- Journal Article2010Implications of conserving an ecosystem modifier: Increasing green turtle (Chelonia mydas) densities substantially alters seagrass meadowsBiological Conservation 143: 2730-2738
Ecosystem modifiers have the ability to significantly alter the ecosystem they inhabit sometimes with serious consequences for their own populations. We evaluated the ability of green turtles (Chelonia mydas) to modify seagrass ecosystems by their foraging activity. This study was conducted in a seagrass-dominated lagoon in the Lakshadweep Islands, Indian Ocean, where a stable high-density congregation of green turtles is present. We determined a gradient of turtle density in the lagoon and measured the intensity of turtle herbivory across the gradient. We then measured the impact of increasing grazing on seagrass structural parameters, growth and flowering along this gradient. Our results indicate that turtles substantially change seagrass meadow structure (canopy height, shoot length, width and density), reduce flowering and can potentially even cause changes in the species composition of the meadow. We discuss the implications of these results for seagrass ecosystem function, green turtle movement and human attitudes. When conserving ecosystem modifiers like the green turtle, any management strategy needs to include a detailed knowledge of the roles these species play in the ecosystems they inhabit.
- Journal Article2010Behavior of Asian elephant (Elephas maximus) in a land-use mosaic: implications for human-elephant coexistence in the Anamalai hills, IndiaWildlife Biology in Practice 6: 69-80.Download
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Understanding behavior of elephants in human-dominated landscapes can facilitate creation of management tools for conflict resolution and help foster human-elephant coexistence. We studied behavior of Asian elephants (Elephas maximus) in the Valparai plateau, a 220 km² landscape matrix of rainforest fragments, tea, coffee, and Eucalyptus plantations in the Anamalai Hills of the Western Ghats of India. We studied the nearest neighbor distance among elephants within the herd and their feeding behavior in habitat mosaics. We also recorded reactions of elephants to human proximity and number of people in the vicinity. We employed scan sampling for data collection. Feeding by elephants was lowest in open canopy habitat of tea, and it gradually increased in canopy covered plantations of coffee and Eucalyptus and in densely covered natural vegetation. Vigilance behavior of elephants was lowest in forest fragments and riverine vegetation as they could avoid encountering humans. This behavior peaked in tea plantations due to intense human activity there. Elephants maintained closer inter-individual distances in tea and this distance gradually increased in canopy habitats of coffee, Eucalyptus and natural vegetation. More humans in the vicinity and closer proximity to elephants reduced feeding and increased agitation in elephants, while proximity to settlements did not have any influence. We, therefore, suggest that protection and non-conversion of canopy habitats, restoration of rivers with native species, and maintaining distance from elephants would foster normal activities of elephants and help promote human-elephant coexistence in such landscapes.
- Journal Article2010Bird use of rice fields in the Indian subcontinentWaterbirds 33 (Special Publication 1): 44-70.
The Indian subcontinent has the world’s highest cropland cover per unit area with rice (Oryza sativa) being the second-most important crop, and is home to nearly 1,300 species of birds. The significance of rice fields as bird habitat in the region is not well understood and the subject is reviewed using a combination of published and secondary information. Rice fields in the subcontinent are used by at least 351 species, although only 2.7% of birds occurring in the subcontinent breed in rice fields. The spread of rice cultivation and its attendant secondary habitats may have contributed to the increase in range and population of 64 common species but is threatening hundreds of other species, many of conservation concern. Most work in the region has focused on birds as pests of rice. Few studies have been conducted on the habits of birds that use rice fields and fewer still have compared how rice fields and similar natural habitats differ. Although rice harvesting has caused nest mortality for breeding birds, there is no comparable information from natural habitats. The guild structure of birds in rice fields is similar to that overall in the region except for a higher representation of carnivores. Rice fields are used primarily by grassland and wetland species. There are large information gaps that require filling to be able to ascertain the utility or impact of rice fields to bird populations and, thus, many research opportunities.
