self- male urine; and 3) TGS, both self and conspecific. The bulls' flehmen ..... castrated. Asian bull was. 0.08 ng/ml. The low. T values agree with the bull's.
BIOLOGY
OF
REPRODUCTION
30,
Testosterone
(1984)
and Dihydrotestosterone
Elephant LOIS
3 52-362
Serum
and Temporal
E. RASMUSSEN,”2 IRVEN and MICHAEL Department
Chemistry
of
Oregon
Gland
J.
0. BUSS,3 SCHMIDT5
and
Biochemical
Graduate
Beaverton,
Oregon
Department
in
Secretions DAVID
L. HESS4
Sciences2
Center 97006
of Zoology3
Washington
State
Pullman,
Washington
Reproductive Oregon
Concentrations
University
99164
Physiology4
Primate
Research
Beaverton,
Oregon
Center 97006
and
Washington
Park
Portland,
Oregon
Zoo5 97221
ABSTRACT
Serum donta
and temporal
africana)
and
gland
captive
Asian
cows and eight bulls culled from four females and two pose
was
to
describe
the
(TGS)
secretions
elephants
were obtained
(Elephas
from mature wild African (LoxoSamples were obtained from five National Park, South Africa, and
maximus).
for management purposes in Kruger males residing at the Washington Park Zoo, Portland,
levels
of the
androgens,
testosterone
(T),
Oregon. dihydrotestosterone
and
Our pur(DHT),
these observations with sex, species and behavioral status. differences in serum T were pronounced in the Asian species, whereas male and female concentrations overlapped in the African elephant serum. Serum T concentrations in African females were greater than in Asian females. Serum DHT reflected T levels, except that the striking elevation of testosterone in Asian bulls during musth was not paralleled by equal increases in DHT levels. A species difference observed among males was higher serum T levels in nonmusth Asian bulls (1.84-5.35 ng/ml) compared to the levels in African bulls (0.38-0.68 ng/ml), except for one dominant African bull (6.64 ng/ml). This single African value was still considerably lower than the serum T values of the Asian males during musth. These musth values were the highest serum androgen concentrations: T was between 19 and 40 ng/ml (average 26.10 ng/ml). The TSG values of T and DHT were much higher than serum levels except in the Asian female. T/DHT ratios in TGS were more similar than in serum, One dominant African bull had a T TGS value of 78 ng/ml, which was much higher than the rest of the African males or females, but considerably lower than as Asian bull in musth (547 ng/mI). It seems apparent that a change in androgen status as reflected in serum and TGS levels of T and DHT precedes or is concomitant with overt alteration in behavior in the Asian male. The temporal gland appears to actively concentrate androgens in both African males and females, but in the Asian male the gland secretes only during musth when the greatest concentration of both T and DHT were observed. The apparent difference in the degree of temporal gland secretory activity between the two species suggests a more specific communicative function within the Asian male. and to correlate Male-female
INTRODUCTION
The Accepted Received Reprint
October July
5
18, 1983.
19600
Dr.
L. NW
gland,
a
modified
apocrine
sweat gland located in the temporal fossa (behind the eyes), is a gland unique to elephants
1983.
requests:
Graduate Center, OR 97006.
temporal
E. Rasmussen, Walker Rd.,
and
Oregon
possessed
by
and
Asian
both
African
(Loxodonta
.
Beaverton,
afrcana) with little
-
352
histological
(Elephas and
ma.ximus) anatomical
species variation
ANDROGEN
(Schneider,
1956;
et al., function(s)
1971; Estes and Buss, of this gland are not
berg
lineated structure
despite and
tionary
history
Fernando
CONCENTRATIONS
of
both
gland
is
active
functions, and
during
periods
a variety chemical
helpful
when of
the
bull
possible
hormonal
each
with among
of
inter-
Asian
with
1966); groups
primarily of 5 to
cows
1967). Although characteristics
to
mate
(Buss
the males 35 individuals
and
of
tions (TGS) in preparation),
(Wheeler and
the
temporal
gland
et al., 1982; the frequency
differ between species (Eisenberg and sexes. Female Asian elephants any TGS (Jainudeen years of observations,
et al., 1972). only three of
do not. “musth”
Unique period
and striking for millennia. “At
Asian
time
he
material through has beside his piece, condition
many
1971) exude
a kind
During 3 the eight
have
Asian
described
bull
the
Schmidt,
1978),
as well
as a recent
fatty
in
average,
et
2
testosterone
(T),
in the
as well
1979),
principal
might
be
including
al., The
et al.,
purposes and TGS
serum
development
increased
of Asian
bulls.
