Sexual Harassment Among Female Lion tailed Macaques (Macaca Silenus) in the Wild

10 Pages·2000·5.9 MB·

by  Ajith Kumar

SEXUAL HARASSMENTAMONG FEMALE LION-TAILED MACAQUES
{MACACA SILENUS) IN THE WILD1
AjithKumar2
(With three text-figures)
Key words: reproductive suppression, sexual swelling, Maccica silenus mounting frequency
,
Adultfemalelion-tailedmacaquesoftenharasssexuallyinteractingadultmaleandfemalemembers
of the group. The extent of harassment and its implication for reproduction by females was
studied in a group in the Anaimalai (presently Indira Gandhi) Wildlife Sanctuary, Tamil Nadu,
India. Nearly 1560 hours ofobservation were made on the same group during nine months in
1979-80and 15 monthsin 1982-84. Atotal of577 sexual interactionsbetween single adultmale
and femaleswererecorded. Mostofthesexual mountingsoccurred when the femaleshad sexual
swelling with apeak 2-4days priorto deflation ofthe swelling. Most ofthe harassment was by
femaleswith sexual swelling. Harassmentdecreased the probability ofmating taking place once
asexual interaction had been initiated(from0.582to 0.07). Aggressive harassment significantly
reduced the duration of mating (from 9.12 secs to 6.16 secs), and thus probably prevented
ejaculation. The percentage ofsexual interactions that were harassed increased with the number
of females with sexual swelling. Postponement of conception due to harassment might be a
major reason for the absence ofa synchrony in conceptions and births similar to that seen in
sexual swelling soon after the summer amenorrhea. Sexual harassment is unlikely to serve as a
behavioural meansofpopulation regulation. Thisisbecausefewerfemalesshowsexual swelling
as the group becomes larger, probably due to increasing competition for food resources. The
major reason for the occurrence of sexual harassment in the lion-tailed macaque might be
competition amongfemalesformating. Thiscompetition resultsfromahigh synchrony in sexual
swelling among the females, thetendency forgroups to haveonly one adultmale, ahigh female
to male (5:1) ratio, and multiple mount pattern in the male.
Introduction aggressionfromhighrankingfemales(Keveme,
1983). Reproductive suppression of ovulating
Reproductive suppression of ovulating females has also been demonstrated in captive
females occurs in some primates. In Miopithecus talapoin (Abbot et al 1986). In
.,
Theropithecus gelada, females actively disrupt marmoset monkeys (Callithrix jacchus)
eachother’scopulation(Mori, 1979).Inthesame ovulation by subordinate females is physio-
species anovulatory cycles and premature logically suppressedbythemere presence ofthe
terminationofmenstrualcyclesandimplantation dominant females (Abbot, 1988).
occur in low ranking females from social stress Lion-tailed macaque, Confined to the rain
due to harassment by high ranking females forests of the Western Ghats of South India,
(Dunbar, 1980). Reproductive suppressionfrom mostly live inonemale unitswith a meangroup
social stress also occurs in Papio cynocephalus size of 18-20 animals (Kumar, 1995a). The
(Wasser, 1983). In captivity, female rhesus reproductive biology is characterized by a high
monkeys could be prevented from mating by sexratioinfavouroffemales(1:5),aconspicuous
sexual swelling phase to which compulatory
'AcceptedJune,1998 mountings are mostly confined, and a low birth
:SalimAliCentreforOrnithologyandNaturalHistory rate (0.30/female year) compared to other
Anaikatti,Coimbatore641 108,
TamilNadu,India. macaques (Kumar 1987, 1995a). There is also a
42 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 97(1). APR. 2000
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
high degree of synchrony in the incidence of females in the study group. These records were
sexual swelling among the females. Harassment made during five to eight days ofdawn to dusk
ofthe mating pairby others, especiallyby adult observationofthegroupeverymonth,andatleast
females, is frequent. This study examines the once in a week during the remaining part ofthe
extent of harassment of matings pairs and its month. All sexual interactionsbetween the adult
implication for reproduction by the females. male and females were recorded ad libitum
Whether such harassment could play a during dawnto duskobservation, alongwith the
populationregulatoryroleisalsodiscussed,since sexual status ofthe female. The copulatory calls
birth rate has been found to decrease with ofthe females (see below), given during more
increasing group size (Kumar, 1995b). than 80% of the sexual mounting and audible
upto75m,wasusedasanindicatorofmounting.