- Journal Article2010From Bathymetry to Bioshields: A review of post-tsunami ecological research in India and its implications for policyEnvironmental Management 46:329-338
More than half a decade has passed since the December 26th 2004 tsunami hit the Indian coast leaving a trail of ecological, economic and human destruction in its wake. We reviewed the coastal ecological research carried out in India in the light of the tsunami. In addition, we also briefly reviewed the ecological research in other tsunami affected countries in Asia namely Sri Lanka, Indonesia, Thailand and Maldives in order to provide a broader perspective of ecological research after tsunami. A basic search in ISI Web of Knowledge using keywords ‘‘tsunami’’ and ‘‘India’’ resulted in 127 peer reviewed journal articles, of which 39 articles were pertaining to ecological sciences. In comparison, Sri Lanka, Indonesia, Thailand and Mal- dives had, respectively, eight, four, 21 and two articles pertaining to ecology. In India, bioshields received the major share of scientific interest (14 out of 39) while only one study (each) was dedicated to corals, seagrasses, sea- weeds and meiofauna, pointing to the paucity of research attention dedicated to these critical ecosystems. We noted that very few interdisciplinary studies looked at linkages between pure/applied sciences and the social sciences in India. In addition, there appears to be little correlation between the limited research that was done and its influence on policy in India. This review points to gap areas in eco- logical research in India and highlights the lessons learnt from research in other tsunami-affected countries. It also provides guidance on the links between science and policy that are required for effective coastal zone management.
- Journal Article2010Proposed methods to capture and radio-tag the critically endangered Jerdon's Couser in Andhra Pradesh, India.Telemetry in Wildlife Science, ENVIS Bulletin. WII -Dehradun.Download
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Jeganathan, P., Green, R.E., Rahmani, A.R (2010) Proposed methods to capture and radio-tag the critically endangered Jerdon's Couser in Andhra Pradesh, India (in). Sivakumar, K. and Habib,B. (Eds.) 2010. Telemetry in Wildlife Science, ENVIS Bulletin: Widlife & Protected Areas. Vol. 13 No. 1. Wildlife Institute of India, Dehradun - 248001. India. Pp. 205-210.
- Journal Article2010Multi-spatial co-distribution of the endangered Ladakh urial and blue sheep in the arid Trans-Himalayan mountains.Journal of Arid Environments, 74 : 1162–1169.
- Journal Article2010Why should a grazer browse? Livestock impact on winter resource use by bharal Pseudois nayaur.Oecologia, DOI 10.1007/s00442-009-1467-x.
- Journal Article2009Are rice paddies suboptimal breeding habitat for Sarus Cranes in Uttar Pradesh, India?The Condor 111: 611-623
The globally threatened Sarus Crane (Grus antigone) has low annual productivity and occurs mostly in landscapes dominated by agriculture; it is therefore vulnerable to extinction caused by human-related disturbance and mortality. The Sarus Crane’s increased use of rice paddies as breeding habitat has fueled concerns that the species is being forced to use suboptimal habitats. To assess the issue, I studied nest-site selection and quantified nest and brood survival of Sarus Cranes in Uttar Pradesh, northern India, during 2000 and 2001 and evaluated differences between natural wetlands and rice paddies. The cranes preferred wetlands as nesting habitat at the levels of both the landscape and individual territory. The success (daily survival rate) of nests closer to roads was lower, suggesting that human-related mortality played a role. The effect of habitat on nest successwas equivocal, suggesting that rice fields per se are not suboptimal as nesting sites. This result is unique to this area, suggesting that favorable attitudes of farmers still allow Sarus Cranes to nest in rice paddies. Broods hatching later and those in territories with fewer wetlands had a lower probability of survival. Vegetation changes and disturbance during crop harvesting likely decreased brood survival. Maintaining a patchwork of shallow wetlands in rice-dominated landscapes and ensuring that farmers retain a positive attitude toward the species are crucial for survival of Sarus Crane nests and broods.
