Project Associate, Cranes and Wetlands
MSc, Zoology, Goa University, 2002
I am interested in using Geographic Information Systems (GIS) to obtain a better understanding of habitat use and distributions of wild species.
When wetlands are changed to fishponds..
... do conditions change for waterbirds?
- Journal ArticleIn pressSympatric cranes in northern Australia: abundance, breeding success, habitat preference and dietEmu - Austral Ornithology; https://doi.org/10.1080/01584197.2018.1537673
Sympatric breeding of Sarus Cranes (Antigone antigone) and Brolga (A. rubicunda) occurs only in northern Queensland, Australia but factors contributing to this unique sympatry are unknown. Large-scale developments currently planned in this region, with potentially major impacts on cranes, create an urgent need to understand the ecological requirements of each crane species. We carried out a multi-floodplain landscape-scale survey during April-May 2017 and derived metrics for several ecological aspects for the first time for both crane species. The abundance of the two species differed between the floodplains. Both crane species synchronised nest-initiation with rainfall (November to March). Breeding success was higher than past estimates anywhere, with 60% of Sarus Crane pairs and 50% of Brolga pairs fledging chicks. Sarus Cranes preferred four riverine Eucalyptus-dominated regional ecosystems, with 10% using open habitats. Brolgas preferred two non-wooded regional ecosystems, but 32% shared Eucalyptus-dominated regional ecosystems with Sarus Cranes. Stable isotope analyses revealed Sarus diet to be comprised of more diverse vegetation than Brolgas, while Brolgas fed across a wider range of trophic levels. The ecology of Gulf cranes closely matched habits of Sarus Cranes in south Asia, despite disparate conditions suggesting considerable species plasticity. The diverse habitats of the Gulf and varying diet appear to facilitate the cranes’ sympatry, and our study provides basic data for developing long-term conservation plans in the face of development activities.
- Journal Article2016Factors affecting provisioning times of two stork species in lowland NepalWaterbirds, 39: 365-374. doi: http://dx.doi.org/10.1675/063.039.0406
The ecology of stork colonies in south Asia are very poorly understood. Factors affecting provisioning times by adults were evaluated at nests of two stork species, the Asian Openbill (Anastomus oscitans) and the Lesser Adjutant (Leptoptilos javanicus), in lowland Nepal where the landscape is dominated by multi-cropped agriculture fields. Analyses focused on understanding if provisioning times are influenced more due to colony-level variables, wetlands around colonies, or season. Using generalized additive mixed models and the information-theoretic approach, colony-level variables (brood size and chick age) showed non-trivial associations with provisioning times (substantially better than the null model). Univariate models with colony size and wetlands had poor support (worse than the null model). Season, which represented the changing cropping patterns, rainfall, and wetness on the landscape, was the most important variable for both species. The combination of season and wetlands was very important for provisioning Asian Openbills whose chicks fledged during the monsoon (July–October), but not for Lesser Adjutants whose chicks fledged in the drier winter months (November–February). Results strongly suggest that changing cropping patterns to a drier monsoonal crop, or reductions in wetland extents, will be detrimental to storks in Nepal.
- Journal Article2015Wetland loss and waterbird use of wetlands in Palwal district, Haryana, India: The role of agriculture, urbanization and conversion to fish pondsWetlands. DOI 10.1007/s13157-014-0600-8Download
PDF, 1.15 MB
Wetlands in tropical and sub-tropical landscapes
are experiencing changes and loss due to urbanization and
intensive human use, but there is sparse detailed understanding
of how these affect use by wetland-dependent birds.
Urbanization and conversion of community wetlands to private
fish ponds are occurring rapidly in Haryana state in north
India. We conducted a study in Palwal district, Haryana in
2013–2014 to simultaneously understand (i) rates and reasons
for wetland loss between 1970s and 2000s, and (ii) relative
importance of location (towns/ villages versus those amid
agriculture) versus site-specific variables on the winter abundance of 31 waterbird species in these fish ponds. Wetland
extent reduced by 52 %, and average wetland size reduced by
42 % between 1970s and 2000s. Expansion of urban areas
converted 105 agricultural wetlands to town wetlands.
