ChapterPDF Available

Social Status and Antler Development in Red Deer

Authors:

Abstract and Figures

Close correlations between social dominance and levels of some hormones modulated mainly by agonistic behavior have been reported in mammals. The hormone changes which accompany agonistic interactions appear to be more dramatic and longer lasting than those associated, for example, with sexual interactions (Harding 1981). Clearly, dominant animals generally have lower pituitary/adrenocortical activities than submissive animals living with them. Thus, the dominant -+position usually based on aggressive behavior often tends to be related to elevated androgen level, while subordinate status seems to be associated with lower androgen secretion and increasing levels of glucocorticoids (Brain 1980; Leshner 1980). Increased chronic ACTH/glucocorticoid production in subordinate animals suppresses androgens (Brain 1980). In Cervidae the evidence for these relationships has been obtained in white-tailed deer (Bubenik, A. & Bubenik, G. 1976b; Forand et al. 1985), red deer (Short 1979), and reindeer (Stokkan et al. 1980).
Content may be subject to copyright.
Reprinted from
George A. Bubeník Anthony B. Bubeník
Editors
Horns, Pronghorns, and Antlers
Evolution, Morphology, Physiology,
and Social Significance___________
© 1990 Springer-Verlag New York, Inc.
Printed in the United States of America.
Springer-Verlag
New York Berlin Heidelberg
London Paris Tokyo Hong Kong
17
Social Status and Antler
Development in Red Deer
LUDĚK BARTOŠ
Introduction
Close correlations between social dominance and levels of some hormones modu-
lated mainly by agonistic behavior have been reported in mammals. The hormone
changes which accompany agonistic interactions appear to be more dramatic and
longer lasting than those associated, for example, with sexual interactions (Hard
ing 1981). Clearly, dominant animals generally have lower pituitary/adrenocorti
cal activities than submissive animals living with them. Thus, the dominant
position usually based on aggressive behavior often tends to be related to elevated
androgen level, while subordinate status seems to be associated with lower andro-
gen secretion and increasing levels of glucocorticoids (Brain 1980; Leshner 1980).
Increased chronic ACTH/glucocorticoid production in subordinate animals sup-
presses androgens (Brain 1980). In Cervidae the evidence for these relationships
has been obtained in whitetailed deer (Bubenik, A. & Bubenk, G. 1976b; Forand
et al. 1985), red deer (Short 1979), and reindeer (Stokkan et al. 1980).
In theory, the mentioned hormones may be involved in both antler cycle timing
and antler growth. In antlerogenesis the main role seems to be played by andro-
gens. Typically, the more masculine a mammal male appears, the higher testoster-
one concentration in his blood (Crenshaw 1983). Deer are not an exception. Since
the beginning of antler growth, androgens are probably the leading hormones
affecting this process (Bubenik, G. 1982). Crenshaw (1983) injected GnRH into
immature male whitetailed deer and then determined testosterone release. He
obtained high correlation coefficients between testosterone response ratio and
various antler measurements. In another experiment, Brown et al. (1978) found
positive correlations between increasing serum androgen concentrations and
increasing antler mass in bucks. Contrary to physiological levels of androgens,
glucocorticoids were found to suppress antler growth (Bubenik, A. et al. 1976).
The above brief review allows one to put forward the hypotheses that domi-
nance in a male deer is related to: (a) the timing of his antler cycle, i.e., dates of
antler casting and/or cleaning; and (b) the process of his antler growth.
442
17. Social Status and Antler Development 443
FIGURE 1. Number of deer in the observed population. Open circles = hinds. Full circles
= stags.
To test these hypotheses, we studied an enclosed population of "white" red
deer. The following text is based on published results of the study with some
recent data added.
Red Deer Population Studied
The study was carried out in the Žehušice Game Reserve, Central Bohemia,
Czechoslovakia, a fenced park of 2.42 square km, divided into two enclosures.
In this report we used records from the population kept in the main enclosure
(1.26 square km).
The subjects were male members of a herd of red deer, Cervus elaphus, con-
taining many white and partially colored individuals (Bartoš 1980). No red deer
in the reserve are culled, except for wild-colored male progeny. Fig. 1 shows the
number of hinds and stags present in the main enclosure over the study period.
From birth, all stags are identified individually from coat color and physical vari-
ation, so their ages are known exactly. Our analysis has involved all stags older
than 2 years.
Observations were made between 1972 and 1985 (once every 4 weeks), except
during the time of antler casting or cleaning, when they were made daily. The
animals were fed almost every day during the whole year, and so could be inspected
by an observer seated on a tractor during feeding at a distance of approximately
444 L. Bartoš
20 m without any apparent disturbance. The records of stag dominance hierarchy
were made at the time of feeding. The observations of feeding deer lasted 10-70
min, until the animals left the feeding area. During observations, the food was
always deposited in one place to induce competition among the stags. All animals
encountered each other regularly, and if one animal moved away when approached
by another, this was taken as an indication of subordinance. The outcome of such
encounters was invariably clear. The rank order was based on the encounters of
single stags with each animal of the bachelor group. The dates of antler casting and
cleaning were recorded daily by the deerkeeper.
For the analysis, several relative values are used: dominance index (DI) (Bartoš
& Hyánek 1982a)—calculated so that the position in a hierarchy (alpha=l, etc.)
was divided by the number of males present. In those parts of the study, where
it was necessary to study social position of stags in detail, DI is expressed in two
forms (Bartoš & Perner 1985): general dominance index (GDI) —the position in
the hierarchy of all the stags living within the same enclosure divided by their
total number. When used for a single observation of social groups, a measure
called relative dominance index (RDI) was used, i.e., DI within the group being
just observed.
Once the rut was over, stags were separated temporarily from the main herd of
mer, toward the period of antler cleaning. Although the mean age of the stags
monitored was rather low, the alpha stags were not usually the oldest ones (Bartoš
1986a). There were very stable social relationships among the stags throughout
the year in our study herd. Changes in the stag dominance hierarchy increased
with the number of individuals present. The frequency of rank changes during the
period with hard antlers was significantly higher than that during the velvet
period (Bartoš 1986b). Between 1972 and 1983 stags developed a typical linear
hierarchy. Triangular relationships occurred seldomly, being usually a temporal
result of rare changes in the hierarchy during the period of antler casting. Only
during and after the antler casting of 1984 the stability of the hierarchy decreased
and the first permanent triangular relationships appeared. By the end of the year
the hierarchy was stabilized again, this time with numerous nonlinear dominance
relationships (Fig. 2).
Increasing the size of a social group affected animals at the two extremes of the
hierarchy (the alphas and omegas). Increasing group size elicited an increase in
agonistic activity in the former and suppressed it in the latter. The stags which
occupied the middle range of the hierarchy showed a decrease in number of
agonistic interactions when group size increased (Bartoš 1986a).
FIGURE
2.
Structure of dominance hierarchies in three different seasons related to calcu-
lated rank, date of antler casting, and ages of stags.
17. Social Status and Antler Development 445
446 L. Bartoš
TABLE 1. Partial correlation coefficients between domi-
nance and antlertesting dates, and between dominance
index and antlercleaning dates in individual seasons (with
standardized age)
*According to Anděl (1978), the hypothesis was tested that the cor-
relation coefficients are equal. The hypothesis could not be
rejected (P = 0.05) for both antler casting and cleaning—hence,
the estimation using z transformation for all seasons was made.
Social Status and Antler Cycle Timing
The first step of the investigation was to relate rank position to dates of antler
casting and cleaning. The initial study (Bartoš 1980) indicated that the antler
casting time of individual stags was dependent primarily on social status and that
the influence of age was of secondary importance. The stags of higher rank also
tended to shed velvet earlier. After a longer period of time, partial correlation
coefficients were calculated for each season of the period when the stags estab
lished linear hierarchy in Žehušice (x = DI, y = date of antler casting/cleaning,
z = age; Table 1). (Incidental asynchronous cast was calculated as a mean date
of casting of the left and right antlers.)
Both relationships (between DI and casting/cleaning) when influence of age
was eliminated, reached high statistically significant values. The first hypothesis
advanced has been confirmed. The next step was to estimate social factors which
could influence the relationships.
Social Structure and Antler Cycle Timing
The relationships between antler casting and social position under the situation
of stabilized linear and nonlinear hierarchy were compared according to non
linear social relationships occurring since the fall of 1984. For this purpose we
used the data from 1982 (typical linear hierarchy), 1983 (linear hierarchy with an
unusually young stag in the alpha position), and 1985 (nonlinear hierarchy; see
Fig. 2). Data for spikers (deer with first antlers) were not included. For the pur
17. Social Status and Antler Development 447
TABLE 2. Comparison of correlations existing within different types of hierarchy
*P<0.001.
pose of this part of the study, the hierarchy of 1985 was estimated according to
Clutton-Brock et al. (1982). The values were ranked. Order represented a rank
position ofa stag ("rank"). The bachelor groups of stags of 1982,1983, and 1985,
respectively, did not differ in mean ( SE), dates of antler casting (March 31
5 days, March 31 4 days, March 24 4 days, ANOVA, F(2,37) = 0.90, NS),
or in mean ages (4.92 0.53,5.21 0.60,6.00 0.55 years, ANOVA, F(2,37)
= 0.98, NS). The data for each season were calculated separately using partial
correlations (x = DI, y = date of casting, z = age of the stag). The results are
shown in Table 2.
