Behavioural Processes 85 (2010) 58–67
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Behavioural Processes
journal homepage: www.elsevier.com/locate/behavproc
Assessment of dominance hierarchy through urine scent marking and its
chemical constituents in male blackbuck Antelope cervicapra, a critically
endangered species
Thangavel Rajagopal a,b , Govindaraju Archunan a,∗ , Pitchairaj Geraldine c , Chellam Balasundaram c
a
Center for Pheromone Technology, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India
Department of Biotechnology, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi-626123, Tamil Nadu, India
c
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India
b
a r t i c l e
i n f o
Article history:
Received 18 February 2010
Received in revised form 7 May 2010
Accepted 3 June 2010
Keywords:
Dominance hierarchy
Urinary scent marking
Indian Blackbuck
Chemical profiles
Subordinate male
a b s t r a c t
In ungulates the process of chemical communication by urinary scent marking has been directly related to
reproductive dominance, territorial defense and proximity to resources. The differences in the frequency
of urine marking and chemical composition of urine of males Antelope cervicapra before, during and after
the dominance hierarchy period were assessed. The variations in the urine marking and its chemical
profiles of dominant males (n = 9), bachelors (n = 5) and sub-adult males (n = 5) were compared to find
out how the dominance hierarchy influences the confined blackbuck herd under semi-natural captive
conditions. The frequency of urine marking is significantly higher (p < 0.001) in dominant males. Twentyeight major constituents were identified in the urine of dominant males (before, during and after the
dominance hierarchy period), bachelor and sub-adult males. Among these, three specific compounds
namely, 3-hexanone (I), 6-methyl-5-hepten-2-one (II) and 4-methyl-3-heptanone (III) were seen only
in dominant males urine during the dominance hierarchy period. Based on the behavioural observation
and the unique chemical constituents in the urine, it is concluded that the dominant male scent odor
suppresses aggression, scent marking, scent production and territorial patrolling activities of subordinate
males, through which the dominant male establish their hierarchy and attains success in reproduction.
© 2010 Elsevier B.V. All rights reserved.
1. Introduction
Many ungulates are socially characterized by well-defined stable dominance hierarchies (Cassinello, 1995; Cote, 2000; Freeman
et al., 2004; Roden et al., 2005) which often determines the first
or the best access to food, social interactions, and choice of mate
(Roden et al., 2005; Hemelrijik et al., 2008). The hierarchical position of an individual is influenced by various factors including age
(Bison bison: Maher and Byers, 1987; Robitaille and Prescott, 1993),
body weight (Gazella dama: Cassinello and Pieters, 2000), both age
and body weight (Bison bison: Roden et al., 2005), aggressiveness
(Oreamnos americanus: Cote, 2000; Capra hircus: Barroso et al.,
2000; Loxodonta africana: Ganswindt et al., 2005), androgen level
(Pupu puda: Barto et al., 1998; Elaphurus davidianus: Li et al., 2004;
Pan troglodytes: Muller and Wrangham, 2004) and dominance hierarchy is characterized by scent marking/production (Lemur catta:
Kappeler, 1990; Mus domesticus: Hurst, 1990; Oreotragus oreotragus: Roberts and Dunbar, 2000; Propithecus uerreauxi uerreauxi:
∗ Corresponding author. Tel.: +91 431 2407040; fax: +91 431 2407045.
E-mail address: [email protected] (G. Archunan).
0376-6357/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.beproc.2010.06.007
Lewis, 2005; Equus Caballus: Kimura, 2001; Meriones unguiculatus:
Shimozuru et al., 2006).
Typically urinary scent marking involves deposition of social
pheromones to elicit response from a conspecific (Ewer, 1968;
Bowyer et al., 1994; Hoffman et al., 2010). Scent marking
behaviours of many ungulates have been described (Gosling, 1985;
Bowyer et al., 1994); urine and scent glands are the major sources
of the odors (Roberts and Dunbar, 2000; Gosling and Roberts, 2001;
Lewis, 2005). Major functions of urinary scent marking are defense
of territory and resources, advertisement of social status, regulation of social relationships, mate attraction, and advertisement of
reproductive condition (Halpin, 1986; Penn and Potts, 1998; Smith
et al., 2001; Brennan and Kendrick, 2006).
In many ungulates urinary scent marking behaviour not only
mediates aggressive interactions between males but also facilitates male–female interactions. For example, odors of urinary scent
marking help to establish the territory of dominant male and
also to keep the other males away from its territory (Thomsons’s
gazelles, Gazella Thomson: Estes, 1967; Blackbuck, Antelope cervicapra: David, 1973). In ungulates like bontebok, Damaliscus dorcas
dorcas (Schaller, 1967), springbok, Antidorces marsupialis (David,
1973) and wildebeest, Connochaetes taurinus (Estes, 1969) urinary
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
scent marking directs other males as part of a ritualized challenge.
Urinary scent marking in North American elk, Cervus elaphus primarily influences the dominance interactions between adult males
and the urinary pheromones might advertise the physical condition of males (McCullough, 1969; Bowyer and Kitchen, 1987). Male
urine excreted during rut has a strong, pungent and unique odor
which relays information an dominance hierarchy to conspecifics
(Miquelle, 1991) indicating the urine of males may possess critically
important components required in establishing territory and/to
attract females.
Urinary constituents of a few ungulates have been characterized, but the biological role of urinary scent marking is yet to be
investigated. For example, the red deer urine consisted mainly
that derivative of carboxylic acids and some aromatic compounds
(Bakke and Figenschou, 1990). Volatile substances identified in
the urine of white-tailed deer comprise alcohol, aldehyde, furan,
ketone, nitrite, alkene, alkane, thiol ester, disulfide, aromatic ether,
ketal and amine classes of compounds (Miller et al., 1998). The preselection of candidate substances has further resulted in successful
characterization of a few biological urinary pheromones in various zoo animals, farm animals and rodents. For example, urine of
Asian female elephants in estrus contain high concentration of a
volatile (Z)-7-dodecen-1-yl acetate compound which function as
a sex pheromone stimulating male sexual behaviour (Rasmussen
et al., 1997). In addition, the estrus-specific urinary volatile, 1iodoundecane may function as bull attractant (Rameshkumar and
Archunan, 2002). The male mice urinary pheromones like 2-secbutyl-dihydrothiazole and dehydro-exo-brevicomin were active in
eliciting inter-male aggression (Novotny et al., 1985a), attractiveness to females (Jemiolo et al., 1985), and estrus synchronization
(Jemiolo et al., 1986). Another urinary volatile compound 2,5dimethylpyrazine delivered from grouped adult females, delayed
sexual maturation among young female mice (Novotny et al.,
1985b). The urinary compounds and putative pheromones of dominant and subordinate male blackbucks are yet to be identified.
