Browsing by Author "Sankar, K."

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A Study of Vigilance Behaviour of Chital (Axis axis) in Pench Tiger Reserve, Madhya Pradesh
(Wildlife Institute of India, Dehradun, 2009) Ghuman, Sartaj S.; Sankar, K.
Predation is an important agent of natural selection in animal communities and so vigilance behaviour has very high selection pressure acting upon it. During feeding bouts, unless plant density and biomass are high and food intake is limited only by the processing rates, herbivores tend to experience a trade-off between vigilance and feeding. Thus, vigilance as a behaviour pattern ought to be tightly regulated by the cost-benefit ratios. A study on vigilance behaviour of chital (Axis axis) was conducted at Pench Tiger Reserve, Madhya Pradesh from December 2008 to April 2009. The objectives of the study were to examine the determinants of individual and group vigilance in chital; and also to examine the t effect of conspecific behaviour on individual vigilance. I used scan sampling with fixed interval recording to estimate group vigilance and focal animal sampling with continuous recording to estimate individual vigilance levels. Three main factors that are known to affect :, vigilance from studies on other herbivores were examined: group size, density of animals in the group and visibility. Scanning behaviour was used as an estimate of vigilance. 'Scanning' refers to the state when the animal has its head above shoulder level and the senses of sight, smell and hearing are actively 'scanning' the environment. Individual vigilance was found to decrease with increasing group size, decreasing density and increasing visibility. In large groups adult males, fawns and adult females with fawns were found to be significantly more vigilant than females without fawns and yearling males. Group vigilance level was found to increase significantly with increasing group size, even as the group scan level decreased. Individuals seemed to reduce vigilance with relation to group size rather than the group vigilance level. The results suggest that individual chital do not adopt levels of scanning that maximize cooperative predator detection. The benefits of the group size effect vary with age-sex classes and other probable internal and external predation risk Factors and so vigilance is more likely governed by a combination of dilution and detection hypotheses mechanisms, the focus changing from one to the other with individual risk.
A study on predation ecology of large carnivores with special reference to human-carnivore conflicts in Pench Tiger Reserve, Madhya Pradesh, Central India
(Wildlife Institute of India, Dehradun, 2022) Chatterjee, Anindita B.; Sankar, K.; Qureshi, Qamar; Jhala, Y.V.
Seven years of data (2008 – 2015) resulted in phot-capture of 96 unique individual tigers in the study area. The estimated survival rate of individual tigers was high. Survival of female tigers were higher than that of the male tigers but the range was overlapping. Apparent survival and transitional probabilities were best explained by gender specific models. Survival constant was selected as the best model for estimating growth rate of tigers. Calculated annual growth rate was 13% with no observed sex bias.
A study on sympatric carnivores (Tiger, leopard and wild dog) in Mudumalai Tiger Reserve, Tamilnadu, India : final report
(Wildlife Institute of India, Dehradun, 2011) Sankar, K.
A detailed long-term study on prey selection, food habits and population status of sympatric large carnivores (tiger, leopard and dhole) was documented in Mudumalai Tiger Reserve, Tamil Nadu from January 2008 to April 2010.The objectives of the study were to estimate density, group size and composition for prey species of sympatric carnivores, study the food habits and prey selectivity of sympatric carnivores and to estimate the population of sympatric carnivores. The study area was divided into 3 x 3 km2 grids for line transect sampling. In each grid, a line transect (1.5 to 3.13 km) was laid (n = 33) along which the prey density was estimated for two successive years (January 2008 to December 2010). Prey species availability was estimated using line transect method in an intensive study area of 180 km2 comprising dry thorn, deciduous and semi-evergreen forests. The total length of line transects was 41.3 km. Each line transect was walked thrice in the dry season (January to April) and wet season (May to December) yielding a total effort of 369.45 km. Vehicle transects were used to estimate group size and composition of prey species in the intensive study area. Five vehicle transect routes ranging from 15 to 23 km were monitored. Total transect length of 93.5 km was monitored twice a month resulting in a total effort of 3740 km.
A study on vegetation ecology in Pench Tiger Reserve, Madhya Pradesh with reference to gaur (Bos gaurus) using Remote Sensing and GIS techniques.
