Moa River Research Articles

Occupancy and abundance of a West African mangabey species (Cercocebus atysAudebert, 1797) in forest patch habitat

AbstractSooty mangabeys are Old World primates from the Upper Guinea Rainforests of West Africa. They suffer from habitat degradation due to deforestation and hunting for the bush‐meat trade. Tiwai Island and adjacent small islands are a small protected area surrounded by the Moa River that is known for its high diversity of primate species. We evaluated the occupancy and abundance of sooty mangabeys on Tiwai Island and the surrounding islands using camera traps during 2008–2011. Over two seasons, we obtained a naïve occupancy rate of 0.77 for Tiwai Island but only 0.19 for surrounding smaller islands. We used Abundance‐Induced Heterogeneity Model and Royle Repeated Count Model to estimate the abundance of 326 ± 92 (SE) and 530 ± 102 (SE) individuals of sooty mangabeys respectively. Based on these occurrences, sooty mangabeys usually appeared in riparian, mature and young secondary forests. Activity patterns of sooty mangabeys based on circadian patterns of detections confirmed that they were diurnal with several activity peaks during the daylight hours. The results of this study suggest that a viable population of sooty mangabeys still inhabits Tiwai Island and its vicinity, but that their core population is primarily limited to the Tiwai Island reserve. Thus, there is a need to protect the island and its adjacent habitats to ensure the conservation of sooty mangabeys in particular and other primate species in general.

Soils, Geoenvironments and Ecosystem Services of a Protected Area in Western Brazilian Amazonia.

The Serra do Divisor National Park (SDNP) in the Westernmost Brazilian Amazonia possesses unique Mountain landscapes of sub-andean nature, with high geo-biodiversity and pristine environments, with a potential high contribution in ecosystems services. We studied and mapped the basic geo-environmental units of the main sector of the Park, evaluating soil carbon stocks as a key ecosystem service provided by the Protected Area. For the identification, characterization and mapping of the geoenvironmental units, we integrated pedological, geomorphological and vegetation data obtained by local soil survey and field campaigns, as well as secondary data. Eight geoenvironmental units were identified and mapped, distributed in three main compartments: the Serra do Divisor (SD) the upper Moa River and the medium Moa River. This region presents similar environments to the sub-Andean region, notably the Ceja Forest at the top surface of the SD. Soils at the SD have high organic carbon accumulation, with close association with the nutrient-poor, quartz-rich rocks, and shows organic matter illuviation indicating active podzolization. The SDNP encompasses important ecosystems and services linked with high geo-biodiversity, and high soil carbon stocks, representing a new frontier for scientific research in the only area of transitional sub-andean forested landscape in Brazil.

Ergasilus colomesus (Copepoda: Ergasilidae) parasitizing gills of Colomesus asellus(Tetraodontiformes: Tetraodontidae) in the western Brazilian Amazon.

Records about Ergasilus colomesus and its interaction with the host fish are scarce. There is only a report describing this species from specimens collected from the gills of Colomelus asellus, in the State of Amazonas, Brazil. In this sense, this is the first record of E. colomesus parasitizing C. asellus for the southwest of the Brazilian Amazon. Fish were collected in the Môa river, located in the municipality of Cruzeiro do Sul, State of Acre, Brazil, during drought and flood. The fish captured were analyzed, and the parasites found were measured, fixed, and identified. We calculated the parasite indices and evaluated whether the seasonal periods (drought and flood) influence the levels of parasite infestation in their hosts. The prevalence and infestation of E. colomesus in C. asellus were higher in the drought, indicating that the infestation of this copepod probably occurred during this period. The lower number of individuals found during the flood indicates that this is the period when E. colomesus detaches from its host to release of eggs into the environment. In this sense, this study expanded the distribution record of E. colomesus parasitizing C. asellus to southwestern Amazonia.

