Predicting habitat suitability of critically endangered Nepenthes sumatrana

Nepenthes sumatrana is a tropical pitcher plant endemic to Sumatra. It has been categorised as critically endangered based on the IUCN Red List. It often occupies in lowland tropical forest of Sumatra. Its habitat has been threatened by land use conversion in the recent decade. Due to the high threats in the wild, the conservation efforts are necessarily required. It is not possible to assess all locations that are suitable for this species. In terms of addressing that issue, Species Distribution Modelling is considered as an alternative way to identify the regions that have the similar environmental conditions to where the species is known to occur. The occurrence records were derived from Global Biodiversity Information Facility and reliable scientific papers. Topography, soil, climate and land cover were used as predictors of the model. MaxEnt algorithm was used to predict the habitat suitability. MaxEnt produces a predictive model with the AUC value of 0.833 indicating that the model has a good performance. The suitable habitats are predicted in several different locations in Sumatra. The information about predicted suitability habitat would be useful to prioritize the protected areas of this species. Furthermore, our findings would be valuable for the discovery of unknown subpopulation.

Agarwood Tree Characteristics based on Different Growing Habitat and Ecophysiological Attributes in the Papuan Tropical Forests

Understanding tropical forest characteristics, including forest derivative products such as agarwood, is pivotal. This study focused on perceiving an ideal habitat of the lowland tropical forest ecosystem of West Papua for agarwood-producing tree species. In further, this study identified a close association of biotic and abiotic characteristics to underpin agarwood-producing tree growth. Six sites in three different locations were established to ascertain forest composition and the associated insects. Soil samples were collected to analyze their physical and chemical properties using the Kjeldahl, the Walky and Black, and Atomic Absorption Spectrophotometry (AAS). In addition, temperature, relative humidity, and light intensity were measured. The results noticed two agarwood producing species, Gyrinops caudate and Aquilaria sp., found at an altitude of 400–402 masl in Manokwari, 200–300 masl in Teluk Wondama, and 167.7 masl in Teluk Bintuni. There were no significant differences in temperature, relative humidity, and light intensity. The soil cation exchange capacity was moderate in Manokwari, but it was low in Teluk Wondama and Teluk Bintuni. Total C-organic content in three research sites was classified as high. However, total N content in the three research sites was in the moderate category. The ideal habitat for agarwood in the West Papua forest is from the lowlands to the highlands. Environmental conditions that support the growth of agarwood are moderate temperature, high humidity, and moderate light intensity. Soil fertility also affected the natural growth of agarwood trees. Keywords: abiotic, agarwood association, lowland tropical forest, soil characteristics

Comparing the efficiency of monofilament and traditional nets for capturing bats

Traditional mist nets used for capturing bats have several drawbacks, particularly that they are inefficient at sampling many insectivorous species. One possible alternative is to use monofilament nets, whose netting is made of single strands of yarn instead of several as regular nets, making them less detectable. To date, no study has quantified the capture efficiency of monofilament nets compared to regular mist nets for the study of bats. Here we compare capture efficiency of monofilament and regular mist nets, focusing on bat abundance and species diversity at a lowland tropical forest in southwestern Costa Rica. During our sampling period, we captured 90 individuals and 14 species in regular nets and 125 individuals and 20 species in monofilament nets. The use of monofilament nets increased overall capture rates, but most notably for insectivorous species. Species accumulation curves indicate that samples based on regular nets are significantly underestimating species diversity, most notably as these nets fail at sampling rare species. We show that incorporating monofilament nets into bat studies offers an opportunity to expand records of different guilds and rare bat species and to improve our understanding of poorly-known bat assemblages while using a popular, relatively cheap and portable sampling method.

Range-wide habitat use and Key Biodiversity Area coverage for a lowland tropical forest raptor across an increasingly deforested landscape

Quantifying habitat use is important for understanding how animals meet their requirements for survival and provides useful information for conservation planning. Currently, assessments of range-wide habitat use that delimit species distributions are incomplete for many taxa. The harpy eagle (Harpia harpyja) is a raptor of conservation concern, widely distributed across Neotropical lowland forests, that currently faces threats from increasing habitat loss and fragmentation. Here, we use a logistic regression modelling framework to identify habitat resource selection and predict habitat suitability based on a new method developed from the International Union for the Conservation of Nature Area of Habitat range metric. From the habitat use model, we performed a gap analysis to identify areas of high habitat suitability in regions with limited coverage in the Key Biodiversity Area (KBA) network. Range-wide habitat use indicated that harpy eagles prefer areas of 70-75 % evergreen forest cover, low elevation, and high vegetation heterogeneity. Conversely, harpy eagles avoid areas of >10 % cultivated landcover and mosaic forest, and topographically complex areas. Our habitat use model identified a