attractive since serum T levels
eta!.,
and
Boissin,
females (Macrides M#{252}ller-Schwarze
et and
activity
(Phoenix
et al.,
et al., 1972; Goncharov dominance (Rose et al.,
1981).
of our ranges
and
study were to: of T (essential
maintenance
of
tion
on
the
degree
of
the
Asian
of and
relationship
T
establish for the
male
an indication of aggressive (T/DHT ratios give indirect
the
many corre-
1981;Mossing
Sempere
ality and of DHT
sexu-
states) and informa-
conversion)
in
both
African
elephants,
and
between
dominant
and
aggressive behavior, serum T levels, TGS T levels, and TGS frequency and intensity. Our study was the first measurement of T in both TGS first tions
a
1977),
the
androgen,
as seasonal breeding et al., 1974; GustafMcMillin et al., 1976;
sexual
Maurel
that
male markedly
as TGS
(Rose or male
stress
are similar to species (Guhl,
Breipohl, 1982; Wysocki et levels (Dixson and Gardner,
1980;
or
domi(Schmidt,
suggesting
the
activity
1977)
behavioral
behaviors in other
1981;
1981),
several
aggression,
1981;Maurel
Damber,
1983),
synchro-
unpredictability
a!.,
of
et al.,
not
although
accompanies
aggressive described
serum
are
increased and
Rose
African
1955; 1971; 1976; of
Such
record
musth
report
1978).
sexes
(Strabo,
1839; Sanderson, 1896; Deraniyagala, McGaughey, 1963; Eisenberg et al., Jainudeen et al., 1971b; Buss et al.,
displays,
1979;
apparently
elephants
nance
et
Zoo (WPZ) noted oc-
of
gland
al.,
changes have been noted (63 B.C.-21 A.D.) wrote, discharges
occurs both
Prior to and/or during musth of a darkish secretion from the
including
Silverstein,
the breathing hole which he temples.” Since this ancient
writers in
elephants
temporal
bulls
episodes,
1981), exposure to estrous al., 1974; Johnson, 1977;
to Asian bull elephants is a during which gland secretions
behavioral Strabo
that
bull
all
musth be.
and
curred only during periods of stress such as calving or cow group changes. Young African elephants secrete TGS (Buss et al., 1976), young
and
their
bulls might the liberation
Degen
secre-
et al., rarely
and
months;
lated to factors such (Neaves, 1973; Berndston son and Shemesh, 1976;
Rasmussen, of secretion
Asian cows at the Washington Park produced TGS; the slight secretion
although
bull
varying
day-9
This hypothesis is very male mammals have high
or in John-
not fully described, the physical (McGaughey, 1963), the chemi-
composition
bulls,
1
sense, in
1961;
son,
cal
elephant
different
concentrations
Smith,
live alone (Buss and
(range,
aggression
and African elephants (Buss and Smith, 1966; Buss and Johnson, 1967; Eisenberg et al., 1971; McKay, 1973; Hamilton and Hamilton, 1975; Eisenberg, 1980). Adult African bulls associate briefly
individual
duration
changes,
dominance both
an in
nous
Well-defined social cows with calves and
established
for
irregularly
rigorous
understanding
and
groups,
are
African
1981).
months) and in month of occurrence (Jainudeen et al., 1972). Musth is not seasonal in a
communication
towards
between sexes. family units of
hierarchies,
in
Moss,
year
(Slym,
Evans, 1910). and bull ele-
recognition (Buss et al., 1976). of the societal organization
individual
condition
and
1878;
gland 1896; of cow
communication
actions groups,
(Poole
as a viable
suggest
is
chemical
similar
elephants
The de-
Musth in the Asian bull elephants occurs periodically, usually annually or biannually during approximately the same month each
including
elephants
presumably
Eisen-
1976). clearly
353
of its evolu-
species
individual Knowledge
1963;
ELEPHANTS
numerous descriptions its persistence through
Steel, 1885; Sanderson, Behavioral observations phants
et al.,
IN MALE
and
serum
from
elephants.
