Interior Atlantic Forest Research Articles

Structural Differences in Herbaceous Communities on Edge and Interior Atlantic Forest in South Brazil

The Atlantic Forest is recognized worldwide as hotspots due to its megadiversity. This study aimed to evaluate whether there are differences between the floristic and structural diversity of the herbaceous component in an edge and interior region of the southern Brazilian Atlantic Forest. The study was developed in a forest fragment located in the state of Santa Catarina, south Brazil. The edge of the fragment is characterized by an area up to 10-15m wide, covered massively by herbaceous-subshrub vegetation and rare arboreal individuals. The interior is discontinuously shaded by the arboreal and shrub component contained in the upper strata of the forest. The phytosociological survey used the plot method. 100 plots of 1 m² were established, 50 on the edge of the forest fragment and 50 plots inside it. The phytosociological parameters studied for both areas were absolute frequency (AF), relative frequency (RF), absolute coverage (AC) and relative coverage (RC). Through the treatment and analysis of these data, the importance value index (IVI) of each species was obtained. At the edge of the forest fragment, 18 families and 34 species were identified. Of the 34 species found, 31 are angiosperms (24 dicots and 7 monocots) and 3 are monilophytes. All species are native to the Brazilian flora, with the exception of Centella asiatica and 2 lycophytes. In the interior, 14 species were found, being represented by 10 families. All species in the interior were angiosperms (4 dicots and 8 monocots) and 2 monilophytes. All species are native to the Brazilian flora and have herbaceous habit. The herbaceous community in the interior is different from the herbaceous community at the forest edge. The initial hypothesis of the work was confirmed, since none of the species present at the edge of the forest occurs in the interior of the forest.

Deep Sequencing to Reveal Phylo-Geographic Relationships of Juquitiba Virus in Paraguay.

Several hantaviruses result in zoonotic infections of significant public health concern, causing hemorrhagic fever with renal syndrome (HFRS) or hantavirus cardiopulmonary syndrome (HCPS) in the Old and New World, respectively. Given a 35% case fatality rate, disease-causing New World hantaviruses require a greater understanding of their biology, genetic diversity, and geographical distribution. Juquitiba hantaviruses have been identified in Oligoryzomys nigripes in Brazil, Paraguay, and Uruguay. Brazil has reported the most HCPS cases associated with this virus. We used a multiplexed, amplicon-based PCR strategy to screen and deep-sequence the virus harbored within lung tissues collected from Oligoryzomys species during rodent field collections in southern (Itapúa) and western (Boquerón) Paraguay. No Juquitiba-like hantaviruses were identified in Boquerón. Herein, we report the full-length S and M segments of the Juquitiba hantaviruses identified in Paraguay from O. nigripes. We also report the phylogenetic relationships of the Juquitiba hantaviruses in rodents collected from Itapúa with those previously collected in Canindeyú. We showed, using the TN93 nucleotide substitution model, the coalescent (constant-size) population tree model, and Bayesian inference implemented in the Bayesian evolutionary analysis by sampling trees (BEAST) framework, that the Juquitiba virus lineage in Itapúa is distinct from that in Canindeyú. Our spatiotemporal analysis showed significantly different time to the most recent ancestor (TMRA) estimates between the M and S segments, but a common geographic origin. Our estimates suggest the additional geographic diversity of the Juquitiba virus within the Interior Atlantic Forest and highlight the need for more extensive sampling across this biome.

Population structure, aggregation, and dispersal of Euterpe edulis Mart. at two sites of interior atlantic forest.

Habitat destruction and fragmentation can change environmental conditions and disrupt mutualistic interactions, leading to impacts on natural populations. Here we checked how plant population structure responds to environmental degradation by quantifying effective seed dispersal and patterns of population distribution for the animal-dispersed palm Euterpe edulis Mart. (Arecaceae). Thus, we assessed E. edulis population structure at two locations with different degrees of fragmentation in the Interior Atlantic Forest (west of the State of Paraná, Brazil), where we registered the density of saplings at increasing distances from adults palms and from large trees in the vicinity (perch-trees). We found differences between locations, with aggregated saplings and highest densities at the most fragmented site, although in this site Immature individuals were almost absent. We also identified patches of saplings under perch-trees canopies, in a way which suggests these individuals originate from dispersal events. In both sites, the abundance of Immature saplings was similar either nearby adult palms or perch-trees, pointing to perch-trees being relevant to E. edulis population dynamics. Thus, while conservation of E. edulis in the Interior Atlantic Forest can benefit from such new data, it is still necessary to check whether our findings are recurring and consistently found elsewhere.

