Bats in the Ghats: Agricultural intensification reduces functional diversity and increases trait filtering in a biodiversity hotspot in India

The responses of bats to land-use change have been extensively studied in temperate zones and the neotropics, but little is known from the palaeotropics. Effective conservation in heavily-populated palaeotropical hotspots requires a better understanding of which bats can and cannot survive in human-modified landscapes. We used catching and acoustic transects to examine bat assemblages in the Western Ghats of India, and identify the species most sensitive to agricultural change. We quantified functional diversity and trait filtering of assemblages in forest fragments, tea and coffee plantations, and along rivers in tea plantations with and without forested corridors, compared to protected forests. Functional diversity in forest fragments and shade-grown coffee was similar to that in protected forests, but was far lower in tea plantations. Trait filtering was also strongest in tea plantations. Forested river corridors in tea plantations mitigated much of the loss of functional diversity and the trait filtering seen on rivers in tea plantations without forested corridors. The bats most vulnerable to intensive agriculture were frugivorous, large, had short broad wings, or made constant frequency echolocation calls. The last three features are characteristic of forest animal-eating species that typically take large prey, often by gleaning. Ongoing conservation work to restore forest fragments and retain native trees in coffee plantations should be highly beneficial for bats in this landscape. The maintenance of a mosaic landscape with sufficient patches of forest, shade-grown coffee and riparian corridors will help to maintain landscape wide functional diversity in an area dominated by tea plantations

Gajah. Securing the Future for Elephants in India.

It is estimated that six in every ten wild Asian elephants live in India. This report by the Ministry of Environment and Forests in India outlines plans to safeguard the species and associated habitats in the face of rapid economic expansion and development pressures

Averting biodiversity collapse in tropical forest protected areas

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon¹⁻³. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses⁴⁻⁹. As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions. Our analysis reveals great variation in reserve ‘health’: about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.Keywords: Ecology, Environmental scienc

Breeding Biology of the Malabar Grey Hornbill (Ocyceros Griseus) in Southern Western Ghats, India

Volume: 97Start Page: 15End Page: 2

Sight record of the Oriental Bay Owl (Phodilus badius ripleyi) in the Anaimalai Hills, southern western Ghats, India

Volume: 95Start Page: 343End Page: 34

Correlates of hornbill distribution and abundance in rainforest fragments in the southern Western Ghats, India

The distribution and abundance patterns of Malabar Grey Hornbill Ocyceros griseus and Great Hornbill Buceros bicornis were studied in one undisturbed and one heavily altered rainforest landscape in the southern Western Ghats,India. The Agasthyamalai hills (Kalakad-Mundanthurai Tiger Reserve, KMTR) contained over 400 km(2) of continuous rainforest, whereas the Anamalai hills (now Indira Gandhi Wildlife Sanctuary, IGWS) contained fragments of rainforest in a matrix of tea and coffee plantations. A comparison of point-count and line transect census techniques for Malabar Grey Hornbill at one site indicated much higher density estimates in point-counts (118.4/km(2)) than in line transects (51.5/km(2)), probably due to cumulative count over time in the former technique. Although line transects appeared more suitable for long-term monitoring of hornbill populations, point-counts may be useful for large-scale surveys, especially where forests are fragmented and terrain is unsuitable for line transects. A standard fixed radius point-count method was used to sample different altitude zones (600-1,500 m) in the undisturbed site (342 point-counts) and fragments ranging in size from 0.5 to 2,500 ha in the Anamalais (389 point-counts). In the fragmented landscape, Malabar Grey Hornbill was found in higher altitudes than in KMTR, extending to nearly all the disturbed fragments at mid-elevations (1,000-1,200 m). Great Hornbill persisted in the fragmented landscape using all three large fragments (> 200 ha). It was also recorded in four of five medium-sized fragments (25-200 ha) and one of five small fragments (< 25 ha), which was adjacent to shade coffee plantations. Abundance of Malabar Grey Hornbill declined with altitude and increased with food-tree species richness. Great Hornbill abundance increased with food-tree species richness, suggesting that maintenance of high diversity of hornbill food species in fragments is important for their persistence. It is likely that the smaller and less specialized Malabar Grey Hornbill will survive in disturbed and fragmented forest landscapes, while Great Hornbill is more vulnerable to habitat alteration. Protection and restoration of rainforest fragments and food-tree resources, besides protection of existing large fragments, will aid the conservation of hornbills in the region