(Wildlife Institute of India, Dehradun, 2007) Areendran, G.; Sankar, K.
A study on vegetation ecology with reference to Gaur (Bos gaurus) using remote sensing and Geographic Information System (GIS) in Pench Tiger Reserve (PTR) Madhya Pradesh was conducted from February 1996 to September 2000. The Tiger Reserve is located between 77° 55' W to 79° 35' E & 21° 08' S to 22° 00' N and lies in the southwestern region of the state of Madhya Pradesh. The Tiger Reserve comprises of the Sanctuary and the National Park of the same name, and buffer zone covering an area of 757.85 sq. km. The PTR offers a unique opportunity for research into the aspects of both the ecology and the management of gaur populations and their habitats. This is due to, both, the diverse pattern of habitat, as a result of rich floral composition and varied topology, and gaur populations that can readily be seen almost throughout the year. In Madhya Pradesh alone, the gaur population is found in 10 districts and they are geographically isolated from one another. The main objectives of the study were: 1)To study vegetation communities, composition, species distribution, abundance and richness in Pench Tiger Reserve, Madhya Pradesh. 2)To map vegetation types and quantify landscape characteristics in PTR, 3)To evaluate the available habitat and predict distribution areas of Gaur in PTR, Madhya Pradesh. model the habitat suitability and predict distribution of Gaur in Pench National Park based on Ecological niche factor analysis (ENFA) using Biomapper software Different variables (Aspect, Cover change, Drainage, Elevation, Food dentity, Ground cover, Slope, Vegetation type, Vegetation index ) were used in the model to predict the suitable habitat and distribution of Gaur
Activity Patterns and Food Habits of the Phayre's Leaf Monkey (Trachypithecus phayrei) in Free-Ranging and Captive Conditions in Sepahijala Wildlife Sanctuary, Tripura
(Wildlife Institute of India, Dehradun, 2015) Lama, Pragya Aishwarya; Tyagi, P.C.; Nigam, Parag; Sankar, K.
Maintenance of ex-situ populations of species threatened with extinction is a potential tool for ensuring recovery. Ex-situ conservation efforts though ongoing in India have been minimally documented. The present study aimed to fill gaps in information on the activity patterns and food habits of the endangered Phayre's leaf monkey (Trachypitheclis phayrei), a specialist feeder primarily a foliovore. This aspect was studied both in free-ranging and captive conditions. The study site posed a unique feature wherein the captive study species was located only ill one zoo all. over India which also happened to be within its geographical area. Thus, the Sepahijala Zoological Park (SZP) situated within the Sepahijala Wildlife Sanctuary (SWLS), Tripura was chosen as a study site. It was hypothesized that the activity patterns obtained from both the settings would be similar and that the nutrient composition of the food items consumed in wild and offered in captivity would not be much different from each other. A reconnaissance survey was carried out in which the available population, troop size and composition of Phayre's leaf monkey was assessed in both, the SWLS arid SZP. A IS-minute 'scan sampling' was conducted from dawn to dusk for studying the activity patterns of the troop selected for observation in the wild (after habituation) and in captivity. The activity data was analysed keeping in mind different age and sex categories within the wild and captive troops and across the two different settings. Chi square test was used to test for significant differences inactivity patterns within and across the captive and wild troop. The food habits (plants, plant parts and frequency eaten) of the Phayre's leaf monkey were studied on the basis of scans obtained as well as casual observations of the other free-ranging counterparts. Eaten food plants were identified and nutrient analysis was done for positive and negative nutrients after collecting and drying the samples from the field. Subsequently, it was processed at the laboratory in Wildlife Institute of India, Dehradun. The nutrients analysed were compared using the independent samples t-test.
Aspects of Sloth bear (Melursus ursinus) Ecology in Sanjay Tiger Reserve, Madhya Pradesh
(Wildlife Institute of India, Dehradun, 2022) Chaudhuri, Sankarshan; Sathyakumar, S.; Sankar, K.; Qureshi, Qamar
This study was conducted to identify the aspects of the ecology of sloth bear. I conducted the fieldwork for this study for three years (2017-2019). The broad objectives of this study were: 1. To estimate the occupancy and abundance of sloth bears and identify environmental and anthropogenic factors which influence the same 2. To assess the space use patterns by sloth bears in terms of habitat use and den selection 3. To investigate the seasonal diet patterns of sloth bears 4. To assess the human-sloth bear conflict based on spatio-temporal interaction.
