Seek, and you will find: Cryptic diversity of the cardiopulmonary nematode Angiostrongylus vasorum in the Americas.

Angiostrongylus vasorum is a metastrongylid parasite infecting wild canids and domestic dogs. Its patchy distribution, high pathogenicity and taxonomical classification makes the evolutionary history of A. vasorum intriguing and important to study. First larval stages of A. vasorum were recovered from feces of two grey foxes, Urocyon cinereoargenteus, from Costa Rica. Sequencing and phylogenetic and haplotypic analyses of the ITS2, 18S and cytochrome oxidase subunit 1 (cox1) fragments were performed. Then p- and Nei´s genetic distance, nucleotide substitution rates and species delimitation analyses were conducted with cox1 data of the specimens collected herein and other Angiostrongylus spp. Cophylogenetic congruence and coevolutionary events of Angiostrongylus spp. and their hosts were evaluated using patristic and phenetic distances and maximum parsimony reconciliations. Specimens from Costa Rica clustered in a separate branch from European and Brazilian A. vasorum sequences in the phylogenetic and haplotype network analyses using the ITS2 and cox1 data. In addition, cox1 p-distance of the sequences derived from Costa Rica were up to 8.6 % different to the ones from Europe and Brazil, a finding mirrored in Nei´s genetic distance PCoA. Species delimitation analysis supported a separate group with the sequences from Costa Rica, suggesting that these worms may represent cryptic variants of A. vasorum, a new undescribed taxon or Angiocaulus raillieti, a synonym species of A. vasorum described in Brazil. Moreover, nucleotide substitution rates in A. vasorum were up to six times higher than in the congener Angiostrongylus cantonensis. This finding and the long time elapsed since the last common ancestor between both species may explain the larger diversity in A. vasorum. Finally, cophylogenetic congruence was observed between Angiostrongylus spp. and their hosts, with cospeciation events occurring at deeper taxonomic branching of host order. Altogether, our data suggest that the diversity of the genus Angiostrongylus is larger than expected, since additional species may be circulating in wild canids from the Americas.

Molecular and spatial evaluation of small rodents and Didelphimorphis infected with Mycobacterium leprae in the southern Amazon, Brazil.

BACKGROUND: The high levels of recent transmission of leprosy worldwide demonstrate the necessity of epidemiologic surveillance to understand and control its dissemination. Brazil remains the second in number of cases around the world, indicating active transmission of Mycobacterium leprae (M. leprae) in the population. At this moment, there is a consensus that the bacillus is transmitted by inter-human contact, however, different serologic, molecular, and histopathological approaches indicate the existence of non-human transmission sources. METHODS AND RESULTS: The qPCR assay was used to amplify the molecular targets 16S RNAr and RLEP, in samples of liver, spleen, and ear of wild animals belonging to Didelphimorphia and Rodentia orders, in highly endemic areas of Mato Grosso, Brazil. The RLEP repetitive sequence was positive in 202 (89.0%) samples, with 96 (42.3%) of these also being positive for the 16S gene. Regarding the collection sites, it was observed that the animals were found in areas profoundly deforested, close to urban areas. CONCLUSIONS: Our results suggest that wild animals can play an important role in the maintenance of M. leprae in endemic regions with major anthropic action in Brazil. Therefore, integrating human, animal, and environmental health care with the One Health initiative is highly efficient for the development of effective strategies to contain and control leprosy in Brazil.

Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator.

Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 jaguars/100 km²) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same-sex adults including cooperative fishing, co-traveling, and play. Our study demonstrates that aquatic subsidies, frequently described in omnivores, can also transform the ecology and behavior of obligate carnivores.

Land-use effects on mosquito biodiversity and potential arbovirus emergence in the Southern Amazon, Brazil.

The Amazon rainforest is considered the largest reservoir of culicids and arboviruses in the world. It has been under intense human-driven alteration, especially in the so-called 'Arc of Deforestation', located in the eastern and southern regions. The emergence and transmission of infectious diseases are increasing, potentially due to land-use change. We used landscape-scale mosquito surveillance across a forest fragmentation gradient in the southern Amazon to evaluate the relationship between forest disturbance and the composition and structure of mosquito communities with a particular focus on the potential for arbovirus emergence in the region. Generalized linear models and logistic regression were used to associate the degree of landscape disturbance with arbovirus vectors' richness and abundance. A total of 1,960 culicids, belonging to 50 species, were collected from 2015 to 2016. Among these species, 20 have been associated with the transmission of arboviruses. Our results show an association of land use, more specifically small size of forest remnants with more irregular shape and higher edge density, with the increase of arbovirus vectors' richness and abundance. Six species of mosquito vectors exhibited a higher probability of occurrence in landscapes with medium or high degrees of disturbance. Our results indicate that land-use change influences mosquito communities with potential implications for the emergence of arboviruses.

Hantavirus antibodies among phyllostomid bats from the arc of deforestation in Southern Amazonia, Brazil.

In order to determine whether southern Amazonian bats could harbour hantaviruses we, serologically and molecularly, screened blood, saliva, excreta and organ tissues of 47 bats captured from September to December 2015. We found that only phyllostomid bats presented antibodies against hantavirus. The seropositive bats belonged to two species of Phyllostomid bats: the greater spear-nosed bat Phyllostomus hastatus (omnivorous) and the gnome fruit-eating bat Dermanura gnoma. The overall seroprevalence was of 4.2%. Therefore, we show here that hantaviruses are circulating among phyllostomid bats in the Amazonian arc of deforestation.

Detection of Ilheus virus in mosquitoes from southeast Amazon, Brazil.

