A severe decline in a once numerous species.
A resurvey of the puku antelope in Kasanka National Park, Zambia, documents a severe decline of this once abundant animal.
Knowledge about antelope populations and their dynamics is a key for conservation. Mammalogists from the Zoological Research Museum Alexander Koenig – Leibniz Institute for Animal Biodiversity (ZFMK) in Bonn, Germany, performed a resurvey of the bovids in Kasanka National Park in Zambia in November 2019 with a focus on the population of puku antelopes (Kobus vardonii). The results of the now published study show a decline of 84% of the puku population size compared to a previous survey in 2009-2010. Changes in the population structure and in the spatial distribution indicate that poaching in combination with further adverse factors affected negatively the pukus, but also other bovid species.
The population size of puku was estimated to be 5,038 individuals in 2009-2010. “The evaluation of the population of puku in Kasanka National Park was part of my dissertation where I investigated the ecology and the population status of pukus in selected areas of Zambia” tells Dr. Vera Rduch at the ZFMK (central coordination of GBOL III: Dark Taxa and section Mammalogy) and leading specialist for Pukus. She also wrote the account for the puku antelope in the frame of the Mammalian Species published by the American Society of Mammalogists. “Since that time I maintained my relations to the Kasanka Trust and the Department of National Parks & Wildlife. Several times I came back to Zambia to discuss and exchange ideas about antelopes and their protection. Seeing only very few puku in Kasanka National Park during my trip in 2018 has led to the plan to reinvestigate the antelope community in this protected area.” Thalia Jentke, Research Assistant in the section Mammalogy at the ZFMK, who assisted the data collection and analysis mentions: “We did not intend to estimate just the mere number of individuals in the population, but also to get crucial information about the situation inside the population and about the distribution of the animals.”
Antelopes are a central part of African savannah ecosystems. In combination with rainfall, fire or soil nutrients, antelopes regulate the relative composition of tree and grass cover in the shifting mosaic of habitats. Being prey of carnivores, the abundance and dynamics of antelopes influence the occurrence and diversity of predators. Kasanka National Park, situated in the northern part of the Central Province, is one of the smallest national parks in Zambia. It is managed through a public-private partnership between the Kasanka Trust Ltd. and the Department of National Parks and Wildlife. Kasanka National Park is famous for a spectacular congregation of 10 million straw-coloured fruit bats (Eidolon helvum) that appear every year between November and December. Further, it is home to a key high-density and very visible population of sitatunga antelopes (Tragelaphus spekii). This study focusses on the puku antelope (Kobus vardonii Livingstone, 1857), a medium-sized, golden-yellowish antelope with lyre-shaped horns in males only. Distributed along the rivers and lakes in south central Africa, Tanzania holds the largest population while Zambia can be considered as the centre of its distribution.
This new survey of bovid species used exactly the same methods employed in 2009-2010 and also data collection and subsequent analyses were of the same design. This allowed for the direct comparison between survey periods, especially for the data collected in November 2010 and 2019. Line transect surveys were conducted in November 2019. For each detected bovid, the species and group size was noted. Furthermore, one of three habitat categories to the sighting was attributed to the sighting and, if possible, collected data on the bovid age classes and the body condition of the animals were collected.
The results are alarming: 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. This represents an 84% decline. Smaller group sizes were observed. Within the puku population signs of poaching activities were observed: these were changes in population structure like the decline in male abundance, or fewer male groups. Likewise, there were changes in the spatial distribution as the decline in population density was more pronounced along the park boundaries. Puku became more vigilant and demonstrated significantly longer flight distances in 2019 in comparison with 2010. The status of the puku can be seen as an indicator of the entire bovid community in Kasanka National Park. Formerly, this protected area had a species-rich and abundant bovid community. The observations of bovid species and their numbers collected in November 2019 survey lag behind what was reported 30 years ago and even 10 years ago.
An adverse combination of multiple and also interacting factors led to the decline of the puku population. Increased poaching due to diverse reasons during the last years might have the most severe impact, but the last years being drier than in average also have to be considered. “Our study is a snapshot of the wildlife status in Kasanka National Park“, says Dr. Vera Rduch “Puku are able to multiply quickly. Increased law-enforcement can help to reverse the situation for the puku – and hopefully for the entire unique ecosystem of Kasanka National Park.” The fate of this antelope may draw more attention to stimulate adequate fundraising and mobilize joint efforts in order to preserve this unique wilderness.
Source: The article by Vera Rduch & Thalia Jentke entitled “Alarming decline of bovids in Kasanka National Park, Zambia: a case study of the puku antelope (Kobus vardonii)” was published open access in the African Journal of Ecology: DOI: 10.1111/aje.12843. Link: https://onlinelibrary.wiley.com/doi/full/10.1111/aje.12843, Link to the pdf: https://onlinelibrary.wiley.com/doi/epdf/10.1111/aje.12843
Additionally, the species account for the puku antelope was published very recently in the frame of the Mammalian Species published by the American Society of Mammalogists. Within this series, the current understanding of the biology of a species is summarised that includes systematics, distribution, fossil history, genetics, anatomy, physiology, behaviour, ecology and conservation: Vera Rduch, Kobus vardonii (Artiodactyla: Bovidae), Mammalian Species: 52 (994): 86-104. https://doi.org/10.1093/mspecies/seaa007
Zoological Research Museum Alexander Koenig – Leibniz-Institute for Animal Biodiversity (ZFMK) is an independent research institute. The focus of research is on performing an inventory of the zoological species diversity on earth, on the analysis of changes in biodiversity as a result of environmental factors, and on evolutionary processes at the morphological and molecular levels. ZFMK furthermore explores the context of structure and function of ecological systems, advanced scientific methods, and the study of the history of science. The permanent exhibition “Our blue planet – the living network” offers a genuine nature experience based on naturalistic ecosystem displays.
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Dr. Vera Rduch
central coordination of GBOL III: Dark Taxa / Mammalogy
Tel: +49 228 9122-372
Fax: +49 228 9122-212
Link to the pdf: https://onlinelibrary.wiley.com/doi/epdf/10.1111/aje.12843