The Indian Blackbuck, A. cervicapra is territorial and generally
lives in herds 30–100 individuals. The regulation of its social life
depends to a large extent on chemical communication as reflected
by its various odoriferous skin glands and other sources of chemical
signals. Each group has a territory within which a linear dominance hierarchy is formed by means of aggression interactions.
Previous study has demonstrated that the Indian Blackbucks scent
mark their territory with urine and preorbital glands (David, 1973;
Manimozhi, 1996; Rajagopal and Archunan, 2008; Rajagopal et al.,
2010). We tested the hypothesis that there were differences in the
frequency of scent urination and its chemical composition in dominant male before, during and after the dominance hierarchy period
when compared with that of bachelor male. The study is a first
step in understanding the potential role of urine marking in the
dominance hierarchy of Indian Blackbuck.
59
Table 1
Antelope cervicapra L.: identification features of adult male blackbucks.
Animal (No.)
Number of
twists in horn
Identification characters
1st
4a
2nd
3rd
3a
3a
4th
4a
5th
3a
6th
7th
8th
3a
3a
3a
9th
3a
10th
2a
11th
3a
12th
3b
13th
2a
14th
2a
Narrow horns with pointed tips;
A large size mole in the lower abdomen on
left side
Almost parallel horns with pointed tips
Left horn normal; right horn damaged and
half bent
Slightly twisted narrow horns with curved
tips pointing each other
Broad and compressed horn; tip of the
right horn curved outward
Long broad horns with curved tips outward
Broad horns with their tips curved inward
Long narrow horns with their tips curved
inward
Long broad horn; tip of the right horn
damaged
Narrow twisted horns, tip of the both
horns very long and pointed
Narrow horns, tip of the left horn little
damaged
Long twisted slim horn, tip of the right
horn curved inward; right horn outward
Long parallel horns with their tips straight
onward sky
Broad horns; a large size scare in the right
hind leg
a
b
Thick solid horn.
Slim solid horn.
2.2. Study animals
In the beginning of the study period (June 2007) the Blackbuck
enclosure contained a total population of 75 animals. The group
was classified (Prasad, 1983) into 14 adult males, 21 adult females,
16 sub-adult males, 18 sub-adult females and 6 young ones. The
social hierarchy system (i.e. dominance hierarchy) was studied
in 14 adult males only. Each individual was recognized by variation in shape of the horn and additional morphological features
(Table 1).
2.3. Social status of male blackbuck
The nomenclature of male social status are (Hogg and Forbes,
1997; Mungall, 1977): (1) harem masters (i.e. dominant males)
who hold harems, (2) challengers (i.e. predominant males) without their own harems, but challenge the harem master and try to
hold females, (3) the bachelor group which stay away from female
groups. Indian Blackbucks change their social status from ‘bachelor’ to ‘challenger’ and became ‘harem masters’; but some of them
(bachelors) may never reach the highest social rank during their
lifetime (Mungall, 1977).
2. Material and methods
2.4. Behavioural observation
2.1. Study area
This study was conducted in the conservation and breeding centre of Arignar Anna Zoological Park (AAZP) (13◦ 16 S and 79◦ 54 E
at an altitude of MSL+ 10–100 m), Vandalur, Chennai, South India.
Chennai has the distinction of being the first zoo in India, started in
1855. In 1976, the zoo was moved to the Vandalur Reserve Forest
comprising, an area of about 510 ha near Chennai. The habitat of
AAZP is considered a tropical evergreen scrub, a degraded forest
mostly consisting of thorny bushes. The average annual rainfall is
about 250 mm and the temperature about 26 ◦ C.
Frequency of urine marking behaviour was observed in adult
males (n = 14) using focal sampling method (Altmann, 1974). The
observations were made for 122 days during 18 months from June
2007 to December 2008. The observation schedule was divided into
two shifts: morning 08.00–10.00 h and afternoon 14.00–16.00 h.
The duration of each watch for 2 h each comprised, a total of 4 h
of observation per day. The animals were directly observed using
8 × 40 binoculars in front of the enclosure. The observation included
mapping all visible scent marks and recording the type and locations of marks.
60
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
2.5. Urine collection
Urine samples were collected from dominant males before, during and after the formation of dominance hierarchy period and
also from bachelors and sub-adult males for chemical analysis. To
minimize the effect of individual variation the urine samples were
pooled group wise [dominant (n = 9), bachelor (n = 5) and sub-adult
males (n = 5)]. Urine was collected from the floor immediately after
voiding using a clean, dry 1 cc syringe, and placed in a 2 cc vial.
Once collected, the vials were labelled and placed in a cold thermos flask until reaching the camp at 10.30 am and 5.30 pm, where
the samples were placed in a freezer at −20 ◦ C for GC–MS analysis.
2.6. Extract preparation
Dichloromethane (DCM) was used as a solvent in GC–MS analysis. From each sample 5 ml was taken and mixed with 5 ml DCM (1:1
ratio) and filtered through a silica gel column (60–120 meshes) for
30 min at room temperature. The filtered extract which was 1/5 of
its original volume was cooled with liquid nitrogen to condense it.
2.7. GC–MS analysis
The GC–MS analysis were made using a QP-5000 (Schimadzu,
Japan). The 2 ␮l of extract was injected into the GC–MS on a
30 m glass capillary column with a film thickness of 0.25 ␮m
(30 m × 0.2 mm i.d. coated with UCON HB 2000) using the following temperature programme, initial oven temperature of 40 ◦ C for
4 min increased to 250 ◦ C at a rate of 15 ◦ C for 10 min. The gas chromatography (Schimadzu GC 15A) was equipped with FID detector
connected to an integrator. The area under each peak was used
for quantitative calculations. The detection accuracy was about
1 ng/peak. The relative amount of each component was reported as
the percent of the ion current. The GC–MS was under the computer
control at 70 eV using ammonia as reagent gas at 95 eV performed
chemical ionization. Identification of unknown compounds was
made by probability-based matching using the computer Library
built within the NICT 12 system.
software 11th version to compare the frequency of urine marking
before, during, and after the formation of social hierarchy period in
the dominant and bachelor males.
3. Results
3.1. Duration of dominancy or leadership period
Among the 14 adult male Blackbuck observed under the seminatural captive conditions, 9 were found to have established
dominance hierarchy during the study period from June 2007 to
December 2008. In the beginning the animal number 4 (14th June to
17th July 2007) exhibited dominance and took over the other males
followed by animal numbers 5, 8, 6, 1, 11, 14, 12 and 10, respectively (Table 2). Animal number 14 showed the longest duration of
leadership in the same enclosure for 210 days from 4th May 2008
to 29th November 2008. Subsequently animal numbers 6, 1, and 11
took over the leadership same re-emerging as dominant male (animal number 6 exhibited four times; animal number 1 three times
and animal number 11 two times); however, the duration of leadership period of these animals was vary and ranged between 3 and
20 days. However, animal numbers 2, 3, 7, 9, and 13 never reached
higher social ranking (dominant or predominant) during the entire
study period.