- Journal Article2009Observations of small carnivores in the southern Western Ghats, IndiaSmall Carnivore Conservation 40: 36-40Download
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Despite a diverse assemblage of small carnivores in the forests of the southern Western Ghats in India, there is a paucity of information on their ecology, distribution, behaviour and current conservation status. Chance observations generated during surveys for other purposes are therefore useful. Sightings and signs of small carnivores were recorded opportunistically during a study to assess the distributions of larger mammals in the southern Western Ghats. The study yielded sightings of seven species of viverrids, herpestids and mustelids. The Common Palm Civet Paradoxurus hermaphroditus and Small Indian Civet Viverricula indica were sighted most frequently. The restricted-range Brown Palm Civet Paradoxurus jerdoni was sighted once.
- Journal Article2009MigrantWatch: Changes and Results from the Second YearIndian Birds 4 (4): 122–126 (2008)
- Journal Article2009Winter Ecology of the Arunachal Macaque Macaca munzala in Pangchen Valley, Western Arunachal Pradesh, Northeastern IndiaAmerican Journal of Primatology, 71: 939–947Download
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The newly described Arunachal macaque Macaca munzala occurs largely in sub-tropical to temperate environments at elevations of c. 1,800–3,000 m in Arunachal Pradesh, northeastern India. We studied its over-wintering strategy by comparing the diet, ranging, and behavior of a troop of 24 individuals during winter and spring (December 2005 to May 2006) through instantaneous scan sampling (3,002 records, 448 scans, 112 hr of observation). We also monitored the phenology of food plants. The macaques spent more time (41–66%) feeding in the winter than in spring (33–51%), whereas time spent moving and resting was greater in spring. The diet composed largely of plants, with animal matter being eaten rarely. The number of plant species in the diet increased from 18 to 25 whereas food types rose from 18 to 36 from winter to spring, respectively. Although only two species formed 75% of the winter diet, seven species comprised this proportion in spring. Availability of fruits and young leaves increased in spring; the troop moved more and utilized a larger part of its range during this time. Seasonal changes in behavior could be explained by the scarcity of food and the costs of thermoregulation in winter. Our study suggests that the Arunachal macaque inhabits a highly seasonal environment and has an over-wintering strategy that includes subsisting on a high-fiber diet by increasing the time spent feeding, and minimising energy expenditure by reducing the time spent moving.
- Journal Article2009Corrigendum: mammal persistence and abundance in tropical rainforest remnants in the southern Western Ghats, India.Current Science 97: 612-613.
- Journal Article2009Effects of herbivore species richness on the niche dynamics and distribution of blue sheep in the Trans-Himalaya.Diversity and Distributions, 15, 940–947.
- Journal Article2009Effects of rodents on seed fates of hornbill-dispersed tree species in a tropical forest in north-east India.J. Tropical Ecology 25: 507-514.
- Journal Article2009Observations on Rufous-necked Aceros nipalensis and Brown Anorrhinus austeni Hornbills in Arunachal Pradesh: natural history, conservation status and threats.Indian Birds 5: 108-117.Download
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Among the five species of hornbills that occur in north-eastern India, the least studied are the endangered Rufous-necked Hornbill Aceros nipalensis, and the Brown Hornbill Anorrhinus austeni, which has a restricted distribution in India. Based on field surveys conducted in Namdapha National Park, and several forest divisions in eastern Arunachal Pradesh, during 1996–1999 and 2002–2004, I present information on their distribution and relative abundance. I also present some information on diet, flock sizes, canopy levels used, breeding biology, and nesting records for both these species.
- Journal Article2009A conservation status survey of hornbills (Bucerotidae) in the Western Ghats, India.Indian Birds 5: 90–102.