Heard but not seen: Comparing bat assemblages and study methods in a mosaic landscape in the Western Ghats of India.

We used capture (mist-netting) and acoustic methods to compare the species richness, abundance, and composition of a bat assemblage in different habitats in the Western Ghats of India. In the tropics, catching bats has been more commonly used as a survey method than acoustic recordings. In our study, acoustic methods based on recording echolocation calls detected greater bat activity and more species than mist-netting. However, some species were detected more frequently or exclusively by capture. Ideally, the two methods should be used together to compensate for the biases in each. Using combined capture and acoustic data, we found that protected forests, forest fragments, and shade coffee plantations hosted similar and diverse species assemblages, although some species were recorded more frequently in protected forests. Tea plantations contained very few species from the overall bat assemblage. In riparian habitats, a strip of forested habitat on the river bank improved the habitat for bats compared to rivers with tea planted up to each bank. Our results show that shade coffee plantations are better bat habitat than tea plantations in biodiversity hotspots. However, if tea is to be the dominant land use, forest fragments and riparian corridors can improve the landscape considerably for bats. We encourage coffee growers to retain traditional plantations with mature native trees, rather than reverting to sun grown coffee or coffee shaded by a few species of timber trees

Nest-Site Characteristics and Nesting Success of the Malabar Gray Hornbill in the Southern Western Ghats, India

Volume: 109Start Page: 102End Page: 11

Data from: A conservation status survey of hornbills (Bucerotidae) in the Western Ghats, India

The Western Ghats biodiversity hotspot in India is threatened by habitat loss and fragmentation, which is likely to impact large-bodied, wide-ranging species with specialised requirements such as hornbills. In this survey along the Western Ghats, we surveyed for four hornbill species that occur here: Malabar Pied Hornbill Anthracoceros coronatus, and Indian Grey Hornbill Ocyceros birostris (endemic to South Asia), Malabar Grey Hornbill Ocyceros griseus (endemic to the Western Ghats), and the Great Hornbill Buceros bicornis. We visited 45 localities across five states: Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu. These included 26 wildlife sanctuaries, 5 national parks, 13 reserved forests, and one plantation landscape. Across sites, we walked 80 transect surveys totalling a length of 286.4 km. In all, 631 individual hornbills (412 detections) were recorded across 35 localities. The Malabar Grey Hornbill was most frequently detected, and widely-distributed, followed by the Great, and Malabar Pied hornbills. The Indian Grey Hornbill, more widespread across India, was seen in only two locations in this survey. Hornbill encounter was up to five times higher in moist, and wet forests as compared to dry forest types. Based on hornbill distribution and protected areas, five important hornbill conservation landscapes were identified in the Western Ghats (Amboli–Goa–Dandeli, Anamalai–Parambikulam–Vazhachal, Nilgiris– Wayanad, Someshwara–Sharavati–Mookambika, Neyyar–Peppara–KMTR, and Periyar) along with key reserved forests (Kottiyoor, New Amarambalam, Vazhachal, Nelliampathy, Goodarickal, Kulathupuzha–Palode). Hornbill densities were estimated in two of the above landscapes, and are provided as a baseline. We highlight some key considerations for hornbill research and conservation, and future needs

Bird and mammal survey data from the Western Ghats, India

See ReadMe.txt file (and hbs_metadescription.txt file in Zipped data archive file