Prevalence of bat viruses associated with land-use change in the Atlantic Forest, Brazil.

Bats are critical to maintaining healthy ecosystems and many species are threatened primarily due to global habitat loss. Bats are also important hosts of a range of viruses, several of which have had significant impacts on global public health. The emergence of these viruses has been associated with land-use change and decreased host species richness. Yet, few studies have assessed how bat communities and the viruses they host alter with land-use change, particularly in highly biodiverse sites. In this study, we investigate the effects of deforestation on bat host species richness and diversity, and viral prevalence and richness across five forested sites and three nearby deforested sites in the interior Atlantic Forest of southern Brazil. Nested-PCR and qPCR were used to amplify and detect viral genetic sequence from six viral families (corona-, adeno-, herpes-, hanta-, paramyxo-, and astro-viridae) in 944 blood, saliva and rectal samples collected from 335 bats. We found that deforested sites had a less diverse bat community than forested sites, but higher viral prevalence and richness after controlling for confounding factors. Viral detection was more likely in juvenile males located in deforested sites. Interestingly, we also found a significant effect of host bat species on viral prevalence indicating that viral taxa were detected more frequently in some species than others. In particular, viruses from the Coronaviridae family were detected more frequently in generalist species compared to specialist species. Our findings suggest that deforestation may drive changes in the ecosystem which reduce bat host diversity while increasing the abundance of generalist species which host a wider range of viruses.

Katydids (Orthoptera: Tettigoniidae) from the Iguau National Park, Brazil.

Katydids were surveyed in the Iguau National Park (ParNa Iguau), the largest preserve of the Interior Atlantic Forest in Brazil. Sampling was carried out in three different areas of the ParNa Iguau, including its two predominant phytophysiognomies (Seasonal Semidecidual Forest and Mixed Ombrophilous Forest), and consisted of diurnal and nocturnal active searching for katydids and also using light traps. After collected, specimens were reared until adulthood in order to record their calling songs. Almost a thousand katydids were collected, belonging to 89 species and five subfamilies. Phaneropterinae appeared as the most speciose subfamily (57 species), followed by Conocephalinae (22), Meconematinae and Pseudophyllinae, each one with four species, and Pterochrozinae (two species). Several species were recorded for the first time for the Paran State, for the South Region of Brazil, and also for the country. Calling songs of 34 species were recorded, 29 of them unknown to science. The description of the sound produced by species of some supraspecific taxa (e.g., Aniarae, Cosmophylla and Scaphurae) is here presented for the first time. Data reinforce the relevance of ParNa Iguau for the maintenance of thousands of species from different taxonomic groups and also highlight the catastrophic effects that continuous pressures and threats on the preserve, despite the successive attempts to downgrade this conservation unit, may have on the outstanding biodiversity that is harboured by ParNa Iguau.

Impact of Predator Exclusion and Habitat on Seroprevalence of New World Orthohantavirus Harbored by Two Sympatric Rodents within the Interior Atlantic Forest.

Understanding how perturbations to trophic interactions influence virus–host dynamics is essential in the face of ongoing biodiversity loss and the continued emergence of RNA viruses and their associated zoonoses. Herein, we investigated the role of predator exclusion on rodent communities and the seroprevalence of hantaviruses within the Reserva Natural del Bosque Mbaracayú (RNBM), which is a protected area of the Interior Atlantic Forest (IAF). In the IAF, two sympatric rodent reservoirs, Akodon montensis and Oligoryzomys nigripes, harbor Jaborá and Juquitiba hantavirus (JABV, JUQV), respectively. In this study, we employed two complementary methods for predator exclusion: comprehensive fencing and trapping/removal. The goal of exclusion was to preclude the influence of predation on small mammals on the sampling grids and thereby potentially reduce rodent mortality. Following baseline sampling on three grid pairs with different habitats, we closed the grids and began predator removal. By sampling three habitat types, we controlled for habitat-specific effects, which is important for hantavirus–reservoir dynamics in neotropical ecosystems. Our six-month predator exclusion experiment revealed that the exclusion of terrestrial mammalian predators had little influence on the rodent community or the population dynamics of A. montensis and O. nigripes. Instead, fluctuations in species diversity and species abundances were influenced by sampling session and forest degradation. These results suggest that seasonality and landscape composition play dominant roles in the prevalence of hantaviruses in rodent reservoirs in the IAF ecosystem.