3.2. Urine marking behaviour
The frequency of urine marking was recorded in 14 adult males
(Fig. 1). The frequency of urine marking was recorded as follows:
2.57 ± 0.36 to 4.25 ± 0.18, before the hierarchy formation period;
3.0 ± 0.57 to 5.75 ± 0.27 during the hierarchy formation period;
1.0 ± 0.00 to 3.2 ± 0.36 after the hierarchy formation period in the
dominant males and 0.25 ± 0.25 to 1.65 ± 0.15 in bachelor males
(Table 3). The urine marking frequency (F = 0.001;3.59 = 37.47), was
significantly higher during the formation of hierarchy period followed by before and after the hierarchy period in the dominant
males as compared to bachelor males (Tables 4 and 4a). Further, the
frequency of urine marking and duration of leadership are directly
(r = 0.816, p < 0.001) related in dominant males (Fig. 2).
2.8. Statistical analysis
3.3. Urinary chemical profiles
The total amount of urine marking behaviour of dominant and
subordinate males was performed using the mean ± SE. The data
for the frequency of urine marking behaviour was analysed using
the one-factor analysis of variance (ANOVA) with SPSS statistical
The profiles of volatile compounds obtained before, during and
after the formation of dominance hierarchy periods in the urine of
dominant male (Fig. 3A–C), bachelor (Fig. 4A) and sub-adult male
(Fig. 4B). Each male sample mix contained 10–26 detectable peaks.
Table 2
Duration of leadership in 9 dominant males from June 2007 to December 2008.
Animal (No.)
4
5
8
6
1
6
11
1
6
1
6
11
14
12
10
a
b
Duration of leadership
From
To
14 June 2007
18 July 2007
31 October 2007
12 February 2008
21 February 2008
3 March 2008
23 March 2008
28 March 2008
3 April 2008
8 April 2008
21 April 2008
23 April 2008
4 May 2008
29th November 2008
8th December 2008
17 July 2007
30 October 2007
12 February 2008
21 February 2008
3 March 2008
22 March 2008
27 March 2008
2 April 2008
8 April 2008
21 April 2008
23 April 2008
3 May 2008
29 November 2008
8th December 2008
21st December 2008
Minimum duration of leadership.
Maximum duration of leadership.
Days (No.)
Remarks
35
105
104
10
11
20
5
6
6
14
3a
12
210b
11
14
Natural death due to ageing (12 April 2008)
Natural death (3 December 2008)
Death after leg injury (30 March 2008)
Death due to injury during infighting (23 April 2008)
Death due to eye injury during infighting (17 December 2008)
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
61
Table 3
Antelope cervicapra L. frequency (mean ± SE) of urine marking behaviour by adult males (n = 14) during leadership period (days) from June 2007 to December 2008.
Fig. 1. Breeding lek or resting place and associated scent marking behaviour: (A) territorial or dominant male leg scratching display at dung pile or defecation place, (B)
sniffing display at dung pile, (C) urination display at dung pile and (D) defecation display at dung pile.
62
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
Table 4
Antelope cervicapra L. One-way ANOVA with post hoc comparison of urine marking
behaviour in dominant male before, during and after hierarchy period as compared
to bachelor male.
Variation
Between groups
Within groups
Total
SS
df
MS
F
Sig.
82.445
41.066
3
56
27.482
0.733
37.476
0.001*
123.511
59
The means were compared using DMRT.
*
Statistically highly significant (p < 0.001).
Nearly 28 detectable peaks were noted in the dominant, bachelor and sub-adult males. The peak numbers correspond to the list
of compounds identified (Tables 5 and 6). Visual examination of
all the chromatograms showed that there was a consistent qualitative difference in the chemical profiles before, during and after
the formation of dominance hierarchy period between dominant,
bachelor and sub-adult males. Among the 28 volatile compounds,
22, 26 and 13 compounds were identified in the urine sample of
dominant males before, during and after the formation of dominance hierarchy period, respectively. Further, 12 compounds in the
urine of bachelor males and 10 compounds in the urine of sub-adult
males were identified.
Comparison of the identified compounds before, during and
after the formation of dominance hierarchy periods of dominant,
bachelor and sub-adult males revealed that certain compounds
at peak height were reduced or disappeared or specific to a particular period in dominant, bachelor and sub-adult males. For
Fig. 3. GC–MS profiles of volatile compounds in the urine of dominant males before
(A), during (B) and after (C) the formation of dominance hierarchy period. Peak
number refers to Table 4.
instance, among the 26 compounds present in the urine sample
of dominant male during the formation of dominance hierarchy
period, three compounds viz., 3-hexanone (I), 6-methyl-5-hepten2-one (II) and 4-methyl-3-heptanone (III) are specific during the
Fig. 2. Relationship between duration of leadership period and their relative frequency of urine marking behaviour in dominant males. Linear fit of regression
described by the function y = 3.63x + 0.067*. DM: dominant male. Animal number
6, 1, and 11 reappeared as leader (A.No. 6 exhibited four times; A.No. 1 three times
and A.No. 11 two times).
Table 4a
Comparison of means from Table 4 using DMRT post hoc tests.
Subset for alpha = 0.05
1
Bachelor male
After formation of hierarchy
Before formation of hierarchy
During formation of hierarchy
Significance
2
3
1.0440
1.6147
2.9687
0.087
1.000
4.0707
1.000
Uses harmonic mean sample size = 15.000. Means within a subset are not different
from each other.
Fig. 4. GC–MS profiles of volatile compounds in the urine of bachelor (A) and subadult male blackbucks (B) peak number refers to Table 4.
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
63
Table 5
Antelope cervicapra L. volatile compounds in the urine of dominant and subordinate male.
Peak No.