BACKGROUND: Arbovirus surveillance in field-collected mosquitoes is essential in monitoring virus activity to avoid emergence and outbreaks of arboviruses. METHODS: We used reverse transcription polymerase chain reaction methods to search for arbovirus in mosquitoes collected in Brazil's southeast Amazon forest remnants during 2015-2016. RESULTS: We detected Iheus virus (ILHV) RNA in Culex declarator, Culex (Melanoconion) and Ochlerotatus serratus mosquitoes. CONCLUSIONS: These results indicate ILHV circulation in the studied area, highlighting its potential emergence in human population. More studies are necessary to confirm the roles of these three species in ILHV maintenance.

Empty forest or empty rivers? A century of commercial hunting in Amazonia.

The Amazon basin is the largest and most species-rich tropical forest and river system in the world, playing a pivotal role in global climate regulation and harboring hundreds of traditional and indigenous cultures. It is a matter of intense debate whether the ecosystem is threatened by hunting practices, whereby an "empty forest" loses critical ecological functions. Strikingly, no previous study has examined Amazonian ecosystem resilience through the perspective of the massive 20th century international trade in furs and skins. We present the first historical account of the scale and impacts of this trade and show that whereas aquatic species suffered basin-wide population collapse, terrestrial species did not. We link this differential resilience to the persistence of adequate spatial refuges for terrestrial species, enabling populations to be sustained through source-sink dynamics, contrasting with unremitting hunting pressure on more accessible aquatic habitats. Our findings attest the high vulnerability of aquatic fauna to unregulated hunting, particularly during years of severe drought. We propose that the relative resilience of terrestrial species suggests a marked opportunity for managing, rather than criminalizing, contemporary traditional subsistence hunting in Amazonia, through both the engagement of local people in community-based comanagement programs and science-led conservation governance.

Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests.

Tropical forests are the global cornerstone of biological diversity, and store 55% of the forest carbon stock globally, yet sustained provisioning of these forest ecosystem services may be threatened by hunting-induced extinctions of plant-animal mutualisms that maintain long-term forest dynamics. Large-bodied Atelinae primates and tapirs in particular offer nonredundant seed-dispersal services for many large-seeded Neotropical tree species, which on average have higher wood density than smaller-seeded and wind-dispersed trees. We used field data and models to project the spatial impact of hunting on large primates by ∼ 1 million rural households throughout the Brazilian Amazon. We then used a unique baseline dataset on 2,345 1-ha tree plots arrayed across the Brazilian Amazon to model changes in aboveground forest biomass under different scenarios of hunting-induced large-bodied frugivore extirpation. We project that defaunation of the most harvest-sensitive species will lead to losses in aboveground biomass of between 2.5-5.8% on average, with some losses as high as 26.5-37.8%. These findings highlight an urgent need to manage the sustainability of game hunting in both protected and unprotected tropical forests, and place full biodiversity integrity, including populations of large frugivorous vertebrates, firmly in the agenda of reducing emissions from deforestation and forest degradation (REDD+) programs.

Spatial tools for modeling the sustainability of subsistence hunting in tropical forests.

Subsistence hunting provides a crucial food source for rural populations in tropical forests, but it is often practiced unsustainably. We use the empirical observation that subsistence hunters are central-place foragers to develop three "bio-demographic" hunting models of increasing complexity and realism for assessing the sustainability of hunting of an indicator species. In all our models, we calculate the spatial pattern of depletion of an indicator species (here, a large-bodied primate) across a landscape. Specifically, we show how to identify the area surrounding a human settlement that is expected to suffer local extinction. Our approach is an improvement over well-known sustainability indices of hunting, which are prone to error and do not provide clear links to policy prescriptions. Our first approach models the long-term effect of a single settlement and (1) can be parameterized with easily obtainable field data (such as settlement maps and knowledge of the major weapon used), (2) is simple enough to be used without requiring technical skill, and (3) reveals the asymptotic relationship between local human density and the level of game depletion. Our second model allows multiple settlements with overlapping hunting zones over large spatial scales. Our third model additionally allows temporal changes in human population size and distribution and source-sink dynamics in game populations. Using transect and hunting data from two Amazonian sites, we show that the models accurately predict the spatial distribution of primate depletion. To make these methods accessible, we provide software-based tools, including a toolbox for ArcGIS, to assist in managing and mapping the spatial extent of hunting. The proposed application of our models is to allow the quantitative assessment of settlement stabilization approaches to managing hunting in Amazonia.

The sustainability of subsistence hunting by Matsigenka native communities in Manu National Park, Peru.

The presence of indigenous people in tropical parks has fueled a debate over whether people in parks are conservation allies or direct threats to biodiversity. A well-known example is the Matsigenka (or Machiguenga) population residing in Manu National Park in Peruvian Amazonia. Because the exploitation of wild meat (or bushmeat), especially large vertebrates, represents the most significant internal threat to biodiversity in Manu, we analyzed 1 year of participatory monitoring of game offtake in two Matsigenka native communities within Manu Park (102,397 consumer days and 2,089 prey items). We used the Robinson and Redford (1991) index to identify five prey species hunted at or above maximum sustainable yield within the approximately 150-km(2) core hunting zones of the two communities: woolly monkey (Lagothrix lagotricha), spider monkey (Ateles chamek), white-lipped peccary (Tayassu pecari), Razor-billed Currasow (Mitu tuberosa), and Spix's Guan (Penelope jacquacu). There was little or no evidence that any of these five species has become depleted, other than locally, despite a near doubling of the human population since 1988. Hunter-prey profiles have not changed since 1988, and there has been little change in per capita consumption rates or mean prey weights. The current offtake by the Matsigenka appears to be sustainable, apparently due to source-sink dynamics. Source-sink dynamics imply that even with continued human population growth within a settlement, offtake for each hunted species will eventually reach an asymptote. Thus, stabilizing the Matsigenka population around existing settlements should be a primary policy goal for Manu Park.