- Poster2013Poster designed to carry out awareness programs regarding human-leopard conflictMarch 2013Download
JPG, 1.17 MB
Leopard outreach activities are carried out based on the locations identified through conflict monitoring activity. This poster specifically designed to address conflict issues is distributed to communities to minimize anxiety and help in conflict reduction.
- Journal Article2013Design and Evaluation of a Robust Optical Beam-Interruption-Based Vehicle Classiﬁer SystemIEEE Transactions on Intelligent Transportation Systems 14(3): 1043-1052Download
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This paper presents the design and development of a novel optical vehicle classifier system, which is based on interruption of laser beams, that is suitable for use in places with poor transportation infrastructure. The system can estimate the speed, axle count, wheelbase, tire diameter, and the lane of motion of a vehicle. The design of the system eliminates the need for careful optical alignment, whereas the proposed estimation strategies render the estimates insensitive to angular mounting errors and to unevenness of the road. Strategies to estimate vehicular parameters are described along with the optimization of the geometry of the system to minimize estimation errors due to quantization. The system is subsequently fabricated, and the proposed features of the system are experimentally demonstrated. The relative errors in the estimation of velocity and tire diameter are shown to be within 0.5% and to change by less than 17% for angular mounting errors up to 30°. In the field, the classifier demonstrates accuracy better than 97.5% and 94%, respectively, in the estimation of the wheelbase and lane of motion and can classify vehicles with an average accuracy of over 89.5%.
- Journal Article2013Phenology, seed dispersal and regeneration patterns of Horsfieldia kingii, a rare wild nutmegTropical Conservation Science, 6 (5): 674-689.Download
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We present observational data on the flowering and fruiting patterns, seed dispersal, seedling recruitment and survival of a dioecious Myristicaceae species, Horsfieldia kingii, that occurs in the tropical forests of Arunachal Pradesh. Horsfieldia is rare (1 tree ha1) with a scattered distribution; Horsfieldia trees did not flower every year, and flowering was staggered from April to July. Peak ripe fruit availability of Horsfieldia is from February to March. Failure of fruiting occurred in most years, and only 0-33% of sampled trees bore ripe fruits. Initiation of hornbill breeding coincides with the ripe fruit availability of this species. The percentage of hornbill nests in which nesting is initiated each year varies from 50 to 100% of nests, and our results show a significant positive relationship between the percentage of hornbill nests that are active in a given year and the contribution of the species to hornbill diet (n = 6 years). However, the overall contribution to the breeding season diet of hornbills is very low because of poor fruit availability in most years, resulting in limited seed dispersal at nests. Recruitment and survival of Horsfieldia seedlings below parent trees and hornbill nest trees were low; however, seedling survival was marginally higher at nest trees, suggesting that dispersal by hornbills even in a spatially contagious manner may be critical for this species. However, current recruitment of Horsfieldia at hornbill nests (2010) is significantly lower than at parent trees. This species appears to be seed-limited, while dispersal limitation may play a secondary role in determining its abundance.
- Report2013Hornbill Nest Adoption Program - 2013 Breeding seasonHNAP Report for 2013Download
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2013 Report for Hornbill Nest Adoption Program
- Popular Article2013Shooting down bharalENVIRONDownload
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Talks about exploring a remote valley in Kinnaur and a fascinating sighting of bharal or blue sheep
- Journal Article2013Green turtle herbivory dominates the fate of seagrass primary production in the Lakshadweep islands (Indian Ocean)Marine Ecology Progress Series. 485:235-243
Historical global declines of megaherbivores from marine ecosystems have hitherto contributed to an understanding of seagrass meadow production dominated by detrital path- ways — a paradigm increasingly being questioned by recent re-evaluations of the importance of herbivory. Recoveries in green turtle populations at some locations provide an ideal opportunity to examine effects of high megaherbivore densities on the fate of seagrass production. We conducted direct field measurements of aboveground herbivory and shoot elongation rates in 9 seagrass meadows across 3 atolls in the Lakshadweep Archipelago (India) representing a gradient of green turtle densities. Across all meadows, green turtles consumed an average of 60% of the total leaf growth. As expected, herbivory rates were positively related to turtle density and ranged from being almost absent in meadows with few turtles, to potentially overgrazed meadows (ca. 170% of leaf growth) where turtles were abundant. Turtle herbivory also substantially reduced shoot elongation rates. Simulated grazing through clipping experiments confirmed this trend: growth rates rapidly declined to almost half in clipped plots relative to control plots. At green turtle den- sities similar to historical estimates, herbivory not only dominated the fate of seagrass primary pro- duction but also drastically reduced production rates in grazed meadows. Intensive turtle grazing and associated movement could also modify rates of detrital cycling, leaf export and local carbon burial, with important consequences for the entire seascape.
