ORIGINAL PAPER

Reproductive characteristics of female Bengal tigers,in Ranthambhore Tiger Reserve, India

Randeep Singh & Qamar Qureshi &Kalyanasundaram Sankar & Paul R. Krausman &

Surendra Prakash Goyal

Received: 25 March 2014 /Accepted: 15 April 2014# Springer-Verlag Berlin Heidelberg 2014

Abstract Reproductive characteristics of tigers (Pantheratigris) are important to understand population viability. Westudied the reproductive parameters of female Bengal tigers(P. t. tigris) in a dry, tropical, deciduous habitat inRanthambhore Tiger Reserve (RTR), western India, fromApril 2005 to March 2010. We monitored tigers by directobservation and with cameras placed throughout their habitat.The potential breeding population included 13 adult females.The average age at first reproduction was 3.3 years; 34 cubswere born during the study period (6.2±0.82 per year). Sixty-six percent of the births occurred between October and De-cember. Mean litter size was 2.26±0.52 (n=13, range=1–3).The sex ratio of 32 cubs was 1.29 M:1.00 F. The survival rateof cubs (<12 months) was 85 % (95 % CI=0.68–0.94),whereas that of juveniles (12–24 months), and subadults(24–36months) was 79% (95%CI=0.61–0.91). All breedingfemales were >3 years old. Only 2 of the 13 femalesreproduced twice during the 5 years of the study. The birthinterval was 33.4±3.7 months (range 24–65 months). Themean reproductive rate was 0.59±0.23 cubs/female/year.Our study indicates that tiger populations can grow rapidly ifthe habitat provides adequate protection, an adequate popula-tion of prey, and minimal to no poaching.

Keywords Camera trap . Litter size . Mortality .Pantheratigris tigris . Sex ratio . Survival

Introduction

Reproductive success is a key to survival and continued exis-tence for any species, and understanding species’ reproductiveparameters (e.g., age at first reproduction, reproductive rate,liter size, interbirth interval, and breeding period) is critical todeveloping effective conservation strategies (Carter et al.1999). Reproductive parameters are important to determinepopulation turnover, potential growth rates, and are importantindicators to detect the lineage persistence in a population (i.e.,lineage loss, individual fitness, population viability [Kelly2001; Holt et al. 2003]), population viability (Kelly 2001;Balme et al. 2012), and to examine meta-population dynamics(e.g., determining the reproductive output of source popula-tions; Smith and McDougal 1991; Chapron et al. 2008).

Reproductive data are available for some long-lived carni-vores (i.e., lions Panthera leo; Packer et al. 1988), cheetahs(Acinonyx jubatus; Kelly et al. 1998); leopard (Pantherapardus; Balme et al. 2012), and pumas (Puma concolor;Logan and Sweanor 2001). Yet reproductive parameters ofwild tiger (Panthera tigris) populations are sparsely availableand may vary over their global range. The limited informationon reproductive parameters has been obtained from studies inIndia (Schaller 1967; Sankhala 1978; Chundawat et al. 2002;Singh et al. 2013a), Nepal (Sunquist 1981; Smith andMcDougal 1991; Smith 1993), and the Russian Far East(Smirnov and Miquelle 1999; Kerley et al. 2003). Reproduc-tive parameters may vary among the subspecies of the popu-lations because of the different climatic conditions, habitats,prey densities, and other environmental parameters (Kerleyet al. 2003). Information on how reproductive parameters varyamong subpopulations of the same subspecies surviving indifferent habitats is essential for range-wide conservationplanning (Kerley et al. 2003).

We present reproductive data collected from 2005 to 2010on a protected tiger population in the dry, tropical habitat of

Communicated by C. Gortázar

R. Singh (*) :Q. Qureshi :K. Sankar : S. P. GoyalWildlife Institute of India, Post Box # 18,Dehradun 248 001, Uttarakahnd, Indiae-mail: randeep04@rediffmail.com

P. R. KrausmanBoone and Crockett Program in Wildlife Conservation,University of Montana, Missoula 59812, USA

Eur J Wildl ResDOI 10.1007/s10344-014-0822-3

Ranthambhore Tiger Reserve (RTR), Rajasthan India. Thepopulation in RTR represents a unique gene pool (Sharmaet al. 2008), which is adapted to survive harsh and inclementweather conditions during summer. The open, thorny, decid-uous forest with scanty vegetation and a good road network inRTR provided ideal conditions for tiger sightings (particularlyin the valley and other low-lying areas). Geographic closure ofthe population and easy accessibility provided an opportunityto monitor reproduction through a combination of direct ob-servations and camera trapping. We used an extensive datasetcompiled on tigers (Singh et al. 2013a, b) to establish baselineinformation on reproductive parameters and enhance the un-derstanding of tiger reproductive ecology to facilitate theconservation to improve management strategies for thespecies.