In seasons with linear hierarchy (1982, 1983), correlations between rank and
date of antler casting (with standardized age) reached high, significant values,
while in the season with nonlinear hierarchy it did not show such a close relation-
ship. Thus, the linearity of a hierarchy seems to be one of the important factors
that allows a close relationship between social position of a stag and his antler-
casting time.
Agonistic Activity and Antler Cycle Timing
Years lasting observations allowed more general analysis using data of cycle tim-
ing and social characteristics per unit calendar year. It was found that the
strength of the relationship between stag rank and casting and cleaning order
under the situation of stabilized hierarchy was significantly correlated with most
of the indicators of general aggression (such as the number of killed stags, inci-
dence of broken antlers, etc.; Bartoš 1986b). The higher the level of aggression
within the herd of stags, the closer the relationship between rank and the timing
of the antler cycle indicating that the process of antler cycle timing can be modi-
fied by an aggressive behavior of a stag related to his rank. To prove directly this
suggestion, agonistic activity of selected stags was monitored in detail during
competition at feeding before casting and before cleaning. Animals of the top,
middle, and bottom rank were included. There were significant correlations
between the casting time and the most frequent aggressive acts prior to casting.
The more aggressive a stag, the earlier the date of casting. On the other hand,
there were no statistically significant correlations between agonistic activities
recorded during a velvet period and the date of antler cleaning (Bartoš 1985).
This is consistent with the results presented in Table 1. It can be seen there that
448 L. Bartoš
although both antler casting and cleaning correlated highly with DI, the correla-
tion of the former was markedly higher than that of the latter. Is there any differ-
ence between the periods preceding the casting and cleaning?
Before antler casting (i.e., since the end of the rut), the stags of the studied
herd lived usually in one large group, whereas after casting they tend to disperse
into numerous unstable small groups not separated exclusively from a company
of hinds. Therefore, the stags may be in a different social environment in the two
periods. Presumably, in a situation of changing sizes and memberships of groups,
animals of lower rank may increase their rank temporarily if they are in a group
of the lowest-ranking individuals. On the other hand, dominant animals sepa-
rated from the company of others need not have sufficient social stimulation
which would influence their internal environment. If it is so, then sample
monitoring of individual stags at that time could thus hardly record the same
facets of their aggressive activity. To solve the problem we conducted detailed
observations of the composition of individual social groups of stags throughout
the velvet period (Bartoš & Perner 1985). That is, from the time just after antler
casting of all stags to the time when the last stag is cleaned. The observations
were made approximately every other day within the velvet period. As in other
red deer populations (Appleby 1983; Bützler 1974; Clutton-Brock et al. 1982;
Darling 1937), our stags tended to associate with animals of similar rank and age.
RDI values were calculated for each stag for each observation and were compared
with antler cleaning dates. The correlation coefficients increased toward the time
of cleaning. For the last 2 weeks of the period the coefficients reached levels simi-
lar to those between stags' rank and antler casting. To complete the analysis, the
association between stags was defined. The closest associates of each stag (deter-
mined after Appleby 1983) in the weeks preceding each individual's antler clean-
ing date were identified. The higher-ranked associates of the same age cleaned
significantly earlier than the lower-ranked individual. It was concluded that both
antler casting and cleaning are regulated by hormones modulated by agonistic
behavior related to rank (Bartoš & Perner 1985).
Antler Casting in Different Cervid Species
Until now we have discussed the relationships between rank position and antler
cycle timing in red deer. Forand et al. (1985), observing captive herds of white-
tailed deer, found a highly significant inverse correlation between rank and order
of casting antlers, indicating that dominant white-tailed deer bucks retained their
antlers longer than subordinates. This result is in apparent contrast to what has
been found in our red deer herd (Bartoš 1980, 1986b). The authors (Forand et al.
1985) presented a brief review giving literary evidence that in northern areas of
the United States where antler casting is early and relatively short (from mid-
December and to late January), older, larger, and presumably dominant bucks
cast antlers earlier than their subordinates. For the Midwest, where antler cast-
ing extends from January to late March, white-tailed bucks with large antlers
generally retain them longer than bucks with small antlers. The authors sug-
17. Social Status and Antler Development 449
gested that dominant whitetails in northern ranges may experience considerable
stress and physical exhaustion due to a short but intensive rutting season. Then
they related the suggested stress with increased levels of corticoids reducing
levels of testosterone. They concluded that testosterone levels of subordinate
animals may stay longer above the threshold for antler casting, resulting in longer
retention of antlers.
Are the presented contradictory results based on a methodological mistake, or is
there any speciesspecific differences? The latter seems to be more likely. It is our
suggestion that the difference between red deer and whitetails in the relationship
between rank position and the order in which individuals cast their antlers lies in
the speciesspecific response of antler casting to seasonal pattern of testosterone.
Brown et al. (1983a) have shown that the endocrine control of the antler cycles of
two deer species may differ. It has been well documented that there are species
specific differences in seasonal patterns of casting and new antler growth. Deer
species with seasonally determined antler cycles may be divided into two basic
groups. Group A—those in which casting of old antlers is followed immediately by
growing of a new antler, such as red deer, wapiti, sika, fallow, roe, and Pere David's
deer; Group B—those in which an interval exists between antler casting and new
antler growth such as whitetailed deer, muledeer, moose, reindeer, and caribou
(Bubenik, A. 1966; Goss 1983; Jaczewski 1981a; Sempéré & Boissin 1982). In red
deer, antler casting and regrowth are closely interdependent. Our hypothesis about
the positive correlation between antler casting and rank position of a male fits well
(Bartoš 1980, 1986b). It is presumed that this might be the case for all species
belonging to Group A. On the other hand, in species in Group B, antler casting and
starting of new antler growth are well separated in time, so that they may have dif-
ferent relationships to rank position. While high rank position may associate with
the delay of antler casting, as has been found by Forand et al. (1985), starting of
new antler growth should be enhanced. In other words, the time between antler
casting and new antler growth should be shortest in the highestranking animals of
Group B. To support the above hypothesis, we can submit some empirical data. For
species in Group A: in red deer (Bützler 1974; Lincoln 1972; Lydekker 1898;
Nečas 1959), and wapiti (Bubenik A. 1982a), it is well established that the older
and stronger males cast earlier. For species in Group B: Kozhukchov (1973)
reported in farmed bull moose that young animals cast antlers 13 months earlier
than old animals.
How can we explain the relationships between the behavior and antler casting
and the difference between the two groups of deer species on a hormonal basis?
While males of the species belonging to the Group A need some stimulation of a
new antler growth, it is the decline of testosterone itself after the rutting season
that seems to be responsible for the casting of the antlers which may occur in early
winter in males of Group B (Brown et al. 1983a; Mirarchi et al. 1977b). White
tailed bucks treated with antiandrogen cyproterone acetate immediately after
casting their old antlers did not renew growth of antlers (Bubenik, G. 1982). It
can be predicted that the treatment of males in Group A with antiandrogen before
casting might respond in retaining their antlers. Red deer stags that die in spring
450 L. Bartoš
FIGURE
3.
An overaged stag (in the foreground) who failed to cast antlers in the spring is
sparring with a mature stag carrying fully developed velvet antlers.
in Scotland are almost invariably still carrying their hard antlers (Mitchel in Lin-
coln 1971a; Lincoln & Bubenik, G. 1985). In 1985, the oldest stag of the
Žehušice herd failed to cast his antlers (Fig. 3). He had retained them until next
October, when unfortunately he was shot. It was found that he had fully regressed
testes. The evident fall of testosterone levels was not sufficient to induce casting.
On the other hand, van Ballenberghe (1982) reported several cases of bull moose
which were handicapped by an injury and which cast earlier than others, suggest-
17. Social Status and Antler Development 451
ing that the fall of testosterone levels was potent enough to initiate casting.
The presumed speciesspecific response to seasonal testosterone variation may
be reflected also in the cast antlers. The longer dead antler is attached to the
pedicle, the more it dies back (Lincoln 1984). The species which cast soon after
the rut tend to have a convex casting surface at the base of the cast antlers com-
pared with the concave casting surface in the species which cast later. This is also
apparent when red deer are castrated soon after the rut (Lincoln 1984; Lincoln &
Bubenik 1985).
It has been hypothesized that new antler growth may be initiated by a small
reactivation of sexual function and hence testosterone pulse (Bartoš 1980;
Bubenik, G. 1982; Goss 1983; Sempéré & Boissin 1982). This may correspond
to the initiation of pedicle formation within a male's ontogeny. It has been shown
that during puberty the deer testes must be activated for a short time to induce the
growth of pedicles (Brown etal. 1983a, 1983b; Lincoln 1971; Sempéré & Boissin
1982; Suttie et al. 1984). The initial suggestion that new antler growth may be
induced by the shortterm pulse of testosterone was based more or less on indirect
results (Bartoš 1980). However, now there are rather more direct indications
available. Testosterone titers were determined to increase twice a year in red deer
(Blaxter et al. 1974; Suttie et al. 1984), wapiti (Haigh et al. 1984), whitetailed
deer (Bubenik, A. 1984; Bubenik, G. et al. 1982a; Brown et al. 1983b; Mirarchi
et al. 1977b), and sika deer (Brown et al. 1983a). The effect of testosterone,
modulated by behavior, on the initiation of antler regrowth could probably be
determined by measuring the absolute hormone level. Low amounts of testoster-
one can stimulate bone growth, and higher levels may be inhibiting (Brown et al.
