- Popular Article2013மயில் வதை – தடுக்க என்ன வழி? (On Peafowl-human conflict and its mitigation measures)தினமணி நாளிதழ் – கொண்டாட்டம் இணைப்பில். 6 ஜனவரி 2013. Dinamani – Tamil Newspaper. 6th January 2013.
மயில் வதை – தடுக்க என்ன வழி?தினமணி நாளிதழ் – கொண்டாட்டம் இணைப்பில். 6 ஜனவரி 2013.[Jeganathan, P. (2013). Mayil Vathai – Thadukka enna vazi? (On Peafowl-human conflict and its mitigation measures).]
- Popular Article2013Three different voicesThe Hindu in School, 17 July
- Journal Article2013Greener pastures? High-density feeding aggregations of green turtles precipitate species shifts in seagrass meadowsJournal of Ecology. 101: 1158-1168
1. Historical declines of marine megaherbivores have led to a view of seagrass communities structured largely by abiotic disturbance and plant competition. There is, however, growing recognition of the significance of top-down control through herbivory, on seagrass ecosystem processes, raising the question of how meadows functioned under historically high populations of megaherbivores. 2. We assess the impacts of such intense herbivory on seagrass meadow composition in the Lakshadweep islands (India), where high-density feeding aggregations of green turtles have persisted for over a decade. We use a series of complementary approaches: (i) natural herbivory exclosures (ii) published data on seagrass composition before and after turtles established (at one atoll: Agatti) and (iii) present species composition along a turtle herbivory gradient over multiple atolls.
...to read more, download the full paper
- Book Chapter2013Bonnet macaque Macaca radiataPages 148-169 in A J T Johnsingh and N Manjrekar (editors) Mammals of South Asia, Volume 1, Universities Press, Hyderabad
- 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.
- Popular Article2013Running into the rare brown mongooseThe Hindu in School, 27 March
- Popular Article2013Bringing back a commonerThe Hindu in School, 27 February
- Popular Article2013The great crane projectThe Hindu in School, 20 February
- Popular Article2013My books and their animalsThe Hindi in School, 23 January
- Thesis2013Human-Carnivore Conflicts: understanding predation ecology and livestock damage by snow leopardsPhD thesis Submitted to Manipal University
- Popular Article2013Acrobats on waterThe Hindu in School, 13 February
Jeganathan, P. (2013). Acrobats on water. The Hindu. In school, 13th February.
- Popular Article2013Shooting down bharalENVIRONDownload
PDF, 2.6 MB
Talks about exploring a remote valley in Kinnaur and a fascinating sighting of bharal or blue sheep
- Journal Article2013Influence of gaze and directness of approach on the escape responses of the Indian Rock Lizard, Psammophilus dorsalis (Gray, 1831).Journal of Biosciences. 38(5): 829–833.Download
PDF, 145 KB
Free download from J. Biosciences webpage:
Animals often evaluate the degree of risk posed by a predator and respond accordingly. Since many predators orient their eyes towards prey while attacking, predator gaze and directness of approach could serve as conspicuous indicators of risk to prey. The ability to perceive these cues and discriminate between high and low predation risk should benefit prey species through both higher survival and decreased energy expenditure. We experimentally examined whether Indian rock lizards (Psammophilus dorsalis) can perceive these two indicators of predation risk by measuring the variation in their fleeing behaviour in response to type of gaze and approach by a human predator. Overall, we found that the gaze and approach of the predator influenced flight initiation distance, which also varied with attributes of the prey (i.e. size/sex and tail-raise behaviour). Flight initiation distance (FID) was 43% longer during direct approaches with direct gaze compared with tangential approaches with averted gaze. In further, exploratory, analyses, we found that FID was 23% shorter for adult male lizards than for female or young male (FYM) lizards. In addition, FYM lizards that showed a tail-raise display during approach had a 71% longer FID than those that did not. Our results suggest that multiple factors influence the decision to flee in animals. Further studies are needed to test the generality of these factors and to investigate the proximate mechanisms underlying flight decisions.
- Popular Article2013Securing Habitat of NemoFriday, April 12, Andaman Chronicles.
- Book Chapter2013Anthropogenic Influences on Macaque Populations and Their Genetic ConsequencesPages 209 to 224 in S. Radhakrisna and A. Sinha (editors) The Macaque Connection: Cooperation and Conflict between Humans and Macaques, Springer, New Delhi.Download
PDF, 338 KB
Human–macaque interactions constitute a complex phenomenon influencing perhaps the biology of the macaque more profoundly than ours. At the population level, humans tend to influence the distribution, demography, immunology and even behaviour of the macaque species they interact with though none of these interactions are ever simple. These works at different levels, interacting, in turn, with other environmental factors and most of these impacts are likely to have genetic consequences over the long term. In this chapter, we reviewed available literature on anthropogenic impacts on macaque populations. We should, however, stress that our current state of knowledge, unfortunately, suffers from a serious lack of insight into such genetic impacts. There is, therefore, a dire need for long-term genetic monitoring programmes to understand the effect of anthropogenic factors on the dispersal and demography of different macaque species.