Methods Mountingfrequency/hourwasestimatedforeach
day by dividing the number ofmountings (seen
The analysis is based primarily on data andheard)bythenumberofhoursofobservation.
collectedduringanecologicalstudyononegroup Only days with dawn to dusk observation were
in the Anaimalai (presently Indira Gandhi) selected for analyses, since mounting showed a
Wildlife Sanctuary, Tamil Nadu State, from strong diurnal variation. Five to eight days of
March 1979toMarch 1980, andfromDecember such observations were earned out each month
1982 to March 1984. The group was located in between March 1979 and January 1980 (except
Varagaliyarshola,about25kmsouthofTopSlip, forJulyandAugustwhennodatawascollected)
the Sanctuaryheadquarters. Varagaliyarsholais andagainbetweenDecember 1982andFebruary
about 20 sq. km in area and is the largest ofthe 1984 (except for January and February 1984
rainforestfragmentsintheSanctuary.Thisshola when only two days ofobservations were done
had five or six groups of lion-tailed macaque. each month). A total of631 hours ofad libitum
The main study group had only one adult male records were made in nine months in 1979-80
during both the study periods. There was no and937 hours in 15 months in 1982-84. Besides
thestudygroup,sixothergroupsweremonitored
Table1 at intervals of30-40 days in 1979-80 and 1982-
COMPOSITIONOFTHEMAINSTUDYGROUPINTHE 84.Dataonseasonalityofbirthsweretakenfrom
INDIRAGANDHIWILDLIFESANCTUARY
IN 1979-80AND1982-84 these groups (see Kumar, 1987).
Year Adult Subadult Adult Immatures Total Results
males males females
Jan 1979 1 0 5 6 12 Female Sexual Cycle: The female sexual
Mar 1980 1 0 5 9 15 cycle in the lion-tailed macaque is characterized
MDeacr11998824 11 11 69 192 2137 by the cyclical appearance ofsexual swelling in
the perineal region and at the base of the tail
subadult male in 1979-80, and one in 1982-84. which is conspicuous (Fooden, 1975). The
The number of adult females varied from 5 in swelling phase had a mean length of 14.1 days
(range 8-19 days, n=7) and the non-swelling
1979-80 to 9 in 1982-84 (Table 1).
phase had a mean length of 16.4 days (range 6-
Data on the incidence and duration of
sexual cycles come from records on the sexual 25,n=7).Thecombineddurationofthesephases
gaveameancyclelengthof30.5days. Morethan
status (presence or absence of swelling) of
80%ofthemountingsbytheadultmaleoccurred
JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 97(1), APR. 2000 43
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
Fig. 1: Mounting frequency (perhour) by the adult male on successive days ofasexual swelling cycle ofa
female: mean for six sexual cycles. The sexual cycleswere aligned by the day on which the swellings
disappeared (day 0).
when the female had sexual swelling. Nearly therefore, that there is a summer amenorrhea in
84% ofthese mountings were accompanied by the lion-tailed macaque in the months ofMarch
copulatorycallsofthefemales,comparedtoonly andApril,probablyextendingtoMay.Therewas
9.1% inthe case offemales withoutswelling (x2 a synchrony ofsexual cycles in the study group
=24.9,df=l,/?<0.001).Themountingfrequency soon after the first cycle following the summer
started to increase 3 to 4 days before the amenorrhea (Fig. 2). In 1979, the sexual cycle
appearance ofthe swelling and reached a peak oftwo females started in the last week ofMay,
(of about 3/hour) four days prior to its and in June all the five females ofthe group had
disappearance. It then dropped abruptly almost sexual cycles. The sexual cycle oftwo subadult
to zero on the last day ofswelling (Fig. 1). The females started only in September-October. All
interval between the appearance ofthe swelling the fouradultfemales which showedswelling in
and peak sexual activity varied from 10 to 15 1982-83 did so in synchrony in October 1983,
days, with a mean of 12.2 days (n=6). onesexualcycleafterthefirstcycleoftheseason.
