Hunting of a bat-eared fox (Otocyon megalotis) and an adult Thomson's gazelle (Eudorcas thomsoni) by golden jackals (Canis aureus) in the Ngorongoro Crater, Tanzania
Introduction
Golden jackal (Canis aureus) occurs in sympatry with the two other jackals: silver-backed jackal (C. mesomelas) and side-striped jackal (C. adustus) in the Ngorongoro Crater, Tanzania. It is an opportunistic forager whose diet varies with season and habitat reflecting spatial and temporal availability of food within their ranges (Van LaWick & Van Lawick-Goodall, 1970; Moehlman & Jhala, 2013). Its diet usually consists of invertebrates, fruits, carrion, rodents, lizards, snakes, birds, hares, Thomson's gazelle fawns and sometimes adult Thomson's gazelle and Grant's gazelle in the Serengeti National Park (Moehlman, 1983, 1986, 1989) which is adjacent to Ngorongoro Conservation Area. Successful hunting of adult gazelles by golden jackal is a rare behaviour as it may be energetically costly and risky to medium-sized canids including golden jackals. This study documents the killing and feeding of a bat-eared fox (n = 1) and an adult Thomson's gazelle (n = 1) by golden jackals in the Ngorongoro Crater.
Study area
The observation on hunting of a bat-eared fox took place on 15 August 2014 (dry season) and the hunting of adult female Thomson's gazelle was done on 9 May 2015 (wet season) in the Ngorongoro Crater (3°5′–3°15′S; 35°25′–35°40′E) which covers an area of 260 km2, and is the world's largest caldera with the highest density of predators in the world including lions, spotted hyaenas, cheetah, leopards and jackals (Swanson, 2007). There are two seasons: the dry season (from June to September) and the wet season (from October through May). The crater receives an annual rainfall between 600 mm and 900 mm and temperature is between 24°C and 30°C (Marttila, 2011), the dominant vegetation is tall and short grasslands (Swanson, 2007).
Results and Discussion
Hunting of a bat-eared fox by golden jackals
Three individuals belonging to one family group of golden jackals (male, female and a juvenile) were observed hunting for a bat-eared fox in the Ngorongoro Crater. The jackals were seen trotting, and suddenly came across two individuals of bat-eared foxes near their den at 4.33 pm in a patchy tall grassland. The foxes were chased by the three jackals, and one bat-eared fox was caught and eventually killed. They then started feeding on it. This behaviour is not common and was observed only once in this study. Until I left them at 5.30 pm, the three individuals were still feeding on the fox's carcass.
Hunting of an adult Thomson's gazelle by golden jackals
On 9 May 2015, a territorial pair of a golden jackal (male and female) started hunting for a Thomson's gazelle fawn at 9.44 am (temperature, 18°C; cloud cover, 95%) on short grass plains in Ngorongoro Crater. A group of about ten (10) female Thomson's gazelle surrounded the fawn in defending it from being killed by the hunting jackals. The fawn was successfully caught and killed by the female golden jackal at 9.53 am after the chase that covered about 150 metres. The male jackal then switched to an adult female Thomson's gazelle and bites the female gazelle that was defending her fawn before it was killed by the female golden jackal. The male jackal holds the bite while the gazelle was running away. The female golden jackal and a subadult joined the male golden jackal in attacking the female gazelle. All three jackals which belong to one family group cooperatively brought down the female Thomson's gazelle at 9.55 am near their den with three pups on short grassland. The three individuals of golden jackals then started feeding on the killed gazelle even before it completely died. Until I left them at 4.45 pm, the jackals were still feeding on the Thomson's gazelle carcass.
Hunting and bringing down an adult gazelle by golden jackals is a rare observation as it may be energetically costly and risky to the jackals. However, through cooperation of individuals like the one reported here, three individuals were able to successfully bring down the adult female gazelle. Such opportunity arose when the female gazelle was protecting her fawn and thus probably became vulnerable to jackals. A similar observation happened in Serengeti National Park. There are also some reports on observations of killing of larger preys by other jackal species (silver-backed jackal). Krofel (2008) reported the killing of an adult springbok by silver-backed jackals in Etosha National Park (Namibia). A single silver-backed jackal is also known to kill an adult impala in Moremi Game Reserve in Botswana (Kamler, Foght & Collins, 2009).
