HESC-African-Wild-Dog

African Wild Dog

African wild dogAfrican wild dog Pnp support tile

 

 

Lycaon pictus

OVERVIEW

The African wild dog is one of the most threatened carnivores in the world following its dramatic population decline over the past 30 years. On the African continent where it occurs exclusively, it is now the second most endangered carnivore (after the Ethiopian wolf), and the most endangered in sub-Saharan Africa.

As large tracts of land have been taken over for livestock grazing and cultivation, growing human populations have caused wild dog habitat to become discontinuous. Habitat fragmentation, persecution, and prey loss are the main reasons for their dramatic decline across most of Africa, as wild dog populations have become increasingly isolated in fragments of habitat with few human inhabitants. Because they live at very low densities, even ‘fragments’ of suitable habitat covering thousands of square kilometres do not necessarily sustain viable wild dog populations.

The current decline in the number of African wild dogs may also be partly due to the population dynamics dictated by their social system. African wild dogs are obligate co-operators, and their need for helpers could generate inverse density dependence at the pack level. Declining numbers of pack members will therefore also have a negative impact on the ability of packs to survive under adverse conditions.

Analysis of mitochondrial DNA (mtDNA) nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. The genetic variability of eastern African wild dog populations is comparable to that of southern Africa, and similar to levels of variability found in other large canids. Southern and eastern African populations of wild dogs show about 1% divergence in mtDNA sequence and form two monophyletic assemblages containing three mtDNA genotypes each. No genotypes are shared between the two regions. Morphological analysis supports the distinction of eastern and southern African wild dog populations, and it is suggested that they should be considered separate subspecies.

Short introduction to species: Viable, but small populations of wild dogs remain in several countries in southern and eastern Africa. With adequate protection and management, there is no reason why these populations should not survive. The last populations left in the wild occur in the Kruger National Park (South Africa), the Zambezi and Hwange National Parks (Zimbabwe), the Okavango region (Botswana) and the Selous National Park (Tanzania). Packs from these areas occasionally range beyond the borders of reserves, where they are usually subject to persecution, road accidents, snaring and disease (primarily canine distemper and rabies) contracted from domestic dogs.

CHARACTERISTICS

DISTRIBUTION: Wild dogs were previously distributed throughout sub-Saharan Africa, but they disappeared from 25 of the 39 African countries in which they occurred and currently only about 3 000 to 5 000 wild dogs (600 to 1 000 packs) remain, mostly in southern and eastern Africa where they are confined to a few areas where human population density remains low. Even when they live in well-protected habitats with abundant prey, their low population densities make them unusually susceptible to habitat fragmentation. Most populations, both outside and inside protected areas, may still be declining.

In South Africa wild dogs outside protected areas form a more significant component of the national meta-population than previously thought. Their numbers appeared to fluctuate between 42 and 106 during the period 1996 to 2002. These dogs are most often encountered on the western border of Kruger National Park, in the Limpopo Valley and in northern KwaZulu-Natal. In these areas that are close to the source populations, most wild dogs occur on game ranches with unmodified land cover and low human densities.

MIGRATION PATTERNS: African wild dogs always live at low population densities relative to sympatric large carnivores (those carnivores that occupy the same or overlapping geographic areas). Outside the denning period, wild dogs have enormous home ranges. For example, a pack in Kruger ranged over 80 km2 (50 sq. miles) when denning, but 885 km2 (550 sq. miles) after denning. Wild dog density is negatively correlated with the density of lions and hyenas across study sites in Africa; lions are important predators of both wild dog adults and pups. Probably as a result, wild dogs avoid areas of high lion density, which often are those areas sustaining the highest biomass of prey. Hyenas act as kleptoparasites and steal food from wild dogs, especially in areas of open habitat. Predation by lions and hyenas account for 50% of mortalities in wild dog populations. Intraspecific competition may cause up to 69% of known-cause deaths through infanticide and fights between wild dog packs.

SIZE AND MASS: African wild dogs weigh between 19 and 34 kg (41 and 66 pounds). Females are generally larger than males and they may reach a body mass of 34 kg (75 pounds) while males have an average body mass of 24 kg (53 pounds).

PHYSICAL CHARACTERISTICS: Males and females are similar in appearance though the females are generally larger than the males. Their total length is about 1,22 m  (400 feet, including the tail) with a shoulder height of 65 to 75 cm (2,1 to 2,5 feet). They have large rounded ears and long legs, a bushy tail and shaggy coats coloured black, yellow and white. The colour pattern of each dog is distinct and can be used for individual identification. They are the only canid species lacking dew claws on its front legs.

