Alpine Wildlife Research Centre\ Gran Paradiso National Park\ Torino^ Department of Animal Productions\ Epidemiology and Ecology\ University of Torino\ Torino^ Department of Evolutionary Biology\ Ethology and Behavioural Ecology Group\ University of Siena\ Siena
Male Alpine Chamois Occupy Territories at Hotspots Before the Mating Season Achaz von Hardenberg\ Bruno Bassano\ Alberto Peracino + Sandro Lovari von Hardenberg\ A[\ Bassano\ B[\ Peracino\ A[ + Lovari\ S[ 1999[ Male alpine chamois occupy territories at hotspots before the mating season[ Ethology 095\ 506*529[
Abstract Ungulate mating systems vary broadly both between and within species[ Studies on mating systems in di}erent habitats can provide clues to the ecological factors determining this diversity[ Despite its abundance in the European Alps and its importance as a game species\ surprisingly little is known about the mating system of Alpine chamois Rupicapra rupicapra rupicapra[ We tested the hypothesis that adult males _rst defend mating territories in late spring\ when females segregate from males and well before the Nov[ rut[ In the Gran Paradiso National Park "north!western Italian Alps#\ adult males shared a winter range but occupied individual ranges in summer and early autumn[ Males were more aggressive to each other in the summer than in the spring[ A strong site _delity from one year to the next was found for the summer and early autumn months[ Those males that occupied the same territories both in the summer and during the rut "Nov[# appeared to be at hotspots\ attractive to females during the rut because of reduced snow cover[ Other males appeared to cluster around these hotspots during the rut[ Territories that were _rst occupied during the summer were visited by more females than those that were not established until the rut began[ Our results suggest that the mating system of this population of Alpine chamois consists of the early occupation of clustered mating territories[ The early establishment of mating ter! ritories in areas frequented by females during the rut may lead to reproductive bene_ts for male chamois[ Corresponding author] Prof[ S[ Lovari\ Department of Evolutionary Biology\ Ethology and Behavioural Ecology Group\ University of Siena\ Via P[A[ Mattioli 3\ 42099 Siena\ Italy[ E!mail] lovariÝunisi[it Introduction In mammals\ male mating strategies appear to be determined by the distribution\ U[ S[ Copyright Clearance Center Code Statement] 9068!0502:1999:0956Ð9506,04[99:9
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size and stability of female groups\ which a}ects the relative defensibility of females by males "Clutton!Brock 0878#[ Ungulates are ideal to study the evolution of mating systems\ because they are relatively easy to observe and present a high variability in the mating strategies adopted by males\ both between and within species "Gosling 0875^ Clutton!Brock 0878^ Thirgood et al[ 0888#[ Male mating strategies of ungulates range from non!territorial {following|\ in which males search for oestrous females during the rut and try to defend them from other males\ to the defence of female groups and to territorial strategies\ including single territories\ clustered territories and leks "Gosling 0875^ Clutton!Brock 0878^ Clutton!Brock et al[ 0882#[ There is some disagreement about the de_nition of a territory[ Several authors attempted to propose a common de_nition "Owen!Smith 0866^ Kaufmann 0872^ Maher + Lott 0884#[ Maher + Lott "0884# reviewed 37 de_nitions of territoriality in vertebrate studies and de_ned a territory as {{a _xed space from which an individual\ or group of mutually tolerant individuals\ actively excludes competitors for a speci_c resource or resources||[ This de_nition\ which we adopt in the present study\ includes both ecological and behavioural elements and is thus useful for comparison