The Chicago Zoological Society and the University of Illinois Zoological Pathology Program in collaboration with the Ministry of Environment and Tourism, Namibia, and the Natal Parks Board, South Africa, have an ongoing in situ project involving a multidisciplinary study of southern African carnivores in their native habitat. With these and several other collaborators an expansive, in-depth study of multiple carnivore species is in progress to help determine the overall health of these animals. The species being studied are African lion (Panthera leo), spotted hyena (Crocuta crocuta), African wild dog (Lycaon pictus), cheetah (Acinonyx jubatus), leopard (Panthera pardus), African wild cat (Felis lybica), and the black-backed jackal (Canis mesomelas). To gain a thorough understanding of their current physical condition, we are employing a variety of disciplines, including veterinary medicine, immunology, pathology, reproduction, and genetics. We are using these disciplines in several different free-ranging conditions to learn how various management strategies and population structures affect the wild populations. As we more fully understand the consequences of reduced range, increased opportunity for inbreeding, and disease transmission, we can better predict how our management decisions will affect the overall chance of both short and long-term survival. The study also allows for the establishment of baseline information by which to measure following generations of animals. This paper provides an overview of procedures and preliminary results for lions.
In 1992 this project was initiated in the Hluehluwe/Umfolozi Park (HUP) in South Africa to study the health of an isolated population of African lions. This project then expanded into two additional areas of southern Africa, both of which represented different types of management systems and ecologic niches. These included the Etosha National Park (ENP) and the Bushmanland/Caprivi regions in the Republic of Namibia. Comparisons among these three populations allowed for assessment of several different factors concerning the lions’ overall health status.
The populations in the three areas are quite different:
- The lions from HUP (90,000 ha) came from only three founders and were quite isolated from other African lion populations.
- The Etosha lions are a relatively stable group of animals in an area approximately five times larger than HUP. Estimates of the population were near 350 individuals with animals able to move in and out of the fenced park.
- The animals from the Bushmanland/Caprivi area have had little human interaction because the area is sparsely inhabited by people.
Our goal was to utilize the two free-ranging populations in ENP and Bushmanland/Caprivi and the intensely managed free-ranging group in HUP to establish criteria by which to compare the strengths and weaknesses of the different management techniques for both free-ranging and captive populations.
- Determine the clinical health of individual animals and relate it to the population’s overall health.
- Determine exposure to bacterial and viral diseases.
- Determine the cause of death and disease affecting animals that were found dead.
- Establish a tissue bank from pathology samples taken.
- Determine the semen quality of the males, relate this to overall birthrate and determine if there is seasonal production.
- Determine the parentage, subspecies, and genetic variability of each population and compare this between individuals within the population and between populations.
In order to understand some of the interactions between species and possible effects of disease or poor health on one group of animals, the original work expanded to include spotted hyena, African wild dog, leopard, cheetah, African wild cat, and the black-backed jackal. In order to take more of a complete look at the ecosystem, we felt it important to use the same techniques to evaluate other carnivores in these regions. This would allow us to help determine if one management system favored a particular species and also to evaluate the effects of a potential shift in a population. Management approaches that could increase likelihood of survival include a variety of options such as facilitation of movement of animals across areas of human population where migration would have historically occurred but is now impossible.
To assess these parameters, we do the following:
- General health and baseline medical assessment included performing physical examinations of each animal, collecting blood, performing complete blood counts, serology, serum chemistries, characterizing enteric flora, performing fecal examinations for intestinal parasites, and examining the animals for external parasites.
- Evaluation of the reproductive status included examination of the male reproductive tract and collection of semen. Semen was analyzed using standard criteria including volume, concentrations, motility, status, percent normal/abnormal, and pH. The semen of high quality is frozen and stored in liquid nitrogen for future use in reproductive studies. We are analyzing the semen and comparing data between populations and by season.
- Genetic analysis has included protein electrophoresis, micro satellite analysis, and DNA fingerprinting. These analyses allow us to determine the amount of inbreeding within and between each population, determine parentage, and determine subspecies.
