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Syed Ainul Hussain - One of the best experts on this subject based on the ideXlab platform.
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planning conservation for chambal river basin taking Gharial gavialis gangeticus and ganges river dolphin platanista gangetica as umbrella species
2013Co-Authors: Syed Ainul Hussain, Ruchi Badola, Rishikesh SharmaAbstract:This chapter describes the Chambal River basin and its conservation significance and discusses major issues affecting the conservation status. It also includes important aquatic fauna having Gharial (Gavialis gangeticus) as the flagship species followed by the Gangetic Dolphin Platanista gangetica, Indian Marsh Crocodile or Mugger (Crocodylus palustris) and Smooth-coated Otter (Lutrogale perspicillata). The Chambal River was identified as an important Gharial habitat in 1974 and was declared the “National Chambal Sanctuary” in 1978, followed by the “captive breeding programme” in 1979. Though the Gharial population showed an increasing trend initially, since 2000, the population in the National Chambal Sanctuary has shown a dramatic decline. Between 1992 and 2000, 40% decline in the population was observed. The population of Ganges River Dolphin in the National Chambal Sanctuary was monitored during 1985–2007. The major issues affecting the integrity of the basin such as increasing human population, extraction of river water by the adjoining states of Madhya Pradesh, Rajasthan and Uttar Pradesh, discharge of industrial and domestic effluent into the river and control of soil erosion and ravine formation have been discussed. The prerequisites such as development and strengthening of the policy and legislation support for integrated river basin management, involvement of stakeholders and minimising the impacts of land use and water abstraction have been emphasised. As a conservation strategy, involvement of local communities through ecotourism, existing network of forest protection and village eco-development committees located in the basin have also been suggested.
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basking site and water depth selection by Gharial gavialis gangeticus gmelin 1789 crocodylia reptilia in national chambal sanctuary india and its implication for river conservation
Aquatic Conservation-marine and Freshwater Ecosystems, 2009Co-Authors: Syed Ainul HussainAbstract:1. The species diversity of inland waters is among the most threatened of all ecosystems and in many parts of the world it is in continuing and accelerating decline. Such decline could be restrained by acknowledging the scope of target species, so that all relevant stages in their life cycle are considered. 2. The Gharial Gavialis gangeticus is a prominent riverine species of the Indus, Ganges, Brahmaputra and Mahanadi river systems that is becoming increasingly rare due to reduction in water flow and available nesting beaches, modification of river morphology and increased mortality in fishing nets. Despite these threats, scientific information on habitat selection by Gharial is still inadequate, which hinders conservation measures. 3. This paper presents the population status, basking site selection and water depth preferences of different size-classes of Gharial based on a study conducted in the National Chambal Sanctuary, India. 4. Between 1992 and 2007 a 40% decline in the Gharial population was observed in the National Chambal Sanctuary. The decline was prominent in the recruitment class ( 180 to 270 cm) comprising both wild and reintroduced Gharial. 5. Along the Chambal River, Gharial preferred sandy parts of the river banks and sand bars for basking and showed less preference for rocky river banks and rocky outcrops. Clay river banks were least preferred. 6. Juvenile Gharials 180 cm (including sub-adults and adults) preferred water depths >4 m. 7. Increasing demands for sand for development activities, and water abstraction for irrigation and energy generation coupled with mortality in fishing nets, are likely to affect Gharial and other aquatic species, and steps need to be taken to maintain the minimum river flow necessary to sustain ecosystem processes. Copyright © 2009 John Wiley & Sons, Ltd.
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reproductive success hatchling survival and rate of increase of Gharial gavialis gangeticus in national chambal sanctuary india
Biological Conservation, 1999Co-Authors: Syed Ainul HussainAbstract:Abstract The Gharial Gavialis gangeticus Gmelin is endemic to the Indian subcontinent and was on the verge of extinction in India by the mid-1970's. As a conservation measure, since 1979 captive reared Gharials have been reintroduced in several protected areas. The reproductive success and hatchling survival in one of these managed populations was determined by monitoring 124 nests between 1987 and 1989. Population rate of increase in a 425 km stretch of the Chambal River, National Chambal Sanctuary, was determined by surveys every alternate year between 1988 and 1992. The mean clutch size (36.51±0.65 eggs) showed no significant variation between years (ANOVA, F=0.821, p=0.443). Number of infertile eggs per clutch was (2.99±0.160) and no significant difference in the mean number of infertile eggs per nest was found between years (ANOVA, F=0.534, p=0.588). The overall fertility was 91.8%. and it did not vary among years (ANOVA, F=0.075, p=0.927). A substantial number of eggs (32.1%) were lost between egg laying and hatching, largely due to eggs being damaged during nest searches, predation, desiccation and unknown reasons. Predation losses increased between 1987 and 1989, and varied significantly between years (ANOVA, F=3.970, p=0.021). During the study period the overall hatching success was 67.9%. Mean recruitment of 1-year old to the population was 7.7, 8.8 in 1987–1988 and 6.6% in 1989–1990. This indicates 92.3% hatchling mortality within the first year. The egg to post monsoon survivorship was 6.6% in 1987–1988 and 4.3% in 1989–1990, with a mean of 5.5% during the study period. The density of Gharial increased from 1.93 Gharial/river km in 1988 to 2.52 during 1992. The overall exponential rate of increase in the population was 0.179 (p=0.012) or equivalent to 19.6% p.a between 1979 and 1992. The total number of nests increased from 45 in 1987 to 57 in 1989. The average annual exponential rate of increase in the nesting between 1979 and 1989 was 0.149 (p=0.0002) or equivalent to 16.1% p.a. Variations in egg and hatchling survivorship, inconsistency in the number of Gharial released, the location and the time of release, and mortality in fishing nets are biases in the data.