with other studies "Maher + Lott 0884#[ Owen!Smith "0866# reviewed territoriality in ungulates and found that territories share the following charac! teristics] mutually exclusive areas defended by one territorial individual who rarely moves beyond its limits\ who challenges intruding conspeci_cs of the same sex in its own territory and behaves submissively outside it[ Territorial individuals often advertise their presence by visual\ auditory or olfactory displays "Owen!Smith 0866#[ Studies on di}erent species in di}erent ecological conditions are needed to de_ne a general framework to explain the variety of mating systems in ungulates "Clutton!Brock 0878#[ The Alpine chamois Rupicapra rupicapra rupicapra "L[ 0647#\ Bovidae] Capri! nae\ is probably the most abundant ungulate in the Alps "Giacometti et al[ 0886#[ Despite its importance as a game species and a rich anecdotal literature "e[g[ Couturier 0827^ Knaus + Schroder 0872#\ little is known about its social organ! isation "Kramer 0858^ Meile + Bubenik 0868^ Ingold + Marbacher 0880# and space use "Hamr 0873\ 0874^ Shank 0874#[ Within the Caprinae subfamily\ {following| is the most widespread mating system[ The broken\ often mountainous\ terrain with rigorous climate and highly seasonal food resources\ where caprinae have apparently evolved "Schaller 0866^ Geist 0874#\ generates group instability and synchrony of oestrus!periods\ which militate against the development of male territoriality "Gosling 0875#[ Synchronized oestrus is strongly selected for in ungulates inhabiting highly seasonal environments with short growing seasons] late!breeding females give birth late in the spring and their o}spring su}er a decreased survival "bighorn sheep Ovis canadensis\ Festa! Bianchet 0877^ red deer Cervus elaphus\ Guinnes et al[ 0867#[ The Japanese serow Capricornis crispus\ living in highly productive dense montane forests\ is the only caprine to show individual territoriality\ with over! lapping male and female territories "Kishimoto + Kawamichi 0885#[ In the Apennine chamois Rupicapra pyrenaica ornata\ in autumn\ sedentary males try to defend female groups forming on clumped food resources\ but females
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tend to disperse when in oestrus\ forcing males to switch to {following| "Lovari + Locati 0880#[ Adult male Alpine chamois are intolerant of each other during the Nov[ rut\ and they try to keep the greatest possible number of females in their home ranges "Kramer 0858#[ In summer\ females move to high pastures\ while males stay at lower altitudes "Shank 0874#[ Meile + Bubenik "0868# and Hamr "0873# suggested that adult male Alpine chamois may have exclusive summer home ranges[ In a descriptive paper\ Meile + Bubenik "0868# stated that these summer areas roughly correspond to each male|s rutting grounds\ and are occupied as soon as the snow melts in the spring[ Meile + Bubenik "0868# and Hamr "0873# did not specify whether these summer areas are actively defended by males[ The aim of our study was to investigate the mating strategy of adult male Alpine chamois^ we asked the following questions] 0[ Are adult males territorial in summer< We predicted that\ if males are territorial "sensu Maher + Lott 0884# in summerÐautumn\ they should show\ compared to the non!territorial period] "a# a signi_cantly lower degree of inter! individual home range overlap "i[e[ mutually exclusive areas#^ "b# a higher intra! sexual aggressiveness "i[e[ active defence of territories#^ "c# site _delity\ because if males bene_t from defence of a speci_c resource in one year\ they should try to defend it again the following year[ 1[ Why are males territorial in summer\ when there are no oestrous females< Perhaps males defend mating territories\ which females will visit during the rut[ The defence of mating territories outside the rut has been