1978b). The more dominant males have earlier, higher, and more frequent
testosterone pulses within the range of Brown et al.'s 'low amount'; a new antler
bone growth may thus be initiated more vigorously and the antler casting in spe-
cies in Group A may occur earlier (Bartoš 1980). In males in Group B, new
antler growth of dominants may start earlier even though antler casting had
occurred later.
In general, fighting stimulates the level of glucocorticoids (see Introduction).
Increased corticoid levels inhibit antler growth (Bubenik, A. et al. 1976).
Adrenal hypertrophy may occur in deer under conditions of stress (Bubenik, G.
& Bubenik, A. 1965; Hughes and Mall 1958), a reaction which may delay antler
casting in fallow and red deer (Fig. 4) (Bubenik, G. 1982; Topiňski 1975),
representatives of species Group A. Hypothetically, the species of Group B
should be affected in just the opposite way by stress, enhancing antler casting. A
role of some other hormones may be expected. Nevertheless, this possibility is
not included in this simplified model.
If our earlier hypothesis is correct, how does it fit to antler casting caused by
castration? From the point of view of the hypothesis, we should expect a sudden
fall in testosterone levels after castration, followed by temporary restoration of
androgen levels (of adrenal origin?) which afterward definitely declines. To our
knowledge, the detailed pattern of testosterone decline after castration has not
been investigated. However, there are some indirect data. After orchidectomy,
452 L. Bartoš
FIGURE 4. Asynchronously casting stags are on average older and higher ranking than
those casting synchronously. Among the asynchronously casting stags, the higher a stag
ranked, the shorter interval between the dates of casting of both his antlers (Bartoš and
Perner 1987).
17. Social Status and Antler Development 453
LH levels increased more than four times in red deer (Lincoln & Kay 1979) and
more than four times in white-tailed bucks (Bubeník, G. et al. 1982a). In theory,
testosterone secretion from the adrenal gland may be facilitated by this way to a
short-term surge. Under such circumstances the difference between the two
groups of Cervids should be diminished. This seems to be the case. As reported
by Goss (1983), after castration, renewed antler growth occurs soon after the old
antlers have been lost, even in those species in which there is normally a lag
between these two events. However, the time of antler regrowth after castration
is season-dependent in both groups of the deer species (Lincoln 1984; Bubenik,
G., personal communication).
How would the above hypothesis explain that some solitary-living old individ-
uals may cast their antlers rather early in the period of antler casting when com-
pared to most of other conspecifics in Zehuiice while performing minimal social
interactions? In experiments with artificially altered daylight and its influence on
the antler cycle, it was shown that older males can sometimes express endoge-
nous annual antler growth, irrespective of artificial light conditions (Goss
1969a). This may be the case in solitary-living stags. On the other hand, the
absence of social stimulation may cause the observed fact that these solitary-
living stags always cast antlers later than the younger top dominant ones living in
social groups (Bartoš 1980).
It must be emphasized, however, that general good nutritional status of a popu-
lation seems to be an essential factor allowing an expression of the behavior in
antlerogenesis. Suttie (1980a) found in red deer that the quality of nutrition
influences the seasonal levels of testosterone and prolactin. Good nutrition
caused even rutting of his stags twice a year, in spring and fall. In this respect, it
is important to note that there is also sufficient evidence confirming a species-
specific dependence of antler casting on nutrition. In red deer, Darling (1937)
and A. Bubenik (1966) argued that inadequate nutrition after the rut significantly
delays casting. Also, Lincoln (1971a) stated that red deer stags in poor condition
cast their antlers later. Watson (1971) showed that antler casting among red deer
was delayed by food restriction brought about by severe weather conditions, but
supplemental feeding could reverse this trend. Similarly, in experiments with
farmed deer, Suttie & Kay (1982) and Fennessy & Suttie (1985) found a trend for
antlers of a nutritionally unrestricted group to be cast 1-2 weeks before the res-
tricted group. In contrast, Long et al. (1959) showed that nutritional deprivation
of white-tailed deer in the spring hastened antler casting. Also Lincoln & G.
Bubenik (1985) stated that white-tailed deer cast their antlers earlier than normal
in winter in response to poor feeding and loss of condition, while the regrowth
of new antlers in such animals occurs later than normal in spring. Ozoga & Verme
(1982) reported an influence of improved nutrition on antler casting in white-
tailed deer. Supplementally fed bucks in the enclosure retained their antlers
several months longer than did the bucks in that area. West & Nordan (1976a)
found similar relations in mule-deer. Better fed captive bucks often cast antlers
later than wild bucks.
454 L. Bartoš
Conversely some other data do not support the above hypothesis, either for
Group A or Group B. Gibson & Guinness (1980) reported, for example, that red
deer stags with the highest reproductive success (and hence of the highest rank)
during the rut cast their antlers later than others. Presumably poor condition nega-
tively affects the spring testosterone pulsation of these animals as in Suttie's
(1980a) restricted group [see also the abovementioned experience of Darling
(1937) and A. Bubenik (1966)]. The same explanation may account for all the dis-
crepancies in casting of whitetailed deer of various geographical origin cited
earlier (Forand et al. 1985). In northern areas, one may expect worse nutrition of
the deer than in southern areas. Dominant bucks are not able to maintain levels of
testosterone above the threshold for antler casting because they are significantly
more exhausted after rutting activity than their subordinates. Earlier casting in
dominant bucks thus may occur. Moreover, seasonal fall in testosterone levels
under conditions of naturally restricted nutrition cannot be stimulated substan-
tially by dominant related behavior, which may also explain why the casting time
in whitetailed deer is more synchronized and occurs earlier in the season in north-
ern than in southern areas as reported by Forand et al. (1985). Under better general
conditions, in the Midwest, such behavior may lead to maintenance of elevated
testosterone levels of dominant bucks causing the delay of antler casting.
Antler Cleaning and Deer Species
Contrary to casting, antler cleaning seems to follow the same pattern in both
groups of deer species in relation to social position. A tendency for a positive
correlation between rank and order in which males clean antlers was found not
only in our red deer (Table 1), but also in captive whitetailed deer (Forand et al.
1985). The stimulatory effects of social interactions among dominant males
probably elevate levels of testosterone, while the interactions elevate glucocorti-
coids and depress testosterone levels in subordinates. As a result, antler cleaning
may occur earlier in dominants and later in subordinates.
Many authors have suggested that antler cleaning dates are fully dependent on
age, such as in red deer (Butzler 1974; Darling 1937; Nečas 1959) and in other
cervids (e.g., Hirth 1977). Spikeantlerěd deer clean antlers later than fork
antlered males in red deer (Bubenik, A. 1966; Darling 1937; Jaczewski 1981a;
Lincoln 1971b; Nečas 1959), whitetailed deer (Hirth 1977; Jacobson & Griffin
1982; Scanlon 1977), and moose (van Ballenberghe 1982). Nevertheless, there
are also contradictory reports, mainly from captive populations. Both the earliest
and the latest cleaning dates were observed among yearlings in fallow deer
(Chapman & Chapman 1975; Štěrba & Klusák 1984), in whitetailed deer
(Jacobson & Griffin 1982), and in our red deer herd. Exceptionally early cleaning
by yearlings may be observed under natural conditions, too [e.g., in moose (van
Ballenberghe 1982)]. Here again, different opportunities for social grouping and
hence for differential social stimulation of the process, as well as differential
opportunity to be stressed, may be involved.
17. Social Status and Antler Development 455
Social Status and Antler Growth
The possibility of a relationship between social position and antler size in Cer-
vids has been widely discussed.
Some authors have suggested that antlers advertise an individual's dominance
status (Beninde 1937; Bubenik, A. 1968, 1982b; Geist 1966b; Henshaw 1969),
but variable results have been obtained in field studies designed to assess this.
Espmark (1964) in reindeer and Lincoln (1972) in red deer found that after the
loss of antlers, either naturally or artificially, individuals became less effective in
competition with other males, resulting in loss of social rank in the bachelor
group. Biitzler (1974) measured the lengths and weights of cast antlers from stags
of known social position. There was a positive correlation between these mea-
surements and social position but the author questioned whether the relationship
was genuine. Clutton-Brock et al. (1979) observed more than 100 rutting fights
between red deer on the isle of Rhum in Scotland and found a weak correlation
between the number of points on the antlers and fighting ability. No relationship
between antler length and fighting success was apparent. Appleby (1982) also
observed red deer of the same population and found that the rank of mature stags
in winter was correlated to antler length. Winter rank in mature stags was, how-
ever, correlated significantly with the weight of their antlers in one of two study
years. Suttie (1980b) found in a group of farmed stags that antler weight but not
antler length or number of points was positively correlated with social position.
