How the presence of other carnivores affects the behaviour of Lycaon pictus
Photo from Pixabay
Lycaon pictus, otherwise known as the African Wild Dog, is the largest canine found in Africa. Distinguished by their mottled coat, which has patches of brown, black, red, white and yellow fur, you will find them inhabiting sub-Saharan habitats. Being a group-living species, pack sizes can range from six to 20 individuals, typically more before they became endangered. This species is centred around their social interactions with one another; it is very uncommon for individuals to fight for dominance but instead focus on supporting pack health. As a lesser-known carnivore in the sub-Sahara, there is considerably less research and studies into the African Wild Dog than their big cat counterparts, such as Panthera leo.
Interspecific competition between carnivores is intense in sub-Saharan habitats. Being a mesopredator, the African Wild Dog has larger competitors, such as hyenas (Hyaenidae) and lions (Panthera leo). These relationships can impact the success of African Wild Dogs and influence their pack density. Across the ecosystems that they inhabit, hyenas outnumber wild dogs anywhere from 8:1 to 122:1, while lions can outnumber wild dogs from 3:1 to 21:1 (Creel and Creel, 1996). Hyenas and wild dogs prey selection can largely overlap, but this interspecific competition is more intense because hyenas are also scavengers. In areas where they are common, they will often steal kills from wild dogs. In turn, this reduces the feeding time on each kill and reduce the energy gained by wild dogs. In a paper published by Gorman et al. (Nature 391, 479–481), he stated that the kleptoparasitism by Hyenas, even on a small scale, resulted in a dramatic increase in the effort to recover the loss by wild dogs. Typically, wild dogs will hunt for a small proportion of the day, maybe just a few hours, as the light begins to fade. However, by breaking down the paper and looking at the factors that he stated, such as the assumption that the energy intake equals the total energy expenditure in dogs (B.Jongeling and Koetsier, 2014), the paper begins to break down with the claims being unfounded. Instead, wild dogs are routinely observed eating more than is required (B.Jongeling and Koetsier, 2014), which is why Gorman et al. further underestimated the amount of prey caught. By regularly overeating, wild dogs can survive the loss of their kills through kleptoparasitism. As a result, there is no need for further hunting as they have already buffered the loss.
While lions are much less likely to affect wild dogs in terms of kleptoparasitism, they pose a much more severe threat to the survival of wild dogs. Hyenas killings are uncommon, but lions are common to kill wild dogs, especially their pups. This predation can be shown by three separate attempts to reintroduce wild dogs into the Etosha National Park in Namibia (Scheepers and Venzke, 1995). All three were unsuccessful because the conditions needed to survive were not met. Those released were captive-bred, meaning they were inexperienced in hunting and suffered greatly from lion predation. As a mesopredator, the smaller size of the wild dog means that even though they are in a pack, lions can easily overpower them, especially when it is a pride. It should also be noted that lions have been observed to kill wild dogs wherever possible, and there is no set situation such as stealing a kill that causes this. Due to this desire to kill, wild dogs attempt to avoid lions at all costs and this can be further seen in their selection of territory (Webster, McNutt and McComb, 2011).
With their hierarchy, the most dominant male and female in a wild dog pack are the ones to breed each year. They are typically monogamous, meaning that they will breed for life. While it is uncommon for other pack members to breed, there are instances where a subordinate female will be allowed to raise their own young. During this reproductive phase, a wild dog pack is at their most vulnerable. They select a den where they can rear their pups, confined to the den for three months, which prevents them from continuously moving as they normally would. All of these factors not only mean that pups are vulnerable to direct predation from lions but that the adult pack members are also more susceptible to lion-induced mortality. To better understand the behaviour of African Wild Dogs and the presence of lions, the Zimbabwe Parks and Wildlife Management Authority funded a study by RJ Groom, K Lannas and CR Jackson to observe any behavioural shift as an area's lion density increases. During pre lion times, wild dogs pack sizes were significantly larger. However, as the population of lions nearby began to increase, the pack composition began to change as lions predated on pups, altering the pup to adult ratio (Groom, Lannas and Jackson, 2017). This study also observed that due to the increased lion-induced mortality, there was a behavioural shift in the sites selected for denning. If you compare the site selection in the pre-lion era, dens could be located in areas with higher prey densities, but as the lion population increased, sites were moved to much more rugged terrain with lower prey densities, which was much less accessible for lions. With sites being found in much more remote areas, the commute to high prey density areas was longer, showing a preference for pack health and security. As a result of changing pack composition, wild dogs could face a deadly fate as fewer pack members can threaten their young's defence and affect their effectiveness in hunting.
As observed in previous re-introduction attempts of wild dogs, this mesopredator is highly influenced by the larger predators that shares its habitat. Further research must be funded into the inter-species relationships found to understand better how we can succeed in conservation attempts. As habitats begin to shrink from human encroachment, wild dogs will be pushed further to the brink of extinction as interactions between them and larger carnivores become more frequent.
References:
B.Jongeling, T. and Koetsier, T., 2014. The predicament of the African wild dog, Lycaon pictus, is less precarious than claimed. [online] Wiley, p.466. Available at: <https://onlinelibrary.wiley.com/doi/epdf/10.1111/aje.12142> [Accessed 28 October 2021].
Creel, S. and Creel, N., 1996. Limitation of African Wild Dogs by Competition with Larger Carnivores. [online] Wiley, p.1. Available at: <https://www-jstor-org.ezproxy.sussex.ac.uk/stable/2386867?seq=1#metadata_info_tab_contents> [Accessed 28 October 2021].
Groom, R., Lannas, K. and Jackson, C., 2017. The impact of lions on the demography and ecology of endangered African wild dogs. [online] Animal Conservation, pp.382-390. Available at: <https://www.webofscience.com/wos/woscc/full-record/WOS:000406368500009> [Accessed 28 October 2021].
Scheepers, J. and Venzke, K., 1995. Attempts to reintroduce African wild dogs Lycaon pictus into Etosha National Park, Namibia. [online] South African Journal Of Wildlife Research, pp.138-140. Available at: <https://www-webofscience-com.ezproxy.sussex.ac.uk/wos/woscc/full-record/WOS:A1995UA64000006> [Accessed 28 October 2021].
Webster, H., McNutt, J. and McComb, K., 2011. African Wild Dogs as a Fugitive Species: Playback Experiments Investigate How Wild Dogs Respond to their Major Competitors. Wiley, pp.147-156.