- Book Chapter2013Goral Nemorhaedus goralMammals of South Asia (eds A. J. T. Johnsingh & N.Manjrekar).Universities Press, Hyderabad.
- Report2013MigrantWatch 2007-2012Unpublished report, Citizen Science Programme, National Centre for Biological Sciences.
- Popular Article2012தட்டான் பார்க்கலாம் வாங்க (Lets watch Odonates)துளிர். ஜனவரி 2012. பக்கம் 16-18 / Thulir. Science monthly magazine for Kids. January Pp 7-10
தட்டான்பார்க்கலாம்வாங்க.துளிர். ஜனவரி 2012. பக்கம் 16-18. [Jeganathan, P. (2012).Thattan Pakkalam Vanga.Thulir. Science monthly magazine for Kids. January Pp 7-10(Lets watch Odonates)]
- Popular Article2012சின்னஞ்சிறுகுருவே…(On Ants)புதிய தலைமுறை. 26ஜூலை 2012. Puthiya Thalaimurai. 26th July 2012.
- Journal Article2012Impact of vehicular traffic on large mammal use of highway-edges in southern IndiaCurrent Science 102(7): 1047-1051Download
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India’s phenomenal economic growth over the last decade has been accompanied by a much-needed expansion and improvement in transport and other infrastructure networks. While there are legally mandated assessments of the potential ecological impacts of such infrastructure projects prior to implementation, rarely are there post-implementation assessments of their real ecological impacts. In this communication, we present results of a preliminary study examining the impact of vehicular traffic on the usage of road edges by large mammals along a highway passing through Nagarahole Tiger Reserve, southern India. We estimated large mammal encounter rates at remotely triggered camera traps on two consecutive sections of the same highway – one closed to vehicular traffic and the other open to vehicles only during daytime. We observed lower encounter rates of chital, gaur and elephants at camera traps in the highway segment with higher vehicular traffic density, suggesting that these species avoided busy highways. Based on our findings, we emphasize the importance of continued ecological impact assessments of development projects to identify and mitigate unforeseen impacts. Further, an approach to development planning that integrates conservation concerns, especially where development projects coincide with ecologically critical areas, is urgently needed in India.
- Journal Article2012Socio-economic drivers of Forest Cover Change in Assam: A Historical PerspectiveEconomic and Political Weekly 47(5): 64-72Download
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This article analyses the historical context of forest cover change in the upper Brahmaputra Valley of Assam during the precolonial, colonial and the postcolonial periods, locating these changes within the political economy and demographic milieu of each regime.In the current context of rising populations linked to immigration from neighbouring regions, dwindling share of agriculture in the state’s gross domestic product, and recent incentives to small tea growers in risk-prone agricultural landscapes, serious challenges remain to securing forests in this region. Empowering local communities and institutions, understanding tea plantation dynamics and managing the causes and consequences of recent demographic change are crucial to the conservation of forests there.
- Popular Article2012As the crow flies…The Hindu in School, 25 April
Jeganathan, P. (2012). As the crow flies… The Hindu in School, 25April.
- Popular Article2012A home for the house sparrowThe Hindu in School, 18 April
Jeganathan, P. (2012). A home for the house sparrow. The Hindu in School, 18 April.
- Popular Article2012The fading of an invisible mapThe Hindu, February 11th, Magazine Section
- Popular Article2012மரமும் மரியேனும். (On old trees and Marianne North)புதிய தலைமுறை. 18அக்டோபர் 2012. Puthiya Thalaimurai. 18th October 2012.
- Popular Article2012தேசாந்திரியின்தோற்றப்பிழை. (On the impact of polarized light on Wandering Gliders)புதிய தலைமுறை. 23 ஆகஸ்டு 2012. Puthiya Thalaimurai. 23rd August 2012.
- Popular Article2012காப்பிநல்லதா?டீநல்லதா? (On best practices in sustainable agriculture of Coffee and Tea)புதிய தலைமுறை. 6 செப்டம்பர் 2012. Puthiya Thalaimurai. 6th September 2012.
காப்பிநல்லதா? டீநல்லதா?. காக்கைக்குருவிஎங்கள்ஜாதிதொடர்-9. புதியதலைமுறை. 6 செப்டம்பர் 2012.[Jeganathan, P. (2012).Kappi nallatha? Tea nallatha?. Kakkai Kuruvi Engal Jathi-Series, Article No.9. Puthiya Thalaimurai. 6th September 2012. (On best practices in sustainable agriculture of Coffee and Tea)]
- Popular Article2012நம் முகத்தில் முழித்த நரி (On Golden Jackal conservation)புதிய தலைமுறை. 20செப்டம்பர் 2012. Puthiya Thalaimurai. 20th September 2012.
- Popular Article2012களைகள் ஓய்வதில்லை. (On Invasive Alien Plants)புதிய தலைமுறை. 27 செப்டம்பர் 2012. Puthiya Thalaimurai. 27th September 2012.