Bioacoustics of Lupulella mesomelas

Breeding. Mating is accompanied by increased vocalization and territoriality in both sexes. Dominant individuals within a territory constantly harass same-sex subordinates to prevent them from mating. In southern Africa mating generally occurs from late May to August, and following a gestation period of about 60 days, births occur from around July to October. It has been suggested that summerbirths are timed to coincide with the reproductive season of important rodent prey, and winter births with an increase in the availability of ungulate carcasses at the end of winter. Littersize is typically between one and six, and pups are born in modified termitaria or other convenient burrows, often with multiple entrances. The same den sites may be used from year to year. Pups first emerge from the den at three weeks, are weaned at 8-9 weeks, and are completely independent of the den at 14 weeks. Alloparental care is well documented and consists of feeding pups by regurgitation and guarding them when the parents are foraging. One “helper” may increase the average numberof pups surviving per mated pair from one to three, and two such “helpers” further increase survival to four pups. Pups reach sexual maturity at about eleven months, and even at this early age they can disperse at distances of more than 100 km .

Movements, Home range and Social organization. The monogamous mated pair, which appears to be a life-long association in most cases, is the basis of social structure, and if one member of a pair dies the other often will lose its territory. Blackbacked Jackals are territorial and use feces and urine to demarcate their territorial boundaries. Territories are spatially and temporally relatively stable, and intruders are aggressively expelled by territory holders. Water sources are shared with intruders, but the intruders perform submissive behaviorto territory holders, even to their pups. Density and group size is dependent on food biomass and dispersion. In South Africa , home range size averaged 18-2 km ® (n = 14). In the more arid south-western Kalahari, adult ranges varied from 2:6-5-2 km ? (n = 7) and mean sub-adult ranges were 6-3 km ? (n = 4). In Zimbabwe , home ranges were largest in the cold, dry season (c. 1:0-1-3 km ?*) and smaller in the hot dry season (c. 0-3-0-6 km ?), while in the Rift Valley in Kenya , home ranges varied from 0-7-3-5 km ®*. Home ranges are universally defended and mutually exclusive for pairs, with the exception of a population on the Namibian coast for which average home range size varied from 7-1-24-9 km * (n = 4). A high-pitched, whining howl is used to communicate with group members and is often used to call the group together in the early evening; this may also function in territorial advertisement. Howling often stimulates the same behavior in adjacent territories or in nearby individuals. A three- to five-syllable alarm call, consisting of an explosive yelp followed by a series of shorter high-pitched yelps, is used when disturbed and may be frantic and prolonged when the jackals are mobbing a Leopard (Panthera pardus). A low-pitched, gruff bark is used to warn pups of intruders near the den, and whines are used to call to pups. Also noted is use of a “clattering distress call” and a loud yelp when alarmed. Interestingly, Black-backed Jackals are much less vocal where they occur alongside the Golden Jackal, which is the only jackal species heard to howl in East Africa.