Afifullah Khan

Abundance and Prey Availability Assessment of Ganges River Dolphin (Platanista gangetica gangetica) in a Stretch of Upper Ganges River, India

The present study was conducted between January and June 2007 to assess the abundance and density of Ganges River dolphin (Platanista gangetica gangetica) and their prey in a 28-km stretch of the River Ganges between Narora Barrage and Anupshahar. Two different sampling methods were used to estimate dolphin densities. Estimated density was 2.58 ± 0.40 individuals/km2 (mean ± 1 SE) using the direct count method and 4.97 ± 0.60 individuals/km 2 using the boat-based, line-transect distance methods, with an encounter rate of 0.52 ± 0.068 individuals/km and detection probability of 0.647. No significant differences between the upstream and downstream counts (t = 1.29, df = 9, p > 0.05) were detected. The adult male to adult female ratio was 0.66: 1.00, whereas the calf to adult female ratio was 0.42: 1.00. We collected 16 fish species of length class varying from 3.5 to 20 cm (range of preferred size of dolphin prey) with a total density of 176.42 fish/km2 and a total average biomass of 5.36 kg/km 2 . Dolphin density showed a significant positive relationship (R 2 = 0.587) with density of Reba fish (Cirrhinus reba) (β = 0.31, p = 0.00) and Baam fish (Mastacembelus armatus) (β = 0.50, p = 0.04) and also with water depth (β = 0.17, p = 0.03). Presence of dolphins varied across different water depth categories (χ2 = 106.38, df = 3, p < 0.01) and different parts of the river (χ 2 = 21.68, df = 2, p = 0.00) with more than 50% of dolphin sightings occurring in confluences, indicating their preference for deep water pools.

Time Dependent Activity Pattern of Ganges River Dolphin Platanista gangetica gangetica and its Response to Human Presence in Upper Ganges River, India

Abstract. Information on activity profile of the Ganges river dolphin (Platanista gangetica gangetica) and its responses to human interference were lacking. A study following focal animal sampling protocol with individual-follow method and assessment of human interference on dolphin occurrence and behavior was hence conducted. Based on logical reasoning and prior assumptions, dolphin activities were broadly categorized into four types viz., surfacing, movement, chasing/feeding and underwater. Percentage frequencies of occurrence of these activities in dolphin activity budget were 50%, 26%, 6% and 18% with corresponding time allocations of 1%, 60%, 4% and 35%, respectively; without any significant difference between male and female activity patterns (&khgr;2 = 0.832, df = 3, P > 0.05). Five different modes of surfacing were observed with dive-times ranging from 4 to 504 sec and average prey chase-time of 38 (SD = ±29) sec. Human interference had a negative relationship with dolphin presence (&bgr; = -0.6398, z = -3.816, P < 0.001). All recorded dolphin activities showed a positive relationship with human presence except underwater activity (&bgr; = -0.1115, z = -3.76, P < 0.001). Detailed behavioral study and proper check on increasing anthropogenic influence is necessary to ensure the species safe survival.

Factors determining occupancy of Ganges River dolphin (Platanista gangetica gangetica) during differing river discharges in the upper Ganges, India

Abstract Habitat selection by a species during scarcity and varying resource availability can give important insights into the requirements crucial to its survival. We conducted a study in a stretch of the upper Ganges River to assess the status and distribution of endangered Ganges River dolphins (Platanista gangetica gangetica) and fishing activities. We also evaluated the resource selection criteria of the species using an occupancy-based approach to determine the influence of different habitat covariates on dolphin detection and occupancy across varying river discharge conditions. Occupancy modeling indicated that water depth, fish relative abundance, and fishing intensity were the best predictors of dolphin occupancy. Increase in fishing activities was identified as the most significant threat to dolphin conservation in this stretch of river. We suggest strengthening awareness and capacity building of fishermen communities and programs for improving their livelihoods. Our study extends the applicability of occupancy-based surveys to elusive aquatic mammal species and recommends its scope throughout the entire distribution range of the species so that it can help to identify priorities for its conservation and management.

Status of Wildlife Habitats in Ramnagar Forest Division, Terai-Arc Landscape, Uttarakhand, India

The Terai-Arc Landscape in the foothills of Himalaya supports a mosaic of wildlife habitats that sustains an amazing biodiversity. The high human pressure coupled with developmental activities, not only degrade wildlife habitats but restrict the dispersal of wild animals particularly in multiple-use managed forest. We determined the status of wildlife habitats in Ramnagar Forest Division classifying Landsat 8 OLI/TIRS image acquired on April 2015. Landsat Aster GDEM data of 17 October 2011 was used to assess slope, aspect and elevation of the study area. Sal forest was the dominant class and it was followed by sal mixed forest, mixed forest, human habitation and barren land. The elevation ranges between 307m and 1892m amsl with sizable area having gentle slope (50 to 100). Most of the region was south facing. Importance of these habitats for mammals of western Terai-Arc Landscape has been discussed. The current information is expected to serve as baseline information for planning future management strategies and determining changes in wildlife habitats.

Dietary Spectrum of Two Sympatric Canid Species in Ladakh, India

We have conducted a study between May and August 2013 to understand the dietary spectrum of two canid species: Tibetan wolf (Canis lupus chanco) and Red fox (Vulpes vulpes) in one of the most inhospitable landscape of the world. Ladakh is characterized by harsh environmental conditions and low primary productivity and therefore animal populations, particularly of large and medium sized herbivores are also low and sparsely distributed. This in turn poses a challenge to the survival of predators. We have attempted to investigate the ways by which the two sympatric canid species are optimizing feeding for their survival in an environment where there is scarcity of wild prey base. Scats of the two species were collected from Chiktan and Rangdum valleys and undigested food remnants were identified. The dietary spectrum of Tibetan wolf was composed of six prey species (2 wild and 4 livestock species). The share of livestock species in the diet was maximum (RO: 62.0%). The Red fox being an opportunistic feeder consumed 19 forgeable items, including small and medium sized mammals, birds, reptiles, insects, plant material, eggs, stones and debris. The livestock species contributed maximum to the diet of Red fox (RO: 22.9%). The dietary niche breadths of both species were more or less similar (0.53 and 0.58) and indicating a generalist feeding behavior. Both the species are surviving in the same environment with a dietary overlap of 0.60. The given information is expected to aid further studies in Indian Trans-Himalaya.