Materials and methods

Study area

The study was conducted in RTR (25° 54′ to 26° 12′ N, 76°22′ to 76° 39′ E), in Sawai Madhopur district of Rajasthan,India. Intensive data collection was undertaken in the corezone (392 km2). The RTR is located on the Aravalli andVindhya hill ranges. The region received an average annualrainfall of 800 mm, and temperatures were as low as 2 °C inJanuary and as high as 47 °C in May. The vegetation of RTRcorresponded to those of northern tropical, dry, deciduousforests and the northern tropical thorn forest (Champion andSeth 1968). The vegetation of RTR is representative of atypical, dry, and deciduous dhok (Anogeissus pendula) forest.Apart from dhok, the other species commonly found arekadaya (Sterculia urens), salai (Boswellia serrata), raunj(Acacia leucophloea), amaltas (Cassia fistula), palash (Buteamonosperma), tendu (Diospyros melanoxylon), gurjan(Lannea coromandelica), and jamun (Syzigium cumini).Ranthambhore was characterized by a subtropical dry climatewith four distinct seasons as follows: winter (December–Feb-ruary), summer (March–June), monsoon (July–September),and post monsoon (October–November). Carnivores in-cluded tigers, leopards (P. pardus), sloth bears (Melursusursinus), and striped hyaenas (Hyaena hyaena). The RTRsupported five species of wild ungulates, including the chital(Axis axis), sambar (Rusa unicolor), nilgai (Boselaphustragocamelus), chinkara (Gazella gazelle), and wild pig (Susscrofa).

Camera trapping

An intensive camera trapping study was conducted in the corearea of RTR in 2005 (Chauhan et al. 2005) after the decline ofthe tiger population from unknown causes in 2004 (S. P.

Goyal, personal observation). During 2005, the tiger popula-tion in RTR consisted of 19 individual tigers (4 M, 10 F, and 5cubs [3 M and 2 F <12 months of age]) distributed within160 km2 (Chauhan et al. 2005). We individually identifiedeach tiger by their stripe pattern on their left and right side(Karanth and Nichols 1998), and assigned a unique code toeach individual tiger. We used these data as a base populationsize and monitored the population continuously from 2005 to2010 using camera traps and direct observations.

Monitoring female tigers and their reproductive characteristics

We monitored female tigers from April 2005 to March 2010regularly using automatic remotely triggered camera traps(Karanth and Nichols 1998), and direct observations of tigers.In 2005 and 2006, we sampled 160 km2 but expanded thestudy area to 223 km2 from 2007 to 2010 (Fig. 1). The detailsof camera trap system we used in this study is provided bySingh et al. (2013b).

The study area was divided into 1×1 km grids (n=224),and remotely triggered camera trap systems were placed ineach grid. Due to constrains in resources (camera traps), thestudy area was divided into three spatially separated blocks,and were systematically sampled in a phased manner under“survey design 4” (Karanth and Nichols 2002). We sampledeach block with groups of 50–70 camera traps and each blockwas trapped 3 times per year. Surveys started in October andlasted to June each year except in the rainy seasons (July toSeptember) and for 15–20 nights each time (Table 1). Becauseof the good network of roads, all the trapping sites in each ofthese study periods were checked 2/week to download pic-tures and change batteries and film. Initially, all individualswere marked as identified females with cubs and femalewithout cubs. We assumed females captured with cubs inour study area during 2005 and 2006 were ≥3 years(36 months) because the earliest record of a female’s first litterwas 33 months (n=1) in our study area (Singh et al. 2014) andmean age of females at first parturition was 51.3months (n=7;Singh et al. 2014).

In 2005, 30 % of the females photo-captured were withcubs, and we assumed that they were ≥3 years old. Theremaining 50 % of females were captured with cubs in2006, and 20 % of females were not sighted or captured oncameras during the study. We are confident that all the iden-tified females in 2005 and 2006 were ≥3 years (i.e., breedingfemales) because we have the known age of females bornduring our study. We monitored each adult tigress throughoutthe year using automatic remotely trigged camera traps andintensive searches throughout the habitat. If identified tigresswere not captured >1 month in a camera trap, we attempted toobserve them on foot patrols during the day and at night (usingsearch lights in a vehicle near water points and roads). Themonitoring of tigers in RTR provided information about the

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reproductive characteristics of female tigers including theproportion of females that reproduce each year, annual birthrate, age at first reproduction, seasonality of birth, meaninterval between litters, mean litter size, recruitment rate,cub mortality, sex ratio of litters, and cub age at dispersal,emigration, immigration, and mortality.