observed in the American pronghorn Antilocapra americana "Byers 0886# and in several African ungulates "hartebeest Alcelaphus buselaphus\ wildebeest Connochaetes taurinus and topi Dam! aliscus korrigum\ Gosling 0875#[ In the African species\ males defend territories in the dry season although their body condition deteriorates faster than that of non! territorial males "Gosling 0875#[ Male red deer Cervus elaphus\ in southern Spain\ defend clustered mating territories during the rut and the earlier a male occupies his territory the more females he will keep later on "Carranza et al[ 0889#[ In all these cases\ females show predictable ranging movements\ as seems to be the case for Alpine chamois[ During the rut\ females are attracted to clumped\ limited resources\ which males try to defend[ According to Gosling "0875#\ the defence of mating territories outside the rut may have been selected for by the advantages of being in residence at the start of the rut[ Owners may have an advantage in contests for territory ownership "Maynard!Smith + Prince 0862^ Maynard!Smith 0871# and could maintain a {good| territory during the rut[ This hypothesis leads to the following predictions] "a# summer territories should coincide with or include mating territories^ "b# early occupation of territories should lead to greater reproductive success[ Study Area Our study was carried out in 0883Ð84\ in the high Orco Valley\ in the Gran Paradiso National Park "Western Italian Alps\ 34>15?N\ 6>97?E#[ The study area lies
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between 0799 and 1399 m a[s[l[ and includes both slopes of the valley[ Alpine meadows "mainly Festuca varia# are located in the south facing slope\ while the north facing slope is characterized by a larch wood Larix decidua and thick alder shrubs Alnus viridis[ Mean temperature ranged from Ð7>C in Dec[ to Mar[ to ¦07>C in Jun[ to Sep[ Maximum snow depth was 299 cm in 0883 and 077 cm in 0884[ The chamois population in Gran Paradiso National Park has been protected since 0811 and has a density of ¼ 6 animals:099 ha in Orco Valley "based on 0883 and 0884 censuses#[ In late winter and spring the study area is also used by ³099 Alpine ibex Capra ibex[ No large mammalian predator is present in the study area and the chamois population appears to be limited by winter mortality "Peracino + Bassano 0876#[ Methods Capture\ Marking and Radio!Tracking of Animals 0
Six adult "4 :1Ð090:1 years old# males were darted with xylazine and ketamine "29 mg ¦ 64 mg# and individually marked with radio collars "Televilt# and coloured ear tags[ Chamois were usually released within 29 min of capture[ Five adult males were radio!tracked for 1 yr "Dec[ 0882 to Dec[ 0884#[ One male was followed for 0 yr only "Dec[ 0883 to Dec[ 0884^ Table 0#[ Between two and nine _xes per week per individual were recorded[ Most _xes "67)# were followed by direct observation of the animal^ the other _xes were triangulated from at least three bearings "White + Garrott 0889#[ Observation Methods
Agonistic encounters were recorded ad libitum "Altmann 0863#[ Two males standing within a distance of 49 m from each other were considered as engaged in an agonistic encounter if they displayed any of the following behavioural patterns] Approach\ Chase\ Neck up\ Marking\ Horning\ Penile Display and Hook as described in Lovari "0874#[ According to Kramer "0858# and to Lovari + Locati "0880# these patterns have a clear aggressive connotation in Rupicapra spp[
Table 0] Age at capture "years#\ body weight "kg# and radio!tracking period of the six male chamois considered in this study Chamois M0 M1 M2 M3 M4 M5