Antoine Cadi - One of the best experts on this subject based on the ideXlab platform.
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does reintroduction stabilize the population of the critically endangered Gharial gavialis gangeticus gavialidae in chitwan national park nepal
Aquatic Conservation-marine and Freshwater Ecosystems, 2010Co-Authors: Jeanmarie Ballouard, Pauline Priol, Jean Oison, Alexandre Ciliberti, Antoine CadiAbstract:1Despite conservation programmes (India 1975, Nepal 1978) Gharial populations (Gavialis gangeticus) have declined over their entire distribution range. Information about the current status and main threats is needed to implement effective conservation measures. 2This study presents a survey (2003/2004) of the largest Nepalese Gharial population in the Chitwan National Park that has benefited from regular re-introduction of young Gharials since 1981. 3Population size estimates fluctuate between 34 (2003) and 38 (2004). The reintroduction programme, although of limited success, has helped to maintain the Gharial population. 4Gharials bask preferentially in large sand banks, and these sites must be protected. 5The main threats are from a dam that causes fish depletion and flushes Gharials from the protected area, sand mining and grazing that destroy basking sites, fishing that causes food shortage, drift nets that kill Gharial, and water pollution. 6Improvement in the survival of reintroduced Gharials is needed. Strict protection of preferred basking sites and prohibition of fishing in the main settling zones are the principal conservation measures while in the long term, education and participatory management by local people are also necessary. Copyright © 2010 John Wiley & Sons, Ltd.
Mark Everard - One of the best experts on this subject based on the ideXlab platform.
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Gharial gavialis gangeticus populations and human influences on habitat on the river chambal india
Aquatic Conservation-marine and Freshwater Ecosystems, 2011Co-Authors: Suyash Katdare, Arjun Srivathsa, Apoorva Joshi, Pritish Panke, Ruchik Pande, Dharmendra Khandal, Mark EverardAbstract:The Gharial, Gavialis gangeticus (Gmelin 1789), a piscivorous reptile of Asian river systems, is increasingly threatened by diverse human pressures. Three survey expeditions were launched to monitor Gharial populations, notable wildlife, and the activities and attitudes of local people in a 110km stretch of the Chambal River in the National Chambal Reserve (NCS), India. Only 15% of Gharial observed in December 2009 were in the upstream 54% of the surveyed river length. This coincides with the highest density of disturbance including water pumps, fishermen, and the highest growth in fishing activity since December 2008. Although fishing is recognized as a significant threat to Gharial, no strong relationship was found between numbers of Gharial and fishermen. However, numbers of water pumps, indicative of the intensity of agricultural activity, had a negative relationship with Gharial numbers. This relationship was strengthened by omitting the upstream (Pali to Rameshwaram) survey reach, the tourist area of the NCS, which is also potentially affected by upstream reaches. The downstream 46% of surveyed river length in December 2009 supported 85% of Gharial (consistent with trends in other surveys), including 91.6% of males and 81.8% of juveniles. This reach is classified as a High Population Recorded Area of high potential conservation importance, also containing better habitat quality and lower human disturbance. A positive relationship was found between Gharial numbers and sand habitat features. However, the Davar to Ghoonsai survey reach had low Gharial numbers despite abundant sand features, perhaps due to a substantial length of the Ghoonsai sand bank having been converted or agriculture. This may have significant implications for Gharial conservation. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd. 21 4 June 2011 10.1002/aqc.1195 Research Article Research Articles Copyright © 2011 John Wiley & Sons, Ltd..
C J Stevenson - One of the best experts on this subject based on the ideXlab platform.
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conservation of the indian Gharial gavialis gangeticus successes and failures
International Zoo Yearbook, 2015Co-Authors: C J StevensonAbstract:The Gharial Gavialis gangeticus, a long-snouted crocodilian endemic to the Indian subcontinent, is Critically Endangered and has teetered on the brink of extinction for the past several decades. From historical populations of perhaps 10 000 animals, Gharials numbered in the hundreds by 1974. Project Crocodile – an Indian government initiative – became a poster boy for crocodile conservation. Based almost entirely around a head-starting programme, the effectiveness of Project Crocodile was called into question when populations crashed again in the late 1990s. In the 21st century, with the support of the international zoo community and the International Union for Conservation of Nature/Species Survival Commission's Crocodile Specialist Group, Madras Crocodile Bank Trust began to address the shortcomings of Gharial conservation up to that point, to ensure that future plans for the species would succeed.
