Prevalence and drivers of poison use by South African commercial farmers and perceptions of alternative livestock protection measures

Abstract

The use of poison to eliminate predators is causing African vulture populations to collapse. To understand the prevalence and motivations of this practice we conducted an extensive survey with South African commercial farmers. Using a specialised questioning technique and ad hoc quantitative methods we found that an estimated 22% and 31% of farmers used poison over a 1-year and 5-year period, respectively. Poison use hotspots generally coincided with small stock farming areas. The strongest predictor of poison use was whether farmers believed the practice to be common amongst their peers. Our results suggest that farmers' attitudes to vultures are primarily positive, and farmers are less likely to use poisons if they frequently encounter vultures on their farm. Overall, our findings provide an understanding on poison use that provides leverage points to change farmers' behaviour and help avert the African vulture crisis and possible cascading ecosystem impacts.

Keywords: Human-wildlife conflict; Predator management; Vulture conservation; Wildlife crime.

Fig. 1

Factors associated to the use of poison by South African commercial livestock farmers over a 1-year (blue) and 5-year period (red) in the present study. Variable coefficients (dots) and standard error (lines) are derived from multivariate regression models using a non-linear least squares estimator

Fig. 2

Partial dependence effects plots showing the association of different factors (x-axis) to the probability of poison use among South African commercial livestock farmers over a 1-year (solid line) and a 5-year period (dashed line) in the present study. All variables have been logged and scaled. Variable effects displayed include farmer perceptions of the prevalence of poisoning under their neighbours (a), attitudes towards vultures (b), number of small stock (c), proportion of livestock predated (d), attitude towards predators (e) and frequency of vulture sightings (f)

Fig. 3

Interpolated predicted probabilities of poison use over a a 1-year period, and b a 5-year period, from a multivariate regression analysis of a list experiment involving South African commercial livestock farmers. Poisoning probability is indicated by the colour shading, while protected areas and land under traditional authority (communal farmland) are in grey. Distribution of sampling points (bottom right map) is indicated for both the treatment (red dots) and control group (blue dots). South African provinces are denoted (bottom centre) as WC  Western Cape, NC Northern Cape, NW North West, LP Limpopo, MP Mpumalanga, GT Gauteng, FS Free State, KZN KwaZulu-Natal, and EC Eastern Cape (LS indicates the country Lesotho). To assist visualisation and interpretation the colour ramp was scaled to include 2–98% of the data values

Fig. 4

Farmer perceptions of the effectiveness of various livestock depredation avoidance methods. The percentage of farmers listing each method on a Likert scale varying from very ineffective to very effective is indicated