During the summer the encounter probability of adult males is lower than in the spring and in the mating season\ because of the spatial segregation of the home ranges[ To avoid a seasonal bias\ we calculated\ for each male\ a seasonal aggression index "AI#] AI Nae:Tnc where Nae Number of agonistic encounters\ and Tnc Total number of cases in which each male was seen with other adult males within a radius of 49 m[ The Tnc and the Nae were counted by considering all events in which two males were seen within a distance of 49 m during sampling _xes and during focal!animal observations used to assess time!budgets[ Repeated interactions with the same male\ in the same observation bout\ were not considered] as soon as we saw two males together\ we classi_ed them as engaged in an agonistic encounter or not\ so the actual number of agonistic encounters may have been underestimated[ The AI ranges from 9 to 0\ with AI being 0 if the individual interacts aggressively with every male seen within 49 m\ and 9 if the individual always ignores other males[ The AIs of each male were compared in spring "Mar[ to May# and summer "Jun[ to Sep[#[ During the 0884 rut we recorded the mean number of females:hour inside the home ranges of marked males by counting them every 04 min\ during 77 h of focal animal observations "Altmann 0863#[ Most observations were made simul! taneously\ observing the rutting area from across the valley[ Focal males were chosen randomly\ and an e}ort was made to homogeneously distribute obser! vations on every male over time of day and phase of rut[ The date of territory occupancy by males was the day when an individual was _rst seen within the 84) home range occupied in the following Nov[ Weather data were obtained from a station situated within the study area at an altitude of c[ 1199 m a[s[l[ We calculated the mean snow depth per 1!mo period from snow depths measured daily at the station[ Space Use
Seasonal di}erences in space use were evaluated over bimonthly periods "Dec[ to Jan[\ Feb[ to Mar[\ Apr[ to May\ Jun[ to Jul[\ Aug[ to Sep[#[ Oct[ and Nov[ were considered separately because the mating period is in Nov[ Home ranges were calculated as minimum convex polygons "MCP# "White + Garrot 0889# using WILDTRAK for Macintosh "Todd 0882#[ Percentages of 099 and 84 MCP were used for statistical analyses[ We calculated annual and 5!mo "Dec[ to Jun[\ or winter to spring\ and Jul[ to Nov[\ or summer to autumn# home range sizes[ Home range size was also calculated for each bimonthly period[ Home range centres were de_ned as the arithmetic mean of all _xes within each home range "Todd 0882#\ and we calculated Euclidean distances between the home range centres of di}erent individuals in the same period[ For every individual\ we also calculated Euclidean distances between the centre of the home range in Nov[ and in all other bimonthly periods in the same year\ to estimate the overlap of summer and mating territories "White + Garrot 0889#[ We estimated home range overlap as percentage of overlap
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between home ranges "84) MCP# of all dyads\ in each period[ The home range distance and overlap values used in statistical analyses were calculated as means for every individual\ to avoid pseudo!replication "Machlis et al[ 0874#[ Data Analysis
Repeated measures ANOVA was used to detect di}erences among bimonthly periods in home range size\ overlap and distance[ Overlap data were arcsine!square root transformed to meet normality[ If ANOVA revealed a signi_cant e}ect among bimonthly periods\ the least signi_cant di}erence "LSD# test was used to detect pair!wise di}erences[ All other tests were non!parametric "Siegel + Castellan 0877# unless otherwise speci_ed[ Cluster analysis "UPGMA clustering method] Romesburg 0873#\ using the coordinates of home range centres in 0883 and 0884 as variables and Euclidean distances as distance measure\ was performed for each bimonthly period to test whether individuals showed seasonal site _delity from one year to the next[ All p!values were considered signi_cant at a level of 9[94[ All tests are two tailed\ except for the Page test for ordered alternatives "Siegel + Castellan 0877#[