Behavioural patterns and food habits of re-introduced gaur (Bos gaurus gaurus) in Bandhavgarh Tiger Reserve, Madhya Pradesh.
(Wildlife Institute of India, Dehradun, 2015) Manjrekar, Manas P.; Sankar, K.; Qureshi, Qamar
The present study was designed to study the behavioural patterns and food habits of the reintroduced gaur population in Bandhavgarh Tiger Reserve. The study was carried out from March 2012 to February 2014. For the collection of data on the behavioural patterns of gaur the scan sampling technique was used and 13 distinct activities of gaur were identified viz. feeding, moving, resting, standing, autogrooming, allogrooming, sexual behaviour, aggressive behaviour, drinking, salt licking, vocalising, defecating/urinating and alert behaviour. In the present study the social interactions among the members of a gaur herd were classified as allogrooming, dominance-subordination interactions and sexual behaviour. Four types of dominance-subordination interactions were recorded among gaur during the study period in Bandhavgarh.
Comparison of tiger population estimated using non-invasive techniques of pugmark, camera trap and DNA based analysis of hair and scat in Ranthambhore Tiger Reserve Phase II: Estimation of tiger population : Executive summary
(Wildlife Institute of India, Dehradun, 2012) Singh, R.; Pandey, P.; Saxena, L.; Qureshi, Q.; Sankar, K.; Goyal, S.P.
Conservation ecology of the endangered diurnal primates and gaur in Trishna Wildlife Sanctuary, Tripura.
(Wildlife Institute of India, Dehradun, 2006) Dasgupta, Sabyasachi; Gupta, A.K.; Sankar, K.
The aim of the study was to prepare land cover & vegetation maps, quantify vegetation structure and composition in different vegetation types, and assess the status, distribution and habitat use and feeding ecology of capped langur (Trachypithecus pileatus), hoolock gibbon (Bunopithecus hoolock), pig-tailed macaque (Macaca nemestrina) and gaur (Bos gaums gaums) in Trishna Wildlife Sanctuary (TWS) (23° 12' - 23° 32' N to 91° 15' - 91° 30' E), Tripura. Attempt was made to discuss single species vs. multi species approach in conservation and suggest conservation recommendations for the study species and the vegetation resources of the study area.Fieldwork was carried out between January 2002 and June 2004.
Ecology and management of savanna vegetation in Sariska Tiger Reserve, Rajasthan.
(Wildlife Institute of India, Dehradun, 2015) Bhatt, Priyanka; Rawat, G.S.; Sankar, K.
This study is aimed to document the role of various abiotic and biotic factors playing a vital role in the coexistence of trees and grasses. Attempts have been made to bridge the research gaps related to the structure and composition of forest vegetation, phenology diversity and regeneration patterns along the landscape. Hence, present study was initiated with a view to collect baseline data that would be helpful in monitoring the forest changes in future. It provides information about the savanna vegetation and the dynamics and also deals with the vegetation composition, species diversity, richness and other phyto- sociological parameters, Vegeation structure, composition and factors affecting the savanna vegetation in Sariska Tiger Reserve. Objectives are : 1. To study the phenology of savanna species 2. To study the aut-ecology of dominant savanna grasses and tree species of Sariska with reference to biotic and abiotic factors 3. To study the impact of invasive species and management implications: case study of Adhatoda vasica
Ecology of Leopard (Panthera pardus) in Sanjay Gandhi National Park Maharashtra with Special Reference to its Abundance Prey Selection and Food Habits
(Wildlife Institute of India, Dehradun, 2015) Surve, Nikit; Sathyakumar, S.; Sankar, K.