Compound name
Dominant (hierarchy period)
Subordinate
Before
During
After
Bachelor
Sub-adult
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
2-Propenoic acid
2,2-Dimethyl propane
3-Hexanone (I)
2,2-Dimethyl butane
Phenol
1,5-Hexadien-3-ol
2-Methyl cyclopentanone
3-Methyl-1-pentanol
6-methyl-5-hepten-2-one (II)
2,2-Dimethyl propanoic acid
3-Methyl-2-methyl pyridine
4-Methyl phenol
3-Methyl-2-methyl hexane
4-Pyridine carboxylic acid
2,2-Dimethyl heptane
4-Pentanal
4-Methyl-3-haptanone (III)
2,2,5,5-Tetramethyl hexane
Bis-(1,1-dimethyl ethyl) diazene
3,5-Dimethyl-1-hexane
1-Bromo-2,2-dimethyl propane
1,2-Dimethyl-3-(1-methyl ethyl) cyclopentanol
3,7-Dimethyl-1-octanol
2-Methyoxyl-2-butanoic acid
2,9-Dimethyl decane
6-Ethyl-2-methyl decane
1-Chloro tetradecane
1-Iodo octane
+++
+++
−−−
+++
+++
+++
+++
+++
−−−
+++
+++
−−−
+++
+++
+++
+++
−−−
+++
+++
+++
+++
−−−
+++
+++
−−−
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
−−−
+++
+++
+++
+++
+++
+++
+++
+++
+++
−−−
+++
+++
+++
+++
+++
+++
+++
−−−
−−−
+++
−−−
−−−
−−−
+++
−−−
+++
−−−
+++
−−−
−−−
+++
+++
−−−
+++
+++
−−−
+++
+++
+++
+++
−−−
−−−
−−−
−−−
+++
−−−
−−−
+++
−−−
−−−
−−−
+++
−−−
+++
−−−
−−−
−−−
−−−
+++
+++
−−−
+++
+++
−−−
+++
+++
+++
−−−
+++
−−−
−−−
−−−
−−−
−−−
−−−
+++
−−−
−−−
+++
+++
−−−
+++
−−−
−−−
−−−
−−−
+++
+++
−−−
+++
+++
−−−
+++
+++
−−−
−−−
−−−
−−−
−−−
−−−
Total number of volatiles
22
26
13
12
10
Abbreviation: +++, present; − − −, absent.
formation of dominance hierarchy period. However, the peaks
of 10 compounds i.e. 2, 5, 6, 11, 13, 14, 20, 26, 27 and 28
(2,2-dimethyl propane, phenol, 1,5-hexadien-3-ol, 3-methyl-2methyl pyridine, 3-methyl-2-methyl hexane, 2-pyridine carboxylic
acid, 3,5-dimethyl-1-hexane, 6-ethyl-2-methyl decane, 1-chloro
tetradecane, 1-ido octane) appeared higher in the dominant male
during the hierarchy period than before hierarchy period; but
these were not present after the completion of hierarchy period
in dominant male, also bachelor and sub-adult male urine sample.
Further, the compound 2-methyoxyl-2-butanoic acid (Peak
No. 24) appeared before, during and after the formation of
Table 6
Volatile compounds identified in the urine of dominant and subordinate male and their nature of compound, molecular weight and formula.
Peak no.
Compound
Nature
Molecular weight
Molecular formula
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
2-Propenoic acid
2,2-Dimethyl propane
3-Hexanone (I)
2,2-Dimethyl butane
Phenol
1,5-Hexadien-3-ol
2-Methyl cyclopentanone
3-Methyl-1-pentanol
6-Methyl-5-hepten-2-one (II)
2,2-Dimethyl propanoic acid
3-Methyl-2-methyl pyridine
4-Methyl phenol
3-Methyl-2-methyl hexane
4-Pyridine carboxylic acid
2,2-Dimethyl heptane
4-Pentanal
4-Methyl-3-haptanone (III)
2,2,5,5-Tetramethyl hexane
Bis-(1,1-dimethyl ethyl) diazene
3,5-Dimethyl-1-hexane
1-Bromo-2,2-dimethyl propane
1,2-Dimethyl-3-(1-methyl ethyl) cyclopentanol
3,7-Dimethyl-1-octanol
2-Methyoxyl-2-butanoic acid
2,9-Dimethyl decane
6-Ethyl-2-methyl decane
1-Chloro tetradecane
1-Iodo octane
Carboxylic acid
Alkane
Ketone
Alkane
Phenol
Alcohol
Ketone
Alcohol
Ketone
Carboxylic acid
Pyridine
Phenol
Alkane
Carboxylic acid
Alkane
Aldehyde
Ketone
Alkane
Alkene
Alkane
Alkane
Alcohol
Alcohol
Carboxylic acid
Alkane
Alkane
Alkane
Alkane
72
72
100
86
94
98
98
102
126
102
107
108
114
123
128
130
166
142
142
145
151
156
158
162
170
184
232
240
C3 H4 O2
C5 H12
C6 H12 O
C6 H14
C6 H6 O
C6 H10 O
C6 H10 O
C6 H14 O
C8 H14 O
C5 H10 O2
C7 H9 N
C7 H8 O
C8H18
C6 H5 NO2
C9 H20
C8H18 O
C10 H14 O2
C10 H22
C8 H18 N
C10 H25
C5 H11 Br
C10 H20 O
C10 H22 O
C8 H18 O3
C12 H26
C13 H28
C14 H29 Cl
C8 H17 I
64
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
Fig. 5. Distribution of dung pile (i.e. places of urination and defecation) in a Blackbuck enclosure. * Represents scattered dung pile of dominant male in and around food
trough in the enclosure. Dung piles of all bachelor blackbucks are scattered only near edge of the enclosure.
dominance hierarchy periods only in the dominant male urine.
The compounds present in all male urine samples, were 2,2dimethyl butane, 3-methyl-1-pentanol, 2,2-dimethyl propanoic
acid, 2,2-dimethyl heptane, 4-pentanal, 2,2,5,5-tetramethyl hexane, bis-(1,1-dimethyl ethyl) diazene and 1-bromo-2,2-dimethyl
propane (i.e. during the three different stages in dominant, bachelor
and sub-adult males).
All the compounds identified in the urine of dominant, bachelor
and sub-adult male, had a molecular weight above 72 and less than
240. The gas chromatography analysis showed that the compounds
fall between the retention times between 5 and 45 min.
4. Discussion
The frequency of urine marking by the dominant male during
hierarchy formation period (p < 0.001) is higher when compared
to before and after the hierarchy period as compared to bachelor males. The result is in agreement with earlier investigations,
which have described that the dominant male urine scent marking behaviour (i.e. odor) may adversely affect the fighting ability,
suppressing the social and sexual behaviour of subordinate males
in several species like pine vole, Microtus pinetoram (Brant et al.,
1998), wolves, Canis lupus (Derix et al., 1993), dwarf monogooses,
Helagale parvula (Clutton-Brock et al., 2001) and African wild dogs,
Lycaon pictus (Courchamp et al., 2002). Primates like Saguinus
oedipus (French et al., 1984), S. fuscicollis (Epple and Eatz, 1984)
and Callithrix kuhli (Smith et al., 1997) the dominant male primer
pheromones create hormonal suppression; the dominant females
scent marking odors inhibit the reproductive cyclicity in subordinate females (Smith and Abbott, 1998; Wirtu et al., 2004). The
higher frequency of urine marking behaviour is directly associated
with higher levels of gonadal (i.e. testosterone) steroids (Thiessen
and Rice, 1976; Arteaga et al., 2008) and facilitates attraction of
opposite sex (Novotny et al., 1990; Rich and Hurst, 1998, 1999) and
advertise the ownership and competitive ability (Thom and Hurst,
2004).
