Carnivore coexistence without competition: giant otters are more nocturnal around dens than sympatric neotropical otters.

Nocturnal activity of tropical otters is rarely reported. To date no studies have documented den use by sympatric giant (Pteronura brasiliensis) and neotropical otters (Lontra longicaudis). We used camera-traps to monitor den use by sympatric otters along an equatorial Amazonian river. Camera-traps provided evidence that giant otters were more nocturnal around dens than sympatric neotropical otters. Nocturnal activity was recorded in 11% of giant otter photos (n = 14 of 125 photos), but was recorded only once for neotropical otters. Den use by giant and neotropical otters overlapped spatially and temporally but not concurrently. We hypothesize that previously reported nocturnal activity in neotropical otters is facilitated by the absence or low density of giant otters. Our results also underscore the need to use complementary techniques together with den counts for monitoring otters as sympatric species can use the same dens.

Human disturbances and the daytime activity of sympatric otters along equatorial Amazonian rivers.

Background: Previous studies suggest coexistence between sympatric neotropical (Lontra longicaudis) and giant otters (Pteronura brasiliensis) maybe facilitated by temporal and spatial differences in activity. Yet, to date there has been no systematic evaluation of activity of these species in sympatry. Here we use extensive multi-year field data to compare temporal and spatial patterns in the diurnal activity of sympatric giant and neotropical otters to answer three questions: Do temporal patterns in daytime river use change in relation to seasonal river levels (low, rising, high and declining river levels), do they change due to human disturbances (boats and fishing nets) and do patterns in neotropical otter activity change due to the presence of the larger sized giant otter? Methods: Direct observations of both species were recorded using standardized boat surveys along 218 km of rivers over 53 months during nine years (2011-2013 and 2015-2020). Complementary techniques (Generalized Additive Models, Kernel density estimates and non-parametric tests,) were used to compare diurnal activity patterns along rivers subdivided into 41 river reaches. Results: The presence of giant otters decreased threefold from 67% of the least disturbed reaches (few boats no fishing nets) to 18% of the most disturbed reaches with many boats and fishing nets. In contrast neotropical otter presence nearly doubled from 44% of the least disturbed to 73% of the most disturbed reaches with fewest giant otter detections. Both species were observed across all daytime hours but were observed rarely on the same day. There was no evidence to suggest simultaneous use of the same reach. When species were detected on the same day, they were separated spatially (median distance between species 12.5 km) and temporally (median time difference 3.0 hours). There was little change in activity of either species among seasons. Giant otters were less active in river reaches with fishing nets and boat use, whereas neotropical otter activity did not appear to be strongly affected by these activities. Conclusions: Our findings support evidence that diurnal activity in both otter species is flexible, with daytime activity changing due to human disturbances in the case of giant otters.

Anthropogenic influences on the distribution of a threatened apex-predator around sustainable-use reserves following hydropower dam installation.

Although previous studies demonstrate declines in many large bodied species following hydropower dam installation, others suggest that some species, including the giant otter (Pteronura brasiliensis) may return to newly created reservoir habitats. Yet, there is a lack of evidence to support such theories. Here, we analyzed the effects of a hydropower dam on giant otters using a before-after control-impact study design in the eastern Brazilian Amazon. We collected data 3 years before (2011-2012 and 2015) and after (2017-2019) dam construction, totaling 6,459 km of surveys along rivers with 43 direct sightings of giant otters. Contrary to expectations, our results revealed that giant otters did not remain nor did they return to the dam reservoir. Beyond the zone directly impacted by the dam giant otter occurrence and relative abundance declined next to sustainable-use reserves where the river was more intensely used by people. Our study showed that in the absence of active management sustainable-use reserves and low human density were not sufficient to maintain this apex-predator. Our findings suggest a need to proactively create and maintain areas with low levels of anthropogenic disturbance to enable sustainable coexistence between energy demands and biodiversity across Amazonia.

Crop damage by vertebrates in Latin America: current knowledge and potential future management directions.