- Journal Article2009Brewing trouble: coffee invasion in relation to edges and forest structure in tropical rainforest fragments of the Western Ghats, IndiaBiological Invasions 11: 2387–2400
While the conservation impacts of invasive plant species on tropical biodiversity is widely recognised, little is known of the potential for cultivated crops turning invasive in tropical forest regions. In the Western Ghats biodiversity hotspot, India, fragmented rainforests often adjoin coffee plantations. This study in the Anamalai hills assessed the effects of distance from edges and forest structure on the occurrence and abundance of shade-tolerant coffee (Arabica Coffea arabica and Robusta C. canephora) in four fragments (32–200 ha) using replicate line transects laid from the edges into the interiors. The coffee species cultivated in adjoining plantations was more abundant than the other coffee species inside study fragments, showing a clear decline in stem density from edge (0 m) to interior (250 m), suggesting the influence of propagule pressure of adjoining plantations, coupled with edge effects and seed dispersal by animals. Significant positive correlations of coffee density with canopy cover indicate the potential threat of coffee invasion even in closed canopy rainforests. Stem density of Coffea arabica (150–1,825 stems/ha) was higher in more disturbed fragments, whereas Coffea canephora had spread in disturbed and undisturbed sites achieving much higher densities (6.3–11,486 stems/ha). In addition, a negative relationship between C. canephora and native shrub density indicates its potential detrimental effects on native plants
- Journal Article2009Restoring rainforest fragments: survival of mixed-native species seedlings under contrasting site conditions in the Western Ghats, India.Restoration Ecology 17: 137-147.Download
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Historical fragmentation and a current annual deforestation rate of 1.2% in the Western Ghats biodiversity hotspot have resulted in a human-dominated landscape of plantations, agriculture, and developed areas, with embedded rainforest fragments that form biodiversity refuges and animal corridors. On private lands in the Anamalai hills, India, we established restoration sites within three rainforest fragments (5, 19, and 100 ha) representing varying levels of degradation such as open meadow, highly degraded sites with dense Lantana camara invasion, abandoned exotic tree plantations (Eucalyptus grandis and Maesopsis eminii), and sites with mixed-native and exotic tree canopy. Between 2000 and 2004, we planted annually during the southwest monsoon 7,538 nursery raised seedlings of around 127 species in nine sites (0.15–1.0 ha). Seedlings monitored at 6-monthly intervals showed higher mortality over the dry season than the wet season and survival rates over a 2-year period of between 34.4 and 90.3% under different site conditions. Seedling survival was higher in sites with complete weed removal as against partial removal along planting lines and higher in open meadow and under shade than in sites that earlier had dense weed invasion. Of 44 species examined, survival across sites after 24 months for a majority of species (27 species, 61.4%) was higher than 50%. Retaining regenerating native species during weed clearing operations was crucial for rapid reestablishment of a first layer of canopy to shade out weeds and enhance survival of shade-tolerant rainforest seedlings.
- Journal Article2009First underwater sighting and preliminary behavioural observations of Dugongs(Dugong dugon) in the wild from Indian waters, Andaman Islands.Journal of Threatened Taxa 1 (1): 49-53.
- Journal Article2009Endangered markhor Capra falconeri in India: through war and insurgencyOryx 43(3): 407-411Download
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The flare horned markhor Capra falconeri occurs in northern Pakistan, Afghanistan, India, Uzbekistan and Tajikistan. Most of the species’ range is along volatile international borders and limited information is available, especially for the population of the Pir Panjal or Kashmir markhor C. f. falconeri in India. From October 2004 to April 2005 we therefore conducted the first range-wide survey of the species in India since independence. The markhor's range has shrunk from c. 300 km2 in the late 1940s to c. 120 km2 in 2004–2005. Our surveys and interviews with key local informants indicate that 350–375 markhor may yet exist in the region. All the populations are small (usually < 50) and fragmented. International conflicts, developmental projects, the needs of an increasing human population and poaching, along with lack of awareness, are the primary threats to the species. The largest population in India, in Kajinag, may have potential for long-term survival if immediate conservation measures can be implemented.