Himalayan thoroughfare: Migratory routes of ducks over the rooftop of the world
No abstract available.
Book chapter↗
Geology topics
Tsewang Namgail
Publications and source records attributed to Tsewang Namgail.
Migratory ducks and protected wetlands in India
India is the most important wintering ground for migratory ducks in the Central Asian Flyway. Because of its latitudinal and climatic extent, the country provides a diversity of wetland habitats for migratory ducks (Ali & Ripley 1978). India is the seventh largest country in the world with an area of about 3.3 million km2 or 2.4% of the world’s land-area. Mainland India stretches nearly 3200 km from north to south (6° to 36° N), and 3000 km from west to east (68° to 98° E). Given this huge geographical extent, migratory ducks wintering in the southern part of the country need to refuel at several wetlands before they cross the Himalayas on their way to the breeding areas in Central Asia and Siberia.
Book chapter↗
Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size
Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.
Current Zoology↗
Biomass and diversity of dry alpine plant communities along altitudinal gradients in the Himalayas
A non-linear relationship between phytodiversity and altitude has widely been reported, but the relationship between phytomass and altitude remains little understood. We examined the phytomass and diversity of vascular plants along altitudinal gradients on the dry alpine rangelands of Ladakh, western Himalaya. We used generalized linear and generalized additive models to assess the relationship between these vegetation parameters and altitude. We found a hump-shaped relationship between aboveground phytomass and altitude. We suspect that this is engendered by low rainfall and trampling/excessive grazing at lower slopes by domestic livestock, and low temperature and low nutrient levels at higher slopes. We also found a unimodal relationship between plant species-richness and altitude at a single mountain as well as at the scale of entire Ladakh. The species-richness at the single mountain peaked between 5,000 and 5,200 m, while it peaked between 3,500 and 4,000 m at entire Ladakh level. Perhaps biotic factors such as grazing and precipitation are, respectively, important in generating this pattern at the single mountain and entire Ladakh.
Ladakh region↗