lower percentage of the total fighting was related to food
(52.4%), compared to the control trio (67.3%). The dominant
fawn would frequently attack the two subordinates for no
apparent reason. During periods 7 and 8, when spatial
restriction was greatest, these fawns displayed less total
aggression than they did during periods 5 and 6.

Intensity of aggression varied between treatment
periods but, unlike the control trio, the space-limited
group used more intense displays at the end of the study

than at the beginning (Table 3).

10

Table 4.--Mean number of play encounters per hour of
observation during successive 12-day periods.

 

 

 

 

Treatment Aggressive Play Non—Aggressive Play
Peri°d A B c A B C
l 9.3 2.1 4.1 2.6 1.3 1.3

2 6.0 4.1 0.6 3.5 1.3 0.1

3 3.3 3.0 0.1 6.0 1.5 0.6

4 5.3 1.3 0.1 3.6 2.3 0.0

S 8.6 1.5 0.0 5.6 1.1 0.5

6 3.3 0.6 0.3 1.5 0.5 1.3

7 3.1 0.8 0.0 3.6 1.8 0.1

8 5.8 0.0 0.0 5.0 0.1 0.0

 

The space-limited group played less than the
control group (Table 4) and also played less during period
one before the pen was reduced in size. Despite this
initial difference between groups, play decreased at a
greater rate in trio B than in control trio A. Further-
more, aggressive play decreased at a faster rate than non-

aggressive play.

Food-Limited Trio
Fighting for food increased (Table 2) until the
fourth period when a 25.0 percentage reduction in feed
was realized. Fighting then decreased until the level of

reduction reached 50.8 percent when the number of

11

encounters increased sharply. In order to explain this
bimodal distribution (Fig. l), the change in relationship
between fawns was examined. The majority of aggression in
all trios was seen between the fawns of dominance rank 1
and rank 2. Conflict between the dominant rank 1 and the
most subordinate rank 3 was also significant. Very little
fighting was observed between ranks 2 and 3 in either the
control or space-limited groups, yet fighting between ranks
2 and 3 in the food-limited group was pronounced. Change
in the rate of fighting between these two fawns (Table 5)
accounted for most of the initial increase and progressive
decrease in group aggression for the trio.

Initially the food-limited group either fed
together or took turns at the feeder. As food was reduced:
all three fawns began to increase fighting. At 25.0 per-
centage reduction the dominant fawn began to keep the rank
2 deer away from the feeder, but the dominant and rank 3
fawns fed together. As a result of this change in social
organization at the feeder, fighting between 1 and 3
dropped since the dominant appeared to become more tolerant
of the subordinate. Fighting between rank 2 and 3 fawns
was reduced while the dominant kept the rank 2 deer from
the feeder and hence decreased the opportunity for 2 and
3 to interact. At the maximum reduction of food, during
periods 7 and 8, the social structure at the feeder again
changed and the dominant also began to keep the rank 3

deer from the feeder for the first 10—15 minutes of the

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13

Table 5.--Mean number of aggressive encounters over food
between pairs of individuals per hour of

 

 

 

 

 

 

observation.
Trio
Treatment A B C
Periods
Individuals
1&2 1&3 2&3 1&2 1&3 2&3 1&2 1&3 2&3
l 3.0 1.3 0.5 0.1 0.8 0.3 0.8 0.1 1.0
2 1.0 0.5 0.1 0.8 0.6 0.0 0.3 0.6 1.1
3 1.1 1.1 0.3 2.0 1.3 0.1 2.1 1.3 2.1
4 0.5 0.1 0.1 0.6 1.0 0.0 1.5 2.8 1.3
5 0.8 0.1 0.1 2.0 0.6 0.1 1.5 0.8 0.6
6 0.5 0.3 0.3 1.3 1.1 0.0 0.8 0.8 0.0
7 0.8 0.6 0.0 0.3 0.5 0.0 6.1 3.8 1.0
8 2.1 0.8 0.1 1.8 0.0 0.1 7.0 4.1 0.8

 

14

observation interval. The rank 2 deer no longer passively
waited but made continuous attempts to gain access to the
feeder. The number of encounters between all fawns
increased.