Background: Crop farming contributes to one of the most extensive land use activities in the world, and cropland areas continue to rise. Many vertebrate species feed on crops, which has caused an increase in human-wildlife conflicts in croplands. Crop-feeding damages the economy of local communities and causes retaliation against the responsible vertebrates in several forms, including lethal practices such as hunting and poisoning. Lethal control may cause the local extirpation of some species, affecting ecological processes and patterns. Therefore, it is necessary to find non-lethal alternatives that can protect both local economies and wildlife. Research has been conducted in Africa and Asia, focusing on elephants and primates, and the effectiveness of some non-lethal alternatives, such as chili-based repellents and beehives, is being investigated. However, there has been very little research on this topic in Central and South America. The goal of this review is to assess the current knowledge on crop damage by vertebrates in Central and South America and indicate future research directions. Survey methodology: We reviewed the available scientific literature reporting crop damage by vertebrates in Central and South America, and the Caribbean, published between 1980 and 2020, through systematic searches on Web of Science, Scopus, and Google Scholar. We analyzed the temporal and geographical distributions of the studies, the crops and vertebrate species these studies considered, the crop protection techniques used, and their effectiveness. Results: We retrieved only 113 studies on crop damage by vertebrates in Latin America, but there was an increasing trend in the number of studies published over time. Most of the studies were conducted in Brazil, Argentina, Mexico, and Costa Rica. Four orders of mammals (Rodentia, Carnivora, Artiodactyla, and Primates) and four orders of birds (Passeriformes, Columbiformes, Psittaciformes, and Anseriformes) were the most common groups of crop-feeding vertebrates. The most prominent crop was corn, which was featured in 49% of the studies. Other notable crops include rice, sorghum, and sugarcane. The most reported method for protecting crops was lethal control through hunting or poisoning. Non-lethal techniques were found to be less prevalent. Less than half of the studies that mentioned the use of protection techniques indicated their effectiveness, and only 10 studies evaluated it by performing scientific experiments and reporting their results. Conclusions: Central and South America is still underrepresented in research on vertebrate crop-feeding. There is a need for experimentation-based robust research to find crop protection techniques that minimize harm to vertebrates while effectively reducing damage to crops. While this is being studied, habitat loss and fragmentation need to be halted to prevent the native vertebrates from turning to crops for food.

Community based actions save Yellow-spotted river turtle (Podocnemis unifilis) eggs and hatchlings flooded by rapid river level rises.

The conservation and recovery of increasingly threatened tropical freshwater turtle populations depends on effective management plans and actions. Here we show that community-based actions saved Yellow-spotted river turtle (Podocnemis unifilis) eggs submerged by unseasonal flooding and ensured the release of hatchlings. We recovered 926 eggs and 65 premature hatchlings from 74 submerged nests at 16 flooded nesting areas along 75 km of waterways. The rescued eggs were transferred to a rearing center and incubated. Hatchlings emerged from eggs that had remained underwater for up to two days. Hatchlings were maintained in 250-500 L nursery tanks until yolk sac scars had closed. Healthy hatchlings were then immediately released around the original nesting areas. We released 599 hatchlings (60.4%) from 991 submerged eggs and hatchlings. Egg survival (61.7% (571/926)) was substantially less than hatchling survival (94.2% (599/636)) but within the expected range of values reported for this species. These findings suggest that Yellow-spotted river turtle eggs and embryos are resistant to short-term submersion, which could help explain the widespread distribution of this species across highly seasonal Amazonian rivers. Management plans should take the possible survival of submerged eggs into consideration as part of species conservation and recovery actions.

Substrate influences human removal of freshwater turtle nests in the eastern Brazilian Amazon.

Substrate type determines nesting success and fitness in turtles and is a critical consideration for nesting area protection and restoration. Here, we evaluated the effect of substrate on nest removal by humans in the eastern Brazilian Amazon. We analyzed substrate composition and fate of 216 P. unifilis nests along 88 km of rivers. River segment and substrate type were the most important predictors of nest removal by humans. We found up to 36% lower removal of nests in fine sand and experimental results support the hypothesis that wind more often obscures tracks of nesting females in substrates with more (>66%) fine sand. Our findings are useful for informing the restoration of artificial nesting areas across the Amazon, as nesting area substrates should be selected not only to maintain hatchling sex ratios, but also to minimize nest removal by humans.