In
comparison of these
of two
captive addition,
Asian we
or report
wild the
T and DHT in the secrespecies, including several
samples of secretions from ing intensities of musth.
Asian
bulls
in vary-
RASMUSSEN
354
MATERIALS
AND
METHODS
mediately frozen in dry ice and thawed only once for aliquot subdivision. TGS was collected at the same time in glass syringes and frozen in glass vials (Wheeler et al., 1982). For the Asian elephants, the unique hydraulically operated restraining chute at WPZ enabled the unanesthetized holding of elephants, including dangerous bulls Zoo staff obtained blood from both cows and bulls via either the ear or leg veins. Samples were obtained between 0800-1400 h. Four females and two males were sampled in duplicate
serum.
were obtained Bull #1. The serum sample Bull #3 was a single sample. As often as feasible, serum samples were also obtained from Bulls #1 and #2 in musth. Three simultaneous serum and musth secretion samples, and a single serum sample were obtained from Bull #2, whereas only a single simultaneous serum and TGS sample was obtained from Bull #1. The paucity of samples from Bull #1 was the result of his use in another program. Asian elephant blood samples were processed identically to the African elephant blood samples, both in the field and in the laboratory. T and DHT were assayed in duplicate or triplicate (fluid volume dependent) in volumes ranging from 0.5-1000 MI by radioimmunoassay in both Asian and African samples after ether extraction and separation by column chromatography on Sephadex LH-20 (Resko et al., 1980). Average blank values (assay buffer) for the T and DHT assays were 3.5 ± 1.8 and from
Bull
18.6 coveries
±
Four
#2
nonmusth
samples from
and one sample from the castrated
9.8 pg respectively, after chromatography
while the percent of rewere 69.8% and 71.0%, were corrected for both
respectively. Reported values blank and extraction/chromatographic losses. Intraand interassay coefficients of variation did not exceed 17% for either assay. The Asian elephants’ samples were
compared
with
serum
and
TGS
African elephants. The unique nature of the single female Asian TGS sample and the serum sample from the castrated bull merit their inclusion in this study. The behavioral observations were recorded by one of the authors (L.E.R.) and three trained postgraduate student volunteers during a 3-year period. One bull was observed 1.5 h, 5 days a week in a systematic manner. The second bull was observed less systematically. Additional observations by four elephant keepers were included in the data. The traits scored as characteristic of and occurring only during musth in two Asian bulls were: TGS; urine dribbling; retracted penis; glazed eyes; and reduction in food and fluid intake. Aggressive acts such as charging the keepers and ‘trunking” other elephants occurred during musth, and there was deliberate destruction of objects ordinarily ignored. Such behaviors were seldom seen during the 9to 12-month nonmusth interval. Flehmen responses to self and conspecific urine, and to self and conspecific TGS, are listed and scored in Table 1. Scoring of total urinations was somewhat random in 1981 but was systematized in 1982-83. The number of urine spots flehmened to was listed as percent of flehmen response. Investigator-placed samples included: 1) conspecific male urine; 2) selfmale urine; and 3) TGS, both self and conspecific. The bulls’ flehmen responses were scored. A bull occasionally rubbed some TGS on the posts or walls; the responses of the other bull are recorded in Table 1. twelve
serum and twelve TGS samples from eight male and five female African elephants were obtained during culling operations at Kruger National Park, South Africa.6 Some of these samples were the same as described by Wheeler et al. (1982). The animals were sacrificed either by gunshot or overdoses of the neuromuscular relaxant, succinyl choline chloride, between 0800-1400 h. The disadvantages of these methods for the obtainment of TGS and serum were recognized, but at the time these were the only possible ways to obtain simultaneous TGS and serum samples. Recognizing the stressful conditions, highly elevated T, perhaps resultant from adrenal stimulation of T production, was anticipated. None of these African bulls were considered to be in a musth state equivalent to that described for Asian bulls, although two were characterized as dominant males. In the field, the first priority immediately after the African elephants were killed was the drawing of blood samples from the leg vein. The samples were immediately refrigerated. After clot formation, the samples were centrifuged using a hand-operated field centrifuge. The serum was removed and imTwelve
for
ET AL
samples
from
RESULTS Behavioral
Observations
Musth
Figure
records.