When data from 1979-80 and 1982-84 (Fouroftheremainingfivefemaleswere inpost-
werecombined, swellingswere seeninthestudy partum amenorrhea. The fifth, the oldest female
group m all months of the year except March ofthegroup, didnotshowswelling in 1982-84).
andApril. InMay, swellingwas seenonly inthe Thecycleofthesubadultfemalestartedonlyone
last week in 1979 and none in 1983 (Fig. 2). month later.
Although there are no systematic data from the Sexual Harassment: Sexual harassment
other groups, no swellings were seen in them consisted ofactivities by members ofthe group
duringMarch-Mayof1979and 1983.Itappears. that apparently interfered with sexual
44 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY. 97(1), APR. 2000
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
Months(1979-80)
Months(1983-84)
One sexual swelling cycle
|| |
Sexual swellings leading to conception
Fig. 2: The distribution ofsexual cycles and conceptions in the adult females ofthe study group
in 1970-80 and 1982-84.
interactionsbetweenadultmaleandfemale. Such until the mounting was over. Mountings
interference occurredin 12.8%ofthe577 sexual involving females with and without sexual
interactions observed. Interference occurred at swellingswereequallyharassedbytheimmatures
the premounting stage (i.e. afterthe initiation of (Fisher exact testp=0.33). Moreover, mounting
sexual interactionbutbeforemounting) oratthe did not appear to discontinue as a result ofsuch
mounting stage. Most of the interference were harassment.
at the latter stage (70.3%). Harassment by the subadult and adult
Out of 74 harassments recorded, 23.0% females was related to the sexual status of the
were by infants and juveniles. These occurred female interacting with the male. In 1982-84.
mostly at the mounting stage, and consisted of 11.9% ofthe 270 sexual interactions involving
rushing to the mating pair, and then moving females with swelling were harassed by other
m
about rapidly in short arcs about 2-3 away adult females, while none ofthe 69 mountings
(with tail-wagging and uttering ‘uh uh’ sounds) involving females without swelling were
JOURNAL BOMBAYNATURAL HISTORYSOCIETY, 97(1), APR. 2000 45
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
harassed (%2=7.7, df=l, /?<0.01). In 1979-80, (/-test, t=2.6, p<0.05).
13.1% ofthe 145 sexual interactions involving In short, harassment (a) was mostly by
females with swelling were harassed by other adult females with sexual swelling; (b) was
adult females as opposed to only 2.2% of 90 targeted at females with sexual swelling (c)
sexual interactions involving female without drasticallydecreasedtheprobabilityofmounting
sexual swelling (%2=6.8, df=l, /?<0.01). About taking place after the initiations of a sexual
5.2% of the sexual interactions were harassed interaction, from 0.582 to 0.07; (d) caused a
by the subadult and adult females at the pre- premature termination of mounting and thus
mounting stage and a further 12.1% at the probablypreventedejaculation;and(e)redirected
mounting stage. mounting from the harassed to the harasser.
Harassment at the pre-mounting stage Harassment and Synchrony in Sexual
consistedofafemalepresentingtotheadultmale Swelling: The frequency of harassment varied
while another female was presenting, often with the number of females with swelling. At
betweenthemaleandthefirstfemale. Sometimes the pre-mounting stage, 1.3% of the sexual
a female rushed to a presenting female with interactionswereharassedwithtwofemaleswith
aggressivecallsandchaseditawayfromthemale swelling and 13.7% with four such females
orphysicallypreventedthe male frommounting (X2=14.5, df=3, /?<0.001, Table 2). Harassment
by pulling it by the tail or by standing in the at the mounting stage also increased with the
way. Harassment at the premounting stage number of females with swelling in the group,
occasionally resulted in the redirection of although the difference was not significant
mounting to the harasser (21.4%). More often it (X2=5.09, df=3, /?>0.10). Harassment at the
prevented mounting from taking place. The mounting stage was significantly more frequent
percentage ofsexual initiations which ended in when there were three females with swelling
mountingwhenharassedbyadultfemales(7.0%) (33.3%) compared to when there was only one
was significantly lower than those which were (7.3%, Fisher exact test, p=0.04).
not harassed (58.2%, %2=12.0, df=l, /?<0.001).