Community involvement works where enforcement fails: conservation success through community-based management of Amazon river turtle nests.

Law enforcement is widely regarded as a cornerstone to effective natural resource management. Practical guidelines for the optimal use of enforcement measures are lacking particularly in areas protected under sustainable and/or mixed use management regimes and where legal institution are weak. Focusing on the yellow-spotted river turtles (Podocnemis unifilis) along 33 km of river that runs between two sustainable-use reserves in the Brazilian Amazon as an illustrative example, we show that two years of patrols to enforce lawful protection regulations had no effect on nest harvesting. In contrast, during one year when community-based management approaches were enacted harvest levels dropped nearly threefold to a rate (26%) that is likely sufficient for river turtle population recovery. Our findings support previous studies that show how community participation, if appropriately implemented, can facilitate effective natural resource management where law enforcement is limited or ineffective.

Beyond harm's reach? Submersion of river turtle nesting areas and implications for restoration actions after Amazon hydropower development.

The global expansion of energy demands combined with abundant rainfall, large water volumes and high flow in tropical rivers have led to an unprecedented expansion of dam constructions in the Amazon. This expansion generates an urgent need for refined approaches to river management; specifically a move away from decision-making governed by overly generalized guidelines. For the first time we quantify direct impacts of hydropower reservoir establishment on an Amazon fresh water turtle. We conducted surveys along 150 km of rivers upstream of a new dam construction during the low water months that correspond to the nesting season of Podocnemis unifilis in the study area. Comparison of nest-areas before (2011, 2015) and after (2016) reservoir filling show that reservoir impacts extend 13% beyond legally defined limits. The submerged nesting areas accounted for a total of 3.8 ha of nesting habitat that was inundated as a direct result of the reservoir filling in 2016. Our findings highlight limitations in the development and implementation of existing Brazilian environmental impact assessment process. We also propose potential ways to mitigate the negative impacts of dams on freshwater turtles and the Amazonian freshwater ecosystems they inhabit.

Illegal use of natural resources in federal protected areas of the Brazilian Amazon.

BACKGROUND: The Brazilian Amazon is the world's largest rainforest regions and plays a key role in biodiversity conservation as well as climate adaptation and mitigation. The government has created a network of protected areas (PAs) to ensure long-term conservation of the region. However, despite the importance of and positive advances in the establishment of PAs, natural resource depletion in the Brazilian Amazon is pervasive. METHODS: We evaluated a total of 4,243 official law enforcement records generated between 2010 and 2015 to understand the geographical distribution of the illegal use of resources in federal PAs in the Brazilian Amazon. We classified illegal activities into ten categories and used generalized additive models (GAMs) to evaluate the relationship between illegal use of natural resources inside PAs with management type, age of PAs, population density, and accessibility. RESULTS: We found 27 types of illegal use of natural resources that were grouped into 10 categories of illegal activities. Most infractions were related to suppression and degradation of vegetation (37.40%), followed by illegal fishing (27.30%) and hunting activities (18.20%). The explanatory power of the GAMs was low for all categories of illegal activity, with a maximum explained variation of 41.2% for illegal activities as a whole, and a minimum of 14.6% for hunting activities. DISCUSSION: These findings demonstrate that even though PAs are fundamental for nature conservation in the Brazilian Amazon, the pressures and threats posed by human activities include a broad range of illegal uses of natural resources. Population density up to 50 km from a PA is a key variable, influencing illegal activities. These threats endanger long-term conservation and many efforts are still needed to maintain PAs that are large enough and sufficiently intact to maintain ecosystem functions and protect biodiversity.

Gamebird responses to anthropogenic forest fragmentation and degradation in a southern Amazonian landscape.