To perform the tests and procedures outlined above, several collaborators from a variety of fields have been brought together to do these assessments.
This project has several collaborators involved and thus, only the primary people in each region and portion of the study will be listed. Dr. Michael Briggs is the principal investigator for the project and coordinator of studies in the United States. Dr. Robert Murnane, University of Illinois Zoo Pathology Program is implementing the pathology, microbiology, and parasitology portions of the study. Dr. Jacques Flamand was project coordinator for the HUP portion. The project coordinators in Namibia were Kallie Venzke, former control warden of Etosha, Dr. Phillip Stander, Large Carnivore Biologist of Bushmanland Region, and Lue Scheepers, Regional Biologist-Caprivi Strip. Dr. Jean Dubach is the molecular geneticist from Brookfield Zoo performing genetic evaluation, Dr. Jim Evermann at Washington State University is the collaborator regarding disease surveillance, and Dr. Suzanne Kennedy-Stoskopf is evaluating immune functions.
Current Status and Developments
To date, we have completed nine trips to the parks over the 6-year period and have samples from 270 lions, 45 spotted hyena, 20 jackal, 7 African wild cat, 6 cheetah, 5 African wild dog, and 3 leopards. The areas of study are general physical health, genetics, morphometrics, semen production, disease exposure (serology), immune function, presence of ecto- and endoparasites, description of enteric flora, and pathology. A summary of each area of study follows, including some raw data and findings for lions.
We have performed physical examinations on approximately 120 lions and collected semen samples on 37 males. Ten of these animals were sampled in both the dry and the wet season. We have conducted serologic evaluations on 184 individual lions. These evaluations thus far have only looked for exposure to feline immunodeficiency virus, feline leukemia virus, and canine distemper virus. Genetic samples have been evaluated using DNA fingerprinting, protein electrophoresis, microsatellite techniques as well as mini-satellite techniques. Fecal and hair samples have been collected and analyzed from 48 lions and 16 hyena for metazoan and protozoan parasites. Complete postmortem evaluations have been done on 14 lions and one hyena, including gross and histologic evaluations. There have been an additional eight histopathology exams performed on lions from the study area. There have been approximately 100 CBCs and 50 serum chemistry analyses performed.
General physical examinations were performed by veterinarians on approximately 120 of the animals immobilized. A variety of maladies have been observed, most of which were apparently traumatic and chronic. Animals have been noted to have a fractured femur, a dislocated shoulder, a dislocated stifle, and a subluxation of the lumbar vertebrae. Trauma to the eyes with lacerations and punctures were noted, as well as many fractured teeth. These animals were males in dominant roles maintaining prides and only in one case was the animal in poor body condition. There were no signs of respiratory or cardiac diseases present.
The lions examined to date include animals from HUP, Etosha National Park, Bushmanland, the Caprivi Strip, the Transvaal (Phinda Wildlife Reserve), and captive lions of unknown origin. The results suggest there is not enough genetic distance to classify the Southern, free-ranging groups as separate subspecies. Also, data indicate that in Etosha dominant males are not the exclusive sires in known prides. This reflects the thoughts of the Ministry staff that pride males do not maintain exclusive breeding rights to pride females. Questions have arisen regarding the translocation of lions from Namibia to HUP, but the genetics issue does not appear to merit great concern, since the genetic distance is not consistent with subspeciation. The HUP population has less genetic variability than the Etosha population, but the variation observed is not categorized as “dangerously low.”
The semen studies show seasonal production in the lions in both Etosha and HUP. To confirm this, there needs to be a larger sample size of animals sampled during both the dry and the wet seasons. Obtaining enough males in both the wet and dry seasons has been problematic, yet with further study these preliminary results will likely be confirmed. The animals in Etosha and HUP had an increase in both the concentration and quality (status) of the semen in the dry season, September to November, as compared to the wet season, February to April.
