Louise H. Emmons

Comparative feeding ecology of felids in a neotropical rainforest

SummaryDiet and habitat use of jaguar, puma, and ocelot, and populations of their mammalian prey, were studied in an undisturbed rainforest in southeastern Peru. Analysis of scats (feces) showed terrestrial mammals to be the chief prey of all three felids, but reptiles and birds were also numerically important in the diets of ocelot and jaguar. Prey diversity is high and the cats evidently take any readily captured vertebrate. For major terrestrial mammal prey of felids, density, biomass, prey/predator ratios, and annual offtake from the study area are estimated. All three cat species seem to hunt by opportunistic encounter of prey. Most mammalian prey species were taken in about the ratios of occurrence, but peccaries were taken by jaguar more often than expected. Most prey of jaguar have a body weight of >1 kg, those of ocelot, ≤1 kg. Jaguar often used waterside habitats, where they captured caiman and river turtles. Puma did not use these habitats or resources, although the puma prey sample was too small for much inference. The possible effects of felids on study area prey populations are discussed. Large and small cats partition prey at the body weight region where prey switches from low to high reproductive rates.

Geographical variation in fertility, phenology, and composition of the understory of neotropical forests

We compare levels of flowering and fruiting in 55 samples of Neotropical forest understory from 13 sites in 6 countries. Each sample consists of a census of fertile understory plants along a transect. Changes in species richness and density of fertile understory plants are correlated with rainfall and soil fertility. Areas with weak (or no) dry seasons and intermediate to rich soils average 64 fertile plant species and 174 individuals per sample, whereas areas with poor soil and a strong dry season average only 5 fertile species and 8 fertile individuals. Areas with either strong dry seasons and good soils or weak dry seasons and very poor soils have intermediate values. Taxonomic composition of the understory also changes predictably with rainfall and soil fertility. In increasingly stressed forests changes are found in understory structure, with sequential loss of terrestrial herbs, epiphytes, understory shrubs, and lianas. The understory of the poorest soil site consists almost entirely of young trees. The effects of seasonal differences at a given site are small compared with between-site differences. We suggest that the level of understory fertility may provide a simple indicator of overall ecosystem productivity. THE UNDERSTORY OF A TROPICAL RAIN FOREST iS composed of a different set of species than is the canopy. The understory, though often neglected, is an integral and important part of the plant community. For example, understory species constitute 25 percent of the species and 24 percent of the individuals sampled in 1000 m2 at a wet-forest site in western Ecuador (Gentry and Dodson 1987). In a coastal Ecuador moist forest, 2 1 percent of the species and 44 percent of the individuals in a similar sample are restricted to the understory. The importance of understory plants is evident from local species lists: 46 percent of the Rio Palenque species (Dodson and Gentry 1978), 43 percent of the Barro Colorado Island, Panama species (Croat 1978), and 47 percent of the Jauneche (Dodson et al. 1985) species are herbs, shrubs, and small trees. These figures are overestimates, since a number of the species included in such lists are weedy and found rarely, if at all, inside the closed forest, but the overall importance of the understory to rainforest plant diversity is clear. The understory supports a different fauna than does the canopy. Many species of insects, birds, and mammals are restricted to the understory, and understory plants are major food sources for this biota. For example, hermit hummingbirds, major pollinators for many plant taxa, are exclusively understory birds. Such frugivores as birds of the family Pipridae and bats of the genus Carollia are largely dependent on understory fruits (e.g., Snow 1965, Stiles 1981, Fleming 1985). Temperate zone studies have shown that response of the forest understory to environmental gradients can differ from that of the canopy (summary in Whittaker 1977). For the tropics, we now have data that show predictable patterns of change in plant community composition across such environmental gradients as annual precipitation (Gentry 1982a, 1987, in press). Surprisingly little attention has been focused on the easily accessible understory, and few data are available for comparing the structure or floristic composition of the rainforest understory in differ-

A comparison of the diets of three major groups of primary consumers of Gabon (primates, squirrels and ruminants)

SummaryThe diets of three major groups of frugivores-folivores of an African rain forest (squirrels, ruminants, primates) are compared and the relationship of food habits to body weight, habitat and foraging height examined. A number of common trends in the trophic patterns are found in the three groups. Over half of the fruit species identified in the diets of any one taxon are exploited in common with one or more of the others. The parts of fruit usually eaten are different for each group but for a number of species, the same fruit parts are searched for by the species of the three taxa.

