By Simon Pooley, 11th July 2019
Crocodiles are distributed across 91 countries, are culturally significant, economically valuable, biologically and behaviourally fascinating, and important apex predators of waterways. Eight species of crocodile also regularly bite humans and livestock (see Crocbite for more information on the Worldwide Crocodilian Attack Database). Of these, the Nile crocodile Crocodylus niloticus is often identified as the species most implicated in such attacks. In Africa, Nile crocodiles are alleged to be the wild animal responsible for most attacks on humans. However, few data are available to substantiate this: of the 30 countries where attacks are known to occur, there are data (of varying quality, much of it short term) for only 12 countries.
George Powell and I analysed reported attacks on people by C. niloticus in South Africa and eSwatini (formerly Swaziland) during 1949–2016, identifying spatial and temporal patterns in attack incidence, as well as victim demographics. Through a literature review and archival searches I had identified records of 214 confirmed attacks with sufficient data for statistical analysis. Ecological and management context was taken into account, in collaboration with co-authors Dr Xander Combrink and Dr Hannes Botha. Our analysis provides valuable information on the seasonality and location of attacks, and the demographics of attack victims. These data could help focus mitigation efforts, provided that local contexts are taken into account, as we argue in our paper published in Oryx.
Historically in South Africa many crocodile attacks occurred in locations that share borders with former homeland areas or along rivers bordering protected areas with healthy populations of crocodiles. These homeland areas were where the former Apartheid government resettled Africans on remote rural land. We identified and mapped key water bodies for attacks. We noted an upward trend in bites in the interior of South Africa since 2000, which is probably the result of encounters with crocodiles in unexpected places, notably dams. Crocodiles seek refuge in such places following the seasonal drying up of rivers, disturbances along river banks, the raising of dam walls, and pollution of rivers. Illegal fishing in dams, usually conducted at night when crocodiles are most active, is a concern. The effects of local environmental contexts are important, for both humans and crocodiles, influencing when and where they come into contact.
Our findings contradict the assumption that in Africa women and girls are disproportionately at risk of being attacked by crocodiles because of their role in preforming domestic chores. In our study region, 65% of victims were male. Another key finding is that 51% of bite victims were aged 0–15 years, and 62% of victims aged 20 years or younger. The high proportion of child victims, especially aged 11–15 years, 72.5% of whom were boys, suggests this demographic should be a focus for mitigation efforts.
Such statistics, however, don’t reveal the traumatic experiences of individual attack victims, something we did not focus on in this paper. What happens to victims after attacks is seldom studied, although they may sustain life-changing physical or psychological injuries, which have clear conservation implications. Good mitigation work will build on the data and analysis we have produced, identify patterns and questions, and then focus in again on particular problem areas to identify specific local challenges. For instance, although overall men and boys comprised the greatest proportion of victims, this was not universally the case. Historically, most bites along the Pongolo River in northern KwaZulu-Natal Province, South Africa, were on women and girls performing domestic chores. Over time, the proportion of attacks on victims performing domestic chores has declined in our study region, with more bites on people involved in recreational activities (mostly while swimming, but also while fishing). Better provision of services for some rural communities, and a decline in some traditional activities such as fonya basket fishing or waterlily bulb collecting may be contributing to this shift.
In our paper we identify the high risk areas for crocodile bites in South Africa and eSwatini, and suggest low-cost mitigation interventions focusing on the problem areas and issues we identify. These include providing safe crossing and swimming places, water tanks or enclosures, and either training teams to capture problem animals or licensing commercial crocodile farms or qualified individuals to do so. Education activities on crocodile behaviour and on avoiding attacks can draw on booklets and posters freely available for outreach work (see below).
Although bites from crocodile are uncommon, with just a few attacks per year, they garner intense media attention. In countries where crocodiles are farmed but not sourced from local wild populations, and where taboos against eating crocodiles have begun to fall away, it is important to collect, analyse and communicate accurate information on bites. Crocodiles are categorized as Vulnerable in the region, and do not thrive outside protected areas as well as other species. We hope that our data and the attention our paper brings to crocodiles in South Africa and eSwatini will contribute to minimizing bites on people and to the continued survival of the species in the region’s waterways.
Watch Simon Pooley talk about some of his research on crocodile attacks in this episode of CNN’s Inside Africa:
The article Synthesizing Nile crocodile Crocodylus niloticus attack data and historical context to inform mitigation efforts in South Africa and eSwatini (Swaziland) is available in Oryx—The International Journal of Conservation.