van Aarde Rudi J, Pimm Stuart L, Guldemond Robert, Huang Ryan, Maré Celesté
Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa.
Nicholas School of the Environment, Duke University, Durham, NC, USA.
PeerJ. 2021 Jan 11;9:e10686. doi: 10.7717/peerj.10686. eCollection 2021.
The cause of deaths of 350 elephants in 2020 in a relatively small unprotected area of northern Botswana is unknown, and may never be known. Media speculations about it ignore ecological realities. Worse, they make conjectures that can be detrimental to wildlife and sometimes discredit conservation incentives. A broader understanding of the ecological and conservation issues speaks to elephant management across the Kavango-Zambezi Transfrontier Conservation Area that extends across Botswana, Namibia, Angola, Zambia, and Zimbabwe. Our communication addresses these. Malicious poisoning and poaching are unlikely to have played a role. Other species were unaffected, and elephant carcases had their tusks intact. Restriction of freshwater supplies that force elephants to use pans as a water source possibly polluted by blue-green algae blooms is a possible cause, but as yet not supported by evidence. No other species were involved. A contagious disease is the more probable one. Fences and a deep channel of water confine these elephants' dispersal. These factors explain the elephants' relatively high population growth rate despite a spell of increased poaching during 2014-2018. While the deaths represent only ~2% of the area's elephants, the additive effects of poaching and stress induced by people protecting their crops cause alarm. Confinement and relatively high densities probably explain why the die-off occurred only here. It suggests a re-alignment or removal of fences that restrict elephant movements and limits year-round access to freshwater.
2020年，博茨瓦纳北部一个相对较小的未受保护区域内有350头大象死亡，原因不明，可能永远无法知晓。媒体对此的猜测忽视了生态现实。更糟糕的是，他们的猜测可能对野生动物有害，有时还会损害保护激励措施。对生态和保护问题有更广泛的理解有助于对卡万戈-赞比西跨界保护区（该保护区横跨博茨瓦纳、纳米比亚、安哥拉、赞比亚和津巴布韦）的大象进行管理。我们的交流涉及这些问题。恶意投毒和偷猎不太可能是原因。其他物种未受影响，大象尸体的象牙也完好无损。限制淡水供应迫使大象使用可能被蓝藻大量繁殖污染的水洼作为水源，这可能是一个原因，但目前尚无证据支持。没有涉及其他物种。传染病更有可能是原因。围栏和一条深水道限制了这些大象的扩散。这些因素解释了尽管在2014年至2018年期间偷猎有所增加，但大象的种群增长率相对较高。虽然死亡大象仅占该地区大象总数的约2%，但偷猎以及人们保护庄稼所带来的压力的叠加效应令人担忧。限制和相对较高的密度可能解释了为何只有这里出现了大象死亡事件。这表明需要重新调整或拆除限制大象活动并限制全年获取淡水的围栏。
