M Sc Dissertation(WII)

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Author: search.filters.author.Johnson, J.A.Has files: Yes

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    Tadpoles with a Trick : Overwintering Ecology of Tadpoles in a Himalayan Stream, Uttarakhand India
    (Wildlife Institute of India, Dehradun, 2021) Jithin, V.; Das, Abhijit; Johnson, J.A.
    Overwintering is a unique phenomenon of delaying metamorphosis in amphibian larvae at low temperature conditions prevailing at high elevation and latitude. This study is first of its kind in India to look at selected ecological aspects of overwintering tadpoles of Nanorana spp. in a Himalayan stream
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    The Effect of Land-use Changes on Odonate Assemblages in the Central Western Ghats
    (Wildlife Institute of India, Dehradun, 2024) Gowda, H.N. Rakshit; Gautam, Ritesh; Johnson, J.A.
    Odonata, the only apex insect predator in both terrestrial and aquatic life forms, are widely used as biological indicators of the health of aquatic ecosystems across the globe. The Riparian land uses such as commercial plantations negatively impact the Odonata assemblages, causing the homogenisation of habitats with generalist species and the extinction of specialist species. These land uses affect the riparian vegetation, habitat structure, and water quality parameters, which are crucial for Odonates to complete their life cycle. To understand the impact of commercial plantations on stream-associated Odonata assemblages at the sub-order level, three treatments comprising a combination of forest and areca plantations on either bank of streams were selected. The habitat variables, such as ambient temperature and canopy cover, along with stream parameters like flow and water quality parameters such as pH and water temperature, significantly influenced the Odonate assemblages. The sub-orders, Dragonflies and Damselflies, differed in their response to altered (Areca plantations and plantation-forest edge) and preserved sites (forested sites). These outcomes highlight the importance of the dependency of Odonata on particular sets of variables and the consideration of suborders of Odonata separately as indicator groups for the quality of aquatic ecosystems.
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    RISK ASSESSMENT OF POTENTIALLY TOXIC ELEMENTS IN THE HABITAT, AND DIET OF SMOOTH-COATED OTTER (Lutrogale perspicillata) IN TUNGABHADRA OTTER CONSERVATION RESERVE (TOCR), KARNATAKA
    (Wildlife Institute of India, Dehradun, 2024) Ahmed K., Niyaz; Johnson, J.A.; Hussain, S.A.; Sah, Ruchika
    Smooth-coated otter (Lutrogale perspicillata), is a vital indicator species for freshwater ecosystems, playing a crucial role in maintaining ecological balance. Despite their essential place in the food web, they are always neglected compared to other terrestrial carnivores. This study explores the distribution, diet, and, ecotoxicological exposures to smooth-coated otters in Tungabhadra Otter Conservation Reserve, Karnataka. The study area, encompassing a 36km stretch of the Tungabhadra River (TOCR), is a unique habitat facing significant anthropogenic pressures, including mining activities and pollution, which threaten the local biodiversity and otter populations. The distribution of smooth-coated otters in TOCR was assessed through intensive sign surveys, revealing a clumped distribution pattern. Otter signs, including spraints, pugmarks, and grooming sites were dominant signs found in the landscape. Dietary analysis was examined by analysing the spraints (scat), using two methods frequency of occurrence method, and the score bulk estimate method revealing a predominantly piscivorous diet. The diet consisted of about 14 species out of which 69.53% is constituted of non–native fish species (Oreochromis mossambicus, Labeo rohita, Cyprinus carpio, and Cirrhinus cirrhosus). Ecotoxicological assessments were performed on water, sediment, fish, and spraint samples to evaluate the presence of potentially toxic elements (PTEs). While PTE concentrations in water and sediment were generally below harmful thresholds, their presence poses a long-term risk through bioaccumulation. Risk assessment indicated significant potential health risks from metals like mercury and arsenic, which could impact otter heal
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    See Through Sound : Understanding the Pattern of Habitat use by Ganetic River Dolphin in the Kaziranga Part of Brahmaputra River
    (Wildlife Institute of India, Dehradun, 2019) Abhishek, B.; Qureshi, Qamar; Johnson, J.A.
    Studying the habitat and its associated features is important because of its driving factors that limits the abundance and distribution of a species. This study mainly focuses upon the abundance, distribution, activity and habitat use pattern of Gangetic river dolphins in part of the Brahmaputra River that flows through Kaziranga National Park. The abundance of Gangetic river dolphin and its relatedness to the different habitat features of the river and fish species were studied. The 92 km length of river in the study area was divided in to 43 segments, which were further broadly classified in to different river morphology.
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    Ecological responses of Intertidal Benthic communities to certain abiotic factors in Nancowry islands, Nicobar
    (Wildlife Institute of India, Dehradun, 2017) Kandregula, Samyukta Rao; Sivakumar, K.; Johnson, J.A.
