The Iwokrama Programme is a partnership between the Commonwealth and the people of Guyana. Iwokrama brings together local people, national and international interests in a variety of businesses. The idea of Iwokrama was born during the 1989 Commonwealth Heads of Government Meeting and Iwokrama has grown to be the Commonwealth's Flagship environment project. Iwokrama is a working example of developing partnerships for effective natural resource management and sustainable human development. This paper describes the background to Iwokrama and the role of the faunal surveys of the Iwokrama Forest led by the Academy of Natural Sciences, Philadelphia in the early development of Iwokrama. Thirty researchers spent over thirty months in the Iwokrama Forest, a virtually pristine tropical rainforest, between July 1996 and January 1998. These researchers came from more than ten research institutes to carry out the faunal surveys of the Iwokrama Forest. This work has made the fauna of the Iwokrama Forest one of the best documented in Northern South America. However, much more work remains to be done as we have only scratched the biodiversity surface of Iwokrama. The papers assembled here are the result of that work.

Archaeological investigations within Iwokrama Forest document significant Archaic and Horticultural occupations throughout the Reserve. Significantly, no evidence of earlier Paleoindian occupations (pre-7,000 B.P.) is documented. The Archaic Period from 7,000 to 3,000 B.P. (before present) is characterized by a variety of site types including artificial stone depressions and sharpening grooves, petroglyphs and a lithic tool manufacturing station. Petroglyphs reflect the Enumerative and Fish Trap Petroglyph Traditions better known from the savannah and rivers in southern Guyana. Archaic Period sites are found along major rivers and in the Iwokrama Mountains. Horticultural Period occupations dating from 3,000 B.P. to the Historic Period (mid-18^th century), include eight archaeological sites that have produced a wide range of vessel forms similar to Koriabo, Taruma and Rupununi types found elsewhere in Guyana. The occurrence of polychrome types by 3,000 B.P. indicates an early arrival of such styles in the area.

Five plant checklists from areas on and adjacent to the Guiana Shield were analyzed and used to test hypotheses of the salient properties of the flora of northeastern South America. Newly available checklists of Iwokrama, Mabura Hill, and Kaieteur Falls (all three in Guyana), Central French Guiana, and Reserva Ducke near Manaus, Brazil were compiled and their nomenclatural synonymies standardized. Data from checklists provide an attractive alternative to transect or plot data because they are based on rigorously determined plants of all habit types rather than the sterile vouchers of tree species often used in plot or transect studies. Descriptive data were compiled from the checklists regarding diversity, overlap, and endemism. Ranking of diversity at the family level was subjected to Kendall's coefficient of concordance of ranks test and Spearman rank correlation coefficients to evaluate similarities among the five sites. A UPGMA dendrogram was created from data for the presence or absence of species shared by two or more sites. The results indicate strong similarity among the three sites in Guyana and between Central French Guiana and Reserva Ducke, supporting a model of plant distributions determined by the presence or absence of sandstone or white sands rather than disjunct between the Roraima sandstone formation (“Guiana Highland”) and other areas of the Guiana Shield. Relatively little overlap was found even between adjacent areas with ostensibly very similar abiotic environments, indicating that plant diversity will not necessarily be protected by conserving representative areas selected on the basis of general characteristics.

Fishes were collected from the rivers in and around the Iwokrama Forest during January–February and November–December 1997. Four hundred species of fish were recorded from forty families in ten orders. Many of these fishes are newly recorded from Guyana and several are thought to be endemic. The number of species recorded for the area is surprising given the low level of effort and suggests that this area may be particularly important from a fish diversity perspective. This paper focuses on species of particular interest from a management perspective including those considered economically important, rare or endangered. The paper is also the basis for developing fisheries management systems in the Iwokrama Forest and Rupununi Wetlands.

We compared species richness estimates for eight camps sampled in 1997 to inventory the herpetofauna of the Iwokrama Forest. Regression analyses and Coleman curves documented that species richness was lowest in the camp at the highest elevation. We also found that the four standard sampling methods we used in 1997 differed significantly in detecting species. All methods were necessary to generate a complete species list of 141 species, but visual encounter surveys and opportunistic collecting discovered the largest number of species in Iwokrama. Our results show that meaningful comparisons of species diversity are only possible when effort has been standardized.

As part of a larger project on biodiversity and conservation in Guyana, we documented 130 species of mammals from Iwokrama Forest. This included 7 marsupials, 4 xenarthrans, 86 bats, 5 primates, 8 carnivores, 1 perissodactyl, 4 artiodactyls, and 15 rodents. As is typical for most Neotropical sites, the 86 species of bats represent over half of the mammal diversity. Standardized collecting methods implemented in the 1997 faunal survey of Iwokrama Forest in central Guyana enabled us also to investigate species diversity and abundance resulting from the inventory of mammals. Four species of fruit-eating bats (Artibeus lituratus, A. obscurus, A. planirostris, and Carollia perspicillata) were the most abundant and accounted for 43% of the 2,097 total captures in mist nets and harp traps during 79 nights of sampling. For nonvolant mammals, terrestrial spiny rats (Proechimys spp.) represented over half (55%) of the 65 captures in primarily live box-style traps. We estimate that our inventory is approximately 70% complete with an additional 57 species of mammals expected to occur in Iwokrama Forest. More specialized field techniques are required to attain a complete inventory of mammals, and long-term monitoring should be established at several sites to study spatial and temporal variation.

