The 19th century zoos were already important sources of biological knowledge. Numerous species could only be studied well because there were living examples available to scientific researchers in zoos. Because of this, zoos played an important role in the development of descriptive biological sciences: anatomy, morphology, taxonomy, classification, study of locomotion, feeding, etc. Science has also made good use of the existence of zoos in this century. Many of the early behavioural studies were carried out in zoos, and a great amount of the present medical understanding of exotic animals is a result of research in zoos. Studies on nutrition, reproduction, physiology, psychology and many other such aspects also have yielded much information.

Zoos manage diverse collections of animals from all over the world. An enormous amount of scientific knowledge is required about virtually all biological and medical aspects of the animals that are held. This knowledge is necessary to feed, house, and care for the animals, to stimulate their reproduction and to keep them healthy. It is also necessary in order to achieve the maximal educational potential of zoos.

The need for scientific knowledge has grown considerably since it became clear that zoo collections must not only be managed over the short term, but must also remain healthy and viable over the long term, and since it became established irrefutably that zoos could offer an essential contribution to the conservation of species and habitats through the maintenance of ex situ populations. Comparatively new branches of science, such as genetics, population biology, conservation biology, biotechnology and others, have been added to the long list of areas that serve as necessary foundations for zoo practices.

A considerable amount of knowledge has been accumulated during the 150 years of modern zoo history. Thus, the educational value of zoos is enormously increased, countless animals survive and reproduce much better than earlier, and their populations can be managed and conserved for the future. A great part of the knowledge acquired has been recorded in reports, books, journals, magazines and other publications, and in databases. The present day zoo world includes thousands of knowledgable collaborators, ranging from zoologists, veterinarians and other scientists, to educators, curators, and keepers. Together these collaborators represent an enormous source of information.

The World Zoo Conservation Strategy emphasizes that it is the task of each zoo individually to optimize use of available knowledge resources in order to further conservation goals, and of all zoos collectively to make all of the written and unwritten information easily accessible and usable for the entire global zoo network.

Despite the immense amount of knowledge that has been gathered, there is still a great need for additional information. The more that is known about zoo animals and their biological characteristics, the more questions there are. Additionally, the more involved zoos become in species conservation and nature conservation, the greater the demands become on all aspects of management, and the more scientific information required to meet these demands.

The World Zoo Conservation Strategy concludes that gaps in understanding must be filled through research. This must be developed through directed scientific research projects, and through analysis of the stream of empirical and experimental data that are collected and recorded in each zoo on a daily basis. Research is not an exclusive undertaking that should involve only a limited scientific staff, rather each zoo employee should be involved either directly or indirectly in its pursuit. Because zoos have to consider a broad scale of bioscientific factors in their conservation goals, research topics will also be diverse. Box 18 presents an overview of the most important categories of required research.

Despite the great need for research in relation to conservation objectives, manpower and financial resources for extensive research is rarely available in zoos. Many zoos do not have a full-time researcher on staff, a relatively small number have one or more researchers, and in a few exceptional cases zoos have a research department with a full, professional research staff. Nevertheless, countless zoo workers (scientific, curatorial, and keeper staff) undertake some research in addition to their normal daily tasks, and continually collect data that can form the basis for analytical study. The total research output from zoos is therefore considerable despite the shortage of research staff.

Much of the cost of research in zoos is paid by the zoos themselves. The amount of money available for research varies significantly between zoos. It is difficult to arrive at an estimate for actual research investment, as many zoo workers collect research data in combination with other duties. Research funding opportunities for zoos, other than their own income, include subsidies, research grants, and sporadic funding through external institutions, e.g. universities, research fund, or nature conservation bodies.

The World Zoo Conservation Strategy concludes that zoos should try to increase their own financial contribution whenever possible to further intensify and expand necessary research efforts. Additionally, they should work both independently and cooperatively to obtain external research funding. The Strategy calls on research and conservation bodies to realize that zoo-based research has great scientific and conservation value (see 10.9), justifying substantial financial contributions.

As resources for research are limited, the World Zoo Conservation Strategy calls for the establishment of research priorities on different levels:

It is impossible to give within the framework of this document a summary of all the professional areas, subdisciplines, and related sciences that are of importance to the conservation objectives of zoos. Thus, only a short overview of important research categories is provided here:

The Strategy emphasizes that establishment of research priorities and formulation of action plans requires coordination between all parties involved. Because of the low number of researchers per zoo, good coordination is essential for maximizing research effectiveness. It is necessary for avoiding unnecessary duplication of effort, and also for giving sufficient consideration to all of the diverse research areas.

Research in zoos frequently suffers from a shortage of research material. The number of animals per species present within one zoo is often too small to address a species-specific research question within a limited amount of time. It is frequently necessary to have material and data from a number of zoos in order to do valid research.

The World Zoo Conservation Strategy advises that research should be increasingly within the framework of breeding programmes, in which the regional or world population of a species forms the research material.

Another possible method of increasing the available research material is through the establishment of material banks. Much research involves use of materials that can be fairly easily collected in a zoo, and that can be held for a long period of time, e.g. blood, serum, urine, tissue, and whole animals resulting from natural mortality.

The Strategy calls on the zoo research community to establish banks in which materials can be stored in order to increase efficiency of research in a number of areas; such banks could be established within the framework of regional breeding programme organizations. However, global coordination is required in order to avoid unnecessary duplication.

A third possibility for making more efficient use of research materials is to establish data banks for basic data, and for this the uniform registration of animal data via ISIS-ARKS computer software forms a good basis.

The World Zoo Conservation Strategy recommends further expansion of databases for such basic data as feeding, behaviour, medical aspects, and many other variables related to zoo animals. Once built, such databases will greatly simplify analytical and comparative research.

Results of zoo research are often published in professional scientific books and journals, and consequently are directed to a scientific audience outside the zoo world. However, zoo research should also increase the knowledge within the zoos, and zoos must be able to evaluate the practical relevance of research results. Obviously most zoos are not equipped with a large team of diverse experts that can evaluate what are often very specialized publications in the scientific literature.

The World Zoo Conservation Strategy calls on all researchers to publish their results in literature that is available to zoos, with the accent on relevancy whenever possible. The International Zoo Yearbook and journals within the zoo world are entirely suitable, and symposia, conferences, and workshops where results can be presented are frequently organized.

In many cases, results of research in zoos remain in the form of internal reports and are not freely accessible in publications. Because these reports often include information that is also important for other zoos, the Strategy recommends to make them as accessible as possible. Short reports in relevant zoo journals and newsletters can contribute to this.

Much of the information acquired through zoo research is of great relevance to conservation generally and to the conservation of species and habitats in particular. This is undoubtedly true for all the basic information collected for countless animal species. It is also true for the various techniques (veterinary-medical, reproductive, genetic, husbandry, management of animal social groups, etc.), and for the understanding of management and conservation of small populations. The knowledge and techniques developed in zoos are also increasingly applied to management and conservation of wild populations.

Many zoos publish much of this information so that it is accessible and useful for conservation. Zoos also provide service to nature protection by making a large amount of knowledge, experience, and expertise available. Zoos participate in numerous nature protection projects by providing both people and means; they regularly contribute important information and their employees function in diverse committees, working groups, and research groups that are involved with nature conservation. It is significant that zoo personnel have prominent roles in the majority of IUCN/SSC Specialist Groups. They also often serve on the editorial boards of international serial research publications in conservation biology, and may be involved in the teaching and supervision of students.