JOURNAL OF ETHNOBIOLOGY AND ETHNOMEDICINE REVIEW Open Access

Agrarian rural dwellers in Nigeria produce about 95% of locally grown food commodities. The low accessibility to and affordability of orthodox medicine by rural dwellers and their need to keep healthy to be economically productive, have led to their dependence on traditional medicine. This paper posits an increasing acceptance of traditional medicine country-wide and advanced reasons for this trend. The fact that traditional medicine practitioners' concept of disease is on a wider plane vis-à-vis orthodox medicine practitioners' has culminated in some socio-cultural and magico-religious practices observed in preparation and use of plant medicines for farmers' health management. Possible scientific reasons were advanced for some of these practices to show the nexus between traditional medicine and orthodox medicine. The paper concludes that the psychological aspect of traditional medicine are reflected in its socio-cultural and magico-religious practices and suggests that government should fund research into traditional medicine to identify components of it that can be integrated into the national health system.


Introduction
There have been extremely close connections of dependence and co-dependence between humans and animals throughout history [1][2][3][4][5][6][7]. Research suggests that humans evolved from a vegetarian lifestyle to the one including meat in their diets around 2.5 million years ago (at the dawn of the genus Homo) [8,9], though just how much of the prehistoric diet included animals is difficult to tell from archeological evidence [10]. Up until around 12,000 years ago, humans derived food and raw materials from wild animals and plants [11]. Other evidence of ancient human-animal relationships can be seen in rock paintings that depict wild animals such as bison, horses and deer with human figures hunting them. This sort of evidence corroborates the observation of Marques [12] that human-animal interactions have constituted basic connections in all societies throughout history.
The variety of interactions (both past and present) that human cultures maintain with animals is the subject matter of Ethnozoology, a science that has its roots as deep within the past as the first relationships between humans and other animals. According to Sax [13], human attitudes towards animals probably evolved long before our first attempts to portray them artistically or examine them scientifically. In this sense, it has been speculated that the origin of ethnozoology coincides with the appearance of humans as a species or, perhaps more correctly, with the first contacts between our species and other animals [14]. This view of ethnozoology assumes that these interactions are an integral part of human culture and society.
The rich fauna and cultural diversity found in Brazil, with many different species of animals being used for an extremely wide diversity of purposes by Amerindian societies (as well as the descendents of the original European colonists and African slaves), presents an excellent backdrop for examining the relationships that exist between humans and other animals. The first records and contributions to ethnozoology were produced by early naturalists and explorers who demonstrated interest in the fauna as well as the zoological knowledge of native residents. These naturalists generally compiled lists of native animals together with their regional and scientific names and descriptions of their uses [15]. Nevertheless, the scientific research in the area has been intensifying in recent years, and Brazil is currently one of the most important sources of scientific production in this area.
The history of ethnozoology cannot be separated from the history of zoology, and the first records and contributions to this discipline were produced by naturalists and explorers. Historically, ethnozoological publications grew out of studies undertaken in academic areas such as zoology, human ecology, sociology and anthropology -reflecting the interdisciplinary character of ethnozoology. This review presents an historical view of ethnozoological research in Brazil and examines its evolution, tendencies, and future perspectives.

Procedures
In examining the development and tendencies of Ethnozoology in Brazil, we analyzed papers published on this theme through March/2011. Only texts that had been published in scientific periodicals, books, or book chapters that considered human/faunal relationships were considered. Searches were made for articles available through international online databases such as Web of Science, Scopus, and Google Scholar as well as specific journal web sites. We used the following search key words: Ethnozoology, Ethnoentomology, Ethnoichthyology, Historical ethnozoology, Cynegetic activities, Ethnocarcinology, Ethnoornithology, Ethnotaxonomy, Ethnomastozoology, Ethnoherpetology, Ethnomalacology, Animal use and Zootherapy. It is important to note that a number of papers could be classified into more than one category, but for purposes of this revision we considered only the principal theme of the work in deciding its category (e.g. a publication focused on the medicinal uses of reptiles was considered under the heading of zootherapy, and not ethnoherpetology. We recorded the location where the works were published, which allowed to identify their distribution according to biomes and regions where the studies were performed.