Miura (1984) reported for male sika deer that large antlers were related to
dominance.
All the mentioned studies were based on observations at the time when the
male deer had completed their antler growth. That is, the studies compared the
relationship between males' fighting abilities and size of their grown antlers. The
criticism of the suggested behavioral significance of grown antlers was made in
red deer during the rutting season. The fighting ability of individual stags
changes during the course of the rut as their body condition declines, and
individuals vary in the timing of their declines. Consequently, a stag that assessed
its opponents on criteria that did not vary with changes in body condition during
the rut would take many incorrect decisions (Clutton-Brock et al. 1979, 1982).
In our previous studies we have already suggested that social position and related
agonistic activity of stags during the velvet period influence the antler weight,
length and number of points, and therefore the size of grown antlers are a conse-
quence of previous social position and not vice versa (Bartoš & Hyánek 1982a,
1982b). Also Wólfel (1983) claimed possible role of rank position of a male
yearling red deer in antler development. The aim of the following study was to
assess in detail how the social position of a growing red deer stag is related to var-
ious measures of antler development.
In red deer, the gain in antler growth or development correlates in the first 5-6
years almost linearly with body growth and weight. Afterwards, i.e., after the
stags have reached their mature body size, there is always a substantial variation
456 L. Bartoš
TABLE 3. Relationships of general and relative dominance indices to antler weight and
length, and number of antler points
General dominance index (GDI)
Relative dominance index (RDI)
Antler weight
-0.77**
-0.87**
Antler length
-0.63*
-0.78**
No. of antler points
0 93***
—0.99***
*P<0.05.
**P<0.01.
***P<0.001.
(Bubenik, A. 1966, 1982; Huxley 1931). Hence we have simplified the antler
growth into a model that states that antlers increase linearly during a stag's
ontogeny up to 5 years of his age, while afterwards there is not regular increase.
[The same pattern has been found also in a red deer stag's social position by
Appleby (1980) and Bartoš & Hyánek (1982a).] According to the model pro-
posed, a linear regression of growth of all the antler measurements and
dominance indices (DI's) during the period of antler growth was estimated for
each stag. Then values for two extreme ages of a stag's ontogeny were calculated
(2 years—the beginning of the first regular branched antler growth, and 5
years —the end of body development). Such calculated values of the DI were cor-
related with those of antler measurements. The results of the analysis (Bartoš
et al. 1988) showed that high-ranking stags of both extreme ages had heavier,
longer and more branched antlers. The social position involved (DI) had always
been estimated during the period of formation of the future antler. However, as
mentioned earlier, in Zehušice the bachelor group tended to disintegrate during
the velvet period. Thus DI does not reflect detailed changes in social environ-
ment. Hence we further presumed: If we compared GDI and RDI throughout the
period of antler growth of a stag, then correlation between antler size characteris-
tics and the indices should fit better to RDI than to former one. To solve the
problem we used the data of 1983 when we followed the distribution of all stags
in individual social groups. We used the records of the period between antler
casting and cleaning for each stag. It represented 59.71 ±2.70 different observa-
tions for a stag. Cast antlers of 11 individuals were collected during the following
spring and measured. The values of GDI of the velvet period of these stags were
equal to those of RDI in one case, while they were not equal in ten cases (Sign
test, P = 0.01). All the values used in the analysis (GDI, RDI, antler weight and
length, and number of points) were adjusted for age using an analysis of linear
regression (Snedecor & Cochrane 1965). Correlation coefficients between the
indices and selected antler size characteristics are shown in Table 3.
The correlation coefficients between antler characteristics and GDI were
lower than those between antler characteristics and RDI in all three cases. So the
presumption has been fully supported.
The results presented should be taken as applying to a model. The living condi-
tions in Zehušice differ in several ways from those elsewhere. The situation in
17. Social Status and Antler Development 457
FIGURE 5.
A
mature stag who cast one antler is "flailing" in an attempt to hold the rank
over a subadult, antler-carrying stag.
this herd is difficult to compare with the free-living individuals. The deer could
not leave the fenced area. So that the animals were unable to separate fully from
others and interactions with conspecifics could not be avoided. From Suttie's
(1985) observations of farmed red deer stags, it was apparent that although a sta-
ble hierarchy existed in bachelor herds, it did not prevent aggression. Suttie
found that the level of aggression was much higher than in the wild. He concluded
that members of a hierarchy may be stressed to an extent not seen in the wild.
Hence physiological consequences of aggression related to rank position under
conditions of restricted space may be expressed more markedly than those under
natural conditions. On the other hand, it seems to be likely that a population such
as ours may be a relevant model for free-living populations, since the conse-
quences of high density in the pen which may influence antler structure (and/or
antler cycle timing) are more evident under these defined living conditions. The
behavioral significance of the antlers may be of secondary importance depending
on social background of a studied herd and/or on previous social experience of
a male deer. In Žehušice, the bachelor group of stags is constant throughout the
year. The same animals encounter each other during the velvet period as during
the rest of the year. This results in a very stable social hierarchy. Social status
remains almost constant even after antler casting (Fig. 5) or antler breakage
(Bartoš 1986b). It is no wonder that there is a close correlation between rank
position and antler length, antler weight and the number of tines found also out
458 L. Bartoš
of the velvet period (Bartoš & Hyánek 1982b). In freeliving populations, reduc-
tion in gregariousness immediately after antler casting is known among red deer
stags (Biitzler 1974; Geist 1982; Lincoln et al. 1970). This may result in a less
pronounced relationship between rank position and antler size. Just before the
rut, bachelor groups completely disintegrate and stags widely disperse (Bützler
1974; CluttonBrock et al. 1982; Darling 1937; Lincoln etal. 1970; Nečas 1959).
During the rutting season, strange stags may be encountered. Sexual competition
during that time brings a strong motivation for fighting. This may encourage
stags to ignore experience gained in a bachelor group during the antler growth
that taught them to avoid an interaction with larger antlered individuals. That is
probably why CluttonBrock et al. (1979) did not find any simple relationship
between success in rutting fights and antler size. After the rut, stags usually
return to their original ranges (Biitzler 1974; CluttonBrock et al. 1982; Darling
1937; Lincoln et al. 1970). Winter groups thus consist mainly of stags which had
been present during antler development. Hence Appleby (1982) was able to
detect at least partly some relationships between rank and antler characteristics
in his winter observations. The behavioral meaning of fully grown antlers and the
physiological consequence of the stag's behavior on antler growth seem to have
quite a different basis. Behavioral meaning of the antler size of red deer stags
probably depends on social background of the studied population and previous
experience of an individual. Hence, there are a number of studies suggesting no
consistent tendency for males to avoid fighting individuals with larger antlers, at
least in red deer (Appleby 1982; CluttonBrock et al. 1979; Krzywiňski 1978;
Lydekker 1898), while under some circumstances there is evidence of an advan-
tage to bear large antlers (Bartoš & Hyánek 1982b; Bubenk, A. 1982b). The
physiological consequence of the stag's behavior on antler growth may act since
the beginning of the velvet period. The more dominant a stag, the higher the
seasonally attained levels of androgens, the greater the enhancement of antler tis-
sue formation. This suggestion has been supported by Shilang & Shanzi (1985)
who found that a small amount of androgens to sika deer stag's food during the
velvet period stimulated their antler growth. On the other hand, the lowest rank-
ing stags may lack this androgen stimulation and the presumably elevated
glucocorticoid levels may actually suppress antler growth (see Introduction). A
fall in social hierarchy in aged stags may be an initiation of their antlers "going
back." A. Bubenik (1982a) stated that in disorganized populations, a stag could
be "over the hill" at 1011 years, as opposed to 1618 years in stags of well
organized herds. In young male deer, the size of antlers increases with increasing
body size in succeeding seasons (Bubenik A. 1966; Goss 1983; Jaczewski 1981a).
The seasonal peaks of testosterone also increase in parallel with antler and body
growth, as was shown in red deer (Bubenik, A. 1984; Lincoln 1971a), roe deer
(Sempéré & Lacroix 1982), and whitetailed deer (Bubenik & Schams 1986).
Bubenik, G. et al. (unpublished, shown in Bubenik, A. 1982a) found in red deer
that young animals had the highest levels of Cortisol which then declined in prime
stags (410 years) and then rose again in old ones (11+ years).
Cameron (1892, cited in Goss 1983) was probably the first who reported the
primary importance of body weight in a combat of deer. He said that not males
17. Social Status and Antler Development 459
with heaviest antlers are favored in fights, but those with the heaviest body
weight. Clutton-Brock (1982) has argued that antler size is related to individual
differences in body size and weight. To support it, there is a large amount of evi-
dence for a relationship between body size and weight in red deer and antler
weight (Appleby 1982; Clutton-Brock et al. 1979, 1982; Huxley 1926, 1931;
Hyvärinen et al. 1977). Initially, there was no body weight data available for our
"white" stags. However, there were some indications that body weight did not
have exclusive influence on the relationship between rank position and antler
development (Bartoš et al. 1988). In the 1985 season, we succeeded in obtaining
the data of the relative body weight of the stags under study. A close correlation
between body weight of a stag and his rank position was found when the age was
statistically standardized (r = 0.79, P<0.01). On the other hand, a nonsignifi-
cant (P>0.05) correlation was apparent between body weight of a stag and the
size of his antlers (with eliminated influence of age) under the living conditions
of the park, while rank did not correlate with several antler characteristics such
as antler length, etc. When body weight was controlled by partial correlation,
rank correlated with antler length, number of tines, number of points on the
royal, bez tine, third point of the royal, and length of all the royal points. On the
other hand, when rank was controlled by partial correlation, there was still no
significant correlation between body weight and antler characteristics (Bartoš
et al. 1988). This was contrary to results of the above-mentioned authors.
