Social organization, home ranges, and extraterritorial forays of black‐backed jackals

We radio‐tracked 15 black‐backed jackals(Canis mesomelas)from 8 adjacent family groups onBenfontein Game Farm(i.e., Benfontein)in South Africa to investigate their movement patterns and socialorganization. Jackal family groups consisted of mated pairs(alphas),0–3 nonbreeding adults(betas), andpups, depending on the season. Mean(±SE)home‐range size of alphas(9.4±1.2 km2,n=6)did not differ(P=0.766)from betas(9.8±0.7 km2,n=8). Most beta jackals(8of10)remained philopatric on Ben-fontein, apparently because of the high density of springbok(Antidorcas marsupialis), their preferred prey.Three of 5 alphas and all 8 betas went on extraterritorial forays(i.e., forays). Generally, betas spent more oftheir active time on forays(2–20% of time)than alphas(0–3%;P=0.048), and betas went farther on forays(2–8km)than alphas(2–3 km;P=0.003). The number of forays differed(P<0.001)among seasons; mostforays occurred during summer(64%)when jackals visited neighboring livestock farms, apparently topredate on domestic sheep. Overall, our results indicate forays by jackals are affected by social status,seasonal availability of preferred prey, and the reproductive cycle of jackals. To reduce jackal predation onlivestock farms near reserves, we recommend that preventative measures(e.g., use of herders, jackal controlactivities)be increased during summer when jackals are most likely to travel outside reserves. © 2019 TheWildlife Society

Social organization, home ranges, and extraterritorial forays of black‐backed jackals

We radio‐tracked 15 black‐backed jackals(Canis mesomelas)from 8 adjacent family groups onBenfontein Game Farm(i.e., Benfontein)in South Africa to investigate their movement patterns and socialorganization. Jackal family groups consisted of mated pairs(alphas),0–3 nonbreeding adults(betas), andpups, depending on the season. Mean(±SE)home‐range size of alphas(9.4±1.2 km2,n=6)did not differ(P=0.766)from betas(9.8±0.7 km2,n=8). Most beta jackals(8of10)remained philopatric on Ben-fontein, apparently because of the high density of springbok(Antidorcas marsupialis), their preferred prey.Three of 5 alphas and all 8 betas went on extraterritorial forays(i.e., forays). Generally, betas spent more oftheir active time on forays(2–20% of time)than alphas(0–3%;P=0.048), and betas went farther on forays(2–8km)than alphas(2–3 km;P=0.003). The number of forays differed(P<0.001)among seasons; mostforays occurred during summer(64%)when jackals visited neighboring livestock farms, apparently topredate on domestic sheep. Overall, our results indicate forays by jackals are affected by social status,seasonal availability of preferred prey, and the reproductive cycle of jackals. To reduce jackal predation onlivestock farms near reserves, we recommend that preventative measures(e.g., use of herders, jackal controlactivities)be increased during summer when jackals are most likely to travel outside reserves. © 2019 TheWildlife Society

Goose persistence in fall strongly influences Arctic fox diet, but not reproductive success, in the southern Arctic

Food availability is the primary limitation for terrestrial Arctic predators, many of which rely on rodents that fluctuate in abundance over a 3–5-year period. During rodent scarcity, predators such as Arctic foxes (Vulpes lagopus) consume alternative prey, such as migratory birds, which are plentiful during summer. In most of the Arctic these birds return south by August, but in northern Manitoba, near the southern edge of the Arctic fox distribution, large numbers of lesser snow geese (Chen caerulescens caerulescens) and Canada geese (Branta canadensis interior) persist into October. This extended availability of geese late into fall may reduce the dependence of Arctic foxes on rodents. We used stable isotope and faecal analyses to reconstruct the Arctic fox fall and winter diet and related the most probable contributions of lemmings, goose eggs and juvenile geese with changes in prey availability and fox reproduction. Geese were a potentially important component of the fall diet for Arctic foxes, especially in years with high goose productivity, but rodents were the main component of the diet in late winter, even though rodents were scarce each summer (2010–2013). Furthermore, rodent density had a greater influence on Arctic fox reproduction, which was correlated with the subsequent winter harvest, than any other variable examined. Although geese were important fall prey for Arctic foxes at the southern edge of their distribution, they did not buffer declines in availability of rodents, which were the primary prey in April when food availability is critical for Arctic fox reproduction