We used the following age categories (Karanth 2003): cubs(≤1 year old, associated with, and dependent on theirmothers), juveniles (≤2 years old), subadults or post dispersalfloaters or transients (>2 years old, no longer associating withtheir mothers but not reproducing), and breeding adults

(≥3 years old). The proportion of females (≥3 years old) thathad reproduced was based on direct observations and photo-graphic evidence from camera traps.

Breeding time and litter monitoring

We assumed that breeding occurred if we observed lactatingtigers or could estimate the breeding time based on the ap-pearance of cubs. We did not have any radio-collared individ-ual that gave us actual information, breeding month of femaletiger, and when cubs start moving with the mother. Thus, we

Fig. 1 Area of intensive sampling in Ranthambhore Tiger Reserve, India using camera traps 2005–2010

Table 1 Sampling efforts from April 2005 to March 2010 in Ranthambhore Tiger Reserve, India

S.N. Season Duration Sampled area (km2) No. camera trapping station Trapping days Trap nights No. photo-captures

1. Summer Apr-05 to May-05 160 30 60 358 31

2. Winter Oct-06 to Mar-07 140 106 226 3,380 110

3. Winter Nov-07 to Feb-08 233 224 80 4,480 173

4. Summer Apr-08 to Jun-08 233 167 60 3,340 76

5. Post monsoon Oct-08 to Nov-08 233 140 60 2,800 137

6. Winter Jan-09 to Mar-09 233 194 60 3,880 206

7. Summer Apr-09 to Jun 09 233 178 60 3,560 163

8. Post monsoon Oct-09 to Dec-09 233 181 60 3,620 128

9. Winter Jan-10 to Mar-10 233 165 60 3300 122

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used backdating following published studies on tiger to esti-mate the breeding month of female tigers by backdating2 months from the first appearance of cubs because cubs startmoving with the mother when 2 months old (Smith et al.1987; Majumder et al. 2012). Litters were divided into fourdifferent seasons based on birth dates winter (December–February), summer (March–June), monsoon (July–September), and post monsoon (October–November).

Therefore, once cubs were captured in a camera trap, wemade an intensive effort to observe litter size through pug-marks on the road, by direct sighting, or photo-capture in othercamera traps. We compiled the photographic data set of tigercubs starting from 2 months through 36 months and wecompared the photo-capture of cubs with our data setand estimated the approximate age of the cubs. The tigerpopulation, including cubs, was monitored throughout theyear (Table 1). We sexed animals as they aged andmatured based on size differences between male and fe-male siblings. Sex of cubs was identified by a combina-tion of opportunistic sightings and photographs obtainedthrough camera traps or by observing their genital inphotographs. The open, thorny, deciduous forest withscanty vegetation and a good road network in RTR pro-vided ideal conditions for tiger sightings. When monitor-ing tigers, we often encountered females with cubs and wespent 1–3 h in a particular place to observe the behaviorand activity of females and their cubs, which strengthenedour data to identify more accurately the sex of the cubs.In addition to camera traps, it provided an opportunity forus to know more accurately the liter size and sex of cubs.The sex of cubs was estimated after they were >12 monthsold.

Reproductive rate

We determined the proportion of females that reproduced eachyear, annual birth rate, mean individual birth rate, and recruit-ment rate. The proportion of breeding females that reproducedeach year was recorded through intensive monitoring usingcamera traps, intensive searches (i.e., foot patrolling in dayand night patrolling using search lights and vehicles) oppor-tunistic sighting, and pugmarks. The annual birth rate wasestimated as the number of cubs produced by all femalesdivided by the number of females in the population(>3 years; Persson et al. 2006). The annual mean proportionof breeding females producing cubs was calculated using themethod described by Persson et al. (2006). To estimate thelifetime productivity of individual tigers, the reproductivelyactive age of females was calculated (i.e., tigers were repro-ductively active from 4 to 14 years of age; Crandall 1964;Kleiman 1974; Nowell and Jackson 1996) and multiplied bythe mean annual birth rate.