Aggression also became more intense as food was
reduced (Table 3). The minimum intensity occurred during
period one, before the amount of feed given the trio was
reduced. Maximum intensity occurred during period eight
when the least amount of food was offered. For this trio,
when aggression was frequent, it also tended to be intense
(r2=0.70; p<0.05).

The amount of both aggressive and non-aggressive
play decreased suddenly after the first reduction in feed
(Table 4). Aggressive play was reduced more than non-

aggressive play.

A ressive Submissive and
PIangostures

Ear drop, hard look and sidle were used as threats.

 

Although ear drop was displayed as an independent posture,
it occurred more often in combination with the sidle or
hard look. "Lip curl," the retraction of both upper and
lower lips, was observed on rare occasions in association
with ear drop (Fig. 2).

Contact aggression included hair biting and pulling,
and the strike. Several distinct forms of the strike were
displayed. In some strikes, contact was made during an

upward sweep of the forefoot (Fig. 3). In others, the

15

 

Figure 2. Lip curl was seen in some aggressive
encounters.

 

Figure 5. Some strikes occurred in which contact
with the opponent was made during an
upward sweep of the forefoot.

16

sharp edges of the hoof made contact with the opponent on

a downward sweep of the forefoot. Series of successive
striked were observed on a few occasions. The same fore-
foot was used if the aggressor was stationary but alternate
forefeet were used to strike a fawn which was being chased
from the feeder. The most intense strikes occurred when
the deer used both forefeet simultaneously. The flail,
where deer stand upright and strike with both forefeet, was
never observed. Threat did not precede all strikes.
Sometimes when fawns were in close proximity to each other
strikes were delivered without warning.

Appeasement behaviors were displayed in all trios
but were most pronounced in the space-limited group where
withdrawal from an aggressive encounter was inhibited by
the size of the enclosure. The "crouch" was displayed with
the neck extended and pointed down. A "head bob" was
displayed by twisting the head to the side away from the
opponent and moving it up and down. This posture usually
changed an aggressive encounter into a play encounter.
Additionally, fawns often licked the tarsal gland of a
deer at the feeder and then were granted access to the food
without encountering an aggressive display.

In order to differentiate true aggression from
aggressive play, it was necessary to evaluate the postures
used during play. All aggressive postures previously

discussed were observed during play, often without being

17

displayed in any sequence of intensity. The rush (Fig. 4),
an adult-buck aggressive display, was only observed during
play. "Driving," an adult-buck courtship display (Pruitt,
1954), was observed in play encounters. Driving super-
ficially resembled the hard look but was displayed with a
swinging gait and emphatic stomping of the forefeet while
running towards the play mate (Fig. 5). "Gamboling"
(Espmark, 1969), or energetic jumping into the air, was

rare (Fig. 6).

18

 

 

 

 

 

 

 

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Figure 4. The rush, an adult buck aggressive
posture, was displayed by fawns only
during play.

 

Figure 5. Driving, an adult buck courtship
posture, was displayed by fawns
only during play.

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DISCUSSION

Control Trio

It was anticipated that the pre-treatment period
would limit the high frequencies of aggression often found
in newly-formed social groups when dominance heirarchies
are first being established. However, aggression in the
control trio still decreased over winter. This may have
occurred from continuing definition of the dominance
heirarchy as fawns matured and gained experience inter-
acting with other group members. The decrease in aggression
may also have reflected a seasonal decrease in activity.
Food consumption (French et al., 1955), metabolism (Hoffman
and Robinson, 1966) and activity (Ozoga and Verme, 1970) of
deer have been found to decrease during winter and increase
in spring. The curve for frequency of aggression over food
(Fig. l) in this group also decreased during winter and
increased slightly at the end of winter.

Towards the end of the study the control group used
more threat and less contact aggression during encounters.
This might be expected in groups of maturing juveniles who

become more adept in the use of socialized displays. A

20

21

threat from a fawn of known dominance may have become more
efficient in inducing withdrawal in a subordinate as the
fawns become more experienced with one another and learned

their position in the dominance heirarchy.

Space-Limited Trio

 

The increase in fighting unrelated to food was
primarily due to the flagrant hostility of the dominant
fawn. However, as space was still further reduced,
aggression decreased. This inhibition of aggression during
extreme restriction of range suggests that deer at
especially high densities may not be overly intolerant if
sufficient food is present.