Corrigendum to: Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Corrigendum to: Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Abstract We examined patterns of dietary overlap of phyllostomid bats in interior Atlantic Forest of Paraguay. In addition, we examined microgeographic, seasonal, and species-specific, differences in dietary patterns. We obtained 4,519 dietary records for bats from two sites in eastern Paraguay representing 26 different kinds of resources. The three most abundant resources made up 85% of all dietary records. No significant difference in diets of phyllostomid bats existed between sites. Overlap was high and significantly greater than random. Overlap at both sites was higher in winter than in summer. Consumption of dietary items was different between seasons and reflected changes in consumption primarily of the three most consumed items. Resource breadth was narrower in winter than summer. Sites, season, and species together accounted for 71% of the variation in dietary items. Unique effects, after controlling for variation shared with other factors, of species and season were significant, whereas that of site was not. While much dietary variation in interior Atlantic Forest falls along phylogenetic lines, such patterns are weak and resource utilization appears to be substantively influenced by generalist ecology of bats and seasonal nature of the environment in this system.

Small mammal glucocorticoid concentrations vary with forest fragment size, trap type, and mammal taxa in the Interior Atlantic Forest

Species that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. We extracted glucocorticoids from fur samples of 106 small mammals (rodent genera Akodon and Oligoryzomys, and marsupial genera Gracilinanus and Marmosa) from six forest fragments (2–1200 ha) in the Reserva Natural Tapytá, Caazapá Department, Paraguay. To our knowledge, this is the first publication of corticosterone and cortisol levels for three of the four sampled genera (Akodon, Oligoryzomys, and Marmosa) in this forest system. We discovered three notable results. First, as predicted, glucocorticoid levels were higher in individuals living withing small forest fragments. Second, animals captured live using restraint trapping methods (Sherman traps) had higher glucocorticoid levels than those animals captured using kill traps (Victor traps), suggesting that hair glucocorticoid measures can reflect acute stress levels in addition to long-term glucocorticoid incorporation. These acute levels are likely due to urinary steroids diffusing into the hair shaft. This finding raises a concern about the use of certain trapping techniques in association with fur hormone analysis. Finally, as expected, we also detected genus-specific differences in glucocorticoid levels, as well as cortisol/corticosterone ratios.

Relative contributions of ecological drift and selection on bat community structure in interior Atlantic Forest of Paraguay.

Despite extensive focus on numerous mechanisms that potentially structure Neotropical bat communities, understanding of the relative importance of any is still illusive. Recently, it has been demonstrated that all mechanisms used to explain community organization can be conceptualized as one or a combination of the few higher-level processes of dispersal, drift, selection and speciation. These four higher-level processes have not been addressed equally by Neotropical bat community ecologists. In particular, predictions formulated from a hypothesis of ecological drift have not been tested for any Neotropical bat community. Herein we contrast efficacy of predictions based on the higher-level processes of drift and selection in describing community structure of bats in the Atlantic Forest of eastern Paraguay. Predictions apply to species-environment interactions, patterns of trait variation and beta-diversity, predictability of dominant competitors and responses to seasonality. At best, there was inconsistent support for the operation of either drift or selection within this bat community. Selection, however, had more various forms of support including strong species-environment relationships, predictable patterns of dominant competitors and strong responses to seasonality. Despite stronger support for selection, a number of predictions of drift were supported as well. It is likely that a combination of both of these processes operates across the variable environments experienced in Atlantic Forest. Predictions of both processes are difficult to make operational. Support for drift often comes from failure to demonstrate a significant pattern and should not be considered strong support of a prediction. Similarly, many predictions of selection predict phenotypic patterns among species without specifying a particular trait. This is problematic because the phenotype is multifaceted and a lack of pattern in one measured trait might mask a strong pattern in some other unmeasured trait. Distilling mechanisms of community organization into four higher level processes is a substantial innovation in community ecology. Nonetheless, efforts need to be made to develop a suite of mutually exclusive and falsifiable predictions to facilitate future and more rapid understanding of community organization.

Predictive sampling effort and species-area relationship models for estimating richness in fragmented landscapes.