Genesis and micropedology of soils at Serra do Divisor and Moa river floodplain, northwestern Acre, Brazilian Amazonia

ABSTRACT The northwestern part of the Acre State (Brazil) possesses singular soils in Brazilian Amazonia, but have been very little studied. This study aimed to discuss the genesis and some micropedological aspects of the soils from Serra do Divisor and adjacent floodplain soils of the Moa river, to enhance the knowledge on their formation. A toposequence of soils ranging from the uppermost part of sub-Andean Serra do Divisor to the Alluvial soils of Moa river floodplain was studied, regarding chemical, [...]

Occupancy and habitat use by six species of forest ungulates on Tiwai Island, Sierra Leone

Forest ungulates in West Africa are common bushmeat species and are subject to habitat degradation through deforestation. Based on historical data, there are possibly 12 species of forest Bovidae and Tragulidae found in eastern Sierra Leone. We used camera trapping to assess occupancy by forest ungulates on and around a small protected area, Tiwai Island, Sierra Leone. We then assessed habitat over two field seasons during 2008–2011 for those species where we had sufficient numbers of detections. We detected 6 of 12 potential species and obtained enough data to further assess the habitat of two species. Species detected included the black duiker (Cephalophus niger), bongo (Tragelaphus eurycerus), bushbuck (Tragelaphus scriptus), Maxwell’s duiker (Philantomba maxwellii), water chevrotain (Hyemoschus aquaticus) and yellow-backed duiker (Cephalophus silvicultor). Among detected species, the bongo is considered near threatened. Several of the species not detected might be extirpated from the region, but for several species we found no records of them in the area. For the two species with sufficient detections for analysis, we found that Maxwell’s duikers were common throughout woody and swamp habitat and yellow-backed duikers preferred old growth forests with open understory. Despite widespread deforestation in Sierra Leone, a recent civil war and continued bushmeat trade, it appears that small wildlife refuges such as Tiwai Island continue to provide sanctuary for many of the forest ungulates of the region.Conservation implications: The Guinea Rainforest ecosystem of West Africa has undergone significant human impact and deforestation, negatively impacting all aspects of the biodiversity of the region. In addition, a long-standing civil war in Sierra Leone further exacerbated conservation concerns of many wildlife species. There are some recognised reserves in Sierra Leone, but small reserves managed by local people and conservation organisations have a role to play. Our work on Tiwai Island, along the Moa River in Sierra Leone, demonstrated that a significant proportion of the forest dwelling ungulate biodiversity of the region has been maintained in a small reserve despite isolation and effects of the war. Our work also suggests that Tiwai Island continues to have significant ecological value for ungulate conservation in the region and should be considered a model for establishment of other small reserves to help maintain the region’s biodiversity.

Richness, breeding environments and calling activity of the anurofauna of the lower moa river forest, state of Acre, Brazil

In state of Acre, most anuran research has been carried out in areas of terra firme, whereas alluvial forests remain relatively unexplored. We document the richness, breeding environments and calling season of the anurans of the Lower Moa River in the Alto Jurua (state of Acre), a region considered to harbor high biodiversity. Sampling was conducted in two main areas with different forest typologies (Terra firme forest and Alluvial forest), totaling 256 ha. The diversity of anurans was analyzed using the Shannon-Wiener index, evenness and Berger - Parker dominance. The anurans were sampled from October 2008 to September 2009, using the following sampling methods: sampling at breeding sites, pitfall traps, time constrained visual search during the day (TCVSD); at night (NVTCS) and active search (AS). Fifty anuran species, belonging to eight families, were recorded: Aromobatidae (2), Bufonidae (5), Hemiphractidae (1), Hylidae (25), Leptodactylidae (9), Microhylidae (4), Ranidae (1) and Craugastoridae (3). Pitfall traps totaling 1440 day-buckets in the year. DVTCS had a total sampling effort 72 hours/person/year; NVTCS - 72 hours/person/year and AS - 24 hours/person/year. Greater richness (35 species) was recorded in the alluvial forest, low diversity index and high dominance (H' = 1.69, J' = 0.51, d = 0.62). Most likely, these values were influenced by the high relative abundance of Rhinella margaritifera in this area. The richness of the alluvial forest may be associated with environmental heterogeneity according with the theory of intermediate disturbances. The breeding activity of most species occurred in lentic environments (lakes and temporary ponds) and during the rainy season. When sampling anurans in the Amazon it is important to use two or more sampling method and to consider the different forest typologies of this biome for a better characterization of its richness.