The first works
The first paper published in Brazil with a strict ethnozoological focus appeared in 1939 and described the popular zoological vocabulary used by Brazilian natives [16]. It must be noted, however, that when the first naturalists, colonists, and Jesuits arrived in the country in the 16th century they encountered an abundant, diversified and strange fauna waiting to be documented. According to Ribeiro [17], the discovery of a whole new world in the Americas generated tremendous curiosity among Europeans about the new and different plants and animals that thrived in those lands. In the centuries that followed these first contacts, explorers, chroniclers and naturalists from many disciplines and many parts of Europe set out to describe this exotic cultural universe and the fantastic and unique natural world.
These historical documents provided descriptions of the local fauna and described the hunting techniques employed by local natives in embryonic ethnozoological approaches. According to Papavero [18], the indigenous tribes, notably those who spoke the Tupi language, acted as the first professors of natural history in Brazil, transmitting their detailed knowledge of the fauna and flora to the Jesuits, who were, in this area at least, their students. Based on the information provided by these native tribes, the members of this religious order recorded the first lists and vocabularies of the local fauna. Among these missionaries were José de Anchieta, Gaspar Affonso, Francisco Soares and, especially, Leonardo de Valle who listed nothing less than 351 Tupi names for different animals (in about 1585) -a valuable linguistic and ethnozoological document that was only recently published. Little by little, expeditions through South America revealed an extremely rich fauna composed of animals of rare beauty, such as parrots and macaws (which led to Brazil being called for a certain time the "Land of Parrots"), as well as strange creatures that were very different from any previously known to Europeans. These findings stimulated the naturalists of that time to formulate various theories about the geographical distribution of species in the world [18].
Given that naturalists have been recording ethnozoological knowledge since colonial times, one could consider the roots of ethnozoological in Brazil as dating from the 16 th century -so that the history of ethnozoology in Brazil blends into the history of zoology itself. In truth, it can be said that ethnozoology is old in practice but young in theory, for the discipline is not as modern as it might first appear, with roots going back to the earliest relationships between animals and humans. A number of initiatives began to appear to recuperate zoological data from colonial period documents -an academic area that can be called Historical Ethnozoology. Nelson Papavero (at the University of São Paolo), Dante Luiz Martins Teixeira (Federal University of Rio de Janeiro), and Hitoshi Nomura (University of São Paolo) have published a series of papers on this theme in Brazil [eg. [19][20][21][22][23][24][25]]

Ethnozoological research in Brazil
If on one hand it can be said that ethnozoological documentation dates to the 16 th century, scientific production in this area only began to gain form in Brazil near the beginning of the 21 st century ( Figure 1). In analyzing the distribution of publications (scientific periodicals, books and book chapters) over the years we noted that a large majority of the research on this theme (350 (73.3%) of 487 works) were published within just the last ten years (coinciding with an increase in published works in the many areas of ethnosciences in that country). A review undertaken by Oliveira et al.[26] in the field of ethnobotany, for example, revealed that the numbers of publications in scientific journals had experienced an expressive expansion in the last decade.
The notable concentration of ethnozoological publications in recent years in Brazil is consistent with the historical development of this discipline. The academic development of ethnobiology in this country is only very recent, and greater numbers of publications in recent years would therefore be expected. A total of 487 works were published up until July 2011 ( Figure 1). Starting with the first ethnozoolology publication in 1939, the following years were characterized by small productions (a maximum of six publications/year). In the 1990's publications begin to appear in greater numbers, but only in the 21 st century did journal production really reach expressive numbers. Likewise the diversity of themes examined in ethnozoological research became more numerous and diversified during the Brazilian Ethnobiology and Ethnoecology Symposiums, the National Zoology Congresses, and the Brazilian Ecology Congresses held in recent years; it is hoped that this growth will soon be reflected in increased numbers of publications. Figure 2 lists the themes of ethnozoological publications discussed in the present revision. The subjects considered in these publications can be divided into 13 categories, with the specific themes most frequently treated being: zootherapy -the use of animals and their sub-products in folk medicine (17.86% of the titles), ethnoentomology (12.94%), ethnoichthyology (12.32%), historical ethnozoology (8.83%), cynegetic activities (hunting activities) (5.75%), ethnocarcinology (4.72% each), ethnoornithology (4.11%), ethnotaxonomy (3.08%), education and management (3.7%), the use of animals for magic-religious purposes and cultural symbolisms (3.08%), ethnomastozoology (2.87%), ethnoherpetology (2.46%), and ethnomalacology (2.26%). Any work that did not fit well into the above mentioned categories was classified as "others" (1.02%).