Although large-bodied tropical forest birds are impacted by both habitat loss and fragmentation, their patterns of habitat occupancy will also depend on the degree of forest habitat disturbance, which may interact synergistically or additively with fragmentation effects. Here, we examine the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of persistence of six gamebird taxa in the southern Brazilian Amazon. We use both interview data conducted with long-term residents and/or landowners from 129 remnant forest patches and 15 continuous forest sites and line-transect census data from a subset of 21 forest patches and two continuous forests. Forest patch area was the strongest predictor of species persistence, explaining as much as 46% of the overall variation in gamebird species richness. Logistic regression models showed that anthropogenic disturbance-including surface wildfires, selective logging and hunting pressure-had a variety of effects on species persistence. Most large-bodied gamebird species were sensitive to forest fragmentation, occupying primarily large, high-quality forest patches in higher abundances, and were typically absent from patches <100 ha. Our findings highlight the importance of large (>10,000 ha), relatively undisturbed forest patches to both maximize persistence and maintain baseline abundances of large neotropical forest birds.

Water availability not fruitfall modulates the dry season distribution of frugivorous terrestrial vertebrates in a lowland Amazon forest.

Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit) affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs) were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits) on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores) and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans). A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%). Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans) were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species-specific responses to altitude. Our findings provide a more detailed understanding of how frugivorous vertebrates cope with periods of water and fruit scarcity in lowland Amazon forests.

Implications of Scientific Collaboration Networks on Studies of Aquatic Vertebrates in the Brazilian Amazon.

The quantity of wildlife extracted from the Amazon has increased in the past decades as a consequence of an increase in human population density and income growth. To evaluate the spatial distribution of studies on subsistence and/or commercial hunting conducted in the Brazilian Amazon, we selected eight mid-sized and large-bodied aquatic vertebrate species with a history of human exploitation in the region. We used a combination of searches in the gray and scientific literature from the past 24 years to provide an updated distributional map of studies on the target species. We calculated the distances between the study sites and the locations of the research institutes/universities that the first and last authors of the same study were affiliated to. For the period of 1990 to 2014, we found 105 studies on the subsistence and/or commercial hunting of aquatic vertebrates in the Brazilian Amazon in 271 locations that involved 43 institutions (37 Brazilian and 6 international). The spatial distribution of the studies across the Brazilian Amazon varied, but over 80% took place in the northeast and central Amazon, encompassing three States of the Legal Brazilian Amazon (Amazonas, 51.42%; Pará, 19.05%; and Amapá, 16.19%). Over half of the research study sites (52.91%) were within 500 km of the research institute/university of the first or last authors. Some research institutes/universities did not have any inter-institutional collaborations, while others collaborated with eight or more institutes. Some research institutes/universities conducted many studies, had an extensive collaboration network, and contributed greatly to the network of studies on Amazonian aquatic vertebrates. Our research contributes to the knowledge of studies on the subsistence and/or commercial hunting of the most exploited aquatic vertebrates of the Brazilian Amazon, illustrates the impact that collaboration networks have on research, and highlights potential areas for improvement and the generation of new collaborations.

Bats of a varzea forest in the estuary of the Amazon River, state of Amapá, Northern Brazil / Morcegos de floresta de várzea no estuário do Rio Amazonas, estado do Amapá, Norte do Brasil

The varzea forests of the estuary of the Amazon River cover 25,000 km2within the states of Pará and Amapá. The mammals of those forests, especially bats, are still poorly known. Hence, the present study aimed at inventorying the bat species from three localities of a varzea forest in the estuary of the Amazon River. Between November and December 2013, we selected 18 sampling sites in the mouths of three tributaries of the Amazon River: the rivers Ajuruxí, Maracá, and Mazagão. We set up ten mist nets (12 x 3 m) along a 150-m linear transect in each sampling site, in a total sampling effort of 38,888 m2.h. We captured 403 individual bats of 40 species and five families. We recorded the families: Phyllostomidae (n = 31 species), Emballonuridae (n = 6 species), Moormopidae (n = 1 species), Vespertilionidae (n = 1 species), and Thyropteridae (n = 1 species). Carollia perspicillata, Artibeus planirostris, andCarollia brevicauda comprised 45% of the records. We also made the first record of Glyphonycteris daviesi for Amapá state, and captured rare species, such as Dicludurus albus andMacrophyllum macrophylum. Our results show that the varzea forest of the estuary of the Amazon River harbors high bat diversity, and, hence, conservation policies should be considered for the region. Those policies should encourage the responsible management of açaípalm (Euterpe oleracea) and timber. They should also fight illegal timber exploitation that threatens the fauna and flora of those biodiverse forests.

