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The Golden Jackal is a wide-ranging species whose distribution extends from South-eastern Europe, into South-western Asia, India, Sri Lanka and east across Myanmar up to Thailand. The species also occurs in Africa. Typical jackals are found in Persia (Iran). In Sri Lanka the subspecies Canis aureus lanka Wroughton, 1916 is endemic and is widely distributed in all vegetation zones below 1,500 m. It is particularly common in the low country Dry Zone.
Ecology
The Golden Jackal inhabits mainly the dry, open country with thorn scrub vegetation, grassland and brush. Its habitat can vary immensely, and it may include even areas around human habitation. It is organized into social units based on a pair bond, which persists throughout life. Thus the jackal family life is noted for its stability. The basic social unit is composed of a mated pair and young. Helpers (last year's young) may increase reproductive success. Jackal pairs have mutually exclusive home ranges, while the home ranges of immature individuals overlapping extensively with those of the adult pairs. Furthermore, in a jackal population with a relatively low mortality rate and a fairly high density, not all the adults will be able to establish exclusive home ranges, and so the surplus individuals adopt a subdominant or submissive posture vis-à-vis the adults holding home ranges. Immature individuals either remain in their natal dens and help their parents, or disperse. They behave as sub adults and juveniles do. Although jackals can be encountered at any time of the day, they are particularly active in the early mornings and late evenings, and are well adapted to survive in areas inhabited by man. Intensive hunting activity usually begins before dusk since crepuscular temperatures have been shown to be ideal for scent tracking. Jackals are known to emit an unmistakable howl, especially on moonlit nights, which in India has been interpreted into the words, Dead Hindoo, where, where, where"! It is now known that jackals howl in order to maintain contact among group members, just like the hooting sessions of chimpanzees, which help cement family bonds. In RNP, 70% of the observations are of solitary animals. The group size varies from 3-6 depending on the food availability. The variation in group size indicates that the social structure of jackals is plastic and could vary under different ecological conditions. In the Serengeti, pairs of jackals are known to defend an area of about 3 km in diameter against members of the same species. When large food source is available, territorial boundaries may not be strictly maintained. The advantage in forming pairs among jackals is that at anytime, there is a mate nearby that can assist in hunting, scavenging, defence of kills and defence of territory. Hunting by more than one jackal appears to be more successful and rewarding.
Jackals have excellent sense of hearing which they put to good use in locating their prey in grasslands. Like most predators, they will scavenge rather than hunt. Hunting is both energetically expensive and at times even dangerous. Among large mammals at least, the distinction between "predator" and "scavenger" becomes a bit blurred, as even the arch-scavenger such as the spotted hyena in Africa has been shown to be an active predator, while the noble predator, the lion will scavenge whenever it gets the chance. The diet of jackals is catholic, as they are opportunistic foragers, eating whatever they can catch or scavenge but cooperation between mated pairs can greatly increase hunting success and hence territoriality fades in situations which demand the involvement of several individuals, as in the dismemberment of carcasses. Jackals are skilful hunters of small birds and mammals such as black-naped hare (Lepus negricollis) In the RNP, although a jackal may chase and kill with considerable success prey such as the young of spotted deer (Axis axis), it is more often seen scavenging. Jackals are ever alert to scavenging opportunities provided by kills of larger predators such as the leopard (Panthera pardus) or crocodiles. They can eat a variety of prey ranging from insects, lizards, snakes, to ground nesting birds, hares, and rodents. The afterbirth produced by large herbivores is also eaten. Jackals also search for turtle nests along coastal beaches and feed on the eggs. Larger mammals such as water buffalo (Bubalus bubalis), sambar (Cervus unicolor), spotted deer (Axis axis), wild boar (Sus scrofa) are inaccessible to the jackal by their sheer size. But whenever these animals die or are killed, jackals are assured of a rich and plentiful supply of food. So, why bother to go to all that trouble and run unnecessary risks, when nature offers such a windfall in the shape of a dead animal? Bad meat is not poisonous since harmless bacteria bring about decomposition. Nevertheless, jackals are much less dependent on carrion than is commonly supposed. Like dogs, they bury surplus food but return to it within a day to retrieve it using their sense of sight and smell. When animal food is not available, they will feed on fruits and berries. In areas of human habitation, they can even subsist on garbage. They can also exploit man-introduced food sources such as small livestock and so could cause noticeable damage to poultry farms.
Jackals are territorial and move within clearly defined home ranges, which they mark with their urine. Home range size is small, between 2-3 km2 in RNP but in times of unusual drought, the animals may range over much larger areas. Territories are defended and scent-marked jointly by the pair of jackals. Males are especially hostile to any other males on their territories, and will actively threaten and chase off the intruders. Likewise, resident females are particularly aggressive to any other females that try to enter their territories. This is to ensure sharing of the male and his paternal investment. Among their natural enemies in the wild are the leopard (Panthera pardus) and the python (Python molurus).
Among animals that live in highly organized groups only a few individuals breed. In jackals, only adults breed, and so they alone constitute the genetic nucleus of the population. But not all adult males are guaranteed of breeding opportunities. Some mature jackals, if they are smaller in size and weighing less, are known to remain unmated. The dominant pair suppresses their reproduction. Adult males reach sexual maturity in two years, while females become sexually receptive in a year and come into heat periodically. The period of gestation is about 60 days, after which 3-4 pups are born in a hollow chamber on the ground, or in a hollow tree. The pair bond may weaken at times, but both parents take part in rearing of the young. The pups are very dark at birth and their eyes do not open for 10 days. Lactation may go on up to 8 weeks, and the pups begin to take some solid food once they are 3 months old. It is common for the young of previous year to remain with the parents and the new litter of pups. Adult jackals may transport swallowed food to be regurgitated to the young in the den to minimize food loss to kleptoparasites. Jackals may live up to 13 years in the wild, and slightly longer in captivity.
The Golden Jackal is a fascinating mammal that is worthy of protection on its own merits. It is a species useful as a stabilizing factor in the management of ungulates in RNP. Jackals are great survivors since they are able to adapt to living in human dominated landscapes. Fortunately, they do not come into much conflict with man and so are not persecuted in Sri Lanka. Together with the leopard, the elephant, and the sloth bear, the jackal is considered a prize possession of RNP. Given our poor understanding of the very complex nature of the predator-prey interactions in the wild, the safest management policy for the jackal in RNP would be one of non-interference.
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