10-year
record
gressive
behavioral
similar years. the
data They
of
G. L. Smuts,
see Acknowledgments.
one
bull
temporal episode, overt
gland. During this secretion sign.
agand
the past 3 Table 1,
in
and
changing
times. Musth in these Asian bulls definitively indicated by secretion
Conversely,
was most from the
a short, light musth was usually the sole occasionally
just
prior
to
or just after overt secretion, behavioral characteristics of musth occurred with or without secretion. Heavy musth was characterized by wet
urine
on
the
hind
legs
resulting
from
con-
tinua! uncontrolled urine dribbling, a retracted penis, and dulled, reddened, glazed eyes. Its intensity was indicated by the label, DRAIN, in Fig. (12
1. Especially years) Table
Dr.
duration
unique and
musth episodes. These records in selecting musth collection
of onset 1
increasingly
to be noted of musth
summarizes
bulls for 3 years, des per bull. Data 6
for
bull during as listed
patterns,
of the utilized
intensities
changes
for a second demonstrate,
temporal
length were
the
1 shows
secretion
including during
systematized.
was the in Bull
early
age
#1.
observations
of
three the last
musth episo2 years were
two
ANDROGEN 1. Musth
TABLE
behavioral
CONCENTRATIONS
observations.
Asian bulls’
IN MALE
responses
355
ELEPHANTS
to urine
and TGS. Nonmusth
Musth 1982b
1981a
Bull
interval
interval
#1
1983
Bull #1
Bull
1981-1983
Bull
#1
#2
Bull
#1
(92)c
(120)
(65)
(120+)
10 20
20 40
35 80
8 66
98 1
Bull #2 (985)
(804)
URINE Random
bull
urinations
Totalurinationsobserved Percent
flehmen
response
5 0
Aliquot placed by investigator Flehmen responses Self-urine
Testi Test2 Conspecific
1 1
0
2
2 4
2 3
0 0
---
---
---
---
SECRETION on walls
by
flehmens
observed
Conspecific
other
bull
-
-
-
-
---
#2
bBull
#2 musth
musth
period
1982
to
from
contact
and
when
of
to
Observer-placed formerly
represented flehmen
the
a single
-
2
1
-
-
-
-
-
-
-
-
behavioral
observations).
(no
---
---
observations).
secretions
from
---
bull,
to secrete
began
from
dry
not
in
than
700
h
flehmen musth
during spots
response a bull
dur-
episodes
the observation evoked flehmen (Table
1). Bull
were
watched
samples from same
responses
recorded. only
or other (Table
75 bull,
1).
ml bull
flehmen
in
responses
hard
to
bulls’
responses
several several other
#1
musth
obtain,
Asian
bull,
1).
Musth
we
were
able
to self
and
to secretions
suggesting communication
coland
by
TGS.
Bull
#1
#2
was
added
to
was
both
secretion
on
born
group
a wall
flehmen
interactions. occurred
possible chemical between the the
is
secretion
to test
bioassay situation; of a bull’s flehmen
similar
(Table 1). Bull-to-bull chemical esting set of observations
pre-
evoked
conspecific
rubbed
showed
secreand
also
(Table
but
The
resulted
collected
times in a controlled random observations bull
Musth
secretion.
musth,
a different
to
response
randomly.
of urine, an in-musth
to a bull
from
sented
were
in 1983.
Responses
tion
bulls
During
self-urine
to the
musth’
‘in
periods
to
WPZ distinctly
two
daily during the 1983 musth 76 days; a total of 28 flehmen was
other
the
musth
more for
flehmen/h
during
Responses the were
recorded
occurred the urine
1-4
feces.
the
during
period.
was observed episode lasting bull
2
(no behavioral
alternately
urine by episodes
1982)
a nonmusth
yard
and musth
was
when urination period, 2/3 of
with
urine
eta!.,
responses
1
3d
occasions.
once
observation
lected
1982 was 90 days
those
Only
second
interval
not let out into
(Rasmussen
was 61 days
1981
on ten
Responses
responses
e
-
1
-
---
interval
#1, after
their own feces elephants during musth.
-
(days).