As florestas de várzea do estuário do Rio Amazonas ocupam uma extensão 25. 000 km2, abrangendo os estados do Pará e Amapá. Os mamíferos destas florestas, especificamente morcegos ainda são pouco conhecidos. Este estudo visa apresentar uma lista de espécies de morcegos de três localidades em floresta de várzea no estuário do Rio Amazonas, contribuindo assim com o conhecimento da quiropterofauna desta fitofisionomia. Entre Novembro e Dezembro de 2013 foram selecionados 18 sítios de coletas na foz de três rios tributários do Rio Amazonas: Rio Ajuruxí, Rio Maracá e Rio Mazagão. Com o uso de dez redes de neblina (12 x 3 m) armadas ao longo de um transecto linear de 150 metros em cada sitio de coleta e totalizando um esforço amostral de 38,888 m2. h capturamos 403 indivíduos distribuídos em 40 espécies e cinco famílias. As famílias registradas foram Phyllostomidae (n=31 espécies), Emballonuridae (n=6 espécies), Moormopidae (n=1 espécie), Vespertilionidae (n=1 espécie) e Thyropteridae (n=1 espécie). Carollia perspicillata,Artibeus planirostris e Carollia brevicauda compreenderam 45 % dos registros. Nós documentamos o primeiro registro de Glyphonycteris daviesi para o estado do Amapá. Registramos também espécies raras como Dicludurus albus e Macrophyllum macrophylum. Os dados obtidos neste estudo revelam que as florestas de várzea do estuário do Rio Amazonas abrigam uma alta riqueza e diversidade de morcegos e que politicas de conservação devem ser consideradas para a manutenção desta diversidade. Tais politicas devem ser focadas no incentivo para o manejo responsável do cultivo do açaizeiro (Euterpe oleracea) e da exploração da madeira, além da redução da exploração madeireira ilegal que causa prejuízos a fauna e flora dessas florestas ricas em biodiversidade.

Ecological relationships of meso-scale distribution in 25 neotropical vertebrate species.

Vertebrates are a vital ecological component of Amazon forest biodiversity. Although vertebrates are a functionally important part of various ecosystem services they continue to be threatened by anthropogenic impacts throughout the Amazon. Here we use a standardized, regularly spaced arrangement of camera traps within 25km2 to provide a baseline assessment of vertebrate species diversity in a sustainable use protected area in the eastern Brazilian Amazon. We examined seasonal differences in the per species encounter rates (number of photos per camera trap and number of cameras with photos). Generalized linear models (GLMs) were then used to examine the influence of five variables (altitude, canopy cover, basal area, distance to nearest river and distance to nearest large river) on the number of photos per species and on functional groups. GLMs were also used to examine the relationships between large predators [Jaguar (Panthera onca) and Puma (Puma concolor)] and their prey. A total of 649 independent photos of 25 species were obtained from 1,800 camera trap days (900 each during wet and dry seasons). Only ungulates and rodents showed significant seasonal differences in the number of photos per camera. The number of photos differed between seasons for only three species (Mazama americana, Dasyprocta leporina and Myoprocta acouchy) all of which were photographed more (3 to 10 fold increase) during the wet season. Mazama americana was the only species where a significant difference was found in occupancy, with more photos in more cameras during the wet season. For most groups and species variation in the number of photos per camera was only explained weakly by the GLMs (deviance explained ranging from 10.3 to 54.4%). Terrestrial birds (Crax alector, Psophia crepitans and Tinamus major) and rodents (Cuniculus paca, Dasyprocta leporina and M. acouchy) were the notable exceptions, with our GLMs significantly explaining variation in the distribution of all species (deviance explained ranging from 21.0 to 54.5%). The group and species GLMs showed some novel ecological information from this relatively pristine area. We found no association between large cats and their potential prey. We also found that rodent and bird species were more often recorded closer to streams. As hunters gain access via rivers this finding suggests that there is currently little anthropogenic impact on the species. Our findings provide a standardized baseline for comparison with other sites and with which planned management and extractive activities can be evaluated.