One of the principal reasons that Ethnozoology is still only poorly studied in Brazil is related to legal problems associated with the use of wild animals. Hunting is completely prohibited in the country, and this is known to anyone who sells or uses animal products (making full cooperation with researchers much more difficult). The legal implications of the protection of the local fauna will in turn influence the choice of topics for ethnozoolology studies. The result is that themes such as ethnoichthyology and ethnoentomology represent a significant percentage of the publications -a situation associated with the importance of these faunal groups, but also with the fact that these animals (fish and insects) can generally be used or sold without excessive legal restrictions and this is one reason why there are more studies on this subject. In the case of ethnoichthyology, it is noted that even fishers' behavior and fisheries management have been the object of many studies. The human populations that harvest these resources generally feel more secure about sharing information about their activities. On the other hand, researchers who might wish to study the hunting of wild animals -a very common practice in Brazil in spite  of its notorious illegality -will have to overcome considerably more suspicion and reluctance on the part of their informants.
The focus of ethnozoology publications varies according to the region in which they are developed, as would be expected. The realities of each region, including its cultural diversity and the diverse types of ecosystems that occur there, will strongly influence research directions. Studies dealing with fishing resources (fish, crustaceans and mollusks) are more frequently undertaken in coastal areas, for example, while most of the published papers from the Amazon region have dealt with cynegetic animals and the use of the local fauna by indigenous groups. The environments in which the largest numbers of research projects were undertaken were: coastal and estuary sites (22.38%, n = 109 studies), Caatinga (dryland) areas (18.69%, n = 91), the Amazon region (16.02%, n = 78), and the Atlantic Forest (5.75%, n = 28). Only eleven studies were produced in the Cerrado (savanna) biome (2.26%), and no studies were published focusing on the Pantanal seasonal wetlands. A few projects (n = 10, 2.05%) were undertaken in two or more biomes; many were general studies (32.85%, n = 160) and not restricted to specific biomes (Table 1, Figure 3).
In spite of the quantitative increase of published reports in Brazil, there are still regional imbalances in terms of ethnozoological research and associated scientific production -with research being concentrated in the northeastern region of that country (39%, n = 190) (especially in the states of Bahia and Paraíba). Many of these studies were undertaken in the northern (15.2%, n = 74) and southeastern (11.9%, n = 58) regions of Brazil. In contrast, relatively few ethnozoological studies have been produced focusing on areas in the central-western and southern regions of the country (twelve (2.4%) and ten (2.0%) studies respectively). Eleven studies have been published concerning work undertaken in cities in northern and northeastern Brazil, while 27.1% (n = 132) did not foci on any specific region Figure 4).
The recent quantitative advances in ethnozoological publications were in large part due to the work of new researchers employed in research and teaching positions throughout Brazil who (together with the pioneer researchers) have greatly contributed to the growth of this area. Some of the articles published (n = 31, 6.3%) include the participation of foreign researchers, showing the existence of international links and interactions between researchers from Brazil and others countries. It must be pointed out, however, that the numbers of researchers directly involved with ethnozoological inquires in Brazil are still very small, although many zoologists and ecologists have undertaken research programs in this area even though ethnozoology is not their principal line of research. Another important aspect related to recent advances in ethnozoology is the fact that this subject is now offered in many graduate courses, even in largely specific departments such as Zoology and Ecology (e.g. the State University of Paraiba, and the State University of Feira de Santana). As such, there have been significant increases in the availability of advisors as well as in the numbers of graduate courses on this theme-which have contributed to the recent advances in ethnozoological studies in Brazil and reinforced the growth of this field.
Ethnozoological research papers have appeared in many different national (66.9%, n = 326) and international (33.%, n = 161) publications. Among the texts identified, most have appeared in scientific periodicals. Although these journal articles are the most frequent type of ethnozoological publication, there are currently no specialized ethnozoological journals published in Brazil (and even on a global scale there are relatively few journals focused on ethnobiology). As such, ethnozoological articles have been published in journals covering many different areas, such as traditional medicine, conservation, ethnography, conservation and management, among others. Although the multidisciplinary nature of ethnozoology permits different types of articles to be published in different journals (which has been an important factor stimulating the growth of scientific production on these themes), the results of our present study reinforce the necessity of establishing more journals with specific ethnobiological focuses that can accept texts in both ethnozoology and ethnobotany.