It is interesting to note that in the present study the dominant male often preferred particular place for their urine marking
close to the food trough (i.e. focal point of his territory or breeding
lek) (Fig. 5). A similar result was obtained by several workers who
found that the male ungulates commonly chose the place for the
urination in order to make the territorial determination (Gosling,
1985; Azeve do et al., 1996). It indicates the dominant male generally uses urine as a reliable signal for territory ownership and
as a warning at the border to other males within the territorial
region. It is also reported that the occurrence of male urine marking is related to female reproductive state (Converse et al., 1995;
Gould and Overdorff, 2002). Therefore, the present results suggest
that urine marks may play a major role in the defense of territories against potential intruders and to advertise their agonistic
dominance over the other males and or to attract the females.
Reappearance (i.e. repeated occurrence) of leader and the formation of hierarchy were observed in the animal numbers 6, 1 and
11 during February to April 2008 though for a short period (A.No.
6: 20–3 days; A.No. 1: 14–6 days; A.No. 11: 12–5 days). In mature
free-ranging bulls the dominance relationship between males were
transitory and unstable (Lott, 1979). In our study, though during rut
periods (August–October and March–May) the males loose hierarchy (i.e. rank) it was re-established subsequently. Rajagopal (2009)
reported that more females exhibited heat during these periods.
Therefore, the present results clearly indicate that the formation
and maintenance of dominance hierarchy system is mandatory for
breeding purpose.
In the present study, twenty-eight urinary volatile compounds
were identified in the dominant, bachelor and sub-adult males.
The volatiles identified in the urine belong to the alkanes, alkenes,
alcohols, ketones, phenols, pyridine and carboxylic acids classes
of compounds. These classes of compounds have already been
reported from the urine of other mammals (Dominic, 1991; Miller
et al., 1998; Rekwot et al., 2001; Archunan, 2009).
Urinary compounds identified as unique to dominant male during dominance hierarchy period had molecular weight of <300
and had fewer than 20 carbon atoms. Airborne pheromones usu-
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
65
Table 7
Pheromones reported in various animals and their functions.
S. No.
1
2
3
4
5
6
7
8
9
10
11
a
b
Compound
a
3-Hexanone
b
(Z)-4-Hepten-2-one
6-Methyl-6-hepten-2-oneb
(E)-4-Methyl-4-hepten-3-oneb
6-Methyl-5-hepten-2-onea
6-Hydroxy-6-methyl-3-heptanoneb
5-Hydroxy-4-methyl-3-heptanoneb
2-Heptanoneb
3-Hexanone
6-Methyl-5-hepten-2-one
4-Methyl-3-haptanone
Animal
Function
Reference
White-tailed deer
Higher concentration during breeding season
as compared to non-breeding season
Female attracting
Aggregation
Defensive
Alarm
Accelerate puberty
Aggregation
Attractant in wasp
To be elucidated
To be elucidated
To be elucidated
Miller et al. (1998)
Novel moth
Black beetles
Palpatore
Ant
Mice
Rice weevil
Honeybee
Blackbuck
Blackbuck
Blackbuck
Ekpa et al. (1985)
Zhu et al. (1994)
Ken and Kenji (2001)
Moser et al. (1968)
Novotny et al. (1999)
Walgenbach et al. (1987)
Raymer et al. (1986)
This publication
This publication
This publication
Compounds similar to our identified compounds.
Compounds with slight variation of structure our identified compounds.
ally contain 5–20 carbon atoms and must be volatile to reach the
receiver; pheromones typically have molecular weight about less
than 300 (Bradbury and Vehrencamp, 1998). For example, in whittailed deer, several volatile compounds occur exclusively in the
urine of dominant males during the mating season that had molecular weight <300 (Miller et al., 1998). Similarly, in red deer, volatile
compounds possess molecular weight <300 (Bakke and Figenschou,
1990). Female Asian elephant release a urinary pheromone with 13
carbons and a molecular weight near 300 and proved to attract male
(Rasmussen et al., 1997). In the cow, a specific volatile occur exclusively in urine during the heat period that had molecular weight
less than 300 (Rameshkumar et al., 2000). Therefore, the dominant
unique urinary compounds have physical properties necessary for
consideration as putative pheromones.
The majority of identified urinary compounds are long chain
alkanes. Long chain hydrocarbons are commonly encountered in
both plant and animal kingdom. In fact n-alkanes are among
the commonest constituents of plant wax and play a major role
in bitrophic herbivore-plant interactions (Udayagiri and Marson,
1997). In a few mammals they play a significant role in sexual attraction (Dominic, 1991; Archunan, 2009). For example, an
alkane, 1,5-diemethyl-6-8-dioxodicyclo (3,2,1) octane acts as a
pheromone during musth in elephants (Rasmussen and Perrin,
1999). Before and during hierarchy period the compounds may
be act as chemical signals are 2,2-dimethyl propane, 3-methyl-2methyl hexane, 3,5-dimethyl-1-hexane, 6-ethyl-2-methyl decane,
1-chloro tetradecane and 1-iodo octane may be the putative chemical signals appearing prior to dominant hierarchy period. It is
important to note that the peak area and peak height of these
compounds 3,5-dimethyl-1-hexane, 6-ethyl-2-methyl decane, 1chloro tetradecane and 1-iodo octane in the GC profile were
comparatively higher during hierarchy period than in the before
hierarchy period. This suggests that these compounds may be
maximally produced during hierarchy period even though their
production is inhibited after the hierarchy period of the dominant
male.
In this study in dominant male urine 26 volatile compounds
have been identified during the hierarchy formation period. Among
them, three are volatile compounds, 3-hexanone (I), 6-methyl-5hepten-2-one (II) and 4-methyl-3-haptanone (III) in the molecular
weight range between 84 and 166 and having C6 to C10 carbon atoms. Of these compounds, compound (I) has also been
reported in the white-tailed deer dominant male urine during
breeding season (Miller et al., 1998). Interestingly the compound
(II) has been reported as pheromones in the novel moth, black
beetles, palpatore, ant and mice; the compound (III) has also
been already reported as urinary pheromone in the female mice,
rice weevil and honeybee (Table 7). Hence, the appearance of
these specific compounds in dominant male urine during hierar-
chy period may provide behaviourally important chemical cues
suggesting their role in aggression to male and attraction to
female.
It is well established that urine is a primary medium for
excreting metabolized hormone i.e. testosterone, it may play
a role in the degree of variability in urinary volatiles and aid
in individual recognition (Novotny et al., 1985a,b; Rasmussen
et al., 1997). Many of the by-products of the action of these
steroids, as well as the excreted steroid metabolites, are reflected
in the urinary volatiles. Interestingly, the 10 urinary volatile
(2,2-dimethyl propane, phenol, 1,5-hexadien-3-ol, 3-methyl-2methyl pyridine, 3-methyl-2-methyl hexane, 4-pyridine carboxylic
acid, 3,5-dimethyl-1-hexane, 6-ethyl-2-methyl decane, 1-chloro
tetradecane and 1-ido octane) compounds appeared before and
during the hierarchy formation period in dominant male, but disappeared after the hierarchy period (Table 5). This is reflected in the
changes of their particular constituents after the hierarchy formation period in dominant male, while these compounds could have
some role in chemo signals of the endocrine status. It is reported
that the compounds 2,3-dehydro-exo brevicomin (Novotny et al.,
1984) and 3-ethyl-2,7-dimethyl octane (Achiraman and Archunan,
2005) are found to be unique urinary constituents of the intact
male mouse as compared to castrated mouse, however, these compounds reappeared following testosterone treatment in castrated
male. Hence, the result provides support to the concept that certain
urinary volatile compounds may influence the hormonal as well as
social status.