Nevertheless, it has already been observed in Scotland that live weight need not
correlate with antler size in red deer (Suttie 1980b).
It may be concluded that the relationship between rank position of a stag during
the velvet period and intensity of his antler growth does exist regardless of his
body weight. Those studies showing relationship between body weight and antler
size of stags living in groups should be analyzed also from the point of view of the
stag's rank position in the same time, since under certain conditions rank position
may be even more influential on the antler growth than the body weight.
It can be concluded that the advanced hypothesis was confirmed. Dominance
in male red deer was found to be related to timing of antler cycle and antler
growth. The dominant individuals of socially stabilized group tend to cast and/or
clean antlers earlier and produce larger antlers than subordinate ones.
Acknowledgments. I gratefully acknowledge the excellent field assistant I have
had over many years from V. Perner, the former deerkeeper at Žehušice. I am
indebted to A.B. Bubenik, G.A. Bubenik, R.N.B. Kay, and G.A. Lincoln for
stimulative criticism of an earlier draft of the whole manuscript. Helpful com-
ments of P.T. Brain, T.H. Clutton-Brock, and V. Geist on the part of this chapter
originally prepared for other publication are also very much appreciated.
REFERENCES CITED
Anděl, J. 1978. Matematická statistika. SNTL, Praha.
Appleby, M.C. 1980. Social rank and food access in red deer stags.
Behaviour 74:294-309.
Appleby, H.C. 1982. The consequences and causes of high social rank
in red
deer stags. Behaviour 80:259-273, Appleby, M.C. 1983. Competition in
a red deer stag social group-rank, age and relatedness of opponents.
Anim.Behav. 31:913-918.
Bartoš, L. 1980. The date of antler casting, age and social hierarchy
relationships in the red deer stag. Behav.Process. 5:293-301.
Bartoš, L. 1985. Social activity and the antler cycle in red deer stags. In:
Biology of Deer Production. P.P. Fennessy i K.R. Drew (Eds.),
Roy.Soc.N.Z.Bull. 22:269-272.
Bartoš, L. 1986a. Dominance and aggression in various sized groups of
red deer stags. Aggress.Behav. 12:175-182.
Bartoš, L. 1986b. Relationships between behaviour and antler cycle
lining in red deer. Ethology 71:305-314.
Bartoš, L. &. J. Hyánek. 1982a. Social position in the red deer stag I.
The effect on developing antlers. In: Antler development in Cervidae,
R.D. Brown (Ed.). Caesar Kleberg Wildlife Research Institute,
Kingsville, 451-461.
Bartoš, L. & J. Hyánek. 1982b. Social position in the red deer stag II.
The relationship with developed antlers. In: Antler development in
Cervidae, R.D. Brown (Ed.). Caesar Kleberg Wildlife Research
Institute, Kingsville, 463-466.
Bartoš, L. 4 V. Perner. 1985. Integrity of a red deer stag social group
during velvet period, association of individuals, and timing of antler
cleaning. Behaviour 95:314-323.
Bartoš, L., V. Perner. t S. Loses. 1988. Red deer stags rank position,
body weight and antler growth. Acta Theriol. 33: 209-217.
Bartoš, L. , V. Perner. & B. Prochazka. 1988. On the relationship
between social rank during the velvet period and antler paraneters in a
growing red deer stag. Acta Theriol. 32:403-412.
Beninde, J. 1937. Naturgeschichte des Rothirsches. P. Schops, Leipzig.
Blaxter, K.L., R.N.B. Kay, G.A.M. Sharnan, J.H.M. Cunningham &
H.J. Hamilton. 1974. Farming the red deer. Department of Agriculture
and Fisheries for Scotland, Edinburgh Her Majesty's Stationary
Office.
Brain, P.P. 1980. Adaptive aspects of hormonal correlates of attack and
defence in laboratory mice - a study in ethobiology. In: Adaptive
Capabilities of the Nervous System. P.S. McConnell, G.J. Boer, H.J.
Ronijn, N.E. Vandepoll & M.A. Corner (Eds.), Elsevier North-
Holland Biomedical Press, Amsterdam, 391-413.
Brown, R.D., C.C. Chao & L.W. Faulkner. 1983a. The endocrine
control of the initiation and growth of antlers in white-tailed deer.
Acta Endocrinol. 103:138-144.
Brown, R.D., C.C. Chao 4 L.W. Faulkner. 1983b. Hormone levels and
antler development in white-tailed deer and sika fawns.
Comp.Biochen.Physiol. 75A:385-390.
Brown, R.D., R.L. Cowan & L.C. Griel. 1978. Correlation between
antler and long bone relative bone mass and circulating androgens in
white-tailed deer (Odocoileus virginianus). Amer.J.Vet.Res. 39:1053-
1056.
Bubenik, A.B. 1966. Das Geweih. Paul Parey Verlag, Hamburg, Berlin.
Bubenik, A.B. 1968. The significance of antlers in the social life of
the Cervidae. Deer 1:208-214.
Bubenik, A.B. 1982a. Physiology. In: Elk of North America, Ecology
and Management. J.H. Thomas 4 D.E. ToweiJU (Eds.). Stackpole
Books, Harrisburg, 125-179.
Bubenik, A.B. 1982b. The behavioral aspects of antlerogenesis. In:
Antler development in Cervidae, R.D. Brown (Ed.). Caesar Kleberg
Wildlife Research Institute, Kingsville, 389-449. Bubenik, A.B. 1984.
Ernarung, Verhalten und Umwelt des Schalenwildes. BLV
Verlagsgesellschaft, Miinchen, Wien, Zurich.
Bubenik, A.B. 4 G.A. Bubenik. 1976. Pigmentation in scrotal and other
hairs in deer as indication of sexual activity and social status.
Ann.Meet.Anim.Behav.Soc. No.241.
Bubenik, A.B., R. Tachezy 4 G. Bubenik. 1976. The role of the
pituitary-adrenal axis in the regulation of antler growth processes.
Saugetierkundl.Mitt. 24:1-5.
Bubenik, G.A. 1982. Endocrine regulation of the antler cycle. In: Antler
development in Cervidae, R.D. Brown (Ed.). Caesar Kleberg Wildlife
Research Institute, Kingsville, 73-107.
Bubenik, G.A. 4 A.B. Bubenik. 1965. Adrenal glands in roe-deer. 7th
Congr. IUGB, Beograd, Lublana, 93-97.
Bubenik, G.A., J.M. Morris, S.D. Schams 4 A. Claus. 1982.
Photoperiodicity and circannual levels of LH, FSH, and testosterone
in normal and castrated Bale, white-tailed deer.
Can.J.Physiol.Pharmacol. 60:788-793. Bubenik, G.A. 4 S.D. Schans.
1986. Relationship of age to seasonal levels of LH, FSH, prolactin and
testosterone in male white-tailed deer. Comp.Biochea.Physiol.
83A:179-183.
Butzler, W. 1974. Kampf- und Paarungsverhalten, Soziale
Rangordnung und Aktivitatsperiodik bein Rothirsch. Beiheft
Z.Tierpsychol. No. 16, Paul Parey Verlag, Hamburg, Berlin.
Chapman, D. 4 N. Chapman. 1975. Fallow deer. Terence Dalton,
Lavenham, Suffolk. Clutton-Brock, T.H. 1982. The function of
antlers. Behaviour 79:108-125.
Clutton-Brock, T.H. 4 S.D. Albon. 1979. The roaring or red deer and
the evolution of honest advertisement. Behaviour 69:145-170.
Clutton-Brock, T.H., S.D. Albon, R.M. Gibson 4 F.E. Guinness. 1979.
The logical stag: Adaptive aspects of fighting in red deer (Cervus
elaphus). Anim.Behav. 27:211-225.
Clutton-Brock, T.H., F.E. Guinness, S.D. Albon. 1982. Red deer,
behavior and ecology of two sexes. The University of Chicago
Edinburgh University Press, Edinburgh.
Crenshaw, D.B. 1983. Antler quality prediction by testosterone
radioimmunoassay after GnRH challenge in immature white-tailed
bucks. Caesar Kleberg Wildlife Research Institute, Annual Report, 8-
9.
Darling, F.F. 1937. A herd of red deer. Oxford University Press,
Hunphrey Milford, London.
Espmark, Y. 1964. Studies in dominance-subordination relationship in a
group of semi-domestic reindeer (Rangifer tarandus L.). Anim.Behav.
12:420-426.
Fennesy, P.F. 4 J.M. Suttie. 1985. Antler growth: nutritional and
endocrine factors. In: Biology of Deer Production. P.F. Fennessy 4
K.R. Drew (Eds.), Roy.Soc.N.Z.Bull. 22:239-250.