More information on seasonal production of semen will be obtained through continued sampling in the Caprivi area and in Etosha. This will also expand the genome bank. The males in Caprivi and Etosha had concentrations of sperm that were up to 1450 times higher with status five times higher than HUP. This does not mean the animals in HUP are infertile, but when compared to reproductive capabilities and mean offspring production in other species, they are less likely to have reproductive success.
The animals have had serologic testing for feline immunodeficiency virus or feline lentivirus (FIV), feline leukemia virus (FeLV), and canine distemper virus (CDV). All lions have been evaluated for FIV and FeLV using the ELISA snap kit by IDEXX (IDEXX Veterinary Services, Westbrook, ME) for screening. Of the 184 tests run, there have been no positive or equivocal tests reported. Forty animals (22%) were retested with the Western blot and all were confirmed to be negative. There is also a zero incidence of positive animals for FeLV antibodies. The canine distemper antibody titers ranged from 0 to 1:640. Out of 156 lions tested, twenty were positive and 136 were negative. The highest incidence of canine distemper titers was in Etosha and the lowest incidence in HUP and Bushmanland. It was expected that the animals closest to humans with domestic dogs would have a greater chance of exposure, yet these results seem to indicate the opposite. Therefore, the source of exposure warrants further investigation.
Samples were obtained from HUP and Etosha to evaluate the immune function of the animals. Dr. Suzanne Kennedy-Stoskopf is doing this work. Results are pending.
The most common endoparasites of the Etosha and Caprivi groups were Taenia sp. with several animals showing Strongyloides, Isospora, and Sarcocystis. There were also a few incidences of Echinococcus infection. The only ectoparasites seen were Culicoides and Rhipicephalus sp.
These data also apply to the Etosha and Caprivi animals only. There are several Bacillus sp. present but no B. anthracis, even during the season when carcasses abound with anthrax. There were also many animals with Salmonella sp.
Multiple gross and microscopic evaluations have been performed in Etosha. Lesions were within the realm of those related to generally healthy animals with no obvious disease processes occurring. Most of the animals necropsied are those which were destroyed due to stock raiding events and were shot by local ranchers. This is functioning mainly to establish a database for the free-ranging population, but unusual and/or significant results are being published as they occur. This was the case with the Sarcocystis and gastric spiral bacterial infection, which was reported by Kinsel, et al. Field staff has been trained in necropsy techniques and necropsies are being performed throughout the year by Ministry staff. Histopathology is performed when the tissues are sent to the University of Illinois as part of the ongoing service being provided.
Much of the information which was initially sought has been obtained and there is a good working understanding of the overall status of these populations. Ongoing work continues to update and enhance the original sampling. The researchers continue with the lion work in Namibia with the current focus on lions in Caprivi. Continuing serology, physicals, semen evaluation, and disease surveillance is essential for monitoring the health of the population. It would be of particular interest to observe the changes in the population in HUP should new animals from Etosha be placed in the group. As cubs were produced, the genetically known sire could be determined from the previous samples obtained with the parentage data now held. This would allow for a determination of how the introduction program effects the wild population and could thus allow for a benchmark for further translocations. Also, any changes in sperm production could be evaluated as the population changed.
The authors would like to acknowledge the support of the individuals, institutions and agencies which have made this project possible. The Chicago Zoological Society (Brookfield Zoo and SEACON Conservation grants), the Natal Parks Board, Republic of South Africa, the Ministry of Environment and Tourism, Republic of Namibia, the Chicago Board of Trade Conservation Fund, Chicago Zoological Society Board member (anonymous), University of Illinois, College of Veterinary Medicine, Washington State University and the Washington Animal Diagnostic Disease Laboratory, Jacques Flamand, Lue Scheepers, Kallie Venzke, Phillip Stander, Suzanne Kennedy-Stoskoph, Tony Conway, Anthony Maddock, Thomas Spurgeon, Alan Studley, V. Piper Kimball, Olivia Forge, Gwen Myers, and the entire staff of the CZS Department of Animal Health.