Table2
Harassment at the mounting stage PERCENTAGEOFSEXUALINTERACTIONS,
consistedofrushing to thepairwith growls, and HARASSEDATTHEPREMOUNTINGAND
MOUNTINGSTAGESBYADULTFEMALES,AND
chasing and often physically attacking the
ESTIMATEDPERCENTAGEOFMATINGCURTAILED
female. Presenting in front ofthe mounted pair
was also seen. Mounting of the harasser soon Numberof Sexual %harassed %harassed
after mounting the harassed female occurred in femaleswith interactions premount mounting
11.1%ofthecases.Whenharassmentwasovertly swelling seen mountstage stage
aggressive the harassed female often ran or 0 69 0 0
jumped away before the male had dismounted. 1 108 1.9 7.3
Significantly fewer of the harassed mountings 2 75 1.3 14.3
3 14 7.1 33.3
were accompanied by copulatory calls (63.3%)
4 73 13.7 11.6
than those which were not harassed (83.6%,
X2=4.6, df=l,p<0.05). Harassed mountings had The frequency of mounting by the male
a shorter duration (mean=7.75 secs, s.e=0.89, showed significant differences between days,
n=12),thannormalmountings(mean=9.12secs, depending on the number of females with
s.e=0.35,n=95). However,durationofonlythose swelling. (Kruskal-Wallis one-way analysis of
which were aggressively harassed (mean=6.16 variance(K-Wtest),x2=13.4,p<0.005.Table3).
secs. s.e=0.72, n=9) was significantly shorter However, itdidnot increase inproportion tothe
46 JOURNAL. BOMBAYNATURAL HISTORYSOCIETY, 97(1), APR. 2000
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
Table3 conceptions and births would not show a
MOUNTINGFREQUENCY(PERHOUR)BYTHE
ADULTMALEANDSUBADULTMALEWHENTHERE synchrony similar to that shown by sexual
WERE0TO4FEMALESWITHSEXUALSWELLINGIN swelling, but would be more evenly spread out
THEGROUP across the months.
Numberoffemaleswithswelling The date ofbirths in the group during the
0 1 2 3 4 study period were known. Forthese, the months
Adultmale Mean 0.09 0.42 1.66 1.37 1.53 ofconception were estimated using a gestation
Min. 0.00 0.00 1.14 0.27 1.24 periodof172 days(LindburgandLasley. 1985).
Max. 2.50 1.24 2.53 2.45 1.90 Conceptions did not have a peak corresponding
Subadult Mean 0.04 0.04 0.23 0.30 0.22
Male Min. 0.00 0.00 0.00 0.00 0.00 to thatofsexual swelling atthebeginning ofthe
Max. 1.50 0.10 0.38 0.82 0.36 season (Fig. 1). Ofthe five females which had
swellings in June 1979, only one conceived
number offemales with swelling, but appeared during thatmonth. Therewere no data on sexual
to reach a plateau when there were two females cycles in July and August, but only one each of
with swelling. The single subadult male in the four remaining females conceived in July and
group in 1982-84 had a mating frequency that August.Thecyclesoftheremainingtwofemales
was considerably lower than that of the adult continued in synchrony until one conceived in
male, but seemed to increase as the number of December. Since the second study endedbefore
females with swelling increased (Table 3). the births from the 1983-84 mating season
However, the duration of mounting was (September 1983 toFebruary 1984), stoppageof
considerablyshorterforthesubadultmale(often cycling by females was taken as indicating
less than 5 secs), and also did not show the conception. Twofemaleswhichshowedswelling
characteristicmultiplemountpatternoftheadult inSeptember 1983 didsoagain in October,when
male. the four females which showed sexual swelling
Consequences ofHarassment: Ifharass- during that mating season, did so in synchrony.