Forand, K.J., R.L. Marchington 4 K.V. Miller. 1985. Influence of
dominance rank on the antler cycle of white-tailed deer. J.Mammal.
66:58- 62.
Geist, V. 1966. The evolution of horn-like organs. Behaviour 27:175-
214. Geist, V. 1982. Adaptive behavioral strategies. In: Elk of North
America, Ecology and Management. J.W. Thomas 4 D.E. Toweill
(Eds.),
Stackpole Books, Harrisburg, 219-277.
Gibson, R.M. 4 F.E. Guinness. 1980. Differential reproduction among
red deer (Cervus elaphus) stags on Rhum. J.Anim.Ecol. 49:199-208.
Goss, R.J. 1969. Photoperiodlc control of antler cycles in deer. I. Phase
shift and frequency changes. J.Exp.Zool. 170:311-324.
Goss, R.J. 1983. Deer antlers, regeneration, function and evolution.
Academic Press, New York, London, Paris, San Diego, San
Francisco, Sao Paulo, Sydney, Tokyo, Toronto.
Haigh, J.C., W.F. Gates, G.J. lover & N.C. Rawlings. 1984.
Relationships between seasonal changes in serum testosterone
concentrations, scrotal circumference and sperm morphology of male
wapiti (Cervus elaphus). J.Reprod.Fert. 70:413-418.
Harding, C.F. 1981. Social modulation of circulating hornone leveles in
the male. Amer.Zool. 21:223-231.
Hirth, D.H. 1977. Social behavior of white-tailed deer in relation to
habitat. Wildlife Monogr. No.53:5-55.
Hughes, E. & R. Mall. 1958. Relation of the adrenal cortex to condition
of deer. Calif.Fish Game 44:191-196. Huxley, J.S. 1926. The annual
increment of the antlers of the red deer (Cervus elaphus).
Proc.Zool.Soc.Lond. 67:1021-1036.
Huxley, J.S. 1931. The relative size of antlers in deer.
Proc.Zool.Soc.Lond. 19:819-863.
Hyvarien, H. , R.N.B. Kay & W.J. Hamilton. 1977. Variation in weight,
specific gravity and composition of antlers of red deer (Cervus
elaphus). Brit.J.Nutr. 38:301-311.
Jacobson, H.A. 4 R.N. Griffin. 1982. Antler cycles of white-tailed deer
in Mississippi. In: Antler development in Cervidae, R.D. Brown (Ed.).
Caesar Kleberg Wildlife Research Institute, Kingsville, 15-22.
Jaczewski, Z. 1981. Poroze jeleniowatych. Panstwowe wydawnictwo
rolnicze i lesne, Warsaw.
Kozhukchov, M.B. 1973. Itogi 20-letnyey eksperimentalnoy raboty po
odomashnivaniyu losya v Petchoroilytcheskom zapovednike. In:
Odonoshnivanie losya, T.B. Sablina (Ed.), Nauka, Moskva, 17-27.
Krzywinski, A. 1978. Obserwacje nad sztucznym rozrodem jelenia
szlachetnego (Cervus elaphus L.). Ph.D. Thesis, Institute of Genetics
and Animal Production, Pol.Acad.Sci., Popielno.
Leshner, A.I. 1980. The interaction of experience and neuroendoccrine
factors in determining behavioral adaptation to aggression. In:
Adaptive Capabilities of the Nervous Systen. P.S. McConnell, G.J.
Boer, H.J. Romijn, N.E. Vandepoll & M.A. Corner (Eds.), Elsevier
North-Holland Biomedical Press, Amsterdam, 427-438.
Lincoln, G.A. 1971a. The seasonal reproductive changes in the red deer
stag (Cervus elaphus). J.Zool. 163:105-123.
Lincoln, G.A. 1971b. Puberty in a seasonally breeding male, the red
deer stag (Cervus elaphus). J.Reprod.Fert. 25:41-54.
Lincoln, G.A. 1972. The role of antlers in the behaviour of red deer.
J.Exp.Zool. 182:233-250.
Lincoln, G.A. 1984. Antlers and their regulation - a study using
hummels, hinds and haviers. Proc.Roy.Soc.Edinburgh 826:243-259.
Lincoln, G.A. & G.A. Bubenik. 1985. Antler physiology. In: Biology of
Deer Production. P.P. Fennessy & K.R. Drew (Eds.),
Roy.Soc.N.Z.Bull. 22:474-475.
Lincoln, G.A. & R.N.B. Kay. 1979. Effects of season on the secretion
of LH and testosterone in intact and castrated red deer stags (Cervus
elaphusl.) J.Reprod.Fert. 55:75-80.
Lincoln, G.A. , R.W. Youngson & R.V. Short. 1970. The social and
sexual behaviour of the red deer stag. J.Reprod.Fert.,Suppl. 11:71-
103.
Long, T.A., R.L. Cowan, C.W. Volte, T. Rader t R.H. Swift. 1959.
Effect of seasonal feed restriction on antler development of white-
tailed deer. Penn.Agr.Exp.Sta.Progress Report 209.
Lydekker, R. 1898. The deer of all lands. Rowland Ward, London.
Mirarchi, R.E., P.P. Scanlon & R.L. Kirkpatrick. 1977. Annual changes
in spermatozoan production and associated organs of white-tailed
deer. J.Wildlife Manage. 41:92-99.
Miura, S. 1984. Social behavior and territoriality in male sika deer
(Cervus nippon Temminck 1883) during the rut. Z.Tierpsychol.
64:33-73.
Nečas, J. 1959. Jeleni zver. SZN, Praha. Ozoga, J.J. & L.J. Verme.
1982. Physical and reproductive characteristics of a suplementally-fed
white-tailed deer herd. J.Wildlife Manage. 46:281-301. Scanlon, P.P.
1977. The antler cycle in white-tailed deer a review of recent
development. Trans.NE Deer Study Group, 64-67.
Sempere, A.J. 4 J. Boissin. 1982. Neuroendocrine and endocrine control
of the antler cycle in roe deer. In: Antler developnent in Cervidae,
R.D. Brown (Ed.). Caesar Kleberg Wildlife Research Institute,
Kingsville, 109-122. Sempere, A.J. 4 A. Lacroix. 1982. Temporal and
seasonal relationships between LH, testosterone and antlers in fawn
and adult roe deer (Caoreolus caoreolus L) - a longitudinal study from
birth to 4 years of age. Acta Endocrinol. 99:295-301.
Shilang, Z. 4 W. Shanzi. 1985. Studies of velvet antler, production of
sika deer. In: Biology of Deer Production. P.P. Fennessy & K.R.
Drew (Eds.), Roy.Soc.N.Z.Bull. 22:154.
Short, R.V. 1979. Sexual behavior in red deer. In: Animal
Reproduction, Beltsville Symposia, Vol.3, H.W. Hawk (ed.),
Allanheld, Osnan 4 Co, Montclair, 365-372.
Snedecor, G.W. & W.G. Cochran. 1965. Statistical methods applied to
experiments in agriculture and biology (fifth edition). The Iowa State
University Press, Ames, Iowa. Štěrba, 0. & K. Klusák. 1984.
Reproductive biology of fallow deer, Dama dama. Acta Sci.Nat.Brno
18:1-46.
Stokkan, K.A., K. Hove 4 W.R. Carr. 1980. Plasma concentrations of
testosterone and luteinizing hormone in rutting reindeer bulls
(Rangifer tarandus). Can.J.Zool. 58:2081-2083. Suttie, J.M. 1980a.
Influence of nutrition on growth and sexual maturation of captive red
deer stags. In: Proc.2nd Int.Reindeer/Caribou Symp. E. Reimers,
E.Gaare 4 S. Skjenneberg (Eds.), Roros, Trondheim, 341- 349.
Suttie, J.M. 1980b. The effect of antler removal on dominance and
fighting behaviour in farmed red deer stags. J. Zool. 190:217-224.
Suttie, J.M. 1985. Social dominance in farced red deer stags.
Appl.Anim.Behav.Sci. 14:191-199.
Suttie, J.M. 4 R.N.B. Kay. 1982. The influence of nutrition and
photoperiod on the growth of antlers of young red deer. In: Antler
develo¬pment in Cervidae, R.D. Brown (Ed.). Caesar Kleberg
Wildlife Research In¬stitute, Kingsville, 61-71.
Suttie, J.M., G.A. Lincoln 4 R.N.B. Kay. 1984. Endocrine control of
antler growth in red deer stags. J.Reprod.Fert. 71:7-15.
Topinski, P. 1975. Abnormal antler cycles in deer as a result of stress
inducing factors. Acta theriol. 20:267-279.
Van Ballenberghe, V. 1982. Growth and development of moose antlers
in Alaska. In: Antler development in Cervidae, R.D. Brown (Ed.),
Caesar Kleberg Wildl¬ife Research Institute, Kingsville, 37-48.
Watson, A. 1971. Climate and the antler shedding and performance of
red deer in North-East Scotland. J.Appl.Ecol. 8:53-67. West, N.O. &
H.C. Nordan. 1976. Hormonal regulation of reproduction and the
antler cycle in the male Columbian black-tailed deer (Odocoileus
heaionus coluabianus). Part I. Seasonal changes in the histology of the
reproductive organs, serum testosterone, sperm production, and the
antler cycle. Can.J.Zool. 54:1617-1636. Whitehead, O.K. 1972. Deer
of the world. Constable & Co, London.