Though information is available on the leopard's ecology from natural habitats, very less information is available on the ecology of leopards from human-dominated habitats in India. Hence the study was conducted at Sanjay Gandhi National Park (SGNP), Mumbai where leopard was found to be the apex predator. The total area of SGNP is 104 sq.km. It is covered , by human habitations on all the sides leaving just a narrow tip on the northern side. Camera traps were deployed in a systematic manner covering the entire study area to get leopard images. Leopard density of 21.55 ± 4.6 (SE) at 95% confidence interval was calculated in the study area using Spatially Explicit Capture Recapture models. The wild prey densities were estimated inside SGNP using 'Distance sampling with the help of line transects. The , maximum density amongst ungulates was shown by chital (14.49 ± 5.2[SE]) followed by sambar (7.52 ± 1.7[SE]). Among primates, maximum density was shown by common langur (48.04 ± 8[SE]) followed by bonnet macaque (30.78 ± 12[SE]). Density for other prey species encountered on line transects like wild pig and barking deer were not estimated as they were sighted only twice on the line transects. Dog density on the periphery of SGNP was ca1culated to be 17.26 ± 0.69 (SE) using mark-recapture technique. Food habits of leopards were studied by conducting dietary analysis using leopard scat. The high density of dogs in the periphery of the National Park also reflected in the leopard's diet. Dogs alone contributed 24.46 % of the total biomass consumed in leopard's diet. Domestic prey contributed to 43% whereas wild prey contributed to 57 % of leopard's diet in terms of relative biomass consumed. The study suggests that the leopards are dependent on both wild as well as domestic prey in the study area. Leopards can coexist with humans even amidst urban environs as long as prey population (both domestic and wild) remain sufficient and their habitat is protected.
Ecology of leopard (Panthera pardus) in Sariska Tiger Reserve, Rajasthan : Executive summary
(Wildlife Institute of India, Dehradun, 2013) Sankar, K.; Qureshi, Q.; Jhala, Y.V.; Mondal, K.; Gupta, S.; Chourasia, P.
Ecology of medium and small sized carnivores in Sariska Tiger Reserve, Rajasthan
(Wildlife Institute of India, Dehradun, 2011) Gupta, Shilpi; Sankar, K.; Qureshi, Qamar
To assess wildlife population trends, scientifically based monitoring programs must be carried out. A new generation of camera traps and the use of well developed capture-recapture models have led to an increase in the use of remote surveying and monitoring methodologies for nocturnal species. Population estimates can be done for individually identifiable cryptic nocturnal species through camera trap. The study was carried out in Sariska Tiger Reserve (STR), western Rajasthan, India, (79° 17’ to 76°34’N, 27° 5’ to 27° 33’ E) from November 2007 to June 2009. The objectives of study are (1) To estimate the abundance of medium and small sized carnivores such as striped hyena, jackal, jungle cat, civets and mongoose. (2) To study the prey availability and food habits of medium and small sized carnivores and To assess the habitat suitability for these carnivores. In this study, both capture - recapture method and Royle -Nichols (2003) approach was applied to photographic capture trap data to estimate density and abundance of nocturnal cryptic species. The results of this study presented both numerically and also in the form of habitat suitability maps for all the study species in the study area. These finding have potential to develop basis for managing areas for these medium and small sized carnivores in Sariska and other similar habitat in semi arid zone.
Ecology of striped hyena (Hyaena hyaena) in Sariska Tiger Reserve, Rajasthan
(Wildlife Institute of India, Dehradun, 2019) Mandal, Dibyendu K.; Sankar, K.; Qureshi, Qamar
This study was conceivedto fill gaps in our understanding of striped hyena population parameters, resource utilization and their sociality. Finally, the findings were synthesized to understand the processes shaping diverse sociality of striped hyenas across varying resources in a comparative context under the framework of RDH. The present study was undertaken in Sariska Tiger Reserve (STR), a protected area situated in the semi-arid region of North-Western India. STR is an isolated system which has a sharp boundary with human habitations.