REPRODUCTION: Wild dogs are seasonal, co-operative breeders and whelping generally occurs during the months of April to September after a gestation period of 71 to 73 days. In southern Africa, pups are born mostly from late May to early June. Pups are born in a den, where they remain for the first three months of life. The mother is confined to the den while nursing and she relies on other pack members to feed her during that time. They deliver food to her by regurgitation; later on, they regurgitate to the pups as well. Some pack members also ‘baby-sit’ the pups and chase predators from the den, and take care of the old and sick.

Although up to five breeding females in one pack have been recorded, in most packs only the dominant female (the alpha female) breeds and mates with an unrelated male. Reproductive depression of the other females in a pack is the consequence of limited resources, behavioural patterns and endocrine mechanisms. All pack members help to care for the pups.

Females can whelp every 11 months. The litter size varies but, on average, there are 10 to 11 pups per litter, although there may be 20 or more. Pups are born blind and they leave the den for the first time when 3 to 4 weeks old. Weaning, a gradual process, begins when the pups are 14 days old.

Wild dog females cannot successfully rear pups without assistance and in most cases the pack, rather than the individual, is considered the basic unit within the population. It appears that more pups survive in packs where there are more helpers to assist with their care, but this is not always the case.

The pups are sexually mature after 23 months and they start leaving the pack when they are 1,5 years old. They leave the pack as same-sex groups that join unrelated, opposite-sex groups to form new packs. Males disperse later, in larger groups and further than females; these patterns are aimed at inbreeding avoidance and competition for mating opportunities. All wild dogs of both sexes emigrate when in the presence of their opposite sex parent. Despite frequent opportunities, no dogs mate with close relatives.

HABITAT: Wild dogs prefer woodlands or broken woodlands although they are also found on open plains and savannas. They are independent of water.

THREATS: Direct contact with human activity is responsible for over 50% of recorded adult mortality and for packs living on the borders of national parks, mortality may be as high as 92% because of interaction with humans.

Being captured in snares is another important cause of death. In most places, wild dogs are caught unintentionally in snares set for ungulates, although occasionally snare capture is intentional.

Infectious diseases are of limited importance in the decline of wild dog numbers, but they do play a role in the extinction of small populations, for instance, in the Serengeti. Infectious diseases and competition will generally interact because competitors harbour and transmit the diseases that affect wild dogs.

HUNTING TECHNIQUES AND PREY PREFERENCE: African wild dogs weigh 20 to 25 kg (44 to 55 pounds) on average and are social carnivores that hunt in groups of varying size. Antelopes ranging in body mass from 15 to about 150 kg (33 to 330 pounds) are their major source of prey.

African wild dogs traditionally hunt in groups. This type of hunting in social carnivores is considered to have evolved through natural selection for improved efficiency of prey capture, the ability to kill increased prey size and successful defence of the kill against intraspecific and interspecific kleptoparasitism.

Wild dogs hunt primarily by sight and by daylight, either in the early morning, or in the early evening. The pack often approaches herds of prey within several hundred metres, but they select a particular animal only once the chase begins. The pack functions as a hunting unit and the group cooperates closely in killing and mutual defence. Individuals drawn into this group activity are subject to strong discipline during the chase. A regular group leader selects and runs down the prey. They do not run in relays as commonly assumed, as the leader can overtake the fleetest of game usually after 3 to 4 km (1,9 to 2,5 miles) and within 30 minutes after commencing the chase. During the chase, while the others lag behind, one or two dogs run at a distance of 100 m (109 yards) or more behind the leader, and are positioned to intercept the quarry if it circles or begins to dodge.

As soon as small prey is caught, the pack pulls it apart; large antelopes are bitten in the rear and chunks of muscle and connective tissue are torn from them until they collapse because of exhaustion and shock. Juveniles are allowed to feed first after the kill has been made. Not much remains of a carcass after the pack has fed.

After a kill, wild dogs are subject to interference particularly by hyenas (kleptoparasitism). Spotted hyenas (Crocuta crocuta) are serious competitors for a kill and are capable of driving small packs of wild dogs from their kills. Small hunting groups (1 to 2) are particularly vulnerable to kleptoparasitism because they are unable to fully satiate themselves before the hyenas take over their kills. Intermediate-sized hunting groups may be most effective at meeting nutritional demands over a range of prey sizes. Hunting-group sizes perform best when hyenas interfere with the kill. The extent of time that dogs have access to a kill decreases with increasing numbers of hyenas at a kill, while access time increases with increasing hunting-group size of dogs, and the size of the animals that they killed.