Whitehead, P.E. & E.H. McEwan. 1973. Seasonal variation in the
plasma testosterone concentration of reindeer and caribou. Can.J.Zool.
51:651-658.
Wölfel, H. 1983: Zur Jugentwicklung, Mutter-Kind-Bindung und
Feindver-neidung beim Rothirsch (Cervus elaphus). Z.Jagdwiss.
29:143-162.
... In a study on captive red deer Cervus elaphus we demonstrated that males of higher rank cast their antlers first and also tended to shed the velvet earlier than subordinate ones (15,16). In subsequent studies performed on the same species we found evidence that the social position and the related agonistic activity of males during the velvet period influence antler weight and length and the number of points. ...
... In subsequent studies performed on the same species we found evidence that the social position and the related agonistic activity of males during the velvet period influence antler weight and length and the number of points. These studies have suggested that the antler size is a consequence of the previous social position and not vice versa (16,17). Later we presented evidence that in fallow deer Dama dama the changes in behavior, which were related to rank, modified antler growth. ...
... Conversely subordinate status seemed to be associated with lower androgen secretion and increased levels of glucocorticoids (21,22). Therefore, since the very beginning of our investigations, we assumed that the mechanism of the relationship between rank position and antler cycle timing lies in presumably elevated levels of testosterone in dominant males and decreased concentrations in subordinate individuals (15,16). ...
... During the period of the most rapid antler growth, higher IGF-1 [25,28,31,35] and testosterone [4] values may support antler growth. This relationship might be in place until testosterone reaches levels leading to the suppression of IGF-1 ( [16] and this study), and a consequent mineralization of antler tissues [7]. ...
... This relationship might be in place until testosterone reaches levels leading to the suppression of IGF-1 ( [16] and this study), and a consequent mineralization of antler tissues [7]. If this was true, then dominant pudu males should produce larger antlers than subordinate ones, as reported in several other deer species, such as sika [22], red [4], and fallow deer [5]. Although observations over many years indicate that dominant males of prime age develop the largest antlers (Reyes, unpublished), the specific data that might prove our speculation are not yet available. ...
Article
Full-text available
Pudu (Pudu puda) is the smallest deer of the world. It exhibits a unique seasonal cycle of reproduction, characterized by the biannual peaks of LH and testosterone. In order to elucidate the regulation of reproduction in pudu, plasma concentrations of LH, FSH and testosterone were measured in 3 pairs of adult males (dominant and subordinate), sampled before and after intramuscular administration of GnRH (50 mu g/deer) given at the end of January, one month before the onset of the rut. The hormonal response to GnRH, studied in three pairs of bucks (each pair sharing one pen) was evaluated according to dominance relationship. Unlike the subordinate bucks, the dominant animals responded to pretreatment procedures with rising levels of all three hormones. In all deer, GnRH administration substantially increased LH and testosterone levels, whereas FSH levels did not change significantly. The elevation in testosterone levels after GnRH was significantly higher in dominant bucks, as compared to subordinate ones. Conversely, an opposite trend, higher LH values were detected in the subordinate deer. The variation of FSH levels after GnRH did not differ between both groups. The data from pudu were compared to GnRH stimulation tests performed in other cervids.
... Thus, antler size and complexity vary greatly with an animal's age, which is evident when one compares the spike antlers of a red deer yearling with the impressive multi-tined rack of a prime-aged stag. Among the extrinsic factors affecting antler size and shape, nutrition is likely the most important one (Bartoš, 1990;Brown, 1990;Demarais & Strickland, 2011;Vogt, 1936). ...
Article
Full-text available
Antlers are the most conspicuous trait of cervids and have been used in the past to establish a classification of their fossil and living representatives. Since the availability of molecular data, morphological characters have generally become less important for phylogenetic reconstructions. In recent years, however, the appreciation of morphological characters has increased, and they are now more frequently used in addition to molecular data to reconstruct the evolutionary history of cervids. A persistent challenge when using antler traits in deer systematics is finding a consensus on the homology of structures. Here, we review early and recent attempts to homologize antler structures and objections to this approach, compare and evaluate recent advances on antler homologies, and critically discuss these different views in order to offer a basis for further scientific exchange on the topic. We further present some developmental aspects of antler branching patterns and discuss their potential for reconstructing cervid systematics. The use of heterogeneous data for reconstructing phylogenies has resulted in partly conflicting hypotheses on the systematic position of certain cervid species, on which we also elaborate here. We address current discussions on the use of different molecular markers in cervid systematics and the question whether antler morphology and molecular data can provide a consistent picture on the evolutionary history of cervids. In this context, special attention is given to the antler morphology and the systematic position of the enigmatic Pere David's deer (Elaphurus davidianus).
... An evolved hypothesis suggested that the individual attitude should modify T and C concentrations in a way that the individuals which avoid attacking others should have lower C and T concentrations than those who attack others often. Dominant position in the hierarchy is generally thought to be related to higher concentrations of androgens in the blood that will trigger a more aggressive behavior (Bartoš 1990; Bartoš and Losos, 1997;Bartoš et al. 2000;Wingfield et al. 1990) and lower pituitary/adrenocortical activity than the submissive animals living with them (Rose et al. 1971). Conversely, subordinate individuals are expected to have low levels of androgens and high concentrations of corticosteroids (Bartoš and Losos, 1997;Brain 1980;Leshner 1980), with the latter suppressing the first (Brain 1980). ...
Article
Out of rut, male red deer (Cervus elaphus) associate themselves in bachelor groups where animals compete for rank position via agonistic interactions. In a previous study on red deer, males were recognized either as “Non-Fighters” (NF, low frequency of attacks) or “Fighters” (F, high frequency of attacks). This study, therefore, aims to verify the consistency of the inter-individual differences in fighting attitude across different social contexts and investigate whether they could be considered an individual characteristic. Behavioral consistency was presumed across three different sampling seasons, assuming that NF would have lower cortisol (C) and testosterone (T) concentrations than the F males. In 2015 the males were kept in one large group and labelled NF and F. In 2016, the herd was divided into two subgroups (“NF” and “F”) based on the frequency of attacks. Finally, in 2017, the males were divided into two randomly composed subgroups. Data about agonistic behavior and concentration of C and T were collected during each season. In 2015 the individuals differed only for the fighting attitude. After the division, the frequency of the attacks always increased, being consistently lower in NF than in F. Unexpectedly, a slight increase in the concentration of C was detected in the NF in 2016, compared to the F who experienced no difference neither in 2015 nor 2017. No significant differences were found in T. We concluded that, even though the males had shown behavioral plasticity, their diversified interaction-prone attitude had been maintained despite the modifications of the social environment.
... In many deer species, males which achieve a high position in the social hierarchy tend to have greater body size and weight than males of lower positions [white tailed-deer (Odocoileus virginianus): Townsend and Bailey, 1981;fallow deer: McElligott et al., 2001]. Also, in deer, antler size is positively related to the social rank possessed during the period of antler growing (Bartoš, 1990;Bartoš and Losos, 1997). Antlers from males of higher positions in the social hierarchy cast and grow earlier than those of lower positions, suggesting that males of higher positions experience an earlier increase and a greater frequency of testosterone pulses (see reviews: Bartoš and Bubenik, 2011;Bartoš et al., 2012). ...
Article
An animal's social environment can influence individual physiological and reproductive status, which might have implications for the success of ex situ conservation programs. This study investigated the relationship between an individual's position in the social hierarchy, body and antler size, testosterone concentration, and seminal traits in male pampas deer maintained in all-male groups. The study was performed in a semi-captive population in Uruguay during the rut. Data were collected over a 4 year period from 18 different males kept in five groups each of 4-7 adult males (2-7 y old). An index of individual hierarchical success (hierarchical index; HI) was determined based on agonistic interactions with other males within the group. Males positioned higher in the social hierarchy had larger antlers (p = 0.02). In three out of four groups, testosterone was positively correlated with HI (p < 0.0001). Semen vitality was negatively related to HI in three groups (p < 0.0001); however, a positive relationship was observed in another group (p < 0.0001). In conclusion, position in the social hierarchy of semi-captive male pampas deer was positively related to antler size, and in most groups negatively related to semen vitality.
... We have shown that the structural characteristics of antler are reliable in identifying samples with a useful degree of phylogenetic precision-these two species are separated only by subfamily: Cervinae for red deer and Capreolinae for reindeer [68]. More generally, although the expression of the phenotype could be influenced by multiple endogenous (sex, age, and heredity) and exogenous (nutrition, photoperiod, accidents during development, and social relations) factors specific to each individual [69][70][71][72][73][74][75], the morphometric criteria identified in this study nonetheless appear to be promising biomarkers. ...