The present study documents for the first time the chemical
constituents in the urine of male Indian Blackbucks. Significant
variations in the frequency of urine marking behaviour and chemical composition were observed in the dominant males before,
during and after the hierarchy period when compared with that
of bachelor males. Based on the behavioural evidence and the role
of volatile compounds in the urine supported by literature, it is
concluded that the dominant male may use urine for territorial
marking, to attract opposite sex and to deter the subordinates to
maintain the social hierarchy. Additional behavioural research on
the functional role of the assessed compounds is needed to determine the role of different compounds in social communication.
Acknowledgements
The authors thank Prof. B.V. Burger, Department of Chemistry,
University of Stellenbosh, South Africa, for encouragement and
suggestion, Prof. P.Govindarajalu, for critically sign through the
manuscript and the Chief Wildlife Warden and the Director of
the AAZP, Vandalur, Chennai, for granting permission to carry
out this study. The authors are indebted to Dr K. Senthilkumar
(Veterinary Assistant Surgeon) and Dr Pathan Nazrulla Khan (Zoo
66
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
Veterinarian) of the AAZP for their help in collection of urine
samples. This investigation was supported by grants from the UGCRajiv Ghandi National Fellowship to TR and the facilities made
available to the Department through UGC-SAP and DST-FIST, New
Delhi.
References
Achiraman, S., Archunan, G., 2005. 3-Ethyl-2,7-dimethyl octane, a testosterone
dependent unique urinary sex pheromone in male mouse (Mus musculus). Anim.
Reprod. Sci. 87, 151–161.
Altmann, J., 1974. Observational study of behaviour: sampling methods. Behaviour
22, 377–383.
Archunan, G., 2009. Vertebrate pheromones and their biological importance. J. Exp.
Zool. India 12, 227–239.
Arteaga, L., Bautisa, A., Martinez-Gomez, M., Nicolas, L., Hudson, R., 2008. Scent
marking, dominance and serum testosterone level in male domestic rabbits.
Physiol. Behav. 94, 510–515.
Azeve do, C.V.M., Menezes, A.A.L., Quciroz, J.M., Moreira, L.F.S., 1996. Circadian and
Ultra-dian periodicity of grooming behaviour in family groups of common marmosets (Callithrix jacchus) in captivity. Biol. Rhythm Res. 7, 374–385.
Bakke, J.M., Figenschou, E., 1990. Volatile compounds from the red deer (Cervus
elaphus). Substances secreted via he urine. Comp. Biochem. Physiol. 97, 427–431.
Barroso, F.G., Alados, C.L., Boza, J., 2000. Social hierarchy in the domestic goat: effect
on food habits and production. Appl. Anim. Behav. Sci. 69, 35–53.
Barto, L., Reyes, E., Schams, D., Bubenik, G., Lobos, A., 1998. Rank dependent seasonal
levels of IGF-1, cortisol and reproductive hormones in male pudu (Pudu puda).
Comp. Biochem. Physiol. A 120, 373–378.
Bowyer, R.T., Kitchen, D.W., 1987. Significance of scent-marking by Roosevelt elk. J.
Mammal. 68, 418–423.
Bowyer, R.T., Van Ballenberghe, V., Rock, K.R., 1994. Scent marking by Alaskan
moose: characteristics and spatial distribution of rubbed trees. Can. J. Zool. 72,
2186–2192.
Bradbury, J.M., Vehrencamp, S.L., 1998. Principles of Animal Communication. Sinauer Assoc. Sunderland, Massachusetts, 882 pp.
Brant, C.I., Schwab, T.M., Vandenberg, J.G., Schaefer, R.L., Solomon, N.G., 1998.
Behavioural suppression of female pine voles after replacement of the breeding
male. Anim. Behav. 55, 615–627.
Brennan, P.A., Kendrick, K.M., 2006. Mammalian social odours: attraction and individual recognition. Philos. Trans. R. Soc. Lond. B Biol. Sci. 361, 2061–2078.
Cassinello, J., 1995. Factors modifying female social ranks in Ammotagus. Appl. Anim.
Behav. Sci. 45, 175–180.
Cassinello, J., Pieters, I., 2000. Multi-male captive groups of endangered Dama
gazelle: social rank, aggression, and enclosure effects. Zoo Biol. 19, 121–129.
Clutton-Brock, T.H., Brotherton, P.N.M., Russell, A.F., O’Riain, M.J., Gaynor, D., Kansky,
R., Griffin, A., Manser, M., Sharpe, L., McIlrath, G.M., Small, T., Moss, A., Monfort,
S., 2001. Co-operation, control, and concession in meerkat groups. Science 291,
447–450.
Converse, L.J., Carlson, A.A., Ziegler, T.E., Snowdon, C.T., 1995. Communication of
ovulatory state to mates by female pygmy marmosets, Cebuella pygmaea. Anim.
Behav. 49, 615–621.
Cote, S.D., 2000. Dominance hierarchies in female mountain goats: stability, aggressiveness and determinations of rank. Behaviour 137, 1541–1566.
Courchamp, F., Rasmussen, G.S.A., MacDonald, D.W., 2002. Small pack size imposes a
trade-of between hunting and pup-guarding in the painted hunting dog Lycaon
pictus. Behav. Ecol. 13, 20–27.
David, J.H.M., 1973. The behaviour of the bontebok, Damaliscus dorcas dorcas (Pallas,
1766), with special reference to territorial behaviour. Z. Tierpsychol. 33, 38–107.
Derix, R., Van Hoof, J., De Vries, H., Wensing, J., 1993. Male and female mating competition in wolves: female suppression vs. male intervention. Behaviour 127,
141–171.
Dominic, C.J., 1991. Chemical communication in animals. J. Sci. Res. (Banaras Hindu
Univ.) 41, 157.
Ekpa, O., Wheeler, J.W., Cokendolpher, J.C., Duffield, R.M., 1985. Ketones and alcohols
in the defensive secretion of Leiobunum townsendi weed and a review of the
known exocrine secretion of palpatores (Arachnida: Opiliones). Comp. Biochem.
Physiol. Part B: Biochem. Mol. Biol. 81, 555–557.