Estimation of survival rate at different ages

The percentage of tigers alive was divided into stages:≤12 month old, juveniles (12 to 24 months old), and post-dispersal floaters or transients (>24 month old). Tiger cubsstart moving with their mother when they are ≥2 months old,and tracks of 3–4-month-old cubs were regularly seen withthose of the mother. Cubs frequently remain with the motheruntil they were 18–24 months old (Smith 1993). Survival ofcubs <12 months old was estimated on the basis of intensivesearches, and photo captures. When a female was identified ashaving cubs, we tried to obtain visual observations and mon-itored mother and cubs >4 times/month until the cubs were12 months old to estimate the number of cubs that survived.Survival between the ages of 12–24 and >24 months (dispers-al age) was determined through photo capture of individualsby camera traps and continuous individual-based monitoringprotocol (Singh 2011). We used the Kaplan–Meier methodwith a staggered-entry design (Pollock et al. 1989) to estimatethe survival rates of cubs of the different age classes. Wepooled data from all years to obtain a sufficient sample size.Confidence intervals (95 %) for survival rates were derivedaccording to Pollock et al. (1989).

Results

Sampling efforts

Camera traps were operated for from April 2005 to March2010 (726 days, 28,718 trap nights over 3 different seasons,1,231 photo-captures of tigers; Table 1).

Breeding population and productivity

During the study period, 13 breeding females were identifiedby camera traps and monitored. All 13 females gave birth atleast once, and 2 females gave birth twice during the studyperiod (15 litters; Table 2). The minimum number of breedingfemales in a year was 2, and the maximum was 5 (Fig. 2). Wedid not document any litter in 2009. Two of 13 females weremonitored from birth, and they reproduced for the first time at33 and 48 months. Two females bred twice, and the periodbetween successive births was 24 and 65 months. The meaninterbirth interval was 33.4±3.7 months.

Birth period, litter size, and sex ratio

The mean litter size was 2.26±0.39 (n=15, range=1–3).There were three cubs in five of the litters, two cubs in ninelitters, and one cub in one litter (Table 3). One female raisedfive cubs (1 M and 4 F) in two litters. Of 34 cubs from 15litters, we recorded the sex of 32 cubs produced by 12

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breeding females. There was no significant difference in thesex ratio of cubs at birth, although it was slightly male biasedwith 1.29 M:1.00 F (χ2=1.82, df=3; P=0.61). Ten breedingfemales gave birth to more males than to females (Fig. 3). Ourdata suggested that most of the litters were born in early and latewinter (n=15 litters from 13 mothers). Most births reported inthe post monsoon, 27 % in winter, and 6 % in monsoon. Nobirths were reported during summer (Fig. 4).

Reproductive rate

Twenty-seven individual tigers ≤4 years old (11 F and 16 M)survived until March 2010. The annual mean proportion offemales producing cubs was 0.26±0.08 and ranged from 0.15to 0.63 (Table 4). The mean annual birth rate was 0.59±0.23

cubs/female (Table 4). Assuming a female is reproductivelyactive from 4 to 15 years of age, the total lifetime productivitywould be 6.49 cubs/breeding female in RTR.

Mortality and survival rate of cubs

Cubs died due to several causes (Table 3). The survival rate ofcubs <1 year old was 85 % (95 % CI=0.68–0.94; n=34;Table 5). Seven cubs died during the study period. Five were<1 year old. Three cubs (all F) drowned accidently, and theirbodies were recovered from a well in June 2007. Two cubs(sex not identified) that were captured in camera traps inDecember 2007 were not detected again and we assumed thatthey died of unknown causes when ≤6 months. The survivalrate of juvenile tigers aged 12–24 months was 79 % (95 % CI

Table 2 Reproductive histories of 13 female Bengal tigers recorded from April 2005 to March 2010 in Ranthambhore Tiger Reserve, India

FemaleID

Approximatecondition whenreported

Time reportedwith cubs

Approximate ageat first breeding(±2 month)

Approximate age of litter whenreported first (months)

Timemonitored(months)

Number of littersduring monitoringperiod

Status as onMarch 2010

T-16 Adult April 2005 NA Captured with 6 month cubs 59 2 Alive

T-16 Adult December 2006 NA Captured with 3 month cubs 59 2

T-15 Adult April 2005 NA Captured with 6 month cubs 59 2 Dead

T-15 Adult September 2008 NA Captured with 6 month cubs 59 2

T-14 Adult April 2005 NA Captured with 6 month cubs 59 1 Alive

T-22 Adult December 2006 NA Captured with 8 month cubs 59 1 Alive

T-27 Adult December 2007 NA Captured with 8 month cubs 59 1 Alive

T-30 Adult January 2008 NA Captured with 3 month cubs 59 1 Alive

T-26 Adult June 2007 NA Found with 6-month-old dead cubs 40 1 Alive

T-31 Adult December 2007 NA Captured with 3-month-old cubs 40 1 Alive

T-05 Adult December 2006 NA Reported with 8-month-old cubs 59 1 Alive

T-04 Adult January 2008 NA Captured with 3-month-old cubs 59 1 Dead

T-13 Cub December 2008 48 Captured with 3-month-old cubs 59 1 Alive

T-09 Adult October 2006 NA Captured with 6-month-old cubs 59 1 Alive

T-11 Cub February 2009 33 Captured with 3-month-old cubs 54 1 Alive

0

2

4

6

8

10

12

2005 2006 2007 2008 2009

year

Nu

mb

er o

f an

imal

s

Adult but not breeding female Breeding female male cub female cub

Fig. 2 Male and female tigerborn in the Ranthambhore TigerReserve, India, 2005–2010

