Ecology of black-backed jackal (Canis mesomelas) in a small urban estate

Abstract

Most studies of black-backed jackals (Canis mesomelas) have taken place in areas of two extremes, where they are 1) not persecuted by people, such as in national parks, or 2) heavily persecuted, such as rural areas surrounding livestock farms. In both areas, the black backed jackals are typically wary of people. My study was conducted in the winter of 2019 and summer of 2019/2020, involving black-backed jackals at a small urban estate, the Jackal Creek Golf Estate in the north of Johannesburg, South Africa. This area presents a unique situation where black-backed jackals are thriving and have a reduced wariness of people, which provided an opportunity to assess whether and how the black-backed jackals have adapted to living in human-altered (urban) habitats, the fastest growing land use globally. I studied the biology of the black-backed jackals in urban areas by first considering the extent to which they occur in the urban areas of Greater Johannesburg. I then conducted a specific study on the black-backed jackals occurring at the Jackal Creek Golf Estate to ascertain their activity patterns, their behaviour temporally and spatially, and their diet. I studied the species distribution through surveys of the public using online platforms and found that black-backed jackals occurred mostly in the northern parts of Johannesburg. However, the number of respondents was not large enough to draw meaningful conclusions. My study at the Jackal Creek Golf Estate was conducted mostly using camera traps to capture footage of the seasonal and daily activity profiles of the jackals and their behaviour during their active periods. I also studied the diet of the black-backed jackals through analyses of scat, opportunistically collected at the Estate in winter and summer. Activity patterns were determined using the ‘densityPlot’ function and ‘overlap’ package in R. In winter, the black backed jackals showed a crepuscular (after 18h00) and nocturnal peak (03h00) in activity, and an extended crepuscular peak (from 19h00) and nocturnal activity (from 22h00 to 04h00) in summer in some areas of the Estate. To analyse seasonal differences in behaviour, the ‘glmer’ function in R was used, while temporal and spatial variation in behaviour were analysed using Pearson’s chi-squared contingency table analyses. The most prominent behaviours displayed in both winter and summer were travel (p<0.001) and rest (p<0.001). In the temporal analysis of the behaviours, black-backed jackals displayed both travel and rest behaviours predominantly between 00h00 and 06h00 and again between 18h00 and 24h00, with both behaviours occurring more often in these time brackets in winter compared to summer. Spatially, all behaviours occurred in the western parts of the Estate and travel and rest were the predominant behaviours recorded in all areas of the Estate. Simpson’s diversity 7 and Levin’s standardised indices were calculated to determine diet breadth. The black-backed jackal’s diet showed wide diversity, indicating a generalist diet with a large plant component (presumably incidentally consumed) (77.6%) and animal remains (67.8%). Anthropogenic matter (e.g. pieces of serviettes, glass, and fabric) occurred in the scat in almost equal percentages in both winter (46.5%) and summer (44.4%). Despite the low reported occurrence of black-backed jackals in Greater Johannesburg, the jackals at Jackal Creek Golf Estate have modified some of their behaviour and diet for urban life. Although their crepuscular peak in activity resembles that of naturally occurring black-backed jackals, the nocturnal peak suggests a change in behaviour to avoid human contact. Given their proximity to humans at the Estate, the anthropogenic content of the diet is expected, but their diet also consisted of typically naturally occurring prey, such as rodents. It would appear that black-backed jackals are urban adapters, defined as species that are able to adapt to urban areas while still making use of natural resources.