- Book2013The Macaque Connection: Cooperation and Conflict between Humans and MacaquesSeries: Developments in Primatology: Progress and Prospects, Vol. 43, Springer, New Delhi
Most successful among the non-human primates in terms of geographical distribution and adaptability to ecological habitats, macaques have existed for many thousands of years in close contact with modern humans, the only primate more successful than them. Centuries-old literary works attest to the fact that macaques have always been an intrinsic part of human lives and imaginations. In their interactions with humans, macaques play multiple roles that often transcend the boundaries of categorization. They are often, simultaneously, wildlife and domestic pets, sentient beings and experimental subjects, crop-raiding pests and religious symbols. In many parts of the tropics, macaques are an economic resource for human communities, as they provide meat and money through tourism and the animal trade. Equally, they cause much damage and bring about great economic losses due to their crop- and house-raiding tendencies. A more recent cause for alarm has been the possibility of transmission of diseases to humans due to contact with macaques. Across Asia, macaques, perhaps more than any other animal species, exemplify the multiple facets of synurbization and the conservation problems of commensal species. Humans and macaques associate in rather remarkable ways, and this volume explores the tone and nature of those human-macaque connections by focusing on various forms of interactions between macaques and humans, change in human attitudes vis-à-vis macaques over the ages, cultural views on macaques, human-macaque conflict and its conservation implications. Its holistic perspective of the myriad aspects that illustrate the singular relationship between men and macaques makes it essential reading not only for primatologists and anthropologists but also for anyone interested in the intricacies of human-animal relations.
- Book Review2013Chronicles of the wild -Book review of “Mammals of South Asia by A.J.T. Johnsingh & Nima Manjrekar”.The Asian Age. 23rd February.Download
PDF, 184 KB
Jeganathan, P. (2013). Chronicles of the wild - Book review of “Mammals of South Asia by A.J.T. Johnsingh & Nima Manjrekar”. The Asian Age. 23rd February.
- Dataset2013Data from: Influence of gaze and directness of approach on the escape responses of the Indian rock lizard, Psammophilus dorsalis (Gray, 1831).Dryad Digital Repository. doi:10.5061/dryad.1h551
Contains both raw data and analysis scripts. Permanent link to the dataset and scripts on Dryad:
- Newsletter2013Where have all the dugongs gone? A study on long-term occupancy trends in the Andaman and Nicobar archipelago, India,Sirenews, Newsletter of the IUCN Sirenia Specialist Group, Vol. 60.
- Journal Article2013Spatial and temporal variation in hornbill densities in Namdapha Tiger Reserve, Arunachal Pradesh, north-east IndiaTropical Conservation Science 6:734-748Download
PDF, 642 KB
Asian hornbill populations are declining across their ranges because of hunting and deforestation. Five of the 32 Asian hornbill species occur in north-east India. However, vital information on their abundance from the region remains scanty. Understanding spatiotemporal variation in densities provides crucial information for formulating effective conservation strategies based on species-specific abundance patterns and population trends. We examined spatiotemporal variation in densities of four hornbill species in the Namdapha Tiger Reserve, a site identified as an important site for hornbill conservation in Asia. We collected data through variable-width line transect sampling (effort=842.1 km) in the non-breeding season from 2009-12 to estimate hornbill densities. We had 458 detections of four hornbill species. We have estimated White-throated Brown Hornbill densities (7.9 birds/km2) for the first time throughout its entire range. The mean Rufous-necked Hornbill densities (6.9 birds/km2) were higher than those reported elsewhere. Great (3.9 birds/km2) and Wreathed Hornbill (16.1 birds/km2) densities were comparable with other sites. The peak densities of all hornbill species in November-December are among the highest reported from Asia. Wreathed Hornbill densities showed temporal variation peaking in November-December (68 birds/km2) and drastically declining by March-April (1.3 birds/km2), indicating seasonal altitudinal movement to low elevation areas outside the reserve during the breeding season. Our results underscored the spatial variation in hornbill distribution, with low densities of Great and the White-throated Brown hornbills in higher elevations. Our study demonstrates the global importance of Namdapha for hornbills, given its large area and high densities of four hornbill species.