    The intertidal zone is the amphibious niche between the high and low tides. The invertebrate taxa present here lay bare to several influencing factors and facilitate the flow of energy by participating at each trophic level in the marine ecosystem. This study was carried out in order to assess the community structure of intertidal benthic macro invertebrates. Their associations with various factors known to affect intertidal zones were looked into, in the remote islands of Kamorta and Nancowry in Central Nicobar, Andaman and Nicobar archipelago. Three study sites of varying beach profiles (reflective, intermediate and dissipative) were studied across spatio-temporal scales. Baseline information was drawn 'on the key players of the macrofauna community signals. Replicates need to be studied to confirm the patterns observed. Comprehensive community level analyses (at species) need to be done along with supplementary data through Total Organic Carbon (TOC) analysis and heavy metal analysis (ICP-MS analysis) needs to be done to ascertain the sources and magnitudes of the signals of influencing factors.
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    Riverine Habitats Under Changing Land-use : A Resource Selection Study of Smooth-Coated Otter (Lutrogale perspicillata Geoffroy Saint-Hilaire 1826) in Kabini River and Tributaries
    (Wildlife Institute of India, Dehradun, 2015) Aneesh, C.R.; Hussain, S.A.; Johnson, J.A.; Talukdar, G.
    Habitat selection is an important part of the ecology of semi-aquatic mammals since they are highly specialized animals. River otters are especially vulnerable animals in the present situation due to increasing human disturbance, altering riparian vegetation damming and channelization in river basins. This study looked at the effect of land-use pattern on the habitat selection by otters with special reference to smooth-coated otter (Lutrogale perspicillata) in Kabini river, South India. The study showed fewer presence sites of smooth-coated otter inside the protected areas, due to naturally unsuitable habitats for the species, with shallower stream habitats in hilly terrains. These sites were occupied by Asian small-clawed otters (Aonyx cinerea). However the sign intensity was more in presence locations inside protected area and least in urbanized area. The detailed study in presence only sites revealed that anthropogenic disturbance primarily increasing human presence, fishing and grazing is the most important factor affecting selection of habitat by smooth-coated otter. The intensity of usage of habitat is also governed by disturbance factors. Other environmental factors are only secondary to disturbance factors affecting habitat selection which includes a set of factors pertaining to land and water summarized as slow, deep waters with intact bank cover and/or grassy banks with close escape cover distance. Prey fish species of medium size class (21-40cm) affects the habitat selection. Although Asian small-clawed otter and smooth-coated otter occur in same river system , there is a clear niche partitioning between these two species. The study also Looked at the effect of dams on otters which is the primary factor negatively affecting otter habitats. Yet flow regimes are mostly compensated due to more streams joining the main river channel. Increasing degree of habitat disturbance in different land-uses seems to negatively influence the fluvial functionality which is positively associated with otter habitat. The combined effect of isolation due to reservoir and increasing disturbances in downstream area pushes smooth-coated otters to select habitats upstream that are marginal to them and more suitable for small-clawed otters.
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    Resource Selection and Conservation of Smooth coated otter Lutrogale perspicillata in and Around the Coringa Wildlife Sanctuary, Andhra Pradesh
    (Wildlife Institute of India, Dehradun, 2015) Prasad, Nadendla Leela; Sivakumar, K.; Johnson, J.A.; Hussain, S.A.
    Resource selection of Smooth-coated Otter Lutrogale perspicillata was studied in the Coringa Wildlife Sanctuary, where a two dimensional interface of fishermen-otter present: fishermen fishing in the habitat of otter and otters feeding in the aquaculture farms of fishermen. This is resulting in conflict between Otters and Humans in the region. In this context, this study was carried out to understand the extent of this conflict by studying the food habit of otters and ecological factors that could affect the otter distribution in this mangrove ecosystem. 2. The study was carried out from December 2014 to April 2015 in and around the Coringa Wildlife Sanctuary, which is located at the mouth of the Godavari River, in Andhra Pradesh. 3. Food habit of otters was studied by analysing their spraints that were collected from different parts of the Sanctuary. Habitat and distribution of otters were studied using belt transacts along creeks as otters mostly used banks of the creeks. Further, people perspectives towards otter and intensity of human-otter interface was studied using interview based questionnaire surveys. 4. It was found that the fishes cultured in the aquaculture farms were not present in the creeks of Coringa WLS. 6. The diet analysis of 81 spraints collected from December 2014 to March 2015 revealed that fish comprise of 99% of Smooth coated Otter diet. Of this major portion comprised of Mystus gulio, Oreochromis mossambicus and Liza tade. These species were also found in high abundance during the fish sampling from which relative abundance was calculated. This indicates that Otters in the sanctuary are opportunistic feeder rather than selective. 7. Mystus gulio (long whiskers catfish) found to be the major prey of otter in the Coringa . WLS, constituting 17.8% of weight of all food items found in the spraints and this fish was also eaten by many otters (found in 13.4% of spraints). M gulio was also the most common fishes of the Sanctuary. M gulio followed by Oreochromis mossambicus (Tilapia) constituting 14.6% of weight of all food items found in the spraints. 