Epple, G., Eatz, Y., 1984. Social influences on estrogen excretion and ovarian cyclicity
in saddle back tamarins (Saguinus fuscicollis). Am. J. Primatol. 6, 215–227.
Estes, R.D., 1969. Territorial behaviour of the wildbeest (Connochaetes taurinus
Burchell 1832). Z. Tierpsychol. 26, 284–370.
Estes, R.D., 1967. The comparative behaviour of grants and Thomson’s gazelles. J.
Mammal. 48, 189–209.
Ewer, R.F., 1968. Ethology of Mammals. Plenum Press, New York.
Freeman, E.W., Weiss, E., Brown, J.L., 2004. Examination of the interrelationship of
behaviour, dominance states, and ovarian activity in captive Asian and African
Elephants. Zoo Biol. 23, 431–448.
French, J.A., Abott, D.H., Snowdon, C.T., 1984. The effect of social environment
on estrogen excretion, scent marking, and sociosexual behaviour in tamarins
(Saguinus oedipus). Am. J. Primatol. 6, 155–167.
Ganswindt, A., Rasmussen, H.B., Heistermann, M., Hodges, J.K., 2005. The sexually
active states of free-ranging male African elephants (Loxodonta africana): defining musth and non-musth using endocrinology, physical signals, and behavior.
Horm. Behav. 47, 83–91.
Gosling, L.M., 1985. The even-toed ungulates: order Artiodactyla. Sources,
behavioural context, and function of chemical signals. In: Brown, R.E., Macdonald, D.W. (Eds.), Social odours in mammals, vol. 2. Clarendon, Oxford, pp.
550–618.
Gosling, L.M., Roberts, S.C., 2001. Scent marking by male mammals: cheat proof
signals to competitors and mates. Adv. Study Behav. 30, 169–217.
Gould, L., Overdorff, D.J., 2002. Adult male scent marking in Lemur catta and Eulemur
fulvus rufus. Int. J. Primatol. 23, 575–586.
Halpin, Z.T., 1986. Individual odors among mammals: origins and functions. In:
Rosenblatt, J.S., Beer, C., Busnel, M.C., Slater, P.J.B. (Eds.), Advances in the Study
of Animal Behavior, vol. 16. Academic Press, New York, pp. 39–70.
Hemelrijik, C.K., Wantia, J., Isler, K., 2008. Female dominance over males in primates:
self-organisation and sexual dimorphism. Plos ONE 3, 2678.
Hoffman, K.L., Hernandez Decasa, D.M., Beyer Ruiz, M.E., Gonzalez-Mariscal, G., 2010.
Scent marking by the male domestic rabbit (Oryctolagus cuniculus) is stimulated
by an objects novelty and its specific visual or tactile characteristics. Behav. Brain
Res. 207, 360–367.
Hogg, J.T., Forbes, S.H., 1997. Mating in bighorn sheep frequent male reproduction
via a high-risk unconventional tactic. Behav. Ecol. Sociobiol. 41, 33–48.
Hurst, J.L., 1990. Urine-marking in populations of wild house mice Mus domestius
Rutty. I. Communication between males. Anim. Behav. 40, 209–222.
Jemiolo, B., Alberts, J., Wiggins, S.S., Harvey, S., Novotny, M., 1985. Behavioral and
endocrine responses of female mice to synthetic analogues of volatile compounds in male urine. Anim. Behav. 33, 1114–1118.
Jemiolo, B., Harvey, S., Novotny, M.V., 1986. Promotion of the Whitten effect in
female mice by synthetic analogs of male urinary constituents. Proc. Natl. Acad.
Sci. U.S.A. 83, 4576–4579.
Kappeler, P.M., 1990. Social status and scent marking behaviour in Lemur catta. Anim.
Behav. 40, 774–776.
Ken, F., Kenji, M., 2001. New synthesis of serricornin, the female sex pheromone of
the cigarette beetle. Biosci. Biotech. Biochem. 65, 1429–1433.
Kimura, K., 2001. Volatile substance in faces, urine, and urine-marked faeces of feral
horses. Can. J. Anim. Sci. 81, 411.
Lewis, R.J., 2005. Sex differences in scent-marking in sifaka: mating conflict or male
services? Am. J. Physiol. Anthrobiol. 128, 389–398.
Li, C., Zhigang, J., Yan, Z., Coie, Y., 2004. Relationship between serum testosterone,
dominance and mating success in pere davids deer stags. Ethology 110, 681–691.
Lott, D.F., 1979. Dominance relations and breeding rate in mature male American
bison. Z. Tierpsychol. 49, 418–432.
Maher, C.R., Byers, J.A., 1987. Age-related changes in reproductive effort of male
bison. Behav. Ecol. Sociobiol. 21, 91–96.
Manimozhi, A., 1996. Studies on the preorbital gland and its role in the sexual dominance in the male blackbuck (Antilope cervicapra L.). Ph.D. Thesis. Bharathidasan
University, Tiruchirappalli, India.
McCullough, D.R., 1969. The tule elk: its history, behaviour and ecology. Uni. Calf.
Pub. Zool. 88, 1–200.
Miller, K.V., Jemiolo, B., Cassett, J.W., Jelinek, I., Wiesler, D., Novotny, M., 1998. Putative chemical signals from white-tailed deer (Odocoileus virginianus): social and
seasonal effects on urinary volatile excretion in males. J. Chem. Ecol. 24, 673–
683.
Miquelle, D.G., 1991. Are moose mice? The function of scent urination in moose. Am.
Nat. 138, 460–477.
Moser, J.C., Brownlee, R.C., Silverstein, R., 1968. Alarm pheromones of the ant Atta
texana. J. Insect Physiol. 14, 529–530.
Muller, M.N., Wrangham, R.W., 2004. Dominance, aggression and testosterone in
wild chimpanzees: a test of the challenge hypothesis. Anim. Behav. 67, 113–123.
Mungall, E.C., 1977. Social development of the young blackbuck antelope (Antelope
cervicapra). In: AAZPA Regional conf. Proc. American Association of Zoological
Parks and Aquarium, Washington, USA, pp. 100–109.
Novotny, M.V., Schwende, F.J., Wiesler, D., Jorgenson, J.W., Carmack, M., 1984. Identification of a testosterone-dependent unique volatile constituent of male mouse
urine: 7-exo-ethyl-5-methyl-6,8-dioxabicyclo-[3.2.1]-3-octane. Experientia 40,
217–219.
Novotny, M., Harvey, S., Jemiolo, B., Alberts, J., 1985a. Synthetic pheromones
that promote inter-male aggression in mice. Proc. Natl. Acad. Sci. U.S.A. 82,
2059–2061.
Novotny, M.V., Jemiolo, B., Harvey, S., Wiesler, D., Marchlewska-Koj, A., 1985b.
Adrenal mediated endogenous metabolites inhibiting puberty in female mice.
Science 231, 722–725.