Local awareness of and attitudes towards the pygmy hippopotamusChoeropsis liberiensisin the Moa River Island Complex, Sierra Leone

AbstractThe pygmy hippopotamusChoeropsis liberiensisis an Endangered species found only in the Upper Guinea rainforests of West Africa. Using a two-phase approach, with initial semi-structured interviews followed by more extensive questionnaires, we examined local residents' awareness of and attitudes towards the pygmy hippopotamus along the Moa River near Tiwai Island Wildlife Sanctuary in Sierra Leone. The interviews and questionnaires addressed human–hippopotamus interactions, local knowledge and awareness of pygmy hippopotamus ecology and behaviour, and public attitudes towards hippopotamus conservation. Overall, 22% of questionnaire respondents acknowledged benefits related to hippopotamus conservation; factors affecting the perception of benefits included age, livestock ownership, distance from Tiwai Island and exposure to conservation programmes. The results of this study could be used to inform the conservation of the pygmy hippopotamus and highlight the critical role of local support in the management of threatened species in biodiversity hotspots.

Herpetofauna da floresta do baixo rio Moa em Cruzeiro do Sul, Acre - Brasil

O presente trabalho tem como objetivo apresentar o resultado de um levantamento herpetofaunístico realizado na floresta do baixo rio Moa, em Cruzeiro do Sul, Acre. O estudo foi realizado entre fevereiro de 2008 e setembro de 2009, sendo as espécies registradas através de armadilhas de interceptação e queda (AIQ), procura limita por tempo (PLT), busca ativa (BA), amostragem em sítios reprodutivos (ASR) e encontros ocasionais (EO). A herpetofauna foi amostrada em uma área de aproximadamente 256 hectares em áreas de propriedades particulares, incluindo área aberta antropizada, adjacente a floresta, composta principalmente por pastagens. Na área florestada a amostragem foi realizada em duas trilhas com fisionomias diferentes (Mata de Terra Firme e Mata de Várzea). Foram registradas 103 espécies, sendo 50 de anfíbios anuros e 53 de répteis (35 serpentes, 17 lagartos e um crocodiliano). A curva do coletor atingiu a assíntota para os anfíbios anuros, mas não para os lagartos, serpentes e a herpetofauna (todos os grupos). Nas áreas florestadas foi registrada a maioria das espécies de anfíbios anuros, o mesmo sendo observado para os répteis, sendo que a maioria destes foi registrada na mata de terra firme. A maioria dos anfíbios foi registrada durante a PLT e a ASR, enquanto os répteis foram através de EO e também por PLT. Espera-se um número maior de espécies de serpentes para a localidade do que a riqueza registrada (35 espécies). Salienta-se a importância da preservação de áreas florestadas particulares abrangendo tanto habitats nas margens de rios sujeitos a alagação periódica como de terra firme, uma vez que existem diferenças na composição herpetofaunística em relação a estrutura das florestas. A preservação das áreas de floresta é fundamental para manutenção da diversidade de anfíbios e répteis na Amazônia, que tem sua riqueza diminuída com a transformação de florestas em pastagens e também com a retirada de madeira e abertura de clareiras.

New species of Fissiphallius Martens 1988 from Brazil and notes on the mor-phology of Fissiphalliidae (Arachnida, Opiliones)

The seventh species of Fissiphallidae, Fissiphallius orube sp. nov., and the fourth from Brazil (type locality state of Acre,Cruzeiro do Sul, at the Moa river), is described. The new species differs from the remaining species of the family in lack-ing a pergula, having a knob at the base of the rutrum, and the ocularium spiniform projection with apical portion single or divided in two to three parts.

