Synthesizing Nile crocodile Crocodylus niloticus attack data and historical context to inform mitigation efforts in South Africa and eSwatini (Swaziland)

Introduction

Among the wild animals that attack people and their livestock across Africa, crocodiles (the Nile crocodile Crocodylus niloticus and the West African crocodile Crocodylus suchus) are widely distributed and are claimed to be responsible for most attacks on people (e.g. Lamarque et al., 2009; Dunham et al., 2010). Male Nile crocodiles may exceed 4 m in length, and grow up to 5 m in exceptional cases, taking large prey such as wildebeest Connochaetes spp. and buffalo Syncerus caffer. They are adaptable to local environmental conditions and occur in a wide range of natural and human-made aquatic habitats, such as canals and dams, where they increasingly come into contact with people and their livestock.

Increasing human populations and utilization of rivers, lakes, wetlands and dams (from small farm dams to large irrigation dams), as well as gillnetting (for fish), are resulting in an increasing number of human–crocodile interactions and a perception that adverse encounters between people and crocodiles are increasing (Aust et al., 2009; Lamarque et al., 2009; Fergusson, 2010; Wallace et al., 2011; Zakayo, 2014). The online database CrocBITE (2018) contains records of attacks in 29 African countries, and attacks are known to have occurred in one additional country (Kpéra et al., 2014).

Research articles on crocodile attacks are revealing informative spatial and temporal patterns in attacks, and provide useful information about the demographics of attack victims (recent examples include Brien et al., 2017; Shaney et al., 2017; Vyas & Stevenson, 2017; Das & Jana, 2018), but data for Nile crocodiles are inadequate. Published data of varying quality and quantity (most not peer reviewed) exist for 12 of the 30 African countries where attacks are known to occur (Pooley, 2018). More data, as well as reviews of mitigation efforts, are required urgently (Fergusson, 2010; Pooley, 2015a).

Here we present an analysis of 67 years of data on crocodile attacks on people in South Africa and the Kingdom of Swaziland (now eSwatini) during 1949–2016. We use the resulting generalizations to investigate some of the patterns and challenges identified in specific locations, in the context of the history and management of crocodile attacks in the study region. Drawing on attack data and historical evidence, we suggest ways forward for conservation policy and management of...