Eating habits and Foraging Behavior

Photo Credit: Kwando Safaris

http://thewildsource.com/blog/image.axd?picture=wild-dog-zebra.jpg

http://www.arkive.org/african-wild-dog/lycaon-pictus/image-G4168.html

African wild dogs have been pegged in the past as brutal killing machines that kill slowly and more than is necessary to survive. Many scientists discount these misconceptions with the desire to inform the public that the bashing of this endangered species stems from incorrect hunter legends. Numerous scientific observations have been published and it is now commonly believed that wild dogs are not evil, savage monsters, but the most efficient hunters. In a study by Schaller (1972), 70% of 133 wild dog attempts to bring down prey were successful, while only 23% of 523 lion attempts were successful. One reason wild dogs are more efficient is because they cooperate in packs. With a structured pack, they are able to bring down more profitable animals like a wildebeest.  It is not as feasible for a lone wild dog to take on this large animal himself. Therefore, if the wild dogs cooperate, each individual benefits more than it would if he hunted by himself. Because an individual receives more of a benefit and the cost of sharing it is low in comparison, the wild dogs’ hunting strategy of working together has become the most evolutionarily stable. Any other hunting strategy like taking the killed antelope for ones own would merely put the cheater at a disadvantage. The pack would not let the cheater be involved in a future hunt, for example and as a result, he might not survive. These cheating genes would die with him and the cooperative genes of working together to reap a bigger reward would continue to live on in the cooperative members’ pups.

As mentioned in the post on hunting, wild dogs communicate to each other before a hunt, twittering and whining. Some believe this “social rally” is used to organize the pack and I like to relate this to a sports team pumping themselves up before the big game. However, this ‘game’ can mean life or death for the pack and their offspring. After the rally, the pack targets their prey and takes turns chasing it down. Once the closest wild dog grows tired, another member with the most direct route to the target will step into take its place. The pack then brings down the animal and disembowels it. Sometimes one member will hold the prey’s head, while the other members kill the prize. 

African dogs are not like other canids. They are strict carnivores and do not scavenge. They only eat animals they have killed. Some people may have taken the lack of scavenging behavior to indicate that African wild dogs kill just for the sake of killing, but wild dogs have evolved to be the most efficient killers in order to feed everyone in their pack. Perhaps scavenging behaviors in wild dogs did not evolve because scavenging does not yield enough food to feed the entire pack. It may be more strategic for all the members to put their energies into obtaining the most profitable food source, so that all of their kin may survive. 

References

http://www.outtoafrica.nl/animals/engafricanwilddog.html?zenden=2&subsoort_id=4&bestemming_id=1

http://www.wildlife-pictures-online.com/wild-dogs-hunting.html

http://www.canids.org/species/African_wild_dog.pdf

AWD wild relative?

Family: CanidaeGenus: CuonSpecies: Cuon alpinus

Just as the the African Wild Dog is one of the most endangered carnivores in the world.The Dhole is a pack hunter from Asia. Their color is a reddish brown with long tails tipped in black. They weigh between 27-45 pounds. There has been much prejudice against the Dhole and they have been poisoned, shot and trapped. There may be up to 25 members in a pack. Dholes have a wide range, from the Indian jungles to the Siberian forests. Dholes hunt deer, wild boar, and buffalo. However, Dholes are now facing extinction with their total population estimated to be at 3000. 

According to the Wild Dog Foundation, the Dhole (Cuon Alpinus) of Asia is another forgotten carnivore in the popular world of conservation. As a wild species of Caned, the Dhole share relation with the AWD, and more importantly share a similarly threatened existence. They are often ignored along with other misunderstood Wild Dogs of the world.

Other similarities include:

-A single dominant monogamous pair per pack, with subordinate pack members helping to care for the young of the dominant pair.

-Engage in cooperative group hunting. 

-Rarely any evidence of aggressiveness among pack members (except for the cubs, who like to play fight) and there is almost never any bullying.

Works Cited:

http://wilddog.hypermart.net/Home/Wild_dog_page/WildDog_WebSite/index.htm

http://animaldiversity.ummz.umich.edu/site/accounts/information/Cuon_alpinus.html