Results Annual home range sizes were generally less than 199 ha "Table 1#[ Home range sizes changed between bimonthly periods in 0883 "F5\13 2\ p 9[92# but not in 0884 "F5\29 9[86\ p 9[35^ Table 2#[ Mean bimonthly home range sizes did not vary signi_cantly between years "Wilcoxon signed ranks test] T 2\ n 6#[ A sample of home ranges "0884\ Feb[ to Mar[\ cold season^ Aug[ to Sep[\ warm season^ Nov[\ mating period# is shown in Fig[ 0[
Table 1] Annual home range sizes "ha# of adult male chamois\ calculated as 099) and 84) Minimum Convex Polygons "MCP#\ in the 1 yr of study "0883Ð84# MCP 0883 099) 84) N _xes 0884 099) 84) N _xes
M0
M1
M2
M3
M4
M5
121[7 082[5 119
71[7 42[8 112
003[9 099[9 119
039[5 008[4 119
78[7 63[1 112
Ð Ð
160[8 062[3 099
36[6 21[9 003
82[5 59[8 81
89[5 49[9 091
38[1 03[0 096
85[8 69[2 89
{N _xes| is the total number of _xes used for home range estimate[
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Home range overlap varied between bimonthly periods in both years "0883] F5\13 28[14\ p ³ 9[990^ 0884] F5\29 16[36\ p ³ 9[990#[ Mean home range overlap varied similarly in both years\ with signi_cant di}erences between Apr[ and May\ and Jun[ and Jul[ "LSD test] p ³ 9[990# and between Nov[ and the cold periods from Dec[ to Jan[\ and Apr[ to May "LSD test] 0883\ p ³ 9[990^ 0884\ p ³ 9[994#[ In Nov[ 0883\ home range overlap was smaller than in all other periods "LSD test] p ³ 9[94# except Oct[ In 0884\ home range overlap in Nov[ was not di}erent from that recorded from Jun[ through Oct[ "Fig[ 1#[ Bimonthly mean home range sizes were not correlated to the mean overlap of home ranges "rs 9[24\ n 6#[ Distances between home range centres "Fig[ 1# varied between bimonthly periods in both years "0883] F5\13 29[45\ p ³ 9[990^ 0884] F5\29 59[13\ p ³ 9[990#[ The mean distance between home range centres did not vary from Dec[ to Jan[\ to Apr[ to May "cold season#\ but increased from Apr[ to May to the periods going from Jun[ to Jul[ to Nov[ in both years "LSD test] p ³ 9[94#\ and
Table 2] Mean home range sizes "ha^ 84) MCP^ 2SE in parentheses# for every bimonthly period
0883 N _xes 0884 N _xes
Dec to Jan
Feb to Mar
Apr to May
Jun to Jul
Aug to Sep
Oct
Nov
05[5 "0[4# 16 7[2 "9[7# 09Ð03
20[6 "1[9# 28 7[3 "0[0# 09Ð05
14[5 "0[8# 30 08[0 "0[3# 02Ð07
45[5 "1[8# 33Ð34 04[6 "0[6# 09Ð07
16[5 "1[4# 34Ð37 02[6 "1[9# 01Ð19
7[9 "0[4# 00 09[3 "0[5# 6Ð01
2[2 "9[8# 01 7[1 "0[0# 04Ð10
{N _xes| is the "minimum and maximum# number of _xes used for the estimate of individual home ranges[
Fig[ 0] Home ranges "84) MCP# of six adult male chamois "M0ÐM5#[ a[ Feb[ to Mar[ 0884^ b Aug[ to Sep[ 0884^ c Nov[ 0884[ M0] !ž!\ M1] !Ž!\ M2] !!\ M3] !!\ M4] !R!\ M5] !r!\ Road] !Ð!\ Orco river] ====
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Fig[ 1] Variation in mean overlap percentage and mean distance between the arithmetic centres of the home ranges of male adult Alpine chamois during 0883 "n 4# and 0884 "n 5#
decreased from Aug[ to Sep[ to Nov[ "LSD test] p ³ 9[94#[ Thus\ in the rut "Nov[#\ home ranges clustered together without signi_cant overlap[ In the cold months\ home range overlap increased with snow depth "Page test for ordered alternatives] 0883\ L 538\ n 4\ p ³ 9[990^ 0884\ L 425\ n 5\ p ³ 9[990#\ while home range size did not "0883] L 454[4\ n 4^ 0884] L 306[4\ n 5#[ The aggression index "AI# of male chamois doubled from spring to summer "Mar[ to May] mean 2 SE 9[22 2 9[94^ Jun[ to Sep[] mean 2 SE 9[55 2 9[97^ Wilcoxon signed ranks test] T 9^ n 5^ p ³ 9[94#[ Males won most of the agonistic encounters with other males inside their ranges and lost those outside "Wilcoxon signed ranks test] T 9^ n 4^ p ³ 9[94\ one!tailed^ Table 3#[ We could