Loss of habitat, specifically deforestation, is a major driver of biodiversity loss. Species-area relationship (SAR) models traditionally have been used for estimating species richness, species loss as a function of habitat loss, and extrapolation of richness for given areas. Sampling-species relationships (SSRs) are interrelated yet separate drivers for species richness estimates. Traditionally, however, SAR and SSR models have been used independently and not incorporated into a single approach. We developed and compared predictive models that incorporate sampling effort species-area relationships (SESARS) along the entire Atlantic Forest of South America, and then applied the best-fit model to estimate richness in forest remnants of Interior Atlantic Forest of eastern Paraguay. This framework was applied to non-volant small mammal assemblages that reflect different tolerances to forest loss and fragmentation. In order to account for differences in functionality we estimated small mammal richness of 1) the entire non-volant small mammal assemblage, including introduced species; 2) the native species forest assemblage; and 3) the forest-specialist assemblage, with the latter two assemblages being subsets of the entire assemblage. Finally, we geospatially modeled species richness for each of the three assemblages throughout eastern Paraguay to identify remnants with high species richness. We found that multiple regression power-law interaction-term models that only included area and the interactions of area and sampling as predictors, worked best for predicting species richness for the entire assemblage and the native species forest assemblage, while several traditional SAR models (logistic, power, exponential, and ratio) best described forest-specialist richness. Species richness was significantly different between assemblages. We identified obvious remnants with high species richness in eastern Paraguay, and these remnants often were geographically isolated. We also found relatively high predicted species richness (in relation to the entire range of predicted richness values) in several geographically-isolated, medium-size forest remnants that likely have not been considered as possible priority areas for conservation. These findings highlight the importance of using an empirical dataset, created using sources representing diverse sampling efforts, to develop robust predictive models. This approach is particularly important in geographic locations where field sampling is limited yet the geographic area is experiencing rapid and dramatic land cover changes. When combined, area and sampling are powerful modeling predictors for questions of biogeography, ecology, and conservation, especially when addressing habitat loss and fragmentation.

Discovery of a new genus record for Paraguay, the Atlantic Forest endemic rodent Abrawayaomys (Cricetidae, Sigmodontinae)

Abstract The mammals of Paraguay are still poorly known. We report a new genus for the country, Abrawayaomys, a spiny cricetid rodent endemic for the Interior Atlantic Forest. This record extends the distribution of the genus approximately 100 km, and west of the Paraná River. This addition increases the number of mammals in Paraguay to 184 and verifies that rodents are the most diverse group of mammals in the country. We outline identifying morphological characters of Abrawayaomys and elaborate on the significance of this finding for conservation and biogeography in the region.

Two new species of land planarians (Platyhelminthes, Tricladida, Geoplanidae) from protected areas in the southern extreme of the Paranaense Rainforest, Argentina

Here, we describe two new flatworm species of the genera Obama Carbayo et al., 2013 and Notogynaphallia Ogren & Kawakatsu, 1990 (Geoplaninae) found in riverine forests of central-eastern Argentina. Obama maculatentis sp. nov., which is about 50 mm in length, is characterized by black olive pigmentation on the dorsum, with two irregular rows of black spots, and light grey ventral surface. The eyes, with clear halos, extend to the dorsal surface. The foremost features of the copulatory apparatus include dorsal testes anterior to ovaries, extrabulbar prostatic vesicle with forked proximal portion, protrusible penis, male atrium with a large dorsal fold separating it from the female atrium, ovovitelline ducts ascending at the level of the gonopore, common ovovitelline duct dorsal to the distal portion of the female atrium, female canal ventro-anteriorly flexed, and female atrium with narrow lumen. Notogynaphallia fortuita sp. nov., which is about 30 mm in length, is characterized by beige ground pigmentation with tiny darker spots, cephalic region saffron yellow, and ventral surface light grey. The eyes, with small clear halos, extend to the dorsal surface. Regarding the internal anatomy, this new species shows parenchymatic musculature not organized in discrete layers, testes arising near the anterior end of the body, distal sperm ducts traversing the common muscle coat and joining in a short common sperm duct. The areas in which the land planarians were found represent the southernmost latitudes with representatives of the Interior Atlantic Forest (Paranaense Rainforest) biota, hence their biogeographical and conservation significance.

Características poblacionales de Akodon Montensis en diferentes calidades de su hábitat, y características del microhábitat relacionadas a su presencia en el Bosque Atlántico Interior de Paraguay

Características poblacionales de Akodon Montensis en diferentes calidades de su hábitat, y características del microhábitat relacionadas a su presencia en el Bosque Atlántico Interior de Paraguay

Habitat, species richness and hantaviruses of sigmodontine rodents within the Interior Atlantic Forest, Paraguay.