Anatomy of the Dog

The African wild dogs are very well suited to life on the Savanna.  Similar to greyhounds, they have a light body and long legs; excellent for prolonged hunts. Whats more, the bones of the dogs lower front legs are fused together to keep them from twisting when it runs. They have a thin, long body, and muscular legs with only four toes on each foot, because their dew-claw is missing. The African wild dog's over all body length is between 75 and 100 cm (29 and 39 in), and they stand between 61 and 78 cm. (23 and 30 in.) at the shoulders. Their tail is between 30 and 90 cm. (12 and 15 in.). They weigh 18 to 36 kg (37 to 79 pounds). The males and females are about the same size. The African wild dog is the largest dog in Africa, and the only member of the Lycaon genus. The large rounded ears of the AWD actually help to radiate heat away from its body, while tts short and broad muzzle has powerful muscles that allow it to grab and hang on to its prey. Perhaps of the utmost importance is the multicolored coat of the dogs which helps them blend in with their surroundings. These surroundings are predominately the grasslands of the Savanna. As the grass can grow to be 3 to 6 feet tall the dogs are easily concealed from their prey. However, their coat, which is colored with red, brown, black, yellow, and white areas allows the animals to band together in what to a food item (prey) seems to be a single ungulating mass of countless bloodthirsty wild dogs. Interestingly, each animal has a different pattern of colors and relatively fur. Typically the fur on their muzzle is black and the end of their bushy tails are white. Works Cited http://www.blueplanetbiomes.org/african_wild_dog.htm

That's Disgusting!: Conditioned Taste Aversion in African Wild Dogs

There is an ongoing battle between African wild dogs and farmers living in areas like Botswana, Africa. In one year, predominately African wild dogs and African lions killed 500 livestock animals causing $275,000 in damages. Organizations such as “The Wild Source” and “WildiZe” are working to decrease the amount of African predators killed by humans, who are protecting their livestock, through Conditioned Taste Aversion (CTA). CTA occurs when a predatory animal associates a taste (the conditioned stimulus) with sickness and nausea (the unconditioned stimulus) after consuming livestock, such as cattle. After an animal consumes toxins in her food, a gastrointestinal illness ensues, causing her to find future tastes and scents of cattle undesirable. This evolved form of learning increases the chance of the organism’s survival.

            Conditioned taste aversion studies using thiabendazole are being conducted at the California Wolf Center and one such study in 2009 successfully taught captive Mexican wolves to cease eating ground mutton.  “The Wild Source,” a commercially based organization with research supporting the conservation of African animal species, is also conducting conditioned taste aversion studies in the “Africa Predator Project.” Modeling studies conducted on predators in the United States, such as the Mexican wolf ones, the “Africa Predator Project” aims to use conditioned taste aversion techniques to deter captive lion and wild dogs from pursuing livestock. The ultimate goal is to condition wild, roaming animals to avoid the taste of different livestock animals in order to protect their dwindling numbers from threatened farmers. “Wildize” is also conducting a conditioned taste aversion study on 20 captive lions, suspecting that the results from these efforts will help the movement of using CTA to prevent conflict between farmers and predatory wildlife. In 1997, Woodroffe and Ginsberg documented that 27 percent of adult wild dogs were killed by bullet or poison in five areas of Africa: Kruger National Park, Northern Botswana, Hwange National Park, Selous Game Reserve, and Zambia. Hopefully the application of CTA studies with African wild dogs can be used in the near future to decrease the detrimental influence human predation has on the already small numbers of this endangered species. 

Photo from http://www.pentaxforums.com/forums/post-your-photos/122680-nature-endangered-african-wild-dog.html

References

http://www.conditionedtasteaversion.net/mex-wolf.html

http://www.cogs.indiana.edu/spackled/2011readings/welzl%20et%20al%202001%20-%20conditioned%20taste%20aversion%20as%20a%20learning%20and%20memory%20paradigm.pdf

http://blogs.scientificamerican.com/extinction-countdown/2010/11/10/can-endangered-mexican-wolves-be-conditioned-to-dislike-the-taste-of-sheep/

http://bangordailynews.com/2012/01/28/outdoors/wolves-senses-tapped-to-keep-them-clear-of-cattle/

http://thewildsource.com/africa-predator-project.aspx

http://www.wildize.org/projects/Wildlife-Security/Bill-Given-Condition-Taste-Aversion-CTA-Botswana/56

http://www.canids.org/PUBLICAT/AWDACTPL/4causes.htm#persecution

http://news.yahoo.com/wildize-foundation-founder-eli-weiss-sends-first-conditioned-071925588.html

The Pack Video

I went to the San Diego Zoo twice over the semester and each time the African wild dogs were off exhibit, so here is a video on predatory behavior from National Geographic instead. It follows the lives of the Sheean Pack who live in the iMfolozi Game Reserve in South Africa.

National Geographic. (2011). The Pack: Wild Dogs & Lions [DVD]. Available from 

http://shop.nationalgeographic.com/ngs/product/dvds/animals-and-nature/animals-and-wildlife/the-pack%3A-wild-dogs-%26-lions-dvd-r.

Retrieved video from http://www.youtube.com/watch?v=4N-7H1sSDck&feature=related

Discussion (Spoiler Alert!)  


3 different hunting strategies:

"the skirmish"

the trap

the charge

These two video segments include "The Skirmish."

The African wild dogs were unsuccessful at making a kill when using "the skirmish" technique.