Rodent dispersal of vesicular-arbuscular mycorrhizal fungi in Amazonian Peru

We quantitatively assessed rodent dispersal of vesicular-arbuscular mycor- rhizal fungi in a lowland tropical rain forest. We examined fecal pellets from seven rodent species of the genera Proechimys, Oryzomys, and Mesomys trapped each month from August 1983 through July 1984 at the Cocha Cashu field station in Manu National Park, Peru. We found sporocarps of Sclerocystis coremioides and spores of four Glomus species in 69.3% of fecal samples, with 37.5% of samples containing 2-4 fungus species. There were median numbers of 8.6 S. coremioides sporocarps and 712 Glomus spores/0. 1 g feces. S. coremioides and all Glomus species comprised up to 4.1 and 5.4% of fecal mass, respec- tively. We did not detect differences in fungus consumption by rodent species or sex, but did find significant differences between rodent genera. More than 60% of Proechimys samples contained glomalean fungi in contrast to -37% of Oryzomys samples. Occurrence of the two fungus genera in feces differed seasonally but was generally congruent between Proechimys and Oryzomys. Glomus presence in feces is significantly positively associated with the dry season. Both rodent genera together annually pass 2.96 X 105 S. coremioides sporocarps and 7.30 X 107Glomus spores/ha at Cocha Cashu. We concluded that Proechimys and Oryzomys are likely to be important agents of vesicular-arbuscular mycorrhizal fungus spore dispersal.

Exposure of free-ranging maned wolves (Chrysocyon brachyurus) to infectious and parasitic disease agents in the Noël Kempff Mercado National Park, Bolivia.

Abstract Maned wolves (Chrysocyon brachyurus) are neotropic mammals, listed as a CITES Appendix II species, with a distribution south of the Amazon forest from Bolivia, through northern Argentina and Paraguay and into eastern Brazil and northern Uruguay. Primary threats to the survival of free-ranging maned wolves include habitat loss, road kills, and shooting by farmers. An additional threat to the conservation of maned wolves is the risk of morbidity and mortality due to infectious and parasitic diseases. Captive maned wolves are susceptible to, and die from, common infectious diseases of domestic dogs (Canis familiaris) including canine distemper virus (CDV), canine parvovirus (CPV), rabies virus, and canine adenovirus (CAV). Results from this study show that free-ranging maned wolves in a remote area of Bolivia have been exposed to multiple infectious and parasitic agents of domestic carnivores, including CAV, CDV, CPV, canine coronavirus, rabies virus, Leptospira interrogans spp., Toxoplasma gondii, and Dirofilaria immitis, and may be at increased risk for disease due to these agents.

Species Groups in Proechimys (Rodentia, Echimyidae) as Indicated by Karyology and Bullar Morphology

The genus Proechimys is divisible into four groups of species on the basis of bullar septal patterns. Each of the four groups can be further characterized by distinctive distributions and karyotypes. The subgenus Trinomys and the guairae species group each are comprised of phylogenetically closely-related species. The semispinosus - and brevicauda -groups, although generally distinctive on the basis of bullar septa, are not phylogenetically equivalent to the first two groups. The brevicauda -group, for example, consists of at least three separate species complexes. The taxonomy used in this report reflects several nomenclatural changes from that used in the recent literature. In addition, previously unreported karyotypes are described for P. quadruplicatus, P. gularis, P. decumanus, P. oris, P. oconnelli , and P. mincae .

A Review of the Named Forms of Phyllomys (Rodentia: Echimyidae) with the Description of a New Species from Coastal Brazil

