11. Sep, 2017

Democracy by ‘sneezes’: the African Wild Dog

It is good to shift scenes  by time and while  from the world  under the waterline to the area where many species are now critically endangered:  the dry savannahs  of  the great  African continent. One such remarkable species is the African wild dog (Lycaon pictus: literally painted wolf), a splendid animal also known as African hunting dog,  Cape hunting dog, Painted hunting dog and ‘mbwa mwilu’ in Swahili.

Habitat  As Africa’s last tracts of wilderness are destroyed, wild dogs are forced into areas where they face unfamiliar threats, such as potentially fatal encounters with humans and exposure to the frequently lethal viruses carried by domestic dogs. Many wild dogs are still killed or poisoned by farmers as revenge for eating their chickens. In total now less than 7,000 remain in the wild containing roughly 39 subpopulations. The African wild dog is a canid native to Sub-Saharan Africa, where most species now live in the  savannahs and national parks of Southern East Africa or South Africa, for example  the Moremi Game Reserve  in Botswana, and the Niassa National Reserve in Mozambique. These reserves are relatively unexplored wilderness and  often form the last refuges for African wild dogs,  providing a large area of habitat and haven for  around 450 animals per reserve. The Okavango Delta in Botswana  is massive and unique in that all the water in the Delta does not flow into an ocean but ends in the desert. The farmers who are nearby just need to find ways to co-exist with the dogs and other animals. *

Behavior The African wild dog has long legs, large rounded ears and four toes per foot. Its muscled large ears can turn in in all directions to pick up the faintest sounds. Most species  have patched fur in black, brown, white and yellow. They are known for their strong family bonds and often gather in packs of around ten to 40 individuals. Packs have been known to share food and to assist weak or ill members. Each pack has a strict hierarchy with  an alpha breeding pair in charge of the group and the rest of the pack members as subordinates. Social interactions  like greeting ceremonies,  signs of  appeasement or submission etc. are common, and the dogs communicate by touch, actions, and vocalizations. The female has a litter of 2 to 20 pups, which are cared for by the entire pack.  

Hunting skills The African wild dogs are also fierce and opportunistic predators that hunt medium-sized prey such as antelopes and gazelles. Sometimes  they are after bigger game such as  the zebra and the wildebeest. Their high intelligence and teamwork allows them to adapt to changing scenarios during a hunt. For example when the pack chases a selected individual, some dogs will go after the target, while others will perform flanking movements to cut off any avenues of escape. When the leading dog gets tired, another will take its place. In a sprint, African wild dogs can reach speeds of more than 40 miles per hour. It hunts by approaching its prey silently then chasing it in a run lasting for 10 to 60 minutes. The average chase typically only goes as far as 2 km, during which time the prey animal, if large like a wildebeest,  is repeatedly bitten on the legs, belly and anus until it stops running, while smaller prey is simply pulled down and torn apart with their powerful  jaws and teeth.

The sneeze as signal Amongst the wild dogs’ vocal chatter, biologists have identified “audible, rapid exhalation of air through the nose”, also called sneezing.  After one  dog starts sneezing, the whole pack may take over  the sneeze. Later,  research teams realized that the number of sneezes predicted whether the pack set off to leave or to hunt: it reflected a kind of  collective  decision. Other social carnivores like meerkats (Suricata suricatta)  use a similar decision-making process. It also resembles the increased rate of ‘grunts’ that  occur before Mountain gorilla (G. g. beringei) groups move off from their resting sites.

A recent  study published by Reena Walker a.o.** discovered something interesting. They collected their data from five packs  of African wild dogs in and around the Moremi Game Reserve in the Okavango Delta in Botswana. They found that the number of sneezes needed for the group to depart (i.e. the ‘quorum’) was reduced whenever dominant individuals initiated rallies, suggesting that dominant participation increases the likelihood of a rally’s success. However it was  not an absolute prerequisite, because  the ‘will of the group’ could override dominant preferences when the consensus of subordinates is sufficiently great. The sneezes might either  act as a true voting mechanism or  it may reflect a purely physiological response to a consensus already achieved through other signals that researchers  did not observe.

*People that like to donate to a project devoted to conservation of the African  Dogs  should contact Botswana Predator Conservation Thrust

Sources and links

**Walker RH, King AJ, McNuttJW, Jordan NR. 2017 Sneeze to leave: African wild dogs (Lycaon pictus) use variable quorum thresholds facilitated by sneezes in collective decisions. Proc. R. Soc. B 284: 20170347.

Robbins RL. 2000 Vocal communication in freeranging African wild dogs (Lycaon pictus). Behaviour 137, 1271–1298.

Rutten S, Fleissner G. 2004 On the function of the greeting ceremony in social canids—exemplified by African wild dogs Lycaon pictus. Canid News, 7.3. Online. Estes R, Goddard J. 1967 Prey selection and hunting behavior of the African wild dog. J. Wildl. Manage.,31, 52–70.

https://africageographic.com/blog/10-interesting-facts-african-wild-dogs/

http://www.wildafrica.cz/en/animal/african-wild-dog/

http://www.npr.org/sections/thetwo-way/2017/09/07/549182066/a-quorum-of-sneezes-for-wild-dogs-it-s-not-just-snot-it-s-a-way-to-vote

https://www.nytimes.com/2017/09/06/science/wild-dogs-sneeze-hunt.html

https://www.youtube.com/watch?v=h4SlAc2U1A4

http://phenomena.nationalgeographic.com/2016/03/29/what-wildlife-shows-dont-tell-you-about-african-wild-dogs/