Abstract

Many species of New Zealand’s endemic wildlife are threatened with extinction. Captive management and intensive in-situ management are being used to help reverse the decline of ecosystems and the critically endangered species they contain. Disease could have a huge effect on these vulnerable populations. The New Zealand Department of Conservation (DOC) has taken a proactive approach on the issue of wildlife health. A new wildlife health program aimed at disease prevention in wild and captive native fauna is being developed. The program includes the development of a new wildlife pathology database, the production of disease investigation protocols and health guidelines for DOC staff, the provision of technical advice, the production of guidelines for wildlife health research and for the collection of biomedical data.

Introduction

There has been considerable discussion in recent years concerning the need to evaluate the effect of disease on the reintroduction, repatriation and translocation of species of high conservation value.¹ There have been very few detailed reviews of the disease status in New Zealand’s wildlife² and the collection of baseline biomedical data has been limited³. There have, however, been discussion papers on the effect of diseases on breeding and translocations⁴ and there have been general suggestions on disease avoidance in the conservation of threatened species in New Zealand⁵. These considerations have also been discussed elsewhere.^6,7 This paper discusses the development of a new wildlife health program for New Zealand.

Background

New Zealand has a unique flora and fauna. There are over 70 endemic species of birds, two species of bats, two species of pinnipeds, approximately 75 endemic species of reptiles and five endemic species of frogs. One thousand years of human settlement has had a severe impact on New Zealand’s biodiversity.⁸ More than 50 species have become extinct in this time and several hundred more are presently at risk from extinction. Included as causal factors are the introduction of mammalian predators including the feral cat, mustelids and three species of rat; habitat destruction, degradation and fragmentation; and competition from introduced herbivores such as the brush-tailed possum (Trichosurus vulpecula).

Listed amongst the endangered are several species whose total population number less than 200. These include the kakapo (Strigops habroptilus, a large, flightless, nocturnal parrot), the takahe (Porphyria mantelli, a large flightless gallinule), the Okarito brown kiwi (Apteryx australis) and the black stilt, (Himantopus novaezelandiae). Several other species are also critically endangered.

Conservation techniques used in New Zealand include the development of island reserves that are free from introduced species, mainland habitat restoration and captive management. The restoration of offshore islands has meant that several species are now only found there.

Many threatened species are now managed through recovery programs that have been developed by conservation managers and other interested groups. These programs involve intensive management of the wild population. In addition, several of the programs require a captive management component to help restore populations.

Translocating animals from the wild to establish new populations and the reintroduction of animals from captivity into the wild are all very important aspects of the intensive conservation management.

There is a clear risk of disease becoming an important factor in the further decline of threatened species as they become more intensively managed. Potentially many pathogens can be transferred with the individuals thus introducing further challenges to possibly disease-naive populations. Increases in the population density can, in turn, add to environmental stresses that may increase susceptibility to disease.

There have been a few incidences within New Zealand where disease has played an impact on the captive and wild populations of endangered species. Avian pox and malaria were found in a captive population of the endangered New Zealand dotterel (Chadrius obscurus), which meant that they could not be released into the wild. Several critically endangered black robins (Petroica traversi) developed avian pox which contributed to the deaths of five to six fledglings in 1985. Erythroblastosis, the avian leucosis complex, was diagnosed in Antipodes Island parakeets (Cyanoramphus unicolor),⁹ which had come into direct contact with New Zealand parakeets.

New Zealand’s Wildlife Health Program

The idea of a veterinarian to provide advice to the New Zealand statutory body responsible for conservation was first suggested in 1986. Recent wildlife health issues within the Department of Conservation (DOC), as it is now called, highlighted the need for a more proactive approach to health and disease management. Dr Milton Friend from the National Wildlife Health Research Center in Madison, Wisconsin USA, visited New Zealand in 1993 to review the threat of disease to threatened species management in New Zealand.

Following the visit, a working group comprising veterinarians and DOC staff defined the health management requirements. This resulted in a document: Guidelines for the Health Management of Species under the Wildlife Act. These guidelines are managed by a DOC scientist and a veterinarian employed on contract to the DOC and based at New Zealand’s veterinary school in Palmerston North. The author was employed to develop a health program for New Zealand’s native wildlife.

The new wildlife health program covers many areas. The tasks can be grouped under the following headings.

1.  Defining Wildlife Health Standards

2.  Information Management

3.  Technical Advice and Information Dissemination

4.  Coordination of Resources

Defining Wildlife Health Standards

As part of this new position, it has been most important to set and maintain standards relating to the health management of wildlife both in the wild and in captivity. The guidelines are used by DOC staff to improve and standardize the health management of threatened species. Initially, generic health management guidelines were produced for captive facilities and island reserves which included health monitoring programs for wildlife, recommendations on the movement of animals and personnel and on quarantine and hygiene standards.

Health management plans have also been produced for particular species (e.g., kakapo and takahe). The plans include health monitoring, biomedical data collection, hygiene, translocation, necropsy and common diseases and treatments. Standard protocols have also been produced for necropsy procedures, clinical pathology and baseline health data collection and health monitoring procedures for birds and reptiles. Risk analysis procedures have been outlined for wildlife translocations and developed initially for the introduction of exotic disease into native psittacines.