Abstract To clarify the taxonomy and serve as a foundation for future systematic studies, we searched for the type material associated with all named forms of Brazilian Atlantic tree rats of the genus Phyllomys. For the following ten taxa we found either the originally designated holotypes, syntype series, or contemporary specimens likely to have been seen by the authors: P. blainvilii, P. brasiliensis, P. fossilis, P. nigrispinus, P. unicolor, P. dasythrix, P. lamarum, P. medius, P. thomasi, and P. kerri. For five species the holotype was unambiguously identified. For five other named forms no holotype was originally designated but we found several candidate specimens and for all of these we designate lectotypes. We identify the type localities for all named Phyllomys species and amend those which are ambiguous. We review the taxonomy, diagnosing and redescribing all the named forms of the genus. After examining the type material, we concluded that the rusty-sided tree rat from coastal Brazil, usually identified in the literature as P. brasiliensis, belongs to an unnamed species. We describe and name it here. RESUMEN Com o objetivo de esclarecer a taxonomia e servir de base para futuros estudos sistemáticos, nós procuramos identificar os tipos associados a todas as formas descritas dos ratos arbóreos do gênero Phyllomys. Encontramos, para as seguintes 10 espécies, o holótipo designado originalmente, ou séries de síntipos, ou ainda espécimes contemporâneos provavelmente vistos pelos autores: P. blainvilii, P. brasiliensis, P. fossilis, P. nigrispinus, P. unicolor, P. dasythrix, P. lamarum, P. medius, P. thomasi e P. kerri. Para cinco delas o holótipo foi identificado sem nenhuma dúvida, enquanto que vários espécimes candidatos foram encontrados para cinco outras onde nenhum holótipo foi designado originalmente. Para todos esses nós designamos lectótipos. Nós identificamos as localidades tipo de todas as espécies descritas, corrigindo e restringindo as que eram ambíguas. Também revimos a taxonomia, diagnosticando e descrevendo todas as espécies nomeadas do gênero. Após examinarmos os tipos, concluimos que o rato de espinho ferrugíneo da costa do Brasil, geralmente identificado na literatura como Phyllomys brasiliensis, pertence à uma espécie distinta que ainda não tem nome. Nesse artigo, nós descrevemos e nomeamos essa espécie.

Serosurvey of Pathogens in Domestic Dogs on the Border of Noël Kempff Mercado National Park, Bolivia

Abstract The threat of disease transmission from domestic animals to wildlife has become recognized as an increasing concern within the wildlife community in recent years. Domestic dogs pose a significant risk as reservoirs for infectious diseases, especially for wild canids. As part of a multifaceted ecologic study of maned wolves and other canids in the large, remote Noël Kempff Mercado National Park (NKMNP) in northeastern Bolivia, 40 domestic dogs in two villages and at two smaller settlements bordering the national park were sampled for exposure to canine diseases. High levels of exposure were found to canine distemper virus and canine parvovirus, both of which are known to cause mortality in maned wolves and other carnivores. Moderate to high levels of exposure were found to rabies virus, Ehrlichia canis, and Toxoplasma gondii, as well as significant levels of infection with Dirofilaria immitis. This study reports evidence of exposure to several diseases in the domestic dogs bordering the park. Contact between wild carnivores and dogs has been documented in the sampled villages, therefore dogs likely pose a substantial risk to the carnivores within and near NKMNP. Further measures should be undertaken to decrease the risk of spillover infection from domestic animals into the wild species of this region.

Frugivory in treeshrews (Tupaia)

Four species of treeshrews (Tupaia spp.) studied in the field in Sabah, Malaysia, show intense frugivory concentrated on small, soft, bird-dispersed fruits. Observations of a wild individual and captives of two species show that treeshrews reject indigestible fibers and other parts of fruits before swallowing the pulp. Transit times of fruit through the gut are rapid and body-size dependent, with mean times to first defecation of marker dye of 20 min (range, 13-29 min) for Tupaia minor (≈60 g mass), and 57 min (range, 38-73 min) for Tupaia tana (220 g mass). The intestine of Tupaia species consists of a long small intestine, rudimentary or no cecum, and a greatly reduced, narrow, smooth colon. The fruit-processing method, rapid food transit time, and gut morphology of treeshrews resemble those of frugivorous bats but are unlike those of small primates.

A New Species of the Rodent Genus Oecomys (Cricetidae: Sigmodontinae: Oryzomyini) from Eastern Bolivia, with Emended Definitions of O. concolor (Wagner) and O. mamorae (Thomas)

Abstract We describe a new species of Oecomys, O. sydandersoni (Cricetidae: Sigmodontinae), from the Parque Nacional Noel Kempff Mercado in eastern Bolivia. One of its diagnostic traits, a derived carotid circulatory plan, provides morphological evidence for its close relationship to O. concolor and O. mamorae among the 15 species of Oecomys currently recognized. Notwithstanding this shared trait, other morphological contrasts and morphometric analyses demonstrate the sharp differentiation of the eastern Bolivian form from both of those species. Oecomys sydandersoni, n. sp., is arboreal and was encountered above ground on limbs and woody vines only in densely wooded hummocks scattered through grassland, in contrast to adjacent closed tropical deciduous forest where three other species of Oecomys (O. bicolor, O. roberti, O. trinitatis) were obtained. The new species represents the fourth sigmodontine rodent to be named from this restricted region within eastern Bolivia since 1999. Its documentation served as a platform to summarize the nomenclatural history, morphological recognition, and geographic distribution of O. concolor (Wagner, 1845) and O. mamorae (Thomas, 1906) based on fresh examination of all type material and museum specimens.