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0.61–0.91; n=29; Table 5). Two juvenile males survived>1 year and died when <24 months old due to poisoning.No subadults died during the study; the survival rate of sub-adults was 79 % (95 % CI=0.61–0.91; n=27). Two breedingfemales that had one litter of two cubs each (1:1 sex ratio) died8 and 18 months after parturition due to unknown causes.

Discussion

This is the first study to provide information on the reproduc-tive characteristics of free-ranging Bengal tigers from dry,

tropical, deciduous habitat in India. According to the pub-lished literature (Schaller 1967; Sankhala 1978), tigers breedall year but most frequently from the end of November to earlyApril. In Chitwan National Park, Nepal, cubs are bornthroughout the year, with a birth peak from May to July(Smith and McDougal 1991; Smith 1993). Sunquist andSunquist (2002) report that cubs may be born at any time ofthe year in South Asia and Southeast Asia. However, datafrom zoos in India indicate that there could be a birth peakduring March–June and another smaller peak during August–October (Sankhala 1978). Karanth (2001) reports that there isno peak in births taking place in wild tigers in India. Amur

Table 3 Litter characteristics of female Bengal tigers that reproduced and were monitored between April 2005 and March 2010 in Ranthambhore TigerReserve, India

FemaleID

Litterno.

Approximatelitter birth date

Approximatelitter birthinterval month

Age of cubs(month±2)when litter sizewas determined

Litter sizeat <6 months

Litter size at6–12 months

Litter sizebetween 12and 24 months

Litter size at>24 months

Cause ofmortalitywithin litter

T-16 1 October 2004 0 6 2 2 2 2 –

2 October 2006 24 3 3 3 3 3 –

T-15 1 October 2004 0 6 2 2 2 2 –

2 December 2007 32 6 2 2 2 2 –

T-14 1 October 2004 65 6 1 1 1 1 –

T-22 1 March 2006 48 8 3 3 3 3 –

T-27 1 March 2006 48 8 2 2 2 2 –

T-30 1 October 2007 29 12 3 3 3 3 –

T-26 1 January 2007 38 6 3 0 0 0 Accident

T-31 1 October 2007 29 3 2 0 0 0 Unknown

T-05 1 October 2006 32 8 3 3 3 3 –

T-04 1 October 2007 29 3 2 2 2 2 –

T-13 1 September 2008 3 2 2 2 2 –

T-09 1 February 2006 49 8 2 2 2 2 –

T-11 1 November 2008 3 2 2 0 0 Poisoning

0

1

2

3

4

T-04 T-05 T-09 T-11 T-13 T-14 T-15 T-16 T-22 T-26 T-27 T-30

Num

ber

of c

ubs

Breeding female

male (n=18) female (n=14)

Fig. 3 Number of cubs born to breeding female tigers in Ranthambhore Tiger Reserve, India, 2005–2010

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tigers in the Russian Far East gave birth all through the year,most frequently in late summer (August–October, >50 %),which indicates that conceptions are most frequent duringMarch–May (Kerley et al. 2003). Data on 530 litters of Amurtigers born in zoos in the northern hemisphere indicate thatmost cubs are born between April and June (Seal et al. 1987).Our findings on the breeding period of the tiger in the tropical,dry, deciduous habitat differ from those reported by Smith andMcDougal (1991) and Smith (1993) who indicate that thebirthing peak of the tiger in the Indian subcontinent is in thesummer (April–June). In RTR, most parturition (93 %) oc-curred in post monsoon and winter (October–February). Itmay be due to the influence of harsh climatic conditionsduring summer and the low annual precipitation (<30 mm;India Meteorological Department). The RTR received maxi-mum precipitation during the monsoon (~500 mm). Duringthe monsoon, grass biomass productivity is higher than otherseasons, and prey species have maximum parturition duringpost monsoon and winter (Schaller 1967; Sankar 1994). Theavailability of young prey species and cubs born within these

periods have a higher chance of survival (Logan and Sweanor2001).

