Puku Research Articles

An integrated population model reveals source-sink dynamics for competitively subordinate African wild dogs linked to anthropogenic prey depletion.

Many African large carnivore populations are declining due to decline of the herbivore populations on which they depend. The densities of apex carnivores like the lion and spotted hyena correlate strongly with prey density, but competitively subordinate carnivores like the African wild dog benefit from competitive release when the density of apex carnivores is low, so the expected effect of a simultaneous decrease in resources and dominant competitors is not obvious. Wild dogs in Zambia's South Luangwa Valley Ecosystem occupy four ecologically similar areas with well-described differences in the densities of prey and dominant competitors due to spatial variation in illegal offtake. We used long-term monitoring data to fit a Bayesian integrated population model (IPM) of the demography and dynamics of wild dogs in these four regions. The IPM used Leslie projection to link a Cormack-Jolly-Seber model of area-specific survival (allowing for individual heterogeneity in detection), a zero-inflated Poisson model of area-specific fecundity and a state-space model of population size that used estimates from a closed mark-capture model as the counts from which (latent) population size was estimated. The IPM showed that both survival and reproduction were lowest in the region with the lowest density of preferred prey (puku, Kobus vardonii and impala, Aepyceros melampus), despite little use of this area by lions. Survival and reproduction were highest in the region with the highest prey density and intermediate in the two regions with intermediate prey density. The population growth rate ( ) was positive for the population as a whole, strongly positive in the region with the highest prey density and strongly negative in the region with the lowest prey density. It has long been thought that the benefits of competitive release protect African wild dogs from the costs of low prey density. Our results show that the costs of prey depletion overwhelm the benefits of competitive release and cause local population decline where anthropogenic prey depletion is strong. Because competition is important in many guilds and humans are affecting resources of many types, it is likely that similarly fundamental shifts in population limitation are arising in many systems.

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

AbstractKnowledge about antelope populations and their status is a key for conservation. In November 2019, we used distance sampling to perform a re‐survey of the bovid species in Kasanka National Park, Zambia, with a focus on the puku (Kobus vardonii). Data collection and subsequent analyses were of the same design as in a previous survey in 2009–2010. This allowed for the direct comparison between survey periods, especially for the data collected in November 2010 and 2019. The estimated puku population size decreased from 5,038 (range 3,268–7,238) animals in 2009–2010 to 819 (range 250–2,708) animals in 2019, representing an 84% decline. Smaller group sizes were observed. Changes in population structure (decline in male abundance, fewer male groups) and spatial distribution (decline in population density, especially along the park boundaries) of puku showed signs of increased poaching activities in Kasanka National Park. Also, puku became more vigilant and demonstrated significantly longer flight distances in 2019 in comparison with 2010. A strong decline in puku in combination with clear signs of poaching, as well as the reduced species richness and sightings of other bovids, should become an agenda for long‐term conservation of Kasanka National Park.

Population characteristics and coexistence of puku (Kobus vardonii) and impala (Aepyceros melampus) in and around Kafue National Park, Zambia

Sympatric occurrence of puku (Kobus vardonii) and impala (Aepyceros melampus) characterises large parts of the protected areas in Zambia. The present study assessed traits of the populations as well as spatial and dietary overlap of both antelopes in Kafue National Park and adjacent Game Management Areas in western Zambia. Data were collected via distance sampling along line transects (population and distribution) and via microhistological analyses of dung (diet). Hunting activities might result in fewer males in both antelopes in the Game-Management areas. During the cool dry season there was considerable spatial overlap between puku and impala. However, puku are more abundant in grassland areas, while impala reach highest population densities in intermediate habitats. The diet of puku was characterised by high amounts of grasses during both the cool dry season and the late rainy season. Impala shifted from browsing during the cool dry season to a more grazing diet during the rainy season. This study found niche partitioning via habitat and diet as a key to understand the coexistence of these antelopes and improves our knowledge of Zambian Wildlife.

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

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.

Comparative diet and habitat selection of puku and lech we in northern Botswana

Abstract Differences in resource selection (i.e., habitat selection and diet composition) may allow for coexistence of interspecific competitors. Two congeneric floodplain antelope with broadly similar habitat use are puku (Kobus vardonii) and lechwe (K. leche). In Botswana, puku are restricted to a narrow band of floodplains along the Chobe River, whereas lechwe are far more abundant, with a distribution encompassing the Chobe Riverfront, the Linyanti Swamps, Kwando River, and the Okavango Delta. We investigated factors to try to explain the contrasting distribution patterns of puku and lechwe, including seasonal diet composition and overlap, seasonal nutritional status as indicated by fecal nitrogen and phosphorus, and habitat selection. Dietary overlap ranged from 84% to 90% across seasons. Cynodon dactylon was the greatest contributor to the diets of both puku and lechwe, but there were differences in the relative contributions of particular grass species associated with uplands or floodplains. Fecal ...

Detection of parasites and parasitic infections of free-ranging wildlife on a game ranch in zambia: a challenge for disease control.

Ex-situ conservancies are expanding alternatives to livestock production in Zambia albeit the lack of information on circulating infectious parasites from wildlife. Therefore, 12 wildlife species were examined on a game ranch were all species were found to be infected by Rhipecephalus spp. Haemoparasite infections were estimated at 7.37% (n = 95) with Babesia spp. detected in bushbuck (Tragelaphus scriptus); Anaplasma marginale in impala (Aepyceros melampus) and puku (Kobus vardonii) for the first time in Zambia. The majority of worm species isolated from bovids were not detected in equids and, vice versa. Our findings intimate ecological and behavioural patterns of some animals as deterministic to exposure. Kafue lechwe (Kobus leche kafuensis) had the widest range of worm species with more infected organs than other animals suggesting their semi aquatic nature contributory to prolonged worm exposure compared to other animals. On the other hand, Kafue lechwe had the least tick infections attributable more to shorter attachment periods as they spend prolonged periods submerged in water. Our findings indicate the vital role that wildlife plays in the epidemiology of parasitic diseases. To reduce the infection burden, control measures should be focused on reducing transmission to highly susceptible animal species as described herein.

An assessment of the puku (Kobus vardoniiLivingstone 1857) population at Lake Rukwa, Tanzania

AbstractThe population of puku,Kobus vardonii, at Lake Rukwa, one of only two in Tanzania, is poorly known. A multi‐species dry season game count carried out in Rukwa Game Reserve (RGR) in 2004 estimated a population size of 1729, but was associated with a high margin of error [coefficient of variation (CV) 0.88]. To increase the precision for the local puku population estimate, we conducted a zig‐zag line transect survey restricted only to areas occupied by puku in the dry season of 2006. This survey technique produced an estimate of 776 individuals and the CV was considerably reduced to 0.29. Puku herd size was comparable with the studies carried out in the Kilombero valley, Tanzania and in Kasanka National Park, Zambia, thus broadly confirming the herding ecology of this species. We found that pukus were restricted to the central parts of the floodplains, suggesting an avoidance of habitats used by pastoralists at the edge of RGR. Compared with the estimates of the puku population made in the 1980s, the puku population has declined. We recommend regular monitoring and enforcement of the current management plan to conserve the local puku population.