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