A mean litter size of 2.98 (range 2–5, n=49) in RoyalChitwan National Park, Nepal was reported by Smith andMcDougal (1991), and according to Tamang (1982), the meanlitter size in zoos in Nepal was 2.5, whereas in Indian zoos, itis 2.9 (range 1–6, n=49) according to Sankhala (1978). Kerleyet al. (2003) report that in free-ranging conditions in theRussian Far East, the mean litter size is 2.4±0.6 (range 1–4,n=16). In captivity, the litter size was 1.5–2.5 (Kerley et al.2003). Our observations indicate that the mean litter size inRTR was 2.26±0.39 (n=15, range=1–3), which is closer tothat reported in Chitwan National Park (Smith and McDougal1991), and to the 2.5 cubs/litter of the Amur tiger (Kerley et al.2003).

The mean birth interval for Bengal tigers in Chitwan Na-tional Park is 21.6 months (n=7; Smith and McDougal 1991),Pench Tiger Reserve is 25.2 months (Singh et al. 2013a), andfor Amur tigers the interval is 21.8 months (n=7; Kerley et al.2003). In our study, the birth interval was 33.4 months (range24–65 months), but in Panna Tiger Reserve that had similarecological conditions to RTR, the interval was 21.6 months(Chundawat et al. 2002). The longer birth interval in RTRmight be due to the influence of harsh climatic conditionsduring summer and the low annual precipitation (<800 mm,present study; Singh et al. 2013a). Our results suggest that thereproductive potential of Bengal tigers in a dry habitat ishigher in comparison with a tropical, moist habitats (Smithand McDougal 1991), i.e., birth intervals are slightly longer inRTR and the mean litter sizes are almost the same, but theobserved cub mortality rate is low (15 %) during the first yearcompared to the reported mortality rate of 34 % in a tropical,moist habitat (Smith and McDougal 1991). The mortality ratein the second year (12–24 months) was 6 %, and 17 % in thetropical moist habitat of Nepal (Smith and McDougal 1991).With the exception of the timing of the birth, the reproductivecharacteristics of the female Bengal tiger in the tropical, dryhabitat were similar to those reported for Bengal tigers inNepal (Smith and McDougal 1991). McDougal (1991) esti-mated the mean lifetime reproduction of a female tigers in thetropical, moist habitat in Nepal was 4.5 (dispersing young),whereas our data from a tropical, dry habitat had a correspond-ing figure for 6.6 dispersing young tigers. In isolated

Fig. 4 Seasonal variation in litter size of Bengal tigers in RanthambhoreTiger Reserve, India 2005–2010

Table 4 Summary of annual reproduction for female Bengal tiger(≥3 years old) in Ranthambhore Tiger Reserve, India

Year Number offemalesa

Reproductionb Proportion offemales thatreproduced

Numberof young

Annualbirth ratec

2005 10 3 0.30 5 0.50

2006 8 5 0.63 13 1.63

2007 11 5 0.45 12 1.09

2008 13 2 0.15 4 0.31

2009 11 0 0.00 0 0

2010 13 0 0.00 0 0

15 0.26±0.08 34 0.59±0.23

a Number of females (≥3 years old) monitoredbNumber of females (≥3 years old) reproducingc Number of young cubs divided by number of females (≥3 years old)monitored

Table 5 Survival rate (with 95 % confidence interval (CI)) of tiger withrespect to different age classes in Ranthambhore Tiger Reserve fromApril 2005 to March 2010

Age class Cubs (n) Death Survival rate (95 % CI)

Cub (1–12 months) 34 5 0.85 (0.68–0.94)

Juvenile (12–24 months) 29 2 0.79 (0.61–0.91)

Transient (24–36 months) 27 0 0.79 (0.61–0.91)

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populations, genetic integrity and loss of genetic diversityover time may be minimized if the population growth andsurvival are not hindered and are monitored.

Conservation implication

Dry, tropical deciduous forests in southeastern Asian countriesare fragile ecosystems due to low productivity and unpredict-able climatic conditions. They are prone to forest fragmenta-tion and habitat loss due to developmental activities (Sodhiet al. 2004). The population surviving in these fragmentedhabitats may have varied rate of reproductive success that mayaffect genetic diversity, especially when populations are small(ca ~50 individuals; Berger and Cunningham 1995). There-fore, it is crucial to monitor changes in demography andreproductive parameters. Our study provides insight into thereproductive parameters of female tiger’s inhabiting semiaridregions in western India. We suggest that there should beminimum disturbance to tigers during mating (monsoon andpost monsoon) and parturition (post monsoon and winter).The cub survival rate in RTR is high, so we suggest thatcontinuous monitoring of tiger populations may generate aclearer picture of the mortality, dispersal, and breeding of thissmall and isolated population. Because the existing corridorsin RTR are not functional (Singh et al. 2013b), we recommendthe identification of dispersal corridors and restoration ofconnectivity that may help the long-term persistence of tigersin this semiarid landscape. The information we generated forthe first time for semiarid habitats in India through a long-termstudy will be useful to enhance our understanding of thereproductive behavior of tigers and used as baseline informa-tion for comparison in the future to form part of the manage-ment effectiveness evaluation process implemented by theNational Tiger Conservation Authority, Government of India(Mathur et al. 2014).