Additional competition for prey is posed by interspecies competition between the three smallest carnivores, (leopard, cheetah, and wild dog) as they favour similar prey species. However, each of these carnivore species has a distinct dietary preference and the interspecies conflict because of this is less than expected. Competition with lions appears less intense, but direct predation by lions on wild dogs is important.

The wild dog’s prey preference is dependent on a number of factors but in particular, the mix of prey species in a specific location and this varies between the various regions in Africa in which wild dogs still occur.

Wild dogs generally prefer prey within a body mass range of 16 to 32 kg (35 to 70 pounds) and 120 to 140 kg (264 to 308 pounds), which is abundant and less likely to cause injury when hunted. Females with concealed lambs or calves are most vulnerable. Regardless of the size or the composition of the pack, the mean minimum consumption rate of edible meat is about 1.7 kg (37 pounds) prey per dog per day.

Wild dogs have a strong preference, that varies seasonally, for a number of prey classes. Depending on the region, they select greater kudus (Tragelaphus strepsiceros) throughout the year and though they show little selection between the other prey species they prefer impalas (Aepyceros melampus), bushbuck (Tragelaphus scriptus), or Thomson’s gazelles (Gazella thomsonii) depending on the region and the presence of the specific species. They usually prefer the young of both impalas and kudus, and males at times of the rut. Prey killed by wild dogs is often in a poorer condition than other animals in the same herd, suggesting that they select weaker individuals when hunting.

In eastern Africa, Thomson’s gazelles (Gazella thomsonii) make up 54%, new-born and juvenile wildebeest (Connochaetes taurinus) 36%, Grant’s gazelles (Gazella granti) 8%, and kongoni (Alcelaphus buselaphus cokei) 2% of the prey animals. Thomson’s gazelle were killed most often (67% of 60 kills), and their biomass (48% of total) was equal to the combined biomass of the next two most common prey, impala (24%) and wildebeest (25%).

RELOCATION: Since 1954, several southern African institutions have established captive-breeding programmes to ensure the long-term survival of the African wild dog. To aid this, a studbook was assembled to provide genetic and demographic information for the southern African captive populations.

The captive-breeding programme appears to be successful with a positive population growth, a significant lowering of in-breeding and mean kinship, and an increased genetic diversity. However, genetic variability levels appear lower and levels of in-breeding were higher in captive breeding programmes compared with wild populations.

In South Africa, a plan was launched to manage separate sub-populations of endangered African wild dogs in several small, geographically isolated conservation areas as a single meta-population. This intensive management approach involves the re-introduction of wild dogs into suitable conservation areas and periodic translocations among them.

There have yet been no successful, long-term re-introductions into the southern African wild using captive-bred dogs, mainly due to the lack of close collaboration between captive breeding and nature conservation institutions.

Re-introduction of wild dogs into the wild is probably now technically possible, as long as released groups include wild-caught animals. Several past attempts failed because captive-reared animals lacked skills needed to survive in the wild. Ideally, re-introductions should also involve animals of the appropriate local genotype. Social integration before release for wild dog re-introductions and translocations to be successful is important, as is management manipulation of social relationships, which promote pack formation in pre-release holding facilities.

Releases currently planned in the Republic of South Africa will be locally valuable, but will not establish a population likely to remain viable without intensive management in perpetuity. For these reasons, protecting remaining wild dog populations currently represents a better investment than any attempt at re-introduction.

In Kenya, handling and interventions to try to sustain wild dog numbers failed, apparently because of the stress induced by the processes. The numbers declined and resulted in local extinction of the dogs.

THE ROLE HESC PLAYS IN THE CONSERVATION OF THIS SPECIES: Current conservation efforts in South Africa aim to develop a wild dog meta-population through the re-introduction of wild dogs into fenced reserves. Significant scope for increased distribution expansion exists in the Limpopo and North West Provinces. However, efforts aimed at changing extremely negative landowner attitudes towards wild dogs, are necessary to improve the conservation status of the species outside protected areas. Persecution remains the most serious threat to wild dog populations as they are perceived as a pest that kills livestock, or competes with people for wild ungulates in hunting areas. Their reputation as voracious stock-killers has not been justified and while livestock occasionally are taken, losses to farmers seem to be relatively small, particularly when wild prey is available.

Significant potential also exists for conserving naturally occurring wild dogs in situ on ranch land.

The highest priority for wild dog conservation is to maintain and promote the contiguity of areas available to wildlife. Establishing cross-border parks and buffer zones, and encouraging game ranching on reserve borders, will contribute to the survival of the species.

Within this context, HESC maintains a small group of wild dogs, primarily for display and educational purposes.