Brazil stands out as one of the world's leading producers of ethnozoological studies. These quantitative advances indicate that the country will continue to have an important role in ethnozoological research, and this same tendency has been observed for ethnobotany [26] -which places this country in the global vanguard of  ethnobiological inquires. In spite of this optimistic outlook, however, it is important to note that human resources with specializations in ethnozoology are still relatively scarce, and research centers in this area are restricted to just a few states in the country. On the other hand, interactions between ethnozoologists, zoologists and ecologists have been increasing and will certainly generate more publications and improvements in research quality.
In spite of the quantitative growth of ethnozoological research, there is a clear need for qualitative improvements in the publications generated. Many of the journal articles have had strongly descriptive natures, based simply on lists of species (which are often taxonomically incorrect or are restricted to just the common names of the animals). There is a necessity for planning and preparing studies with greater scientific rigor; for studies addressing specific questions and hypotheses; as well as theoretical and methodological advances that will help consolidate ethnozoology. In their review of ethnobotany in Brazil, Oliveira et al.
[26] noted the tendency to incorporate hypotheses as well as discussions and critical analyses of methodologies, as well as a movement towards focusing on the resolution of practical questions -tendencies that should likewise guide ethnozoological and ethnobiological researchers. The document "Intellectual Imperatives in Ethnobiology" [27], an international guideline to do ethnobiological research, makes it very clear that research projects in ethnobiology should be guided by hypotheses, that appropriate collaborators must be included to assure the use of rigorous methodologies inspired by different but related disciplines, and that statistical analyses and rigorous and appropriate mathematical models must be used to guide data collection and analysis [27]. , the SBEE has assumed an important role in the promotion of different forums for debate in which professionals from the area have been able to discuss the perspectives, limitations, conceptual and theoretical questions, theories, and methodologies, as well as the political and social implications of research in this area. The incorporation of ethnozoology into graduate programs has likewise made important contributions to this process. The challenges that the ethnosciences must face in the coming years include the amplification of graduate programs in regions and biomes that have been as yet little studied, as well as the continued thematic diversification of the field -which will help Brazilian ethnozoology consolidate itself as a modern and multidisciplinary science aligned with international research standards.
Ethnozoology currently confronts a number of challenges, and some of the most urgent items include the establishment of efficient dialogs between different academic areas that interface with ethnozoology; qualitative improvements in research techniques; greater scientific rigor; consolidation of undergraduate and graduate courses; exchanges of experiences in relation to the results produced and the methodologies utilized; and the development of monitoring programs based on sound research into the conservation and sustainable use of natural resources.
One of the main characteristics of human knowledge is its dynamism [26]. Reformulations of objectives, methodologies and theories occur in all of the sciences from time to time -and ethnozoology will not be different in this respect. The fact that ethnozoology has been the target of many recent criticisms has helped transform it into an area of scientific study bursting with new ideas and different reflections. As was noted by Oliveira [26], at a time when the world is debating so many polemic themes concerning the benefits and dangers of scientific/technological advances, the ethnosciences are discussing the possibility of linking scientific research to human priorities (especially to aid traditional populations and societies that have been historically excluded), the urgent necessities of conservation, and the more parsimonious use of natural resources.
In summary, literature researches indicated that ethnozoology has experienced significant advances in recent years in Brazil -although this discipline is still in the process of developing a sound theoretical base and unified methodological programs. A wide range of methodologies and theories have arisen in different areas of learning that can be put to good use if the right questions are asked using ethnozoological approaches.
The dynamism of this discipline in Brazil can be confirmed in the quantitative and qualitative growth of research papers published in scientific journals and discussed at related national events. More proof of the approaching maturity of this discipline can be seen in the numbers of internationally respected Brazilian ethnozoologists who are directly involved in the progress seen in their fields, and the participation of a many Brazilian researchers on editorial commissions and as consultants in renowned periodicals. From a qualitative point of view, however, improvement is still needed in terms of methodological procedures, taxonomic precision, and the use of quantitative techniques. The challenges to studying ethnozoology in Brazil are not small, and the tendencies described in the present study may aid in defining research strategies that will maintain the quantitative growth observed in the recent years but likewise foster needed qualitative improvements.