The rise in intensity of conflict among members of
this trio may have resulted from the inability of a fawn
to completely withdraw after having been defeated in an
encounter. Despite the subordinate fawn's attempt to
escape, the mere presence of the defeated fawn may have
elicited more intense threats from the dominant animal.

Play decreased in this trio, as compared with the
control group. Since play in young ungulates centers
around flight or escape (Meyer-Holzapfel, 1956), and since
flight and escape were restricted as the pen was reduced
in size, play may have been inhibited. Additionally, the
subordinates may have refrained from using play postures
in order to prevent a play encounter from releasing

aggression in the dominant fawn. The finding that

22

aggressive play was reduced more than other forms of play
as pen size was decreased gives further support to this

idea.

Food-Limited Trio

 

Fighting increased with initial food deprivation
and then decreased between 25.0 and 50.8 percent feed
reduction. Southwick (1967) found that rhesus monkeys
(Macaca mulatta) showed a similiar increase and decrease
in fighting with progressively greater food shortages. He
attributed the decrease to fatigue and lethargy resulting
from malnutrition. In the present study, the decrease in
aggression occurred with a change in social organization of
deer at the feeder.

At levels of extreme food deprivation during
periods 7 and 8, fighting again increased. The rank 2 fawn
nearly died from starvation as it lost 22 percent of its
maximum body weight (Table 6). As survival of this fawn
was threatened, aggression showed a maximum increase.

Robinson (1962) subjected 15 fawns to food depri-
vation in order to determine the relationships between
condition and social rank. Three of the deer died from
starvation, but none of these deer was the most subordi—
nate. Similarly in the present study, the rank 2 lost more
weight and was nearer death than the rank 3 fawn. Survival

in deer experiencing winter food shortages might be

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24

expected to be highest for those population segments with
either the most aggressive or least aggressive deer.
Intensity of aggression in this group also in-

creased over winter. The increase in the number of
attempts of the subordinates to approach the feeder or to
refuse withdrawing from the feeder required the display of
more intense postures. Food deprivation has been shown to
lower the threshold for withdrawal responses (Hall, 1941).

Altmann (1952) found that elk (Cervus canadensis)

 

played less on a poor summer range than on a range with
adequate food and cover. The present study experimentally
verified that deer play less at very low levels of
nutrition. The space-reduced group also played less than
the controls, hence play seems to be not only related to
food but appears also to be a sign of general well-being

in fawns.

 

A ressive Submissive and
P1ay_Postures

Thomas et al. (1965) found that buck fawns dis-

 

played the aggressive patterns characteristic of adult
does. The fawns in the present study did display the rush,
an adult buck aggressive display, but only in play
encounters. They frequently butted the chest, forelegs
and flanks of an opponent which would be maladaptive for
adult bucks with antlers. The function of aggressive

display is to determine priority for distributing resources

25

among group members without inflicting injury or wasting
energy. Ritualization and socialization of display
minimizes violent contact and thereby reduces the chance
of a male killing his own offspring (Ewer, 1968). It
follows that the buck fawns were learning how to rush.
Butting of the flank and chest may be an immature form of
the rush.

A separate study was undertaken to document and
investigate the phenomena of hair-pulling and hair-loss.
For the purpose of the present study, hair-pulling was
considered to be an aggressive behavior when it elicited
aggressive display or withdrawal in a competitive situation.

Strikes delivered without threat have been reported
by Thomas, Robinson and Marburger (1965), who stated that
the orderly sequence of display sharing did not always
occur. They found that a less intense posture never
followed a more intense display. Observations during the
present study indicate that the probability of one display
following another is not only dependent on the intensity
of the conflict, but also upon the distance between deer
at the onset of the encounter. Since white-tailed deer
have no fixed geographic territory, the portable territory
around each animal becomes critical, as does the distance
at which other deer are permitted to approach with given
visual displays.

The literature on social strife in the white-tailed

deer has concentrated on aggressive display with less

26

consideration given to submissive or appeasement postures.
One function of socialized display in the Cervidae is to
allow defeated individuals to remain in the herd, thereby
maintaining group cohesion. Submissive and appeasement
behavior may be significant in reducing overt aggression

which disrupts cohesion. In the fallow deer, Dama dama,

 

the submissive posture of lowering the neck has been
described (Burckhardt, 1958) and assumed to be derived from
the attitude of the young when approaching to nurse. Too
few observations were made in the present study to permit
an analysis of submissive behavior other than to report its
occurrence, although its role in species survival may be
important.