REFERENCES

 Comprehensive information about African wild dogs is available in:

Skinner, J.D. and Chimimba, C.T., 2005. The Mammals of the Southern African sub-region. Cambridge University Press.

Further articles of interest include:

Creel, S., & Creel, N. M., 1998. Six ecological factors that may limit African wild dogs, Lycaon pictusAnimal Conservation, 1(01), 1 – 9. http://dx.doi.org/10.1017/S1367943098001012

Creel, S., Creel, N. M., Mills, M. G., & Monfort, S. L., 1997. Rank and reproduction in cooperatively breeding African wild dogs: behavioral and endocrine correlates. Behavioral Ecology, 8(3), 298-306. http://dx.doi.org/10.1093/beheco/8.3.298

Estes, R.D. and Goddard, J., 1967. Prey selection and hunting behavior of the African wild dog. The Journal of Wildlife Management, pp.52-70.

Frantzen, M. A. J., Ferguson, J. W. H., & De Villiers, M. S., 2001. The conservation role of captive African wild dogs (Lycaon pictus). Biological Conservation, 100(2), 253-260. http://dx.doi.org/10.1016/S0006-3207(01)00046-5

Fuller, T.K. and Kat, P.W., 1993. Hunting success of African wild dogs in southwestern Kenya. Journal of Mammalogy, 74(2), pp.464-467.http://dx.doi.org/10.2307/1382403

Fuller, T.K., Kat, P.W., Bulger, J.B., Maddock, A.H., Ginsberg, J.R., Burrows, R., Mcnutt, J.W. and Mills, M.G.L., 1992. Population dynamics of African wild dogs. In Wildlife 2001: Populations (pp. 1125-1139). Springer Netherlands. http://dx.doi.org/10.1007/978-94-011-2868-1_86

Girman, D. J., Mills, M. G. L., Geffen, E., & Wayne, R. K., 1997. A molecular genetic analysis of social structure, dispersal, and interpack relationships of the African wild dog (Lycaon pictus). Behavioral Ecology and Sociobiology, 40(3), 187-198. http://dx.doi.org/10.1007/s002650050332

Gusset, M., Slotow, R., & Somers, M. J., 2006. Divided we fail: the importance of social integration for the re‐introduction of endangered African wild dogs (Lycaon pictus). Journal of Zoology, 270(3), 502-511. http://dx.doi.org/10.1111/j.1469-7998.2006.00168.x

Hayward, M. W., O’Brien, J., Hofmeyr, M., & Kerley, G. I., 2006. Prey preferences of the African wild dog Lycaon pictus (Canidae: Carnivora): ecological requirements for conservation. Journal of Mammalogy, 87(6), 1122-1131. http://dx.doi.org/10.1644/05-MAMM-A-304R2.1

Lindsey, P., Du Toit, J. T., & Mills, M. G. L., 2004. The distribution and population status of African wild dogs (Lycaon pictus) outside protected areas in South Africa. South African Journal of Wildlife Research, 34(2), p-143. http://hdl.handle.net/10520/EJC117192

Maddock, A. H., & Mills, M. G. L., 1994. Population characteristics of African wild dogs Lycaon pictus in the eastern Transvaal lowveld, South Africa, as revealed through photographic records. Biological Conservation, 67(1), 57-62. http://dx.doi.org/10.1016/0006-3207(94)90009-4

McNUTT, J. W., 1996. Sex-biased dispersal in African wild dogs, Lycaon pictusAnimal behaviour, 52(6), 1067 – 1077. http://dx.doi.org/10.1006/anbe.1996.0254

Pole, A., Gordon, I.J., Gorman, M.L. and MacAskill, M., 2004. Prey selection by African wild dogs (Lycaon pictus) in southern Zimbabwe. Journal of Zoology, 262(02), pp.207-215. http://dx.doi.org/10.1017/S0952836903004576

Scheepers, J. L., & Venzke, K. A. E., 1995. Attempts to reintroduce African wild dogs Lycaon pictus into Etosha National Park, Namibia. South African Journal of Wildlife Research, 25(4), 138 – 140. http://hdl.handle.net/10520/EJC116980

Woodroffe, R., & Ginsberg, J. R., 1999. Conserving the African wild dog Lycaon pictus. II. Is there a role for reintroduction?. Oryx, 33(2), 143-151.http://dx.doi.org/10.1046/j.1365-3008.1999.00053.x

Woodroffe, R., Lindsey, P., Romanach, S., Stein, A. and ole Ranah, S.M., 2005. Livestock predation by endangered African wild dogs (Lycaon pictus) in northern Kenya. Biological conservation, 124(2), pp.225-234. http://dx.doi.org/10.1016/j.biocon.2005.01.028