Diet of the puku antelope (Kobus vardonii) and dietary overlap with selected other bovids in Kasanka National Park, Zambia

Abstract

Diet and dietary competition among puku (Kobus vardonii) and other grazing bovids were investigated in Kasanka National Park, Zambia, a prime area for puku. The objective was to provide new insights into the puku's feeding ecology including autecological and synecological traits. Other bovids assessed for their diets were sitatunga (Tragelaphus spekii), reedbuck (Redunca arundinum), Lichtenstein's hartebeest (Alcelaphus lichtensteinii), sable antelope (Hippotragus niger) and African buffalo (Syncerus caffer). Dung was collected during different periods in 2009 and 2010 and examined using microhistological analyses. The diets were assessed for potential differences or overlap using the Pianka Index. Puku feed mainly on monocotyledons and consumed Panicum spp., Brachiaria sp., Sporobolus spp. and Hyparrhenia/Andropogon grasses. Differences in dietary composition between sexes were observed, especially during the cool dry season, as well as differences at a temporal and spatial scale. It can be concluded that puku exhibit a flexible diet with regard to grass species. Diet breadth changed throughout the year being narrowest in the late rainy season but showed no sexual differences. The dietary overlap of puku with other grazing bovids was low. This combination contributes to the puku's extraordinary situation in Kasanka National Park.

Alarming decline of bovids in Kasanka National Park, Zambia: A case study of the puku antelope (Kobus vardonii)

“…Puku feed on grasses (Rduch, 2016a), and as the grass layer decreases with less rainfall, grazers are more affected by changes in rainfall than browsers (Leeuwis et al, 2018). At least three years before the survey 2009–2010, starting from the rainy season 2006–2007, KasNP had high, above‐average rainfalls.…”

“…Puku feed on grasses (Rduch, 2016a), and as the grass layer decreases with less rainfall, grazers are more affected by changes in rainfall than browsers (Leeuwis et al, 2018). comm., 30 Jan 2020).…”

“…For example, no African buffalo was observed during the line transect sampling in 2010, but it was recorded from vehicles and dung samples (Rduch, 2016a (Jeffery et al, 1989). Sitatunga were observed on a regular basis along the Kasanka River (line no.6) which is a good sign for this population.…”

“…Previous research of the puku antelope in KasNP revealed a unique setting with limited dietary competition with other bovid species (Rduch, 2015(Rduch, , 2016a and an almost nonexisting predation pressure by terrestrial predators (Rduch, 2017). In combination with years of good rainfall and constrained poaching, prior to the 2009-2010 survey these factors accounted for a flourishing puku population.…”

Comparative omasum anatomy in ruminants: Relationships with natural diet, digestive physiology, and general considerations on allometric investigations

“…The anatomical data was evaluated using three additional data sets reflecting the natural diet, and the digestive physiology. The natural diet is typically described as the percentage of grass in the natural diet (%grass; Clauss, Kaiser, & Hummel, ) and was available for all species investigated (Akbari, Moradi, Rezaie, & Baghestani, ; Clauss et al, ; Clauss, Hofmann, et al, ; Dittmann, Hummel, et al, ; Gagnon & Chew, ; Meier et al, ; Müller et al, ; Rduch, ; Serbent, Periago, & Leynaud, ; Zerbe et al, ). In order to achieve more convenient parameter estimates for the natural diet, we expressed %grass in this study as the proportion of grass (i.e., ranging from 0 to 1 rather than from 0 to 100).…”