Play postures were shown to be a mixture of dis-
plays from fighting, escape and courtship sequences. Adult
displays, present in varying stages of development, were
shown in fawn play. Gamboling appeared to be the single

posture in the fawns which was specific only to play.

CONCLUS ION

Penned buck fawns expressed considerable social
strife over food, even in a control group given surplus
feed. These six-month old fawns were adept at expressing
aggression using a complex system of visual displays.

The number and intensity of fights, as well as the
amount of play, were related to the availability of food
and space. Fawn groups were able to modify aggression and
play to meet the demands of food and space shortage.
Hence, the null hypothesis of equal change in play and
aggression between the three trios was rejected.

The social organization of these fawns was also
adjusted to distribute stress among group members. Hence
aggressive behavior does not only have individual survival
value but may function at a population level to minimize
winter mortality. 1

Natural selection for deer most capable of
expressing submission as well as those most capable of
expressing dominance may have a stabilizing effect on deer
populations subjected to annual periods of stress and

mortality. This mechanism may prohibit the evolution of

27

28

a deer society composed entirely of aggressive animals
capable of surviving hardship but ultimately selected to

destroy one another.

LITERATURE CITED

LITERATURE CITED

Allen G. 1948. The management of Georgia deer. J. Wildl.
Mgmt. 12(4):428¢432.

Altmann, M. 1952. Social behavior of elk in the Jackson
Hole area of Wyoming. Behavior 4(2):ll6-l43.

Bartlett, I. H. 1950. Michigan deer. Mich. Cons. Dept.

Burckhardt, D. 1958. Kindliches verhalten als
ausdrucksbewegung im fortpflanzungszeremoniell
einiger wiederkauer. Rev. suisse 2001. 65:311-316.

Espmark, Y. 1969. Mother-young relations and development
of behaviour in roe deer. Viltrevy, Swedish Wild-
life 6(6):462-540.

Ewer, R. F. 1968. Ethology of mammals. Logos Press,
London. 418 pp.

French, C. E., L. C. McEwen, R. H. Ingram, and R. W. Swift.
1955. Nutritional requirements of white-tailed deer
for growth and antler development. Pennsylvania
Agr. Exp. Sta. Bull. 600. 50 pp.

Hall, C. S. 1941. Temperament: a survey of animal
studies. Psychol. Bull. 38:909-943.

Hoffman, R. A., and P. F. Robinson. 1966. Changes in some
endocrine glands of white-tailed deer as affected
by season, sex and age. J. Mammal. 47(2):266-280.

Kabat, C., N. E. Collias, and R. C. Guettinger. 1953.
Some winter habits of white-tailed deer and the
development of census methods in the Flay Yard of
northern Wisconsin. Wisc. Cons. Dept., Tech. Wildl.
Bull. 7. 32 pp.

Leyhausen, P. 1956. Verhaltensstudien an katzen. Z.
Tierpsychol. 2:1-120.

29

30

Meyer-Hozlapfel, M. 1956. Das speil bei saugetieren.
Handb. Zool. 8(10):l-36.

Ozoga, J. J. 1972. Aggressive behavior of white-tailed
deer at winter cuttings. J. Wildl. Mgmt. 36(3):
861-868.

Ozoga, J. J., and L. J. Verme. 1970. Winter feeding
patterns of penned white-tailed deer. J. Wildl.
Mgmt. 34(2):431-439.

Pruitt, W. 0., Jr. 1954. Rutting behavior of the white-
tail deer. J. Mammal. 35(1):129-130.

Robinson, W. L. 1962. Social dominance and physical
condition among penned white-tailed deer. J.
Wildl. Mgmt. l3(2):l95-216.

Southwick, C. H. 1967. An experimental study of intra-
group agonistic behavior in Rhesus monkeys.
Behaviour 27(2):182-209.

Thomas, J. W., R. M. Robinson, and R. G. Marburger. 1965.
Social behavior in a white-tailed deer herd
containing hypogonadal males. J. Mammal. 46(2):
314-327.

Webb, W. 1948. Environmental analysis of a winter deer
range. Trans. 13th N. Amer. Wildl. Conf. 442-450.

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