Concordance between macroinvertebrate communities and the typological classification of white and clear-water streams in Western Brazilian Amazonia

In this study we have attempted to answer whether there is correspondence between aquatic macroinvertebrate communities and the typological classification of white and clean-water streams in western Amazonia lowlands. We worked within two distinct hydrographic basins: Moa River catchment (clear-water streams) and Azul River catchment (white-water streams) in Serra do Divisor National Park, Acre State, Brazil, sampling 10 streams in each basin. A total of 2,952 individuals were collected, distributed among 134 taxa. Our results show that macroinvertebrate communities, at genus as well as family level, are in concordance to a priori classifications that distinguish between white and clear water streams. The main implication of our results for biomonitoring is that biotic variation between white and clear streams can be partitioned regionally, which would improve the bioassessment accuracy of the Amazonian streams.

Occurrence of Helminths in Lizards (Reptilia: Squamata) at Lower Moa River Forest, Cruzeiro do Sul, Acre, Brazil

Eleven of 113 (10%) lizards representing 6 of the 17 species (Anolis fuscoauratus, Anolis trachyderma, Plica umbra, Kentropyx pelviceps, Arthrosaura reticulata, and Mabuya nigropunctata) collected in the lower Moa River forest, in the Amazon rainforest in the Brazilian state of Acre, were infected with helminths in the gastrointestinal tracts. The nematodes recovered from lizards were Physaloptera lutzi, Physaloptera retusa, and Physalopteroides venancioi. Three new host records and two new locality records are reported.

Uso do hábitat, atividade e comportamento de Bothriopsis bilineatus e de Bothrops atrox (Serpentes: Viperidae) na floresta do Rio Moa, Acre, Brasil

As serpentes Bothriopsis bilineatus e Bothrops atrox são viperídeos simpátricos na Amazônia, sendo B. atrox comum e B. bilineatus mais rara. Ambas espécies apresentam uma dieta generalista, sendo que B. atrox forrageia principalmente sobre o chão e B. bilineatus é mais arborícola. Aqui, nós descrevemos o uso do habitat e padrão de atividade dessas duas serpentes em uma floresta amazônica no Rio Moa, Cruzeiro do Sul, Acre. Esse estudo foi baseado em observações durante procura visual limitada por tempo e encontros ocasionais de serpentes em uma trilha que é sazonalmente alagada e outra de floresta de terra firme. Durante um total de 360 horas de procura visual limitada por tempo, 11 B. bilineatus e seis B. atrox foram encontradas, enquanto uma B. bilineatus e seis B. atrox foram encontradas durante encontros ocasionais. Todas 12 B. bilineatus foram observadas sobre a vegetação, enquanto somente cinco B. atrox estavam sobre a vegetação (todos juvenis). Durante procura visual limitada por tempo B. bilineatus foi mais comum (0,03 serpentes/hora) do que B. atrox (0,016 serpentes/hora). Essas duas espécies apresentaram diferenças no uso do espaço, sendo que B. bilineatus ocorreu principalmente na área da floresta de terra firme, rica em palmeiras e que não é sazonalmente alagada. Bothrops atrox foi mais abundante na área da floresta próxima aos lagos, que é sazonalmente alagada. Diferenças entre essas duas áreas como a estrutura da vegetação, tipos de ambientes aquáticos, disponibilidade de presas e fatores históricos são possivelmente os fatores responsáveis pela diferença na ocorrência dessas espécies. Estas duas serpentes foram encontradas nos meses mais chuvosos e não foram registradas nos meses mais secos, período em que também existe menor disponibilidade de anuros nesses ambientes. Na maior parte da Amazônia, B. bilineatus parece ser menos frequente que B. atrox, mas na área do presente estudo, a primeira parece ser mais frequente que a última durante procura visual limitada por tempo.