A J Leslie - One of the best experts on this subject based on the ideXlab platform.
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a multi method approach for the inventory of the adult population of a critically endangered crocodilian the Gharial gavialis gangeticus at dhikala corbett tiger reserve incorporating direct counts and trail cameras
International Journal of Biodiversity and Conservation, 2014Co-Authors: S M Chowfin, A J LeslieAbstract:The Corbett Tiger Reserve (CTR), a very highly rated protected area in the State of Uttarakhand, India, is home to the third largest breeding population of adult Gharial globally. It contributes 20% to the estimated global population of 200 - 250 adults of the taxon and it is also the only known population of the taxon which lives predominantly in a lake-like environment. CTR was surveyed for Gharial in 2008 which was the first systematic survey with regard to the taxon since 1974 and the meta-population here was found distributed amongst six sub-populations in the Sarpduli, Dhikala, Kalagarh, Sonanadi, Palain and Adnala Ranges of the Reserve. This paper documents a multi-method approach for the estimation of Gharial at Dhikala (Dhikala Range) namely: at the confluence of the Ramganga River with the Kalagarh Reservoir. It details the use of trail cameras combined with boat surveys along the shoreline and stationary counts for estimating the adult population of Gharial at Dhikala, the site of the largest sub-population of Gharial in CTR. Using this multi-method approach to count basking animals, we estimated the adult population in the area to consist of 32 adults (inclusive of seven adult males) based on the maximum ± minimum (MM) method. We also considered the unknown proportion of adults that may have gone undetected during these surveys by subjecting the data to a Double Sampling analysis. The results are indicative that we were able to sample 88.9% of the adult Gharial population at Dhikala using this Multi-Method Approach. Based on our three population estimates (n= 29, 32 and 36) we averaged the adult population at Dhikala as 32.3 ± 1.69 adults (Mean ± SE) with an encounter rate of 4.01 ± 0.33 adults km⁻¹ over 8.06 km of shoreline. Further, comparing population estimates between 2008 and 2013 based on the maximum ± minimum (MM) method, we estimated that the number of adults in Dhikala increased by 77.8% between 2008 and 2013. This increase in adult Gharial numbers detected in the study area between 2008 and 2013 is primarily a result of: (1) Improved survey techniques which detected more number of animals in the area due to the cumulative effects of population growth from sub-adults to adults, in-migration and the possibility of some animals being missed during the 2008 surveys; (2) improved knowledge and familiarity with the study area; (3) effective protection measures already in place in CTR particularly in Corbett National Park (CNP), which has allowed the adult population to increase naturally without any disturbances. The ability of this multi-method approach in detecting these changes in numbers is important for monitoring the taxon and studying population trends within CNP. Key words: Gharial, Gavialis gangeticus, Corbett Tiger Reserve, Corbett National Park (CNP), trail cameras.
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a preliminary investigation into nesting and nest predation of the critically endangered Gharial gavialis gangeticus at boksar in corbett tiger reserve uttarakhand india
International Journal of Biodiversity and Conservation, 2013Co-Authors: S M Chowfin, A J LeslieAbstract:The Gharial, Gavialis gangeticus, is an endemic crocodilian of the north Indian subcontinent and is also found in the Corbett Tiger Reserve. Surveys in Corbett National Park in 1974 recorded only five Gharial whereas current estimates are 42 adults inclusive of 10 adult males and 59 individuals of smaller size classes. This study confirms that the expanded population in the Kalagarh Reservoir is breeding, although nests appear to be subject to significant predation, thought to be by Varanus bengalenis. Varanids are serious predators on crocodilian eggs in a number of countries. In this case, it is unclear whether such high predation levels are natural situations that apply when they live in a free-flowing river environment, or whether it is a derived state linked to the lake-type environment in which they now reside. Key words: Gharial, Gavialis gangeticus, Corbett Tiger Reserve, Corbett National Park, Boksar, nest predation.
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A preliminary investigation into nesting and nest predation of the critically endangered, Gharial (Gavialis gangeticus) at Boksar in Corbett Tiger Reserve, Uttarakhand, India
2013Co-Authors: S M Chowfin, A J LeslieAbstract:The Gharial, Gavialis gangeticus, is an endemic crocodilian of the north Indian subcontinent and is also found in the Corbett Tiger Reserve. Surveys in Corbett National Park in 1974 recorded only five Gharial whereas current estimates are 42 adults inclusive of 10 adult males and 59 individuals of smaller size classes. This study confirms that the expanded population in the Kalagarh Reservoir is breeding, although nests appear to be subject to significant predation, thought to be by Varanus bengalenis. Varanids are serious predators on crocodilian eggs in a number of countries. In this case, it is unclear whether such high predation levels are natural situations that apply when they live in a free-flowing river environment, or whether it is a derived state linked to the lake-type environment in which they now reside.