Acknowledgments We thank the Director and Dean of the WildlifeInstitute of India for their support. We thank the Rajasthan ForestDepartment and the reserve officials and field staff at RTR forpermissions and for facilitating this work. We especially thank natureguides of RTR and our field assistants, M. S. Gurjar and S. Sharma,for providing support. The Wildlife Institute of India, Dehra Dunprovided financial support for the project. We are also thankful tofour anonymous reviewers who have provided their valuable sug-gestion and comments on an earlier draft.

References

Balme GA, Batchelor A, Britz NDEW, Seymour G, Grover M, Hes L,Macdonald DW, Hunter LTB (2012) Reproductive success of fe-male leopards Panthera pardus: the importance of top-down pro-cesses. Mammal Rev 43:221–237

Berger J, Cunningham C (1995) Multiple bottlenecks, allopatric lineagesand bad lands bison Bos bison: consequences of lineages mixing.Biol Conserv 71:13–22

Carter J, Ackleh AS, Leonard BP, Wang H (1999) Giant panda(Ailuropoda melanoleuca) population dynamics and bamboo (sub-family Bambusoideae) life history: a structured population approachto examining carrying capacity when the prey are semelparous. EcolModel 123:207–223

Champion HG, Seth SK (1968) A revised survey of forest types of India.Government of India, New Delhi

Chapron G, Miquelle DG, Goodrich JM, Legendre S, Clobert J (2008)The impact of poaching versus prey depletion on tigers and otherlarge solitary felids. J Appl Ecol 45:1667–1674

Chauhan DS, Harihar A, Goyal SP, Qureshi Q, Lal PR, Mathur VB(2005) Estimating tiger population using camera traps inRanthambhore National Park. Final report. Wildlife Institute ofIndia, Dehradun, India

Chundawat RS, Gogate N,Malik PK (2002) Understanding tiger ecologyin the tropical dry deciduous forests of Panna Tiger Reserve. Finalreport. Wildlife Institute of India, Dehradun

Crandall L (1964) The management of wild animals in captivity.University of Chicago Press, Chicago, Illinois

HoltWV, Pickard AR, Rodger JC,Wildt DE (2003) Reproductive scienceand integrated conservation. Cambridge University Press,Cambridge, UK

Karanth KU (2001) Tigers. Colin Baxter Photography, ScotlandKaranth KU (2003) Tiger ecology and conservation in the Indian sub-

continent. J Bombay Nat Hist Soc 100:169–189Karanth KU, Nichols JD (1998) Estimation of tiger densities in India

using photographic captures and recaptures. Ecology 79:2852–2862Karanth KU, Nichols JD (2002) Monitoring tigers and their prey: a

manual for researchers, managers and conservationists in TropicalAsia. Centre for Wildlife Studies, Bangalore, India

Kelly MJ (2001) Lineage loss in Serengeti Cheetahs: consequences ofhigh reproductive variance and heritability of fitness on effectivepopulation size. Conserv Biol 15:137–147

Kelly MJ, Laurenson MK, FitzGibbon CD, Collins DA, Durant SM,Frame GW, Bertram BCR, Caro TM (1998) Demography of theSerengeti cheetah (Acinonyx jubatus) population: the first 25 years. JZool 244:473–488

Kerley LL, Goodrich JM, Miquelle DG, Smirnov NY, Quigley HB,Hornocker MG (2003) Reproductive parameters of wild femaleAmur (Siberian) tigers (Panthera tigris altaica). J Mammal 84:288–298

Kleiman D (1974) The estrous cycle of the tiger (Panthera tigris). In:Eaton RL (ed) The world’s cats Woodland Park Zoo. Seattle,Washington, pp 60–75

Logan KA, Sweanor LL (2001) Desert puma: evolutionary ecology andconservation of an enduring carnivore. Island Press, Washington

Majumder A, Basu S, Sankar K, Qureshi Q, Jhala YV, Nigam P (2012)Home ranges of the radio-collared Bengal tigers (Panthera tigristigris L.) in Pench Tiger Reserve, Madhya Pradesh, Central India.Wildl Biol Pract 8:36–49