Novotny, M.V., Jemiolo, B., Harvey, S., 1990. Chemistry of rodent pheromones:
molecular insights into chemical signaling in mammals. In: MacDonald, D.W.,
Muller-Schwarze, D., Natynczuk, S.E. (Eds.), Chemical Signals in Vertebrates 5.
Oxford University Press, New York, pp. 1–22.
Novotny, M., Jemiolo, B., Wiesler, D., Ma, W., Harvey, S., Xu, F., Xie, T.M., Carmack,
M., 1999. A unique urinary constituent, 6-hydroxy-6-methyl-3-heptanone, is a
pheromone that accelerates puberty in female mice. Chem. Biol. 6, 377–383.
Penn, D., Potts, W.K., 1998. Chemical signals and parasite mediated sexual selection.
Trends Ecol. Evol. 13, 391–396.
Prasad, N.L.N.S., 1983. Horn growth in Blackbuck (Antelope cervicapra L.). J. Bombay
Nat. Hist. Soc. 80, 634–635.
Rajagopal, T., Archunan, G., 2008. Scent marking by Indian Blackbuck: characteristics
and spatial distribution of urine, pellet, preorbital and interdigital gland marking
in captivity. In: Reddy, M.V. (Ed.), Biodiversity and Wildlife Conservation. Daya
publishing house, New Delhi, pp. 71–80.
Rajagopal, T., 2009. A study on the reproductive behaviour and pheromones of an
endangered Indian Blackbuck (Antelope cervicapra L.) to enhance captive breed-
T. Rajagopal et al. / Behavioural Processes 85 (2010) 58–67
ing and conservation. Ph.D. Thesis. Bharathidasan University, Tiruchirappalli,
Tamil Nadu, India.
Rajagopal, T., Manimozhi, A., Archunan, G., 2010. Diurnal variation in scent preorbital
gland marking behaviour of captive male Indian Blackbuck (Antelope cervicapra
L.) and its territorial significance. Biol. Rhythm Res (in press).
Rameshkumar, K., Archunan, G., Jeyaramanm, R., Narasimhan, S., 2000. Chemical
characterization of bovine urine with special reference to oestrus. Vet. Res.
Commun. 24, 445.
Rameshkumar, K., Archunan, G., 2002. 1-Iodoundecane: an effective sex attractant
from bovine estrus urine. In: Proc. 20th Symp. Reprod. Biol. Comp. Endocrinol.,
pp. 1–8.
Rasmussen, L.E.L., Lee, T.D., Zhang, A., Roelofs Jr., W.L., Daves, G.D., 1997. Purification,
identification concentration and bioactivity of (Z)-7-dodecene-1-cyl acetate: sex
pheromone of the female Asian elephant, Elephas maximus. Chem. Senses 22,
417–438.
Rasmussen, L.E.L., Perrin, T.E., 1999. Physiological correlation of musth: lipid
metabolites and chemical composition of exudates. Physiol. Behav. 67, 539–549.
Raymer, J., Wiesler, D., Novotny, M., Asa, C., Seal, U.S., Mech, L.D., 1986. Chemical
sent constitutions in the urine of wolf (Canis lupus) and their dependence on
reproductive hormones. J. Chem. Ecol. 12, 297–314.
Rekwot, P.I., Ogwu, D., Oyedipe, E.O., Sekoni, V.O., 2001. The role of pheromones and
biostimulation in animal reproduction. Anim. Reprod. Sci. 65, 157–170.
Rich, T.J., Hurst, J.L., 1998. Scent marks as reliable signals of the competitive ability
of mates. Anim. Behav. 56, 727–735.
Rich, T.J., Hurst, J.L., 1999. The competing counter marks hypothesis: reliable assessment of competitive ability by potential males. Anim. Behav. 58, 1027–1037.
Roberts, S.C., Dunbar, R.I.M., 2000. Female territoriality and the function of scent
marking in a monogamous antelope (Oreotragus oreotragus). Behav. Ecol. Sociobiol. 47, 417–423.
Robitaille, J.F., Prescott, J., 1993. Use of space and activity budgets in relation to age
and social status in a captive herd of American bison, Bison bison. Zoo Biol. 12,
367–379.
67
Roden, C., Vervaecke, H., van Elsacker, L., 2005. Dominance, age and weight in American bison males (Bison bison) during non-rut in semi-natural conditions. Appl.
Anim. Behav. Sci. 92, 169–177.
Schaller, G.B., 1967. The Deer and the Tiger. Chicago University Press, Chicago.
Shimozuru, M., Kikusui, T., Takeuchi, Y., Mori, Y., 2006. Scent-marking and sexual
activity may reflect social hierarchy among group-living male Mongolian gerbils
(Meriones unguiculatus). Physiol. Behav. 30, 644–649.
Smith, T.E., Schaffner, C.M., French, J.A., 1997. Social and developmental influences
on reproductive function in female wieds black tufted-ear marmosets (Callithrix
kuhli). Horm. Behav. 31, 159–168.
Smith, T.E., Abbott, D.H., 1998. Behavioural discrimination between circumgenital
odor from peri-ovulatory dominant and anovulatory female common marmosets (Callithrix jacchus). Am. J. Primatol. 46, 265–284.
Smith, T.E., Tomlinson, A.J., Mlotkiewicz, J.A., Abbott, D.H., 2001. Female marmoset
monkeys (Callithrix jacchus) can be identified from the chemical composition of
their scent marks. Chem. Senses 26, 449–458.
Thiessen, D.D., Rice, M., 1976. Mammalian scent marking and social behaviour. Psychol. Bull. 83, 505–539.
Thom, M.D., Hurst, J.L., 2004. Individual recognition by scent. Ann. Zool. Fenn. 41,
729–745.
Udayagiri, S., Marson, E.E., 1997. Epicuticular wax chemicals in Zea mays influence
oviposition in Ostrinia rubialis. J. Chem. Ecol. 23, 1675–1687.
Walgenbach, C.A., Phillips, J.K., Burkholder, W.E., King, G.G.S., Slessor, K.N., Mori,
K., 1987. Determination of chirality in 5-hydroxy-4-methyl-3-heptanone, the
aggregation pheromone of Sitophilus oryzae (L.) and S. zeamais Mostschulsky.
J. Chem. Ecol. 13, 2159–2166.
Wirtu, G., Pope, C.E., Vaccaro, J., Sarrat, E., Cole, A., Godke, R.A., Dresser, B.L., 2004.
Dominance hierarchy in a herd of female and eland antelope (Taurotragus oryx)
in captivity. Zoo Biol. 23, 323–333.
Zhu, J., Kozlov, M.V., Philipp, P., Francke, W., Lofstedt, C., 1994. Identification of a
noval moth sex pheromone in Eriocrania cicatricella (Zett.) (Lepidoptera: Eriocraniidae) and its phylogenetic implications. J. Chem. Ecol. 21, 29–43.