Information Management

A new computerized database of wildlife health and disease has been developed in MS Access, which evaluates information on mortality, morbidity and biomedical health data. The New Zealand Wildlife Mortality database incorporates retrospective and prospective wildlife health and disease data from all diagnostic laboratories, conservancies and captive institutes. The information can be used to further enhance health management strategies and guidelines and act as a disease surveillance and monitoring tool. One aim was to develop a database structure that is compatible with other regional and global wildlife disease database systems and which allows the sharing of relevant and useful information. The structure has been based on the Canadian Cooperative Wildlife Health Center database.

In order to gather useful information for data input it has been necessary to develop new submission forms and necropsy forms. These have been distributed to all potential submitters. All tissues and wax blocks are also catalogued for retrospective analysis in combination with the New Zealand Registry for Animal Pathology. A bibliography of native and exotic diseases has been catalogued for reference and future planning.

Technical Advice and Information Dissemination

A major part of the work involves giving technical advice to veterinarians, DOC conservation staff, the National Kakapo Team on managing individual cases, and disease outbreaks, nutrition, quarantine and translocation procedures. In some instances, there is a need to be involved directly in field investigation.

Further advice is given on native wildlife submissions to the veterinary school, which includes the interpretation of results and recommendations for management. Offering advice and facilitating wildlife health research is another aspect to the position. DOC staff are also trained in wildlife health procedures including necropsy procedures and health data collection.

All information and data gathered from a variety of sources is disseminated to wildlife managers and veterinarians in order to enhance the management of the threatened species. This is achieved through scientific publication, other publications and direct contact.

Coordination of Resources

Criteria have also been developed for the best use of the National Wildlife Surveillance fund. This fund is offered to all holders of native wildlife and wildlife managers on a prioritized basis. The aim is to ensure that the costs involved in diagnosing the cause of mortality is not hampered by lack of funds when this information would be very useful.

In order to gather as much useful information for the mortality database as possible, it has been necessary to coordinate information from all the diagnostic laboratories and all personnel holding wildlife. The conservancies and recovery groups are given advice on how to budget for health management annually.

A national network and database of veterinarians has been produced to encourage participation in recovery groups, and assistance with ex situ and in situ wildlife conservation programs.

Liaising with outside agencies including the Ministry of Agriculture veterinarians, non-government conservation organizations, zoos and other universities is required to facilitate the achievement of wildlife health tasks as outlined above.

Future Developments

As wildlife health management develops in New Zealand, there will be opportunities to employ further staff to expand on the developments and to undertake postgraduate health research. Training videos will be produced for necropsy procedures and a manual will be developed which will bring all existing guidelines and procedures together.

A New Zealand Wildlife Health Centre that will bring together rehabilitators, oil spill response personnel, clinicians, pathologists, ecologists, nutritionists and epidemiologists is under development.

Acknowledgments

I would like to thank Dr. Mark Vickers for instigating the idea of a wildlife veterinarian and Ms. C. Reed and Drs. P. Prosée, H. Pharo, K. Rose, J. Pauli, P. Stockdale, M. Alley, B. Smits, R. Jakob-Hoff, W Charleston and M. Clemance for input into the Guidelines for the Health Management of Native Wildlife. Thanks also to Dr. T. Bollinger for the kind use of the CCWHC pathology database. I would like to thank Dr. M. Collett for reviewing the manuscript.

Literature Cited

1.  I.U.C.N. 1993b. Monitoring, investigation and surveillance of disease in captive wildlife. J. Zoo and Wildl. Med. 24(3): 374–388.

2.  Boardman, W.S.J. 1996. A review of the non-parasitic infectious diseases of New Zealand’s wildlife. Kokako 3 (1): 15–18.

3.  Boardman, W.S.J. 1995. Clinical pathology baseline normal data for the Kakapo (Strigops habroptilus) Kokako 2(2): 12–13.

4.  Reed, C.E.M and P.H.G. Stockdale. 1994. Disease considerations in captive breeding and translocations of New Zealand’s birds. Ecol Mgt. 2:46–54.

5.  Stockdale, P.H.G., C.E.M. Reed, and S.C. Cork. 1993. General considerations for disease avoidance for threatened species of New Zealand native birds. Report to Director, Species Protection Division, DOC Wellington.

6.  I.U.C.N. 1993a. Infectious disease considerations in reintroduction programs for captive wildlife. J. Zoo and Wildl. Med. 24(3): 394–397.

7.  Viggers, K.L., D.B Lindenmeyer, and D.M Spratt. 1993. The Importance of Disease in Reintroduction Programmes. Wildl. Res. 20:687–698.

8.  Malloy, J. and A. Davis. 1992. Setting Priorities for The Conservation of New Zealand’s Threatened Plants and Animals. Technical Bulletin, DOC Wellington 2nd Ed p7.

9.  Vickers, M.C. 1991. Psittacine erythroblastosis—a new disease of Antipodes and NZ parakeets. Surveillance 18(1): 17–19.