Evaluating methods to monitor tiger abundance and its prey in Indian Sunderbans
(wildlife Institute of India, Dehradun, 2019) Roy, Manjari; Sankar, K.; Qureshi, Qamar
This study conducted to test and evaluate different methods for estimating tiger and its prey population in Sundarban that can be adopted as part of a monitoring programme. For this study techniques were applied for the standard spatially explicit capture-recapture, tailored according to the local conditions to estimate tiger density in Sundarban for three years. Tiger densities were estimated at 4.08 (SE 1.51) in 2010, 5.81 (SE 1.24) in 2012 and 3.15 (SE 0.88) tigers/100 km2 in 2014. The tiger abundance for my camera trapped study area generated through conventional mark-recapture was 11 (SE 2), 24 (SE 3) and 16 (SE 3) tigers for 2010, 2012, 2014 respectively. Ungulates occupy a primary position in the diet of tigers and a monitoring protocol for tiger should inherently include a component of prey base estimation. Boat transect based distance sampling to generate density estimates for four years.
Evaluation of impact of landscape changes on large mammal habitats in Pench Tiger Reserve, Madhya Pradesh, India
(Wildlife Institute of India, Dehradun, 2012) Basu, Santanu; Sankar, K.
A study on the vegetation and wildlife habitats was conducted in the Rajaji-Corbett National Parks and adjoining areas using remote sensing, geographical information system (GIS) and conventional field sampling techniques. Steady increase in anthropogenic pressures in this area has led to degradation and fragmentation of wildlife habitats and related environmental problems. While the two national parks have received attention due to their legal status, the surrounding areas such as the vital corridor connecting the two parks have been largely overlooked. This connecting forest faces dual threat from the surrounding villagers as well as the migratory pastoral communities viz., Gujjars and Bhotias. The literature review reveals that vegetation ecologists have conducted a few studies within Rajaji and Corbett National Parks. Most of the studies pertain to documentation and description of plant species, analysis of community structures, analysis of the problems of sal regeneration and habitat ecology of selected species in isolated areas. However, no effort had so far been made to analyse the overall terrain and landscape features in relation to vegetation structure in the area, which is essential for characterizing the wildlife habitat. Detailed maps depicting the vegetation types, terrain categories and habitat suitability for major ungulates were not available for the area. Similarly, no literature was available on the patterns of plant species diversity in relation to the habitat conditions. Therefore the present study was undertaken in this area. The specific objectives of the study area were to: 1) Spatially analyse the vegetation types, terrain categories and prepare maps for the same using remote sensing, 2) Study the structure and composition of various vegetation types in the corridor area.3) Study the patterns of plant species diversity and other related parameters. 4) Analyse habitat characteristics for major ungulates using Remote Sensing and GIS. The extensive study area was analysed through maps prepared using remote sensing techniques. This area covers about 10,766.7 km 2 and lies between 2900' to 30031' Nand 77015' to 80016' E. It includes the following national parks: a) Rajaji National park (820 km2 29052' to 30015' N and 77055' to 78019' E), and b) Corbett Tiger reserve (1320 km2, including 520 km2 of core area, 29025' to 29040' Nand 7805' to 7905' E).
Evaluation of prey availability and habitat suitability for tigers and its ranging patterns in Sanjay Tiger Reserve, Madhya Pradesh
(Wildlife Institute of India, Dehradun, 2017) Ramesh, K.; Sankar, K.; Kumar, Deleep; Nigam, Parag; Qureshi, Qamar; Raman, K.; Rajasekar, R.; Chaudhuri, Sankarshan; Sundaram, Snehaa; Hazra, Poushali
Tiger conservation in human dominated landscape such as Sanjay Tiger Reserve (STR) has always been challenging for the managers and conservation planners. Anthropogenic factors have affected the area negatively, causing habitat degradation, depletion of prey base and unviable tiger population. STR is considered to be low density tiger population area and require recovery strategy, involving translocation from other areas, since natural colonization is not possible to boost the population to viable state. As a precursor to active population recovery, the project was conceived and implemented to establish baseline on prey availability and habitat suitability for tigers, which also involved understanding ranging patterns of tigers using radiotelemetry. Prey availability in terms of density of wild ungulate was estimated and was found to be low (8.2 ± 0.8 animals per km2), but there is an increasing population trend during the study period (2014- 2017), largely owing to