Four of the nine sigmodontine tribes have species that serve as reservoirs of rodent-borne hantaviruses (RBO-HV), few have been studied in any depth. Several viruses have been associated with human cases of hantavirus pulmonary syndrome often through peridomestic exposure. Jabora (JABV) and Juquitiba (JUQV), harbored by Akodon montensis and Oligoryzomys nigripes, respectively, are endemic and sympatric in the Reserva Natural de Bosque Mbaracayú (RNBM), Paraguay, a protected area of the Interior Atlantic Forest. Rodent communities were surveyed along a 30 km stretch of the RNBM in eight vegetation classifications (Low, High, Bamboo, Riparian and Liana Forests, Bamboo Understory, Cerrado, and Meadow/Grasslands). We collected 417 rodents from which 11 species were identified; Akodon montensis was the predominant species (72%; 95%CI: 64.7%-76.3%), followed by Hylaeamys megacephalus (15% (11.2%-18.2%)) and Oligoryzomys nigripes (9% (6.6%-12.4%)). We examined the statistical associations among habitat (vegetation class) type, rodent species diversity, population structure (age, sex, and weight), and prevalence of RBO-HV antibody and/or viral RNA (Ab/RNA) or characteristic Leishmania tail lesions. Ab/RNA positive rodents were not observed in Cerrado and Low Forest. A. montensis had an overall Ab/RNA prevalence of 7.7% (4.9%-11.3%) and O. nigripes had an overall prevalence of 8.6% (1.8%-23.1%). For A. montensis, the odds of being Ab/RNA positive in High Forest was 3.73 times of the other habitats combined. There was no significant difference among age classes in the proportion of Ab/RNA positive rodents overall (p = 0.66), however, all 11 RNA-positive individuals were adult. Sex and habitat had independent prognostic value for hantaviral Ab/RNA in the study population; age, presence of tail scar/lesion (19% of the rodents) and weight did not. Adjusting for habitat, female rodents had less risk of becoming infected. Importantly, these data suggest habitat preferences of two sympatric rodent reservoirs for two endemic hantaviruses and the importance of including habitat in models of species diversity and habitat fragmentation.

Worrisome isolation: noninvasive genetic analyses shed light on the critical status of a remnant jaguar population

Many carnivore species, particularly felids, are sensitive to land use changes and may disappear from landscapes with reduced natural habitat and increased fragmentation. The jaguar (Panthera onca) is highly affected by these factors and is particularly endangered in the Atlantic Forest (AF) of South America, one of the most threatened biomes in the world. We used noninvasive fecal sampling and microsatellite markers to investigate the genetic diversity of jaguars in one of the last remnant populations of this species in the entire coastal AF. This section of the biome is highly fragmented. We observed low levels of genetic diversity (HO = 0.621, HE = 0.532, AR = 3.195), and estimated a small effective size for the population (Nₑ = 7.9 individuals). We performed comparative analyses incorporating data from previously surveyed populations located farther inland (interior AF), revealing that the coastal population studied shows significant genetic differentiation. Our results support a scenario of anthropogenic, drift-induced differentiation among jaguar populations in small AF fragments, affecting both the interior and coastal components of this biome. Despite its low diversity, we detected putatively unique alleles present in the coastal population, supporting its importance in the context of maintaining the remaining genetic variability of jaguars in the AF. Our results highlight the urgent need to implement coordinated conservation actions for jaguars in this highly impacted biome, including management interventions that foster the restoration of genetic connectivity among isolated remnant populations. Muitas especies de carnivoros, particularmente felinos, sao sensiveis as mudancas no uso do solo e podem desaparecer de paisagens com proporcoes reduzidas de habitat natural e elevada fragmentacao. A onca-pintada (Panthera onca) e muito afetada por esses fatores e esta particularmente ameacada na Mata Atlântica, um dos biomas mais ameacados do mundo. Foram utilizadas amostras fecais nao-invasivas e marcadores microssatelite para investigar a diversidade genetica de oncas-pintadas em uma das ultimas populacoes remanescentes desta especie em toda Mata Atlântica costeira. Esta porcao do bioma esta altamente fragmentada e as poucas populacoes remanescentes de onca-pintada ainda nao foram avaliadas geneticamente. Foram observados baixos niveis de diversidade genetica (HO = 0,621; HE = 0,532; AR = 3,195) e estimado um pequeno tamanho populacional efetivo (Nₑ = 7,9 individuos). Analises comparativas incorporando dados de populacoes anteriormente amostradas e localizadas no interior do bioma (Mata Atlântica de interior) revelaram que a populacao costeira estudada apresenta significativa diferenciacao genetica em relacao aos outros remanescentes. Os resultados obtidos apoiam um cenario de diferenciacao induzida por deriva antropogenica entre populacoes de onca-pintada em pequenos fragmentos da Mata Atlântica, afetando tanto os componentes de interior quanto costeiros deste bioma. Apesar de sua baixa diversidade genetica, foram detectados alelos exclusivos na populacao costeira, indicando a importância deste remanescente para a manutencao do que ainda resta da variabilidade genetica das oncas-pintadas da Mata Atlântica como um todo. Mostra-se necessaria a urgente implementacao de acoes coordenadas de conservacao para as oncas-pintadas neste bioma altamente impactado, incluindo intervencoes de manejo que promovam a restauracao da conectividade genetica entre as populacoes remanescentes e isoladas.