Article
Full-text available
Over the last decade, biomedical 3D-imaging tools have gained widespread use in the analysis of prehistoric bone artefacts. While initial attempts to characterise the major categories used in osseous industry (i.e. bone, antler, and dentine/ivory) have been successful, the taxonomic determination of prehistoric artefacts remains to be investigated. The distinction between reindeer and red deer antler can be challenging, particularly in cases of anthropic and/or taphonomic modifications. In addition to the range of destructive physicochemical identification methods available (mass spectrometry, isotopic ratio, and DNA analysis), X-ray micro-tomography (micro-CT) provides convincing non-destructive 3D images and analyses. This paper presents the experimental protocol (sample scans, image processing, and statistical analysis) we have developed in order to identify modern and archaeological antler collections (from Isturitz, France). This original method is based on bone microstructure analysis combined with advanced statistical support vector machine (SVM) classifiers. A combination of six microarchitecture biomarkers (bone volume fraction, trabecular number, trabecular separation, trabecular thickness, trabecular bone pattern factor, and structure model index) were screened using micro-CT in order to characterise internal alveolar structure. Overall, reindeer alveoli presented a tighter mesh than red deer alveoli, and statistical analysis allowed us to distinguish archaeological antler by species with an accuracy of 96%, regardless of anatomical location on the antler. In conclusion, micro-CT combined with SVM classifiers proves to be a promising additional non-destructive method for antler identification, suitable for archaeological artefacts whose degree of human modification and cultural heritage or scientific value has previously made it impossible (tools, ornaments, etc.).
... Other Cyprinella overwinter as adults (Matthews et al. 2001), and we suspect, based on field collections and our observations of captive fish, that fins regress during the non-breeding season (personal observations). In red deer (Cervus elaphus), the timing of antler loss is dependent on social status and condition (Bartoš 1990), and freshwater fish may provide an exciting opportunity to explore convergent implications of male-male competition on the timing of annual developmental cycles. ...
Article
Adaptive phenotypic divergence can arise when environments vary in ways favoring alternative phenotypic optima. In aquatic habitats, the costs of locomotion are expected to increase with water velocity, generally favoring a more streamlined body and the reduction of traits that produce drag. However, because streamlining in fish may come at the cost of maneuverability, the net benefits of drag reduction can differ not only among habitats, but also among individuals (or classes of individuals) that rely on locomotion for different uses (e.g., males vs. females or adults vs. juveniles). We tested these predictions by exploring relationships among river velocity, body streamlining, ornamental fin size, and male reproductive condition in the steelcolor shiner (Cyprinella whipplei), a small-bodied North American cyprinid. Overall, males in peak reproductive condition (defined by the development of sexually dimorphic tubercles) had less streamlined bodies and larger ornamental fins than males in lower reproductive condition or individuals lacking these secondary sexual characters (females and immature males). There was a relationship between river velocity and body streamlining only for males in peak reproductive condition, but it was in the opposite direction of our predictions: these males were less streamlined in faster rivers. We found only weak support for the prediction that ornamental fin size would be negatively associated with river velocity. Overall, these results suggest either that drag is not an important selective pressure in these habitats, or that the sexual selection advantages of a deep body and large fin compensate any natural selection costs for C. whipplei males. This study highlights the often overlooked diversity of selective pressures acting on streamlining in fishes, and can offer novel insights and predictions allowing a more nuanced understanding of fish ecomorphology.
... nippon), wapiti (C. canadensis), roe deer (Capreolus capreolus), and fallow deer (Dama dama); but in others, such as white-tailed deer (Odocoileus virginianus), reindeer (Rangifer tarandus), and moose (Alces alces), new antler growth may begin only after a period lasting from several weeks to several months (Bartos 1990). The growth of velvet antlers stops about 3-4 mo later, before the beginning of another rutting season, and soft antlers begin to mineralize into hard antlers in response to rising levels of testosterone. ...
Article
Full-text available
Kurtis Jai-Chyi Pei, Kerry Foresman, Bing-Tsan Liu, Long-Hwa Hong, and John Yuh-Lin Yu (2009) Testosterone levels in male Formosan Reeve's muntjac: uncoupling of the reproductive and antler cycles. Zoological Studies 48(1): 120-124. Cervid species are generally assumed to be seasonal in their reproductive activity, and species that develop antlers also do so in a seasonal manner in conjunction with this annual puberty. As gonadotropin endocrine support for reproductive activity wanes, the resultant lowered testosterone levels initiate antler casting. Male Formosan Reeve's muntjac (Muntiacus reeves micrurus) exhibits an annular antler cycle with growth initiating in early May, velvet shedding and antler hardening by early Sept., and casting the following May. This cycle was correlated with fluctuating testosterone levels in a manner somewhat similar to that observed in other cervids. However, this species remains reproductively active year-round with spermatozoa present in the testes and epididymides, with no variation in their quantity or quality. These findings suggest that the testosterone threshold required for antler development in this muntjac may be set higher than that required for spermatogenesis, or conversely, that spermatogenesis might be controlled by other hormones in addition to testosterone. http://zoolstud.sinica.edu.tw/Journals/48.1/120.pdf.
Article
Morphological scaling relationships, or allometries, describe how traits grow coordinately and covary among individuals in a population. The developmental regulation of scaling is essential to generate correctly proportioned adults across a range of body sizes, while the mis‐regulation of scaling may result in congenital birth defects. Research over several decades has identified the developmental mechanisms that regulate the size of individual traits. Nevertheless, we still have poor understanding of how these mechanisms work together to generate correlated size variation among traits in response to environmental and genetic variation. Conceptually, morphological scaling can be generated by size‐regulatory factors that act directly on multiple growing traits (trait‐autonomous scaling), or indirectly via hormones produced by central endocrine organs (systemically regulated scaling), and there are a number of well‐established examples of such mechanisms. There is much less evidence, however, that genetic and environmental variation actually acts on these mechanisms to generate morphological scaling in natural populations. More recent studies indicate that growing organs can themselves regulate the growth of other organs in the body. This suggests that covariation in trait size can be generated by network‐regulated scaling mechanisms that respond to changes in the growth of individual traits. Testing this hypothesis, and one of the main challenges of understanding morphological scaling, requires connecting mechanisms elucidated in the laboratory with patterns of scaling observed in the natural world. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Comparative Development and Evolution > Organ System Comparisons Between Species
Article
Full-text available
Antler cycles are convenient external signs indicating internal changes in reproductive status of male deer. Antler phenology of chital (Axis axis) and sambar (Rusa unicolor) were studied in a deciduous habitat of Mudumalai Tiger Reserve, Western Ghats, using vehicle transects for 2 successive years. Apparent breeding seasonality occurred with the majority of adult stags in hard antlers from May to mid October in chital (>87 %), and October to May in sambar (>68 %). Adult hard antler in chital correlated with mean group size, while sambar showed a weak correlation between adult hard antler and group size. Chitals prefer forming large groups at forest edges and open habitats while sambars prefer dense vegetation cover. Adult hard antlers in chital and sambar showed a weak relation to fawning since most adult females were in oestrus during the peak rutting season. Adult hard antlers in chital associated positively with rainfall and day length while sambar responded weakly to rainfall. We conclude that environmental variables determined species-specific mating strategies in the two deer species.
Chapter
The antlers are one of the secondary sexual characters of males in all genera of Cervidae except Rangifer (where antlers are found in both sexes). Their development, seasonal renewal, maturation, and casting are closely related to the activity of the reproductive system. This fact was already well known to Aristotle, who described the alterations of antlerogenesis caused by castration (Goss 1968). However, it took another 2,000 years before progress in chemistry and endocrinology made it possible to investigate the detail roles of various humoral factors in the regulation of the antler cycle.
Article
The left testis and epididymis were collected from each of 60 wild adult (>12 months old) male white-tailed deer (Odocoileus virginianus) over approximately 1 year in southwest Virginia. Testes and epididymides were weighed separately and numbers of spermatozoa in each organ were determined. All gonadal parameters were at baseline values from February through June. Testis and epididymis weights and testicular spermatozoan numbers rose markedly from June to July. Epididymal spermatozoan numbers increased from July to August as storage of spermatozoa began. Testis and epididymis weights (g) and testicular and epididymal spermatozoan numbers (× 109) increased to maximum values (46.76 ± 8.16 S.E., 7.40 ± 1.11 S.E., 4.406 ± 0.577 S.E., and 6.602 ± 1.600 S.E., respectively) during November when does normally are bred in southwest Virginia. Male deer apparently have breeding capability and sexual libido from the latter part of September through January in the study area. However, the breeding capability of the male had begun to diminish in December as indicated by the regression of all gonadal measurements.
Article
When subjected to reversed light cycles, deer antlers are shed and regenerated six months out of phase with respect to the outdoor environment. They respond solely to the lighting conditions, not to temperature changes. Deer exposed to accelerated years grow antlers more frequently than normal, but in no cases do they produce them more often than every three months. When the annual light cycle is prolonged to 24 months, deer tend to grow antlers every other year in accordance with the artificial cycle. In general, deer forced to grow antlers more frequently than normal produce stunted outgrowths owing to the abbreviated years. Those maintained on extra long light cycles, however, do not grow extra large antlers. Analysis of these data suggests that the onset of antler growth is entrained by increasing day lengths in deer previously sensitized by decreasing days. However, older animals can sometimes express an endogenous yearly antler growth cycle irrespective of certain prevailing artificial lighting conditions.