ment significantly reduces the frequency of The cycle ofonly one stopped after that month.
ejaculatory mating, this could result in a The remaining three females showed swelling
reductioninthechancesofconceptionbyfemale. inNovember(alongwithasubadultfemale),but
This is particularly so if harassment is onlytwo conceptions occurred. The cycle ofthe
asymmetrically distributed among the females, remaining adult female continued until
forexampleduetosocialdominance.Dominance December 1983. The subadult female’s cycle
interactions were relatively few and occurred continued until the end of the field study in
mainlyonmajorfeedingtreeswhenvisibilitywas February 1984.
poor. As a result, the dominance hierarchy of Populationregulation: Sexualharassment
femalesinthemainstudygroupwasnotprecisely could potentially play a population regulatory
known. Moreover, it was often impossible to role since the number offemales that postpone
identify the females because ofthe speed with conception, especially to the next reproductive
whichharassments occurredandpoorvisibility. year, could increase with group size. If this is
Therefore, the reproductive consequences of the case, then the births in the larger groups
harassment was examined indirectly. The should be more dispersed among the months.
distributionofconceptionsandbirthsinthestudy Thiswastestedwithdataonbirthsfromthemam
groupwasusedtotestwhetherfemaleswereless study group and six other groups that were
likely conceive when there were more than one periodically monitored. The seven groups were
female with swelling. If this is so, then divided into two group size classes (12-18 and
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SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
Months
Months
Fig. 3: The distribution ofbirths in two group-size classes, 12-18 (above) and 19-28 (below).
Each square represents one birth.
19-28) based on the mean group size during the Discussion
study period (Fig. 3). Both the classes had the
samemeanbirthdate (Caughley 1977), June 15, Sexual harassment by adult females
but the coefficient of variation for the smaller probably occurs as a consequence of the high
class(205.0%)wasnearlytwicethatofthelarger synchronyofsexualswellingamongthefemales
class (112.2%). Thus, contrary to what was ofa group, a high female/male ratio (5:1), and
expected,birthsinthesmallergroupsweremore thetendencyforthegroupstobe one-maleunits.
dispersedthroughtheyearthanthelargergroups. These could lead to considerable sexual
It is also noteworthy that the main study group competition among the females. The multiple-
had a shorter mating season in 1983-84 when mounting pattern of the male (Fooden, 1975;
thegroup size was 17, comparedtothatin 1979- Kumar and Kurup, 1985) might also impose
80 when the group size was 12 (Fig. 2). constraints on the mating potential ofthe male.
48 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 97(1). APR. 2000
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
Thiscompetitioncouldincreasewiththenumber the mating season gets shorter, and not longer
of females in sexual synchrony. The extent to aspredicted, as the groupbecomes larger. Also,
whichharassmentcouldaffecttheprobabilityof contrary to the second prediction, births were
conception would depend on the stage of the relativelylessdispersedinthe largergroupsthan
sexual cycle in relation to ovulation and the inthesmallergroups.Thiswasprobablybecause
degree of asymmetry in the direction of ofthe violation ofthe above two conditions.
harassment. Even though the frequency of It is known that females do not ovulate
mountinginthefirstweekofswellingwashighly until they reach a particular nutritional level
variable even when there was only one sexually (Frisch and McArthur 1974). Since resource
active female (Kumar, 1987), the peak between competition increases with group size, it could
2-5 days prior to deflation indicates that be expected that the number of females able to
mountings at this stage of the cycle might be build up sufficient nutritional reserves, so as to
critical to conception. Thus, harassment in the start ovulation, would decrease with increasing
last week of swelling could severely affect the group size. There is no systematic data on the
probabilityofconception.Atextremeasymmetry, numberoffemalescominginto sexual cycle as a
in the direction ofharassment, all the curtailed function ofgroup size. In one large group with
mountings couldbe ofthe low-ranking females. more than 25 members, which was regularly
In addition, ifharassments between females of censused,notmorethan4ofthe 12 femaleswere
different ranks differed in aggressiveness (for ever seenwith sexual swelling onthe same day.