Wetlands of different locations could not be differentiated
using waterbird abundance suggesting that wetland conditions
have been homogenized, in part due to conversions to fish
ponds and in part due to urban expansions. Focal waterbird
abundance was affected more due to human activities relative
to location or vegetation. A complex combination of current
management practices and historical determinants of wetland persistence appear to be driving waterbird use of wetlands in
locations like Palwal.
- Journal Article2013Can wetlands maintained for human use also help conserve biodiversity? Landscape–scale patterns of bird use of wetlands in an agricultural landscape in north IndiaBiological Conservation 168: 49-56. http://dx.doi.org/10.1016/j.biocon.2013.09.016
Wetlands in tropical agricultural landscapes are maintained largely by local institutions explicitly for human use, which is assumed to deter biodiversity. Conservation efforts have been biased towards protecting large wetlands that are assumed to be adequate to conserve the majority of species of focal taxa, usually birds. These assumptions remain untested, and landscape-scale conservation planning for wetlands is largely absent, as is a generalised understanding of wetland use by focal taxa. We designed a landscape-scale survey to understand patterns and processes determining beta diversity of birds using agricultural wetlands in south-western Uttar Pradesh, India where wetlands have experienced prolonged and intensive human use for several centuries. Observed bird species richness (99 species in 28 wetlands) is the highest known for any agricultural landscape in south Asia signifying that even intensive human use of wetlands does not necessarily deter their ability to retain biodiversity. Birds exhibited strong scale
dependent wetland use underscoring the need to conserve wetlands of varying sizes and at varying densities on the landscape. Beta diversity was due largely to species turnover (0.877) with minimal effect due to nestedness (0.055) suggesting that conserving a few large wetlands will not adequately meet goals of conserving the majority of wetland bird species. Prevailing assumptions regarding biodiversity conservation in tropical agricultural wetlands require being revised, and a landscape-scale approach that incorporates ecological realities is needed. Incorporating local institutions alongside formal protectionist methods offer a potential win–win situation to maximise conservation of biodiversity in tropical agricultural wetlands.
- Journal Article2012Methodological, temporal and spatial factors affecting modelled occupancy of resident birds in the perennially cultivated landscape of Uttar Pradesh, IndiaLandscape Ecology 27: 59-71. doi:10.1007/s10980-011-9666-3.
Biodiversity persistence in non-woody tropical farmlands is poorly explored, and multispecies assessments with robust landscape-scale designs are sparse. Modeled species occupancy in agricultural mosaics is affected by multiple factors including survey methods (convenience-based versus systematic), landscape-scale agriculture-related variables, and extent of remnant habitat. Changes in seasonal crops can additionally alter landscape and habitat conditions thereby influencing species occupancy. We investigated how these factors affect modeled occupancy of 56 resident bird species using a landscape-scale multi-season occupancy framework across 24 intensively cultivated and human-dominated districts in Uttar Pradesh state, north India. Convenience-based roadside observations provided considerable differences in occupancy estimates and associations with remnant habitat and intensity of cultivation relative to systematic transect counts, and appeared to bias results to roadside conditions. Modeled occupancy of only open-area species improved with increasing intensity of cultivation, while remnant habitat improved modeled occupancy of scrubland, wetland and woodland species. Strong seasonal differences in occupancy were apparent for most species across all habitat guilds. Further habitat loss will be most detrimental to resident scrubland, wetland and woodland species. Uttar Pradesh’s agricultural landscape has a high conservation value, but will require a landscape-level approach to maintain the observed high species richness. Obtaining ecological information from unexplored landscapes using robust landscape-scale surveys offers substantial advantages to understand factors affecting species occupancy, and is necessary for efficient conservation planning.