During "the skirmish," the impalas leaped and bounded away from the Sheean Pack. Impala's can leap up to 33 feet and at the end of a leap they give a high kick with their hind legs.  The dogs of the Sheean pack possibly selected a young impala as their target on the basis that it did not show this kicking behavior . This kicking behavior could possibly be part of an impala strategy that entails appearing strong and difficult to take down. The kicking possibly communicates to the predator that not only can it out run the dog, but that it can outrun the dog while conducting this kicking behavior, which does not help the animal run faster. By kicking, the impala shows off its strength or as the narrotor said, "vigor" in order to discourage the predator from selecting it. If the pack had been successful in taking down the non-kicking impala, this would have been an example of how the genes that result in the kicking behavior evolve and spread, while genes that do not fade out. This impala's genes would not have been passed on if it had been devoured by the pack before it could reproduce. 

Hoo n Twitter

It was mentioned before that African wild dogs are the most social of the canids. They are also known for their complex vocalizations, some of which are unique to the species. Before Africa wild dogs hunt, they approach each other with their head down, ears folded back and mouths open. They then greet one another by touching and rubbing muzzles, licking, and biting. These greeting behaviors are characteristic of begging in pups and this is thought to be where these behaviors originated. During socialization, African wild dogs emit high-pitched squeaking sounds known as “twitters.” They also whimper, squeal, and whine. Unlike wolves, wild dogs do not howl. When they are lost they “hoo,” which is a vocalization that is short, low, and owl-like. It is even believed wild dogs mix the different sounds that they can make to signal ambivalence.

Sound byte of “twitters”:

http://www.awdconservancy.org/wav/twitters.wav

Sound byte of “hoos”:

http://www.awdconservancy.org/wav/hoos.wav

References:

http://www.awdconservancy.org/natural%20history.html

http://www.sandiegozoo.org/animalbytes/t-wild_dog.html

Competition, Kleptoparasitism, and Hunting Group Size

            According to Carbone, Du Toit, and Gordon (1997), the Wild dog population has nearly vanished from the Serengeti plains. During the same period in the Serengeti, the hyena population has more than doubled, which is thought to be due to a substantial increase in the wildebeest and gazelle populations. The shift in population density of these two species has resulted in a significant increase in the ratio of hyenas to wild dogs in the Serengeti. Given that wild dogs are substantially smaller than hyenas, they can be driven off fresh kills by relatively few hyenas. This has been documented in a number of studies (see Eaton 1979; Fanshawe & Fitz Gibbon, 1993; Creel & Creel, 1996) which found a negative relationship between wild dog and hyena densities across six ecosystems.

            A simple model was developed to explore how variation in wild dog hunting group size in the Serengeti influences defense of kills against hyenas, and the trade-off effects this has on intake rate per dog for a given prey size. The article's primary focus is upon the question of whether increased access time at a kill (afforded by group defense against hyenas) compensates for the reduction in each dog's potential share of the carcass and, hence, whether adjustment of hunting group size is a strategy that wild dogs can employ against kleptoparasitism. Of secondary interest is the articles examination of the impact of kleptoparasitism on average profitability of different prey with varying hunting group sizes.

            The authors found that while kleptoparasitism substantially influences the amount of time a hunting group can access a kill, increases in access time with increased hunting group size rarely fully compensate for the reduction in each dog's share of the carcass due to ‘scramble competition’ among the dogs. This was displayed in a profitability index, which included limitations of the probability of capturing different sized prey, gut capacity, food depletion and access time, suggesting that the smaller the hunting group the more vulnerable it is to kleptoparasitism. Where hunting groups  of 1-2 would be particularly vulnerable because they are unable to fully satiate themselves before spotted hyenas take over their kills. Notably, intermediate-sized hunting groups may be most effective at meeting nutritional demands over a range of prey sizes.

Works Cited

Carbone, C., Du Toit, J. T. & Gordan, I. J. (1997). Feeding success in african wild dogs: Does      

kleptoparasitism by spotted hyenas influence hunting group size? Journal of Ecology (66), 318-326.

Welcome Back Video

ARKive - African wild dog video - Lycaon pictus - 15a

This is a video of what I believe to be one African wild dog being reintroduced to the pack after a tracking collar was placed on him/her.  This is the pack's reaction to the foreign object.

That's mine! Territorial Behavior in African Wild Dogs

African wild dogs are found in sub-Saharan Africa, which includes desert environments, flooded grasslands, tropical forests, and tropical grasslands. It is believed that wild dogs once lived throughout Africa, but their habitat size has shrunk to a few countries: Zambia, Zimbabwe, Namibia, Botswana, and Angola. The reduction in habitat has restricted many wild dogs to National reservations and parks. 

