Niche Relationships of an Ungulate Assemblage in a Dry Tropical Forest

Bagchi, Sumanta; Goyal, Surendra Prakash; Sankar, K.

doi:10.1644/bba-024

Cited by 54 publications

(44 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…NMDS attempts to find structure in sets of distance measures by assigning observations to specific locations in a conceptual space, such that similarities between points in this space match the given similarities as closely as possible (Clarke & Warwick, 1994;Norussis, 1997). This enables the visualisation of interspecific differences over habitat features (Clarke & Ainsworth, 1993;Bagchi, Goyal & Sankar, 2003). The response of ibex and livestock was evaluated against habitat measurements related to vegetation, ground cover and terrain from each cell.…”

Section: Discussionmentioning

confidence: 99%

“…The response of ibex and livestock was evaluated against habitat measurements related to vegetation, ground cover and terrain from each cell. Each habitat variable recorded in the cell was considered to be a separate dimension in niche space and the difference between group-centroids of various livestock and ibex were assessed using Euclidean distances (Bagchi et al, 2003). The number of iterations was decided on the basis of Young's S-stress formula and iterations were stopped when the S-stress was less than 0.005 (Spence, 1978;Norussis, 1997).…”

Section: Discussionmentioning

confidence: 99%

“…As with habitat variables, this was again converted into a similarity-matrix on the basis of the Euclidean distances between group-centroids to represent similarity in their diets. These two matrices were combined to obtain a geometrical representation of guildstructure and to identify species having similar resource requirements (belonging to the same guild) using NMDS, thus enabling visualisation of relative niche-positions as in Venn diagrams (Bagchi et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…Such differentiation is necessary for facilitating co-existence (Schoener, 1974;Harris & Miller, 1995;Bagchi et al, 2003) and, in its absence, high levels of resourceuse similarity could imply competition between species (Sale, 1974;Voeten & Prins, 1999). Given that livestock in the study area are maintained at high densities through supplementary winter-feeding ) they can also out-compete ibex.…”

Section: Competition Between Ibex and Livestockmentioning

confidence: 99%

See 3 more Smart Citations

Conflicts between traditional pastoralism and conservation of Himalayan ibex (Capra sibirica) in the Trans‐Himalayan mountains

Bagchi

Mishra

Bhatnagar

2004

Animal Conservation

133

121

View full text Add to dashboard Cite

There is recent evidence to suggest that domestic livestock deplete the density and diversity of wild herbivores in the cold deserts of the Trans-Himalaya by imposing resource limitations. To ascertain the degree and nature of threats faced by Himalayan ibex (Capra sibirica) from seven livestock species, we studied their resource use patterns over space, habitat and food dimensions in the pastures of Pin Valley National Park in the Spiti region of the Indian Himalaya. Species diet profiles were obtained by direct observations. We assessed the similarity in habitat use and diets of ibex and livestock using Non-Metric Multidimensional Scaling. We estimated the influence of the spatial distribution of livestock on habitat and diet choice of ibex by examining their co-occurrence patterns in cells overlaid on the pastures. The observed co-occurrence of ibex and livestock in cells was compared with null-models generated through Monte Carlo simulations. The results suggest that goats and sheep impose resource limitations on ibex and exclude them from certain pastures. In the remaining suitable habitat, ibex share forage with horses. Ibex remained relatively unaffected by other livestock such as yaks, donkeys and cattle. However, most livestock removed large amounts of forage from the pastures (nearly 250 kg of dry matter/day by certain species), thereby reducing forage availability for ibex. Pertinent conservation issues are discussed in the light of multiple-use of parks and current socio-economic transitions in the region, which call for integrating social and ecological feedback into management planning.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Competition Between Ibex and Livestockmentioning

confidence: 99%

See 2 more Smart Citations

Conflicts between traditional pastoralism and conservation of Himalayan ibex (Capra sibirica) in the Trans‐Himalayan mountains

Bagchi

Mishra

Bhatnagar

2004

Animal Conservation

133

121

View full text Add to dashboard Cite

show abstract

“…However, few studies have compared the diets of wild sympatric herbivores in the Asian subtropics (Dinerstein 1980;Martin 1982;Johnsingh and Sankar 1991;Bagchi et al 2003;Steinheim et al 2005). As a step in unravelling the complex interactions among sympatric ungulates in this region, in this study we describe the diets of rhino, swamp deer and hog deer at broader (forage category) and finer scale (within each forage category), and based on the results we discuss the potential for forage competition and facilitation between them.…”

Section: Introductionmentioning

confidence: 99%

Dry season diets of sympatric ungulates in lowland Nepal: competition and facilitation in alluvial tall grasslands

Wegge

Shrestha

Moe

2006

Ecological Research

View full text Add to dashboard Cite

Based on microhistological analyses of faecal material, we compared the early dry season diets of greater one-horned rhinoceros Rhinoceros unicornis, swamp deer Cervus duvauceli and hog deer Axis porcinus, which inhabit the same alluvial grassland habitat complex in lowland Nepal. Their diets were quite similar, both at the forage category level and within subcategories of graminoids and woody plants. Early successional tall grasses, especially Saccharum spontaneum, were the dominant food of all three species, underlining the key role of the threatened alluvial floodplains in large mammal conservation in South Asia. The two deer species ate significantly more graminoids (>66.5%) than did rhino (45.5%), and although they did not differ in proportions of graminoids, swamp deer ate significantly more late successional tall grasses (Narenga porphyrocoma and Themeda spp.) and short grasses (mainly Imperata cylindrica) than hog deer. The two deer consumed almost equal proportions of woody browse (ca. 10%), significantly less than that of rhino (33.0%). The prediction of the Jarman-Bell hypothesis, that large-bodied herbivores are less selective and subsist on lower quality graminoids than smaller ruminants, was not supported by the data. Based on this and previous studies in the same area we propose a conceptual model where the larger megaherbivores (rhino and elephant Elephas maximus) facilitate the smaller swamp deer and hog deer during the monsoonal growing season, while the smaller and more selective deer species outcompete the larger during the dry season when food is more limited. Owing to the all-year sprouting ability of S. spontaneum, facilitation may occur also in the dry season with low numbers of megaherbivores, thus accentuating competitive exclusion at higher deer densities.

show abstract