active protection measures. Amongst the wild ungulates, density of chital was the highest (3.0±0.6/km2) followed by wild pig (2.0±0.6/km2), nilgai (1.8±0.3/km2), chinkara (1.1±0.3/km2) and four horned antelope (1.0±0.4/km2). Livestock (11.6±5.5/km2) was the most abundant animal using the reserve throughout, also contributing to prey base to some extent. Home range of one radio-collared adult male tiger was estimated to be 208.6km2 during May 2015 to July 2015 and the animal got killed to a territorial fight with another male tiger. Similarly, home range of radio-collared (captive-raised) tigress was estimated to be 154.1 km2 during October 2016 - May 2017. Exploring large areas could be attributed to limitation of mate choice and a depleted prey base. Habitat suitability of tiger was assessed based on habitat covariates and it was found that 44% of the total area of tiger reserve is potentially suitable habitat in the current status of prey availability, but the suitability can increase to 61% if prey base can be restored in other areas of the reserve. Carrying capacity of tiger was determined for STR based on the current prey density. It was found that STR can support 11 tigers in this present situation. Population Viability Analysis (PVA) with the carrying capacity of 11 tigers and current population (four individuals, one adult male, two adult females and one juvenile) of tiger in STR showed a poor survival probability (0.12 ±0.03) over a time span of 25 years. However, given the availability of habitat space and potential to increase prey base, doubling of carrying capacity from 11 to 22 tigers is possible with a supplementation of two tigers in every three years until year ten and it will ensure very high survival probability (0.87±0.03). Active recovery strategy should target the futuristic carrying capacity and management actions would have to be geared towards this. In this context, active population recovery and long-term monitoring strategy has been proposed towards successful population recovery and establishment of viable tiger population, along with other habitat covariates.
Food Habits of Tiger (Panthera tigris tigris) in Pench National Park, Madhya Pradesh
(Wildlife Institute of India, Dehradun, 1999) Biswas, Sayentan; Sankar, K.; Chundawat, R.S.
Food habits of tiger was studied in a dry deciduous forest area in Pench National Park, Madhya Pradesh over a period of 6 months from November 1986 to April 1999. Density estimation of major prey species was done to assess availability to tigers. Line transect method was used for estimation of prey density. Scat analysis revealed that chital constituted the major part of is tiger prey followed by sambar and wild pig.
Food habits of tiger (Panthera tigris tigris) in Sariska tiger reserve, Rajasthan
(Wildlife Institute of India, Dehradun, 2003) Avinandan, D.; Sankar, K.; Qureshi, Qamar
The present study aims at understanding relationship between tiger and its prey in a semi arid tract. The study was conducted in Sariska tiger reserve, Rajasthan over a period of six months from November 2002 to April 2003. Density estimation of major wild and domestic prey species was done to assess availability to tigers in terms of density and biomass. The line transect method was used to estimation prey density
Habitat and Food Resources Use in Relation to Sex Age and Group Size in Sambar (Rusa unicolor) During Winter in Dry Tropical Deciduous Habitat of Ranthambore Tiger Reserve, India
(Wildlife Institute of India, Dehradun, 2011) Goswamy, Amit; Goyal, S.P.; Sankar, K.
The study of habitat use depends on various factors' like environmental conditions, resource availability, physiological condition of an animal and sex. The present research for my dissertation shows that it does exist and it attempts to explain how it is happening. Sambar is a major prey species of tiger and other big cats across most of the parks in India. For the conservation of large predators it is important to evaluate and study the habitat requirement of its major prey species in detail to the level of its age and sex categories. My field study was undertaken between Dec 2010 to March 2011. Intensive study area of 90 sq km was selected in Ranthambhore. to quantify resource availability and use by different categories with respect to sex, age and group size during winter. It was found out that there is a difference in the habitat use of sambar due to sex, age and group size categories, out of the many parameters evaluated and comparisons made it was seen that though in some cases the differences were not profound, and some showed only minor changes, but in majority of the cases the trend observed was as per the expectation. Where smaller body size male animals < 3 yrs) and female associated with fawn and subadults always prefer areas having a good quality resource whereas the adult male and sambar in large group size were mainly in the areas of abundant resource rather than the quality.