Effects of reduced-impact logging on medium and large-bodied forest vertebrates in eastern Amazonia / Efeitos da exploração de impacto reduzido em vertebrados de médio e grande porte na Amazônia oriental

Standard line-transect census techniques were deployed to generate a checklist and quantify the abundance of medium and large-bodied vertebrate species in forest areas of eastern Amazonia with and without a history of reduced-impact logging (RIL). Three areas were allocated a total of 1,196.9 km of line-transect census effort. Sampling was conducted from April to June 2012 and from April to August 2013, and detected 29 forest vertebrate species considered in this study belonging to 15 orders, 20 families and 28 genera. Additionally, eight species were recorded outside census walks through direct and indirect observations. Of this total, six species are considered vulnerable according to IUCN (Ateles paniscus, Myrmecophaga tridactyla, Priodontes maximus, Tapirus terrestris, Tayassu peccary, Chelonoidis denticulata). Observed species richness ranged from 21 to 24 species in logged and unlogged areas, and encounter rates along transects were highly variable between treatments. However, the relative abundance of species per transect did not differ between transects in logged and unlogged forests. Of the species detected during censuses, only three showed different relative abundance between the two treatments (Saguinus midas, Tinamus spp. and Dasyprocta leporina). Our results show that the effect of RIL forest management was a relatively unimportant determinant of population abundance for most medium and large vertebrates over the time period of the survey.

Técnicas padronizadas de censo por transecções lineares foram empregadas para gerar uma lista e quantificar a abundância de espécies de vertebrados de médio e grande porte em áreas de floresta na Amazônia oriental, com e sem uma história de exploração de impacto reduzido (EIR). Três áreas foram amostradas com um esforço total de 1.196,9 km de censo ao longo de transectos lineares. A amostragem foi realizada de abril-junho de 2012 e de abril-agosto de 2013, e detectou 29 espécies florestais de vertebrados consideradas neste estudo pertencentes a 15 ordens, 20 famílias e 28 gêneros. Adicionalmente, oito espécies foram registradas fora dos censos ao longo dos transectos por meio de observações diretas e indiretas. Desse total, seis espécies são consideradas vulneráveis de acordo com a IUCN (Ateles paniscus, Myrmecophaga tridactyla, Priodontes maximus, Tapirus terrestris, Tayassu pecari, Chelonoidis denticulata). A riqueza das espécies observada variou de 21 a 24 espécies em áreas com e sem corte seletivo, e as taxas de encontro ao longo dos transectos foram bastante variáveis entre os tratamentos. No entanto, a abundância relativa das espécies por transecto não diferiu entre florestas não exploradas e exploradas. Das espécies detectadas durante o censo, apenas três apresentaram diferentes abundâncias relativas entre os dois tratamentos (Saguinus midas, Tinamus spp. e Dasyprocta leporina). Nossos resultados mostram que o efeito do manejo florestal EIR não foi relativamente determinante para abundância populacional da maioria dos vertebrados de médio e grande porte.

Artificial nest predation rates vary depending on visibility in the eastern Brazilian Amazon / Taxas de predação em ninhos artificiais variam dependendo da visibilidade na Amazônia Oriental Brasileira

Observational and experimental studies have shown that increased concealment of bird nests reduces nest predation rates. The objective of the present study was to evaluate differences in predation rates between two experimental manipulations of artificial ground nests (i.e., clearing an area around the artificial nest or leaving it as natural as possible), and test whether environmental variables also affected nest predation in an undisturbed area of Amazonian forest in eastern Brazil. A generalized linear model was used to examine the influence of five variables (manipulation type, perpendicular distance from the main trail, total basal area of trees surrounding the nest site, understorey density, and liana quantity) on nest predation rates. Model results, showed that manipulation type was the only variable that significantly affected nest predation rates. Thus, to avoid systematic biases, the influence of nest site manipulation must be taken into consideration when conducting experiments with artificial nests.