A territory for a pack can range anywhere in size from 650 to 900 square miles. Territories need to be large enough to support all of the pack members. African wild dogs tend to be crepuscular, which means they are most active at dusk and dawn. They can travel up to 30 miles in a day and tend to travel six miles during a hunt. But because their territory is dwindling, food is not as plentiful, making it necessary for wild dogs to travel further to find food. They can reach speeds of 35 mi/h.

Different packs may have overlapping territories, but wild dogs are unique in that they do not tend to fight amongst themselves. Thus, territorial disputes are not likely in home ranges that encompass more than one pack. They are also unique in that unlike most large predators they do not use vocal calls to communicate to others where their territories lie. They do however mark their territories through scent. They secrete chemicals to communicate boundaries however, they do not mark their territory by urinating. The alpha pair will urinate around a site when the female is in heat, but they use urine more as a sign of dominance.

Interestingly, the Botswana Predator Conservation Trust (BPCT) is working to discover the chemical signals emitted by African wild dogs. This organization’s aim is to mimic these chemical signals and create artificial scents in order to deter the dogs from areas occupied by humans, farms in particular. Killing African wild dogs by gunshot, poison, or snaring to protect livestock is a serious conservation issue due to the damaging impact these actions have on the ever-decreasing dog population. BPCT hopes that African wild dogs will be deterred to go outside the National reservations if these artificial scents are placed on the outskirts of the parks. While the idea is encouraging, I wonder if this will be as effective as it is for wolves, which are unlike African wild dogs in that they are more overtly aggressive. If wild dog packs in the same areas are usually less aggressive compared to related species, logic would follow that the artificial markers would not have as great of a deterring effect as it would for a more aggressive species like the wolves. It would be interesting to compare the two!

https://www.eriezoo.org/PDFS/Animal%20Fact%20Sheets%20for%20Website/African%20Wild%20Dog.pdf

http://library.thinkquest.org/16645/wildlife/wild_dog.shtml

http://www.bbc.co.uk/nature/life/African_Wild_Dog

http://www.kalahari-predator-conservation.com/en/predators/african-wild-dogs

http://www.restek.com/Technical-Resources/Technical-Library/Editorial/editorial_A013

Last of a Dying Breed

An Endangered Species

Once wild dogs were a dominant predatory group across much of Africa. They roamed the great savanna, and played a crucial role in the ecosystem; culling the weak and sickly, maintaining the cycle. During and in some cases, prior to colonization, African wild dogs have been viewed as a threat to the local human inhabitants. This is especially the case following the ‘settling’ of Africa, during which the wild dogs were treated in much the same manner as the wolves of Europe; hunted, poisoned, and encroached upon to the point of extinction. 

Accordingly, there are less than 5,000 wild dogs left in all of Africa. Most populations are restricted to national parks which provide some degree of protection, yet isolate the groups, and risk increasing homogeneity in the gene pool. Moreover, they need enormous areas of several hundred square miles to range, and if the wild dogs venture out these few protected areas, they often come into conflict with people.
Of importance is not to view this as a simple problem faced by wild dogs which can be amended by human intervention. For example, people living in the Samburu Heartland have lost livestock to predators, that include African wild dogs. Fearing for their livelihoods, farmers and ranchers have to protect their own interests, which inevitably results in the direct targeting of any and all predatory species which pose a threat. This is essentially the same problem faced in the United States where efforts to reintroduce native wolf species have met strong resistance by ranchers, and local community residents. 

Conservation Efforts

Through study and potentially understanding of the species in terms of migratory patterns, hunting preferences it may be possible to enhance the degree to which this species may be protected. The African Wildlife Foundation (AWF), along with several other partners including the Samburu-Laikipia Wild Dog Project (SLWDP), local communities and NGOs, is working to strengthen and expand wild dog conservation throughout northern Kenya. However, given the travel patterns of wild dogs -easily travel 25 miles a day in search of prey over difficult terrain- it is incredibly challenging to study their habits. To expedite this research, AWF, with funding from the U.S. Agency for International Development (USAID) and the Dutch Government (DGIS), has employed 12 scouts from five different communities. AWF supplies these experienced trackers with the necessary equipment, and in addition, has initiated critical dialogue between local communities who live in wild dog areas and key researchers to ensure that landowners are well-informed about the research.

Other efforts which have been used in the US to facilitate coexistence of ranchers and wolves may well be applicable to the case of the African Wild Dogs. For instance, fladdery techniques and perhaps even conditioned taste aversion which have been shown to deter wolves from preying on livestock may be generalizable to wild dog populations in Africa. 

                                                       (African Wild Dog, Snared; help stop the war on the worlds species.)

References:

http://www.awf.org/content/wildlife/detail/africanwilddog

http://www.predatorconservation.com/wild%20dog.htm

http://www.bbc.co.uk/nature/life/African_Wild_Dog