Conservation Strategies For The African Wild Dog At The Philadelphia Zoo
Juanita Taylor & Gail E. Seygal
Philadelphia Zoo, Philadelphia, PA
Lycaon pictus represents a singular lineage within Canidae and is only distantly related to other canids. African wild dogs, also called painted wolves or Cape hunting dogs, were once found all over the sub-Sahara of Africa in a variety of habitats. Today they are found in a few scattered pockets of small-protected areas, mostly in east and south Africa. They are severely endangered, with possibly as few as 3,000 surviving in the wild. Fifty-eight institutions house approximately 258 dogs. Our African wild dog research at the Philadelphia Zoo focuses on ways to enrich the environment for these animals and to promote conservation through successful breeding outcomes.
The African wild dog has the body type of a German shepherd with the long thin legs of a Greyhound and weighs 45-60 pounds. They have large rounded ears, which are used for signaling and dissipating heat. The pups are born black with irregular, scattered white markings. They develop their yellow coloration at 6-7 weeks, giving them their distinctive “painted” appearance. Researchers identify each dog by their individually unique coat patterns, like fingerprints. Each dog has a white-tipped tail used as a visual signal for following pack members.
The dogs are nomadic for nine months of the year, and live in packs of two to twenty and can range over territory up to thirty miles each day. The pack consists mostly of related males. Females between the ages of 14-20 months emigrate and form new packs. Only the alpha male and female mate; subordinate females’ pups usually do not survive. Gestation is about 65-70 days with a litter size of approximately ten. After seven weeks in the den, pups are left at the site with a “baby-sitter” and eat regurgitated food provided by the rest of the pack.
The African wild dog is an extremely social pack animal. They exhibit a lot of social contact: vocalization, regurgitation, greetings, cooperative parental care and pack hunting. Their diet in the wild consists mainly of medium-sized ruminants: impala, juvenile kudu, wildebeest, zebra and buffalo. There is no evidence that the dogs live in packs to capture large prey, but the pack size does allow for strength versus competitors and permits more dogs to eat faster and return to the pups. Hunting usually occurs at dawn and dusk, with the middle of the day spent resting in the shade.
The life span of an African wild dog is ten years or less. They are threatened by habitat loss and fragmentation, competition from other predators (lion and hyena), decreased number of prey, disease from domestic dogs, road mortality, and negative attitudes of humans.
The Philadelphia Zoo was chosen by the SSP to breed the African wild dog in order to introduce new DNA into captive populations. In May 1996 we received 3.3 dogs from the DeWildt Cheetah Center in South Africa. The three brothers (born 5/95) and three sisters (born 12/94) had one captive parent and one wild-caught parent. In fall of 1996, challenges among the females occurred and two of the females were transferred to two other zoos.
At this time, the Animal Behavior Committee of the Docent Council was asked to observe the pack for two to three years, using a team of eight docents.
The Philadelphia Zoo is an urban zoo encompassing 45 acres, bounded on three sides by railroad tracks and busy highways. The dog exhibit is located in an area with primarily underdeveloped exhibit areas and fewer visitors.
Located next to the cheetah exhibit, the dog enclosure is approximately 6,700 square feet. It is a savanna type terrain with grasses, small trees, boulders, deadfall, a gully and a five-foot circular pool. There are two small concrete tunnels, one located in the front and one in the back of the exhibit, which the dogs use as sleeping areas and as possible denning areas. There is also a small off-exhibit holding space with concrete floors and hot air heat. Keepers in this exhibit also staff other areas of the zoo; therefore, docent observations are valuable.
Standard one-minute scan and bout sheets are used to record behaviors. Inter-observer reliability testing is conducted throughout the year. Behaviors include: social and solitary activities on the scan sheet and affiliative, aggressive, sexual and marking activities on the bout sheet. Observation is year-round, depending on weather and dog activities. Hours were extended to 3 hrs/day for 28 consecutive days each for baseline and pregnancy data collection.
Data was converted to graphs for incorporation into papers submitted for publication by the docent “dog team.”
In January of 1997, there was evidence that the female had whelped, but the event could not be confirmed. In September 1997, she whelped again, but only 2.1 pups survived and were hand-reared. On February 6, 1998, one of the adult males was found dead in the off-exhibit area. Three days later a second male became sick, was taken to the clinic and died on the operating table. Then, on February 14, although housed off-exhibit in another area of the zoo, two puppies became ill, one died and the other lingered until the 25th and was euthanized. The third remaining puppy, after a two-week re-introduction program, was placed in the exhibit with his parents. He became ill on March 14 and his condition deteriorated until he had to be euthanized on the 21st. After extensive exploration, the cause of death, to date, has not been confirmed other than by a highly contagious pathogen. The two remaining adults seem unaffected by the disease. Devastated by the loss, the dog team was unsure of how to proceed, but was encouraged by the zoo’s animal department and the Vice President of Conservation to continue. ‘
In October of 1998, another whelping resulted in the removal of 2.1 pups to the nursery. No other pups survived. Poor maternal care including observed cannibalism; unknown environmental conditions and cold temperatures are believed to be the cause of deaths; however, it must be pointed out that pup survival rate in the wild is only 30%.
Hoping to increase survival rates for captive populations, -the docent team is embarking on an enrichment program for the African wild dogs. A well-balanced life for people or animals consists of adequate time for work, play and leisure. Research suggests that sensory stimulation for captive animal species can improve their psychological health. In our on-going study at the Philadelphia Zoo, we are introducing visual, tactile, olfactory and gustatory stimuli to our African wild dogs. The Philadelphia Zoo is conservative with this approach and has approved items such as: various types of bedding materials, scented and unscented cardboard boxes, dilute sprays of spices, ice balls, and vegetables which have been introduced into the exhibit. We record the amount of time spent with each stimulus and whether the response becomes habituated. The enrichment activities provide stimulation to the dogs and allow visitors to watch them exploring. Stereotypic activities are often decreased, and there, has been research suggesting that sensory interventions have increased successful reproduction.
Conservation strategies for the African wild dog to survive should be of top priority in zoos, as well as in the wild, or this species may well be extinct within ten years. We hope that the accumulated information from our data collection will benefit other zoos housing African wild dogs. In addition, by implementing enrichment activities, the dogs are more active and visible to the public. Our presence at the exhibit also gives us the opportunity to raise public awareness of the endangered status of the African wild dog, and to convey a valuable message about the importance of conservation in modern zoos.