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use only _ve of the six marked males for this analysis\ as male M5 won all 01 encounters inside his 84) MCP\ but he had no agonistic encounter outside[ If individuals showed seasonal site _delity from one year to the next\ the cluster analysis should correctly cluster the centres of home ranges of the same individuals\ in 0883 and 0884\ into the same cluster[ The home range centres of all chamois in the 1 yr were correctly clustered in Aug[ to Sep[ and Nov[ "Fig[ 2#^ in Jun[ to Jul[ and Oct[ the correct clusters were three^ in Apr[ to May two and just one in Dec[ to Jan[ and Feb[ to Mar[ A strong correlation was found between the mean number of females per hour in each territory during the rut\ and the date of territory occupancy by males "r 9[88^ n 4^ p ³ 9[94#[ The mean number of females:hour in a territory likely approximates a male|s reproductive success[ Only male M3 was unusual\ as he was one of the last to reach the rutting grounds\ but had 1[2 females per hour in his territory "average 9[45 2 9[05 SE females per hour\ n 2#[ The distance between bimonthly home range centres and the home range centre in Nov[ was almost zero during the summer for three out of _ve males in 0883 and for four out of six in 0884\ indicating early occupation of mating territories for some males "Fig[ 3#[ Discussion Adult male chamois had small and exclusive home ranges\ a high degree of site _delity from one year to the next and a high degree of maleÐmale aggressiveness in the summer\ supporting the hypothesis of territoriality "Maher + Lott 0884# in this species[ Furthermore\ males won almost all interactions inside their territories\ while losing most of those outside[ Home range sizes of adult male chamois in our study are amongst the smallest reported for this species "Hamr 0873^ Bogel et al[ 0887#[ Home range sizes were stable and did not change even when inter!individual overlap of home ranges increased during the winter[ The highest degree of inter!individual overlap was found in the cold season\ suggesting the existence of a shared male winter range "Fig[0a#[ This conclusion is supported by the higher mean number of males per hour within a radius of 49 m observed in the spring "Mar[] 0[5 2 9[1 SE# than in summer "Aug[ to Sep[ 9[0 2 9[95 SE#[ Apparently\ snow limited movements and
Table 3] Mean percentage of encounters won inside and outside individual 84) minimum convex polygons of _ve chamois males "ranges are shown in parentheses#
Inside 84) MCP Outside 84) MCP
Mean percentage of encounters won
Mean no[ of encounters:individual
84[2 "75[5Ð099# 11[7 "9Ð49#
02[3 "7Ð12# 4 "0Ð00#
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Fig[ 2] Cluster analysis on the home range centre coordinates of individuals "M0ÐM4# in 0883 and 0884[ indicates the home ranges of the same individual correctly clustered in the 1 years
food resources\ causing males to congregate and resulting in a high degree of home range overlap\ without a}ecting home range size[ Female chamois are gregarious "Kramer 0858^ Schroder 0860# and use large home ranges\ probably in relation to the availability and quality of seasonal food resources "Hamr 0874#\ thus separating from males outside the rut "Shank 0874#[ The high altitude meadows\ used by females in summer\ are usually covered with snow in our study area during the rut\ forcing females to lower altitudes in search of food[ The territories defended by males during the rut were clustered on a South!
Territorial Behaviour in Chamois
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Fig[ 3] Euclidean distances between the centre of the home range in Nov[ and those in all other bimonthly periods for individual males\ in 0883 and 0884[ Individuals represented with a continuous line are those which had already occupied their mating territories in summer[ M0] !ž!\ M1] !Ž!\ M2] !!\ M3] !!\ M4] !R!\ M5] !r!