example,thosebydominantfemalesbeingmore Sincebirths inthelargergroupswerefew, itwas
aggressive)mountingbythelow-rankingfemales unlikely that other females were in post-paitum
could be curtailed more than those ofdominant amenorrhea. Moreover, although the group was
femalessinceaggressiveharassmentsweremore seenalmosteverymonthin 1979, swellingswere
effective in curtailing mounting. seenonlyinJuneandNovember-December(with
Birth rate in the lion-tailed macaques is a 2 and 3-4 females respectively).
decreasingfunctionofgroupsizeandthenumber In addition, the number of adult and
of adult females in the group (Kumar, 1995b). subadultmalesincreasewithgroupsize(Kumar,
Sexual harassment could lead to such an effect 1987). No data was collected on the sexual
andthus serve as apopulationregulatory factor, behaviour of males in multi-male groups. The
if two conditions are met: i) the proportion of limiteddata on sexualbehaviourofthe subadult
femalescomingintosexualsynchronyduringthe male ofthe study group indicate that mounting
mating season should be constant with group frequency ofsubadult males increased with the
size,sothattheirabsolutenumberwouldincrease number ofsexually active females in the group
with group size; and ii) groups should be either (Table3).Evenifmountingsbythesubadultmale
onemaleunitsirrespectiveofgroupsize,orwhen (andprobably low ranking adult males ofmulti-
there is more thanone male, only one ofthem is male groups) are confined to the early follicular
reproductivelyactiveduringallthephasesofthe and luteal phases ofthe cycle, such mountings
sexual cycle ofthe females. Ifthese conditions couldsignificantlyreducethesexualcompetition
are met, then the mating season should be more between the females with overlapping sexual
prolonged with increasing group size, as more cycles. As a result, mountings by the adult male
females postpone conception. Therefore, births (or dominant male in multi-male groups), even
should be more dispersed in the larger groups ifonlyconfinedtothelatefollicularphase, could
and have a higher coefficient ofvariation. The be less harassed by other females which are in
limited data on the main study group shows that otherphases ofthe cycle.
JOURNAL, BOMBAYNATURAL HISTORYSOCIETY. 97(1), APR. 2000 49
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SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
The shortbirthseason inthe largergroups regulatory factor. Increased mortality ofinfants
mightbe, therefore, acumulative functionof(a) borninlateseasonhasbeenreported;forexample
fewerfemales coming into sexualcyclesin each in M. mulatto (Drickammer, 1974) and in
seasonwhichinitselfwouldsignificantlyreduce A. palliatta (Froelich et al., 1981). Since
female sexual competition and (b) more adult postponement of conception is expected to
males in the larger groups which would further increase with group size within the small to
reduce female sexual competition. Thus, it medium-size range, late seasonbirths and infant
appears unlikely that sexual harassment could mortality could be expected to increase with
be a population regulatory factor, in the small group size within that range.
andlargegroups. Intheformer,inspiteoffemale
sexualcompetition(resultingfromonemale and Acknowledgements
several sexually active females), postponement
ofconception is expected to be only within the I am grateful to Tamil Nadu Forest
mating season. Inthe largergroups, on the other Department for facilities provided in the field; to
hand, fewerfemalesovulateinthematingseason. Zoological Survey ofIndia for funding in 1977-
It is possible that ovulating females are still 80, to Wenner-Gren Foundation, L.S.B. Leaky
sufficiently numerous in the medium sized one Foundations, WWF-US, WWF-India, and
male groups, so that sexual competition could Cambridge Commonwealth Trust for grants in
be high. A few females would be forced to 1981-87; and to Wildlife Conservation Society,
postpone conception to the next mating season NewYork, forgrants in 1987-89. Earlierdrafts of
thus leading to/reproductive suppression. thispapergreatlybenefitedfromcommentsbyDrs.