Mathur VB, Gopal R, Yadav SP, Negi HS (2014) ManagementEffectiveness Evaluation of tiger reserves. Technical Manual No.WII-NTCA/01/2010 pp 21

Mcdougal C (1991) Chuchchi: The life of a tigress. In: Seidensticker J,Lumpkin S (eds) Great cats. Merehurst, London, United Kingdom, p104

Nowell K, Jackson P (1996) Wild Cats: Status Survey and ConservationAction Plan IUCN. Gland, Switzerland

Packer C, Herbst L, Pusey AE, Bygott JD, Hanby JP, Cairns SJ,Borgerhoff-Mulder M (1988) Reproductive success in lions. In:Clutton-Brock TH (ed) Reproductive success: studies of individualvariations in contrasting breeding systems. University of ChicagoPress, Chicago, pp 363–383

Eur J Wildl Res

Persson J, Landa A, Andersen R, Segerström P (2006) Reproductivecharacteristics of female wolverines (Gulo gulo) in Scandinavia. JMammal 87:75–79

Pollock KH, Winterstein SR, Bunck CM, Curtis PD (1989) Survivalanalysis in telemetry studies: the staggered entry design. J WildlManage 53:7–15

Sankar K (1994) The ecology of three large sympatric herbivores (chital,sambar, nilgai) with special reference for reserve management inSariska Tiger Reserve, Rajasthan PhD thesis. University ofRajasthan, Jaipur

Sankhala KS (1978) Tiger! The story of the Indian tiger Collins. UnitedKingdom, London

Schaller GB (1967) The deer and the tiger. University of Chicago Press,Chicago

Seal US, Tilson RL, Plotka ED, Reindl NJ, Seal MF (1987) Behavioralindicators and endocrine correlates of estrous and anestrous inSiberian tigers. In: Tilson RL, Seal US (eds) Tigers of the world:the biology, biopolitics, management, and conservation of an en-dangered species. Noyes Publication, Park Ridge, New Jersey, pp244–254

Sharma R, Stuckas H, Bhaskar R, Rajput S, Khan I, Goyal SP, TiedemannR (2008) mtDNA indicates profound population structure in Indiantiger (Panthera tigris tigris). Conserv Genet 10:909–914

Singh R (2011) Assessment of tiger population status and habitat suit-ability using non-invasive and geospatial tools at landscape level inRanthambhore National Park PhD thesis. Gurukula KangriVishvavidhyala, Haridwar, India

Singh R,Mazumdar A, Sankar K, Qureshi Q, Goyal SP, Nigam P (2013a)Interbirth interval and litter size of free-ranging Bengal tiger(Panthera tigris tigris) in dry tropical deciduous forests of India.Eur J Wildl Res 59:629–636

Singh R, Qureshi Q, Sankar K, Krausman PR, Goyal SP (2013b) Use ofcamera traps to determine dispersal of tigers in a semi-arid land-scape, western India. J Arid Environ 98:105–108

Singh R, Krausman PR, Pandey P, Qureshi Q, Sankar K, Goyal SP,Tripathi A (2014) First parturition of tigers in a semi-arid habitat,western India. Eur J Wildl Res 60:383–386

Smirnov EN, Miquelle DG (1999) Population dynamics of the Amurtiger in Sikhote-Alin State Biosphere Reserve. In: Seidensticker J,Christie S, Jackson P (eds) Riding the tiger: Tiger conservation inhuman dominated landscapes. Cambridge University Press,Cambridge, UK, pp 61–70

Smith JLD (1993) The role of dispersal in structuring the Chitwan tigerpopulation. Behaviour 124:169–195

Smith JLD, McDougal CW (1991) The contribution of variance inlifetime reproduction to effective population size in tigers. ConservBiol 5:484–490

Smith JLD, McDougal CW, Sunquist ME (1987) Female land tenuresystem in tigers. In: Tilson RL, Seal US (eds) Tigers of the world:the biology, biopolitics, management, and conservation of an en-dangered species. Noyes Publication, Park Ridge, New Jersey, pp97–109

Sodhi NS, Koh LP, Brook BW, Ng PKL (2004) Southeast Asian biodi-versity: an impending disaster. Trends Ecol Evol 19:654–660. doi:10.1016/j.tree.2004.09.006

Sunquist ME (1981) Social organization of tigers (Panthera tigris) inRoyal Chitwan National Park, Nepal Smithsonian Contrib Zool

Sunquist ME, Sunquist F (2002) Wild Cats of the World. University ofChicago Press, Chicago

Tamang KM (1982) The status of the tiger (Panthera tigris) and its impacton principal prey populations in the Royal Chitwan National Park,Nepal PhD thesis. Michigan State University, East Lansing

Eur J Wildl Res