Seasonal pattern of food habits of large herbivores in riverine alluvial grasslands of Brahmaputra floodplains, Assam

Abstract

Jarman–Bell (1974) hypothesized that in the dry savanna of Africa, small-bodied herbivores tend to browse more on forage with high protein and low fibre content. This implies browsing on high nutritive forage by meso-herbivores, and grazing and mixed feeding on coarse forage by mega-herbivores. We tested this hypothesis in the riverine alluvial grasslands of the Kaziranga National Park (KNP), where seasonal flood and fire play an important role in shaping the vegetation structure. We analyzed the feeding habits and quality of major forage species consumed by three mega-herbivores, viz. greater one-horned rhino, Asian elephant, and Asiatic wild buffalo, and three meso-herbivores, viz. swamp deer, hog deer, and sambar. We found that both mega and meso-herbivores were grazers and mixed feeders. Overall, 25 forage plants constituted more than 70% of their diet. Among monocots, family Poaceae with Saccharum spp. (contributing > 9% of the diet), and, among dicots, family Rhamnaceae with Ziziphus jujuba (contributing > 4% of the diet) fulfilled the dietary needs. In the dry season, the concentration of crude protein, neutral detergent fibre, calcium, sodium, and phosphorous varied significantly between monocots and dicots, whereas only calcium and sodium concentrations varied significantly in the wet season. Dicots were found to be more nutritious throughout the year. Compared to the dry season, the monocots, viz. Alpinia nigra, Carex vesicaria, Cynodon dactylon, Echinochloa crus-galli, Hemarthria compressa, Imperata cylindrica, and Saccharum spp., with their significantly high crude protein, were more nutritious during the wet season. Possibly due to the availability of higher quality monocots in the wet season, both mega and meso-herbivores consume it in high proportion. We concluded that the Jarman–Bell principle does not apply to riverine alluvial grasslands as body size did not explain the interspecific dietary patterns of the mega and meso-herbivores. This can be attributed to seasonal floods, habitat and forage availability, predation risk, and management practices such as controlled burning of the grasslands. The ongoing succession and invasion processes, anthropogenic pressures, and lack of grassland conservation policy are expected to affect the availability of the principal forage and suitable habitat of large herbivores in the Brahmaputra floodplains, which necessitates wet grassland-based management interventions for the continued co-existence of large herbivores in such habitats.

Pollen and non-pollen palynomorph depositional patterns in Kaziranga National Park, India: Implications for palaeoecology and palaeoherbivory analysis

“…The Dillenia - Terminalia - Careya assemblage is significant as it is characteristic of the preferred habitat of wildlife in the Balpakram valley in the Garo hills of Meghalaya (Basumatary et al, 2014) which coincided with the pollen assemblages in KNP. These plants are utilized as the primary food plants preferred by many herbivorous mammals including elephant and deer species (Devi et al, 2022; Neupane et al, 2019; Odden et al, 2005; Steinheim et al, 2005). The consistent abundance of Bombax pollen in the palynoassemblage which is recorded upto 4.7% was marked in comparison to the other associated arboreal taxa.…”

Ecological studies andThreats on African elephant (Loxodonta africana) in Babile Elephant Sanctuary, Eastern Ethiopia

“…Due to its wider range and greater availability (Leweri et al, 2022), and palatability (i.e., having high crude protein, water, and low fibre content), Acacia species were therefore more consumed by elephants in the BES regardless of seasons (Ikanya et al, 2022). Generally, lack of food availability and water in their diet, seasonal variations influence how elephants use their habitat (Devi et al, 2022), and particularly influence the feeding preference for elephants (Beirne et al, 2020).…”