Evidence of a Growing Elephant Poaching Problem in Botswana
Evidence of a Growing Elephant Poaching Problem in Botswana
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DOI：
10.1016/j.cub.2019.05.061
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发表时间：
2019-07-08
期刊：
影响因子：
9.2
通讯作者：
Sutcliffe, Robert
中科院分区：
文献类型：
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作者：
Schlossberg, Scott;Chase, Michael J.;Sutcliffe, Robert
博茨瓦纳拥有大约三分之一的非洲现存草原象（Loxodonta africana）[1,2]，并将在该物种的未来保护中发挥关键作用。迄今为止，博茨瓦纳一直是大象最安全的国家之一，几乎没有偷猎的报道。在这里，我们提出的证据表明，在博茨瓦纳北部，为获取象牙而偷猎大象的行为出现了新的爆发。比较2014年和2018年的航空调查结果，我们发现大象种群数量稳定，但大象尸体的数量有所增加，尤其是那些死亡不到1年的新尸体。较新的尸体聚集在五个“热点”，平均面积为3522公里(2)。我们将热点地区的大象数量与周边地区进行了比较，发现自2014年以来，热点地区的大象数量减少了16%，但周边地区的大象数量增加了10%。2014年至2018年间，死亡超过一年的“老”尸体数量在热点地区增加了78%，但在周边地区减少了3%。为了核实偷猎是否一直在发生，我们使用直升机走访了148具大象尸体，并评估了它们的死因。我们确认所有72具新发现的尸体都被偷猎。我们还确认了76具1岁以上的尸体中有62具（82%）被偷猎，主要发生在一个热点地区。被偷猎的年龄较大的大象都是30-60岁的雄性，很可能是因为它们的长牙而被杀的。这一证据表明，自2017年或可能更早以来，每年数百头大象的象牙偷猎活动一直在博茨瓦纳北部发生。
Botswana holds roughly one-third of Africa's remaining savannah elephants (Loxodonta africana) [1, 2] and will play a key role in the future conservation of this species. To date, Botswana has been one of the safest countries for elephants, with little poaching reported [3]. Here, we present evidence of a new outbreak of elephant poaching for ivory in northern Botswana. Comparing results from 2014 and 2018 aerial surveys, we found that elephant populations were stable, but numbers of elephant carcasses have increased, especially for newer carcasses dead for less than roughly 1 year. Newer carcasses were clustered in five "hotspots" averaging 3,522 km(2) in area. We compared elephant populations in hotspots to the immediately surrounding areas and found that since 2014, elephants have decreased by 16% in hotspots but increased by 10% in surrounding areas. Numbers of "old" carcasses, dead for more than 1 year, increased by 78% in hotspots between 2014 and 2018 but decreased by 3% in surrounding areas. To verify that poaching has been occurring, we used helicopters to visit 148 elephant carcasses and assess their cause of death. We confirmed poaching for all 72 newer carcasses assessed. We also confirmed poaching for 62 of 76 (82%) carcasses older than 1 year, primarily in one hotspot. Poached older carcasses were all males aged 30-60 and likely killed for their large tusks. This evidence suggests that ivory poaching on the scale of hundreds of elephants per year has been occurring in northern Botswana since 2017 or possibly earlier.