Hydrogeotechnical characterization of a metallurgical waste

This paper presents the results of hydrogeotechnical characterization tests carried out on the metallurgical waste (MW) from a tailings impoundment located on the terraces of the Moa River, Cuba. Characterization of the MW includes chemical and mineralogical analysis, oedometer tests, triaxial tests, tensile strength tests, determination of the water retention curve, and shrinkage and permeability tests. The MW, which has a grain-size distribution similar to that of a silt, mainly contains iron and heavy metals minerals and has low plasticity. Consolidated undrained triaxial tests on remoulded samples indicate a dilative behaviour, with a decrease in pore-water pressure near failure. The material is susceptible to liquefaction when subjected to a cyclic load in the triaxial test. Hydraulic conductivity, soil stiffness, and compressive and tensile strength of the MW have an important dependence on the degree of saturation and vary significantly during the drying process. The results indicate that, during the drying process, cracks in the MW initiate in quasi-saturated conditions. The cracks increase the hydraulic conductivity by more than one order of magnitude compared with that of intact samples of MW. The main environmental risk with this MW is the possibility of liquefaction under a cyclic load due to an earthquake and the increase in saturated hydraulic conductivity due to desiccation cracks.Key words: desiccation cracks, hydrogeotechnical properties, liquefaction, metallurgical waste, characterization.

Neotectonic influence on tropical rivers of southwestern Amazon during the late quaternary: the Moa and Ipixuna river basins, Brazil

Abstract Neotectonic influence has conditioned the development of the Moa and Ipixuna fluvial belts in the southwestern Brazilian Amazon region. The area underwent a compressive tectonics with reverse N–S fault dipping to the west that formed an “en echelon system” system from west to east, from the Serras do Divisor ranges to the Jurua river. As a response to stress, subsiding blocks with NW–SE trends were developed. The E–W to N55° W topographic trends could represent transcurrent dextral transtensional faults. Width of alluvial belts increases along the sequence of “en echelon system” blocks. Correlated with the increase of width, the quantity of channels formed by avulsion increases as well. The Moa and Ipixuna alluvial belts, respectively reaching ca. 9 and 7 km maximum width, are “abnormally” wide because they developed in subsiding blocks stretched in a NW–SE trend. Fluvial dynamics was dominated by avulsion in the subsiding blocks during the late Pleistocene and, probably, during part of the Holocene.

Onchocerciasis in New York City

When faced with a patient with travel-associated dermatitis, clinicians often diagnose and treat for a suspected hypersensitivity reaction or infestation with an ectoparasite. We studied a small cluster of travelers from New York, NY, to the Moa River in Sierra Leone who developed dermatitis caused by Onchocerca volvulus. Our patients had relatively long stays in an endemic area and numerous bites by blackflies. Such patients represent a subset of travelers in whom dermatitis should prompt evaluation for onchocerciasis.

Meristic Characters and Electric Organ Discharge of Mormyrops curviceps Roman (Teleostei: Mormyridae) from the Moa River, Sierra Leone, West Africa

Mormyrids of the genus Mormyrops were collected from the Moa River around Tiwai Id., Sierra Leone, West Africa. Meristic analysis and comparison with paratypes identify these fish as Mormyrops curviceps Roman. They differ from M. deliciosus (Roman) in seven meristic characters: the number of lateral-line scales, caudal-peduncle scales, total vertebrae, caudal vertebrae, anal-fin rays, and teeth on the upper and lowerjaws. From M. curviceps we recorded two electric organ discharge (EOD) pulse types, which were not related to developmental stage or sex. Individual EOD lasted on average either 0.471 msec (with a major head-positive phase followed by an equally large head-negative phase), or about three times longer (1.611 msec) with reversed polarity (i.e., a major head-negative phase), followed by a major head-positive phase. We contrast two views concerning mormyrid EOD: 1) the EOD of M. curviceps simply exists in two pulseform morphs; and 2) characteristics of the EOD pulse-form function as a reproductive isolating mechanism, suggesting the existence of sibling species.

The algal flora of two distinct habitats along the Moa River in the state of Acre, Brazil

Twenty-eoght algal samples were collected in September-October, 1984, from two distinct habitats in the state of Acre, Brazil. Eleven were from the Moa River, and 17 were from a sulfur water spring which flows into the Moa River. A total of 74 species, representing 48 genera of algae, were identified from these samples. Forty-nine species were found in the Moa River and 67 in the sulfur water spring. Both coolection site had rich assemblages of cyanophycean algae, chlorophycean algae, and diatoms. Chlorophycean species dominated the algae flora at both sites, cut were more numerous at the sulfur water spring. There was also a definite difference in the relatives proportions of desmids to filamentous chlorophycean algae at the two sites.