Diversidad, sistemática y conservación de roedores en el extremo sudoccidental del Bosque Atlántico Interior

Fil: Lanzone, Cecilia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Posadas; Argentina

Increasing diversity of land planarians (Platyhelminthes: Geoplanidae) in the Interior Atlantic Forest with the description of two new species and new records from Argentina.

Here, we describe two new species of land planarians of the genera Pasipha and Imbira from the Atlantic Forest of Argentina: Pasipha quirogai sp. nov. and Imbira negrita sp. nov. Their external features and internal anatomy distinguish them from their congeners. Pasipha quirogai sp. nov. is about 40mm long, characterized by brown beige dorsal pigmentation with a golden yellow median band and thin graphite black para-median stripes, cylindrical pharynx, extrabulbar prostatic vesicle with paired proximal portion, male atrium with small folds in its proximal part, and female canal opening into the dorso-caudal wall of the female atrium. Imbira negrita sp. nov. is about 110mm long, with jet black dorsal pigmentation, pharynx collar-type, short female canal opening in the postero-dorsal portion of the female atrium, and epithelial lining of female atrium with stratified appearance. We also provide exhaustive descriptions of Geoplana quagga, Obama ladislavii, and Paraba multicolor, all recorded for the first time in Argentina, by analysing anatomical features of taxonomic relevance. In addition, we improve the description of G. quagga, mainly regarding the musculature, secretory cells, and the copulatory apparatus.

Elachistocleis matogrosso Caramaschi 2010, (Amphibia: Anura: Microhylidae) first records for Paraguay

The first Paraguayan records of a Cerrado endemic, Microhylid frog, Elachistocleis matogrosso are reported. Specimens were collected at Reserva Natural de Laguna Blanca, Departmento San Pedro, Paraguay on a temporary poolin an area of transition from Cerrado to degraded interior Atlantic forest,near an artesian lake. These records were in sympatry with congeneric Elachistocleis bicolor.

Threshold effect of habitat loss on bat richness in cerrado-forest landscapes.

Understanding how animal groups respond to contemporary habitat loss and fragmentation is essential for development of strategies for species conservation. Until now, there has been no consensus about how landscape degradation affects the diversity and distribution of Neotropical bats. Some studies demonstrate population declines and species loss in impacted areas, although the magnitude and generality of these effects on bat community structure are unclear. Empirical fragmentation thresholds predict an accentuated drop in biodiversity, and species richness in particular, when less than 30% of the original amount of habitat in the landscape remains. In this study, we tested whether bat species richness demonstrates this threshold response, based on 48 sites distributed across 12 landscapes with 9-88% remaining forest in Brazilian cerrado-forest formations. We also examined the degree to which abundance was similarly affected within four different feeding guilds. The threshold value for richness, below which bat diversity declines precipitously, was estimated at 47% of remaining forest. To verify if the response of bat abundance to habitat loss differed among feeding guilds, we used a model selection approach based on Akaike's information criterion. Models accounted for the amount of riparian forest, semideciduous forest, cerrado, tree plantations, secondary forest, and the total amount of forest in the landscape. We demonstrate a nonlinear effect of the contribution of tree plantations to frugivores, and a positive effect of the amount of cerrado to nectarivores and animalivores, the groups that responded most to decreases in amount of forest. We suggest that bat assemblages in interior Atlantic Forest and cerrado regions of southeastern Brazil are impoverished, since we found lower richness and abundance of different groups in landscapes with lower amounts of forest. The relatively higher threshold value of 47% suggests that bat communities have a relatively lower resistance to habitat degradation than other animal groups. Accordingly, conservation and restoration strategies should focus on increasing the amount of native vegetation of landscapes so as to enhance species richness of bats.