facing slope that was relatively free of snow in Nov[\ thus attractive to females\ who regularly visited it during the rut[ The mating system of male Alpine chamois\ as described in this paper\ shows some characteristics "small clustered territories# reminiscent of a lek system[ A lek is generally de_ned as a cluster of small male mating territories that contain no signi_cant resource attractive to females "Bradbury 0870^ Wiley 0880^ Clutton!Brock et al[ 0882#[ In ungulates\ leks are visited mainly by females in oestrus which\ to do so\ leave the feeding herds[ Generally\ after mating\ females return to the herd "Clutton!Brock et al[ 0882#[ Thus leks do not coincide with the feeding sites of females[
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We found that females returned every Nov[ to the area occupied by territorial males\ probably because the limited snow cover allowed better access to forage than females could expect to _nd elsewhere in the study area at that time of the year[ Females are commonly seen feeding within the cluster of male territories during the rut\ and they appear to stay in this area also before and after their receptive period[ Thus our observations may not support the hypothesis that the cluster of mating territories of Alpine chamois males represent a true lek[ The clustering of mating territories in areas regularly used by females while foraging has also been described for red deer Cervus elaphus "Carranza et al[ 0889#\ fallow deer Cervus dama "Thirgood 0889# and antelopes such as puku Kobus vardoni "Rosser 0881#\ waterbuck Kobus defassa "Spinage 0871# and topi Damaliscus korri! gum[ Males of the latter species defend clusters of small territories in areas of short grassland\ preferred by females for anti!predatory reasons "Gosling 0875#[ Situations where males cluster during the rut at resource hotspots regularly visited by females have been proposed as being intermediate between resource!based territoriality and true leks "Gosling 0875^ Clutton!Brock 0878#[ In our study area\ four out of six adult males occupied the same territories in both summer and rut "Fig[0bÐc and Fig[ 3#\ suggesting an early occupation of mating territories before the arrival of females[ We propose that early occupation of mating territories may give chamois males a reproductive advantage\ as suggested by the strong correlation between the mean number of females per hour in each male territory during the rut and the earliest date of territory occupancy by males[ The males| behaviour may appear surprising\ because the defence of a territory throughout the summer is presumably costly[ A male that defended a territory only from the beginning of the rut would not pay the costs of a prolonged territorial defence and could improve his summer nutrition by moving to the best available pastures each season[ In many species\ however\ residents typically win territorial contests against intruders "Huntingford + Turner 0876^ Archer 0877#[ Di}erent hypotheses have been proposed to explain this {Prior Residence Advantage| "PRA#] residents may have an advantage because of a better knowledge of the area\ or the PRA may have evolved as a {conventional rule| to settle contests "the {bourgeois strategy|] Maynard!Smith 0871#[ More recently it has been proposed\ with a simple learning!based model of territorial establishment\ that the PRA may be the consequence of individuals returning to areas where they had a history of positive experiences "Stamps + Krishnan 0888#[ The PRA appears to be a common characteristic of territorial animals\ including male Alpine chamois[ If prior residence gives an advantage in territorial contests\ individuals who occupied a {good| mating territory before the rut should have a greater probability of maintaining that territory also in the mating season and thus gain a reproductive bene_t[ In conclusion\ our study suggests that the mating strategy of adult male Alpine chamois in our study area consists of early occupation and individual defence of clustered mating territories[ While this type of mating system has been described for some African antelopes\ our study is the _rst documenting it in a mountain ungulate[ The high predictability of the movements of females\ due to the seasonal
Territorial Behaviour in Chamois
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clumping of resources during the rut\ asymmetry in territorial con~icts in favour of established residents\ and relatively low costs of a prolonged territorial defence appear to make the early occupation of clustered mating territories at hotspots an e.cient reproductive strategy for males[ The occurrence of these conditions in di}erent habitats may explain the presence of this strategy in species as taxo! nomically and ecologically di}erent as African antelopes and Alpine chamois[ Acknowledgements This study could not have been carried out without the cooperation of V[ Peracino\ who supported it in many ways] we are greatly indebted to him[ We are also grateful to A[ Guglielmetti\ chief warden of the Orco Valley\ for his collaboration[ We thank the Park wardens L[ Jocolle and P[ Chabod for their help in darting operations[ M[ Giametta helped to collect data on agonistic encounters during the rut in 0884[ Many thanks are due to M[ Festa!Bianchet for helpful discussions and suggestions in the development of this paper[ M[ Gosling and J[ Carranza provided useful insights on the results of our study[ We also thank M[ Apollonio\ J[ A[ Byers\ C[ Celada\ R[ Noe and an anonymous referee for comments on earlier drafts of this manuscript[ Financial support was granted by the Gran Paradiso National Park Agency and the Italian Ministry for University and Research "39 and 59) funds# to S[ L[ Part of the writing up was done while A[v[H[ was at the Departement de Biologie\ Universite de Sherbrooke "Canada#\ supported by a scholarship from the University of Pavia "Italy#[
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