9. Although, all five major aquaculture species offish were found in the spraints of Otter but overall, the aqua farm fishes constituted only the 14.4% of weight of total foods items found in the spraints of otter. Of the total spraints collected, only 17.8% of spraints contained the aqua farm fishes and remaining 82.2 % otter spraints did not have. aqua farms fishes and these otters were seems to be eaten only the wild fishes. 10. The high abundance of invasive tilapia was found in the Ramannapalem creek, which is a less saline creeks adjoining with aqua farms and villages. This fish was the second most preferred diet of otters in the area. This fish breeds in the grasses that are at the banks of creeks. Breeding tilapia was a easier target for otters and therefore, otters were seen close to aqua farms. 11. The factors essential for Otter survival in were found to be more towards land and decrease with increasing distance from land. An ordinal regression model with sign intensity in three ranks revealed that the factors that are playa significant role in Otter distribution are distance from sea had a positive effect on Otter distribution (estimate = 0.403, Standard error =0.225 and P value= 0.073), Width of channel also had a positive effect to an extent (estimate =0.509, Standard error =0.273 and P value = 0.062). Depth of the creek had a negative effect (estimate= -0.624, Standard error = 0.322 and P value=O.053). 12. As the factors that are positively influencing Otter distribution are near villages Otters signs were also found highest in creeks near villages. Thus it was concluded that the presence of Otters mostly towards villages is probably due to presence of suitable habitat near villages rather than fish from aquaculture farms. 13. Fishermen's Traditional Ecological Knowledge of Otters in and around the Coringa Wildlife Sanctuary had also confirmed that otters largely feed in the wild but visit aqua farms occasionally for food or to play. Further, about 79% of people in the region felt that Otters visit their farms at night that confirms the nocturnal behaviour of Otters around human habitation, which is supported by previous studies 14. Further, most of fishermen (75%) believed that otters are high threat to aquaculture when compared to fishing cat and jackals. This is due to group hunting behaviours of otters, whereas fishing cats and jackals visit aquaculture ponds solitarily 15. Interestingly, nearly 11 % of fishermen felt that Otters have caused an income loss of 1-5% followed by 9% of respondents who claimed a loss of 10-30%. But, few farmers (2%) felt that Otters cause nearly 30-50% of loss, who were in the low income group and who can not offer even small loss in income. 16. Generalized Linear Model (GLM) with Poisson distribution revealed that both income and education of fishermen positively influenced their perspectives towards conservation importance of otters in the region. 17. Majority of fishermen (65%) believed that there was a decline in the sightings of otters and they have also believed that the population had been declined in the region. However, in contrast, about 13% of them felt that there was an increase in Otter population over years and most of these respondents who have also believed that high loss of income due to otters visits to their aqua farms. 18. Most of the aqua-farm owners admitted that they always scare and chase away otters when they visits their farms. Though only 11 % of them opted for killing does not mean that people have a positive attitude towards Otter. Boxplot analysis to understand the relationship between people's action towards visiting otters to their farms and their income and education, has revealed that the farm owners who had less income have tried to kill the visiting otters due to their poverty. 19. This study found that fishermen with poverty could not bear even the meagre loss caused by otters to them. Further, the study found that less educated people against the otters in the region. Therefore, additional livelihoods and awareness education to those poor fishermen need to be provided for the long term conservation of otters in the region. EGREE Foundation of Andhra Pradesh, a foundation established with support of GoI-UNDP-GEF Project to sustainably manage the Godavari estuarine has already initiated some programme in this regard but their programme should focus more on fishermen who are with low income 20. It is also proposed to have otter proof fencing for aquafarms especially those farms located along the Ramanapallam creeks. Developing eco- tourism in the sanctuary with the involvement of fishermen and small scale farm owners can also change their attitude towards otters.
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    Effect of Habitat Structure on Odonate Species Richness in Streams of Kalakkand Mundanthurai Tiger Reserve in Tamil Nadu India
    (Wildlife Institute of India, Dehradun, 2013) Anilitty, A.S.; Uniyal, V.P.; Johnson, J.A.
    This study aimed at the responses of species richness of Odonates toward the habitat structure in Kalakkad Mundanthurai Tiger Reserve(KMTR) in Tamil Nadu, India. KMTR lies between latitudes 8° 25' to 8° 53' N and longitudes 77°10' to 77° 35' E with altitude ranging from 50 meters to 1868 meters. Intensive study areas were confined to three beats in Mundanthurai and Kalakkad ranges of KMTR namely Kodamadi, Kannikatti and Sengaltheri. We sampled vegetation and stream structural parameters along with altitude and time of sampling from three drainages, River Thamiraparni, River Servalar and River Kil Manimuthar. Only the second, third and fourth order streams were sampled. Thirty six belt transects were laid and each transect was walked trice. A total of thirty six species were found during the study period. Species richness was calculated using Software· Estimate S version 0.8 and used to do GLM(Generalized Linear Model) in Software R version 3.0.1. Altitude was found to be the most influencing factor on species richness. A second GLM was carried out for the altitude wise stratified data incorporating temporal replicates for each transect. Tree height and stream width were found to be the most influencing factors in this model with p values 0.00007 and 0.001 respectively.