Postponement of conception within the D.J. Olivers, E.L. Bennet, J.M.Y. Robertson, E.
season could serve indirectly as a population Barret, L. Fuller,E.B. Keverne, andG.W. Norton.
REFE ences
Abbott,D.H.(1988):Socialsuppressionofreproductionin BibliothecaPrimatologica 10. Basel,Karger.
primates. In: Comparative Socioecology: The Frisch, R.E. & E. McArthur (1974): Menstrual cycles:
BehaviouralEcologyandHumansandOtherAnimals fatnessasadeterminantofminimumweightforthe
(Eds.V.StandenandR.A. Foely),pp.285-304. maintenanceoronset.Science 185:949-95
Abbot. D.H., E.B. Keverne, G.F. Moore & U. Froelich,J.W.,Thorington,Jr.,&J.S. Otis(1981): The
YoDYiNGYARd (1986): Social suppression of demographyofhowlermonkeys(Alouattapalliata)
reproduction in subordinate talapoin monkeys, on Barro Colorado Island, Panama. International
Miopithecus talapoin. In: Primate Ontogeny, JournalofPrimatology2:207-236.
Cognition and Reproductive Behaviour (Eds. J.G. Keverne. E.B. (1983): Endocrine determinants and
Else and P.C. Lee), Cambridge University Press, constraintsonsexualbehaviourinmonkeys.In: Mate
Cambridge. Pp329-341 Choice,(Ed.P.Bateson).CambridgeUniversityPress,
Caughley,G.(1975): AnalysisofVertebratePopulations. Cambridge,pp.407-420.
Wiley,Chichester. Kumar,A.(1987):TheEcologyandPopulationDynamics
Drickamer. L.C. (1974): A ten-year summary of oftheLion-tailedmacaque(Macacasilenus)inSouth
reproductivedataforfree-rangingMacacamulatto. India.Ph.D. DissertationsubmittedtotheUniversity
FoliaPrimatologica21:61-80. ofCambridge,U.K.
Dunbar, R.I.M. (1980): Determinants and evolutionary Kumar,A.(1995a):Thelifehistory,ecology,distribution
consequences ofdominance among female gelada andconservationproblemsinthewild.In:TheLion-
baboons.BehaviouralEcologyandSociobiology7: taled Macaque: Population and Habitat Viability
253-265. AssessmentWorkshop.ZooOutreach.Coimbatore,
Fooden, .1. (1975): Taxonomy and Evolution ofLiontai1 India. Kumar,A.,S. MolurandS. Walker(Eds.).
and Pigtail Macaques(Primates: Cercopithecidae). Kumar. A. (1995b): Birth rateandsunival in relationto
50 JOURNAL. BOMBAYNATURAL HISTORYSOCIETY. 97(1). APR. 2000
SEXUALHARASSMENTAMONGFEMALELION-TAILEDMACAQUES
groupsizeinthelion-tailedmacaque,Macacosilenus. Macaque:StatusandConservation(Ed.P.G.Heltne).
Primates. 36: 1-9. pp.34-56.Alan R. Liss.NewYork.
Kumar,A.&G.U.Kurup(1985):Sexualbehaviourofthe Mori.A.(1979): Analysisofpopulationchangesbybody
Lion-tailedmacaque,Macacasilenus.In:TheLion- weightintheKoshimatroopofJapanesemonkeys.
tailed Macaque: StatusandConservation(Ed. P.G. Primates20: 371-397.
Heltne),pp, 109-130,AlanR. Liss,NewYork. Wasser, S.K. (1983): Reproductive competition and
Lindburg, D.G. & B.L. Lasely (1985): Strategies of cooperationamongfemaleyellowbaboons.In:Social
optimisingthereproductivepotentialoflion-tailed BehaviourofFemaleVertebrates. (Ed.S.K.Wasser),
macaque colonies in captivity, lit: The Lion-tailed Academic Press,NewYork.pp.349-390.
JOURNAL BOMBAYNATURAL HISTORYSOCIETY. 97(1). APR. 2000 51