Estudos de observação e experimentais demonstraram que ninhos de aves menos visíveis apresentam taxas de predação reduzidas. O objetivo do presente estudo foi avaliar diferenças nas taxas de predação entre duas manipulações experimentais de ninhos artificiais no chão (i.e., limpando uma área em torno do ninho artificial ou deixando o mais natural possível), e testar se variáveis ambientais também poderiam afetar as taxas de predação em uma área intacta de floresta amazônica no leste do Brasil. Um modelo generalizado linear foi utilizado para examinar a influência de cinco variáveis (tipo de manipulação, distância perpendicular da trilha principal, área basal total das árvores em volta do local do ninho, densidade de sub-bosque, e quantidade de lianas) sobre as taxas de predação de ninhos. Os resultados do modelo demonstraram que tipo de manipulação foi a única variável que afetou significativamente as taxas de predação de ninhos. Assim, para evitar vieses sistemáticos, a influência da manipulação do local dos ninhos deve ser levada em consideração na realização de experimentos com ninhos artificiais.

First record of Tigrisoma fasciatum (Such, 1825) (Aves: Ardeidae) in the State of Amapá, Brazil and updated species distribution in Central and South America

The Fasciated Tiger-heron (Tigrisoma fasciatum) is considered endangered in Brazil and Argentina. Although this species has a large range in Central and South America, its records are scattered and scarce. We used a combination of searches in the scientific literature and new field records to provide an updated distributional range of this species. Searches for records and photos of T. fasciatum were conducted using online databases. We also conducted field surveys along the margins of the Araguari and Falsino rivers, in the National Forest of Amapá, a sustainable protected area in the eastern Brazilian Amazon. Our literature review provided a total of 25 new distributional records of T. fasciatum. During our river based surveys we recorded one individual of T. fasciatum, which represents an extension of 499 km from the nearest previously documented occurrence. We present these findings in an up to date distributional map of T. fasciatum and highlight the need of further studies in order to better understand the species distribution and ecology.

O socó-boi-escuro (Tigrisoma fasciatum) é uma espécie considerada em perigo de extinção no Brasil e na Argentina. Apesar de possuir extensa distribuição na América Central e do Sul, os registros são esparsos e escassos. Nós usamos uma combinação de buscas na literatura científica e novos registros de campo para fornecer uma distribuição geográfica atualizada dessa espécie. Buscas por registros e fotos de T. fasciatum foram realizadas em bancos de dados online. Nós também realizamos buscas de campo às margens dos rios Araguari e Falsino, na Floresta Nacional do Amapá, uma Unidade de Conservação de Uso Sustentável na Amazônia Oriental brasileira. Nossa revisão de literatura forneceu um total de 25 novos registros de distribuição de T. fasciatum. Durante nossas buscas ao longo de rios, nós registramos um indivíduo de T. fasciatum, o que representa uma extensão de 499 km de sua mais próxima ocorrência documentada anteriormente. Nós apresentamos esses registros em um mapa atualizado da distribuição geográfica de T. fasciatum e enfatizamos a necessidade de mais estudos para a melhor compreensão da distribuição e ecologia da espécie.

Successful carnivore identification with faecal DNA across a fragmented Amazonian landscape.

The use of scat surveys to obtain DNA has been well documented in temperate areas, where DNA preservation may be more effective than in tropical forests. Samples obtained in the tropics are often exposed to high humidity, warm temperatures, frequent rain and intense sunlight, all of which can rapidly degrade DNA. Despite these potential problems, we demonstrate successful mtDNA amplification and sequencing for faeces of carnivores collected in tropical conditions and quantify how sample condition and environmental variables influence the success of PCR amplification and species identification. Additionally, the feasibility of genotyping nuclear microsatellites from jaguar (Panthera onca) faeces was investigated. From October 2007 to December 2008, 93 faecal samples were collected in the southern Brazilian Amazon. A total of eight carnivore species was successfully identified from 71% of all samples obtained. Information theoretic analysis revealed that the number of PCR attempts before a successful sequence was an important negative predictor across all three responses (success of species identification, success of species identification from the first sequence and PCR amplification success), whereas the relative importance of the other three predictors (sample condition, season and distance from forest edge) varied between the three responses. Nuclear microsatellite amplification from jaguar faeces had lower success rates (15-44%) compared with those of the mtDNA marker. Our results show that DNA obtained from faecal samples works efficiently for carnivore species identification in the Amazon forest and also shows potential for nuclear DNA analysis, thus providing a valuable tool for genetic, ecological and conservation studies.