Bull
temporal gland eBulls were
different
e
-
----
---
Total
-
-
secretion
a.Bull
in 1-4
1d
1
Testi Test2
d1
0
urine
Aliquot placed by investigator Flehmen responses Self-secretion
ing
3
2
Test2
Total
of
2
---
Testi
MUSTH Rubbed
c
---
at
the
An interin 1981-83,
interactions two bulls in
by
responses
WPZ 1980.
and evoked and
Bull
The
first
full year both bulls were at WPZ (1981), the musth period of Bull #1 was tripled in length.
356
RASMUSSEN
ET AL
973
(age
1974
12)
DRAIN-
WET
-
DAMP
-
I
1976
977
978
DR
I
AG
I DR
w. VERYAG
.
JAN
FEB
AG
AG
AG
I H
:a,
,
MA,,
1. Musth
JAG
980
982
PI
FIG.
ku
I
-
0-
HIG1 LG JAG
U. 979
AG
,,,-R
I
MAY
episodes
JUN
JUL
AUG
and periods
SEP
OCT
NOV
of temporal
DEC
gland
JAN
FEB
MAR
secretions.
APR
MAY
JUN
AG=aggressive
JUL
AUG
I
SEP
OCT
NOV
neither
entry
into
been
included
for
urine
in musth,
bull
the
was
yard
in
careful
spots.
When
frequent
In
beginning
either
sniffing,
1982,
to
behavior
cows
checking
and flehmen responses other bull had rubbed observed.
musth,
where
had of
the
or both
secrete
from
a
were
one
previously
bulls,
bull dry
One
ages
bull
nance 6.64
this
was
kept
bull
clearly
as a solitary African
Male
T values,
of
overlap
the
for
Bull
musth duration was will note continuing gressive
age
these
with
T and
DHT
Serum
male
#2,
noted. Our lengthening
changes,
and
the
an
increase
in
observations trends, procorrelations
of
Measurements
T values
(Table
averaged
ng/ml)
with
Serum
T
was
female
of
T
Fig.
0.08
2).
ng/ml
Four
Asian
(range
0.05-
fe-
day, times
T
obser-
his
serum
domi-
T level
lower of
ng/ml.
of
male
samples, T
taken
averaged higher
at
2.61 than
in
T
levels
T
values
the
mid
same
ng/ml, African
some
levels (0.38
four the
ng/ml,
was
castrated
low
be higher 0.53
There
female
a single The
to
averaged
value.
highest
the
level
0.08
serum 2;
field
tended
and
the bull’s tractable behavior. In nonmusth Asian bulls,
T levels.
T
with
of
ng/ml).
indicated
T values
than female double the
records
levels
0.38-0.68
ng/ml.
temporal gland were observed several minutes after being released into a yard recently occupied by the other bull. In 1983, the third year data
the
0.25 six Afri-
the
separate;
bull,
and
5 African
In
years,
(range
Note
averaged
ng/ml).
14-28
bulls.
periods
than
which
ng/ml
value of
lower
0.14-0.46
0.53
vations
was
25-36),
(range
averaged
where the area were of
can
This
(ages
ng/ml
touching,
instances
ng/ml).
females
ground
bulls
checking,
to the walls his temporal ten
0.11
upon
previously
DEC
SW=temporal swelSolid bar represents
behavior,
ling, DR=secreting heavily, W=moderate secretion, D=slight secretion, s=flehmen responses. Packy (21 years old). Dashed line represents Tunga (20 years old). Crosshatched bars represent both the extended length of Packy’s musth period in 1981 and the overlapping of the two bulls’ musth synchrony in 1982.
When
I
(0.46 ng/ml).
Asian
bull
agree
with
nonmusth hour
which
of was
male
the five
serum
ANDROGEN
CONCENTRATIONS
.0 .0.0
-
IN MALE
ELEPHANTS
357
.0.0
.0
00.0
EE.0
EEEc .0OOO0
E
I 0
CI
I
I
N-
F-N
‘
coOO
*
l-’n
0000
-‘0 “O
Or-N -‘Q’O
0
Cl) +1
N
C (6 -
N
N
N
-
N
N
N
N
I).’ I
0
I O
,sI
I
ci
,‘ii
,
U
o
>, N1.-(
0 N
,,
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2
ODE (6 .0
0
0
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,..
0
‘6
‘6
2
V
..,
t I).. I IC
0
0
0
o 6
I.-
‘S
-
U
lB V
2
(6
0000, lB
U
-
U
ON’
N(fl NO
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0 -
(6 1.6)
Ci.)
0.0