This paper is an abridged version of an earlier report describing field work on birds of Iwokrama Forest (IF) between March 1996 and September 1997. The avifauna of IF is discussed in terms of habitat heterogeneity, seasonailty and ongoing monitoring. Avian species richness in IF is similar to other tropical forest localities that have been studied with similar intensity with 476 species having been recorded furing the work reported here. Distinctive habitats such as Humiria-dominated low woodland and scrub with little or no grass cover that grows on areas with nutrient-poor sandy surface soil (Muri scrub) and pre-montane (foothill) forests are also found within IF and both of these habitats contribute significantly to total diversity of IF. IF has relatively high densities of larger frugivorous birds such as cracids, cotingas, and parrots.

Tropical biodiversity researchers are working in ecological, social, and economic contexts that are completely different from those of 150 years ago. In the 1800s, scientists from developed nations studied tropical biodiversity as part of expeditionary work. The social and economic benefits from these studies went to citizens of the developed nations that funded the research. Benefits accrued to foreigners rather than the native inhabitants of tropical nations explored by natural historians. Today, the governments and citizens of tropical nations view biodiversity components as natural resources that can contribute to national cultural, social, and economic development. Modern biodiversity researchers therefore find themselves working under socio-economic conditions that are radically different from those experienced by Darwin, Wallace, Humboldt, Bates and their contemporaries. In the last quarter of a century, biodiversity researchers from developed nations have struggled to meet the changing focus for their research and have substantially modified research processes to meet some of the needs and directions of developing nations. In this essay, we discuss how developed nation biodiversity researchers are changing their approach to working in tropical countries. We illustrate this change by examining how researchers from developed country work in developing countries. We examine potential reasons for conflict between developed nation biodiversity researchers and citizens of developing nations, and suggest potential solutions to these conflicts. In particular, we suggest that developed nation biodiversity researchers continue to place a strong emphasis on outputs that benefit the countries in which they work. We also suggest that biodiversity researchers should seek input from representatives of developing nations in planning projects so that research efforts can meet the needs of the host-country. We use experiences in Guyana, South America, to illustrate collaborative approaches to biodiversity research.

The mouthparts, chelipeds and foregut of two kalliapseudid apseudomorphan species, Kalliapseudes macsweenyi (subfamily Kalliapseudinae) and Psammokalliapseudes granulosus (subfamily Tanapseudinae), are described and compared using light and scanning electron microscopy. The setae on the mouthparts differ considerably between these two species and are directly related to the feeding mechanism, being in accord with the subfamilial kalliapseudid classification. K. macsweenyi possesses plumose setae on the chelipeds, maxillipedal palps, and mandibular palps. The females of P. granulosus possess simple setae on the chelipeds. The males possess plumose setae on the chelipeds, but are directed ventrally, and thus do not form a filter as in K. macsweenyi. Females and males of P. granulosus possess simple and serrate setae on the maxillipedal palps; the mandibular palp is reduced and bears one serrate seta; and both sexes of P. granulosus possess comb setae on the moveable endite of the maxilla. The mandibles of K. macsweenyi are more heavily calcified and have better developed molar processes than those of P. granulosus. Foregut morphology of these two species is nearly identical and could be attributed to their close phylogenetic relationships on the familial level, or to their similar, chiefly detritus-based diets.

A new diatom species is described from the Willamette River, Oregon, USA. The characteristics of this taxon at the light microscopy (LM) and scanning electron microscopy (SEM) levels favor its placement in the genus Adlafia Moser, Lange-Bertalot et Metzeltin. Thus, the name Adlafia multnomahii Morales et Le is proposed. Analysis of additional samples currently deposited in the Academy of Natural Sciences of Philadelphia (ANSP) Diatom Collection yielded other populations of the new taxon from Arkansas, California, Connecticut and New Hampshire. The new taxon is characterized by a lanceolate shape with conspicuously capitate to rostrate ends, distal and proximal raphe ends deflected in opposite directions, round areolae occluded by a perforated velum located on the outer periphery of the areola, and closed girdle bands with one row of areolae, which becomes biseriate toward the apices of the valves. A comparison of the new taxon with other morphologically closely related taxa and its ecological requirements are discussed in the light of existing data and literature.

A new diatom genus typified by the new species Lacunicula sardiniensis Lange-Bertalot, Cavacini, Tagliaventi et Alfinito was recently described by Lange-Bertalot and collaborators from ephemeral pools in Sardinia, Italy. The new genus is mainly characterized by the presence of an external channel system found in the axial area on both sides of the raphe fissure. We present here a detailed analysis of a North American population of the same species from Zollner Creek, Oregon. Based on light microscopy (LM) and scanning electron microscopy (SEM) data, it is proposed that the mentioned species be placed in the genus Craticula Grunow instead. Lacunicula sardiniensis shares many characteristics with species currently placed in Craticula; among them are: 1) the characteristically raised axial area in both internal and external views, 2) the presence of a conopeum along the axial area of the valves, 3) the similarity of areolar and velum patterns and characteristics in both external and internal views of the valves, 4) the similarity in the structure of the raphe and helictoglossa, and 5) the presence of longitudinal ridges on the valve mantle and valve face. Thus, the new combination Craticula sardiniensis (Lange-Bertalot, Cavacini, Tagliaventi et Alfinito) Morales et Le is proposed and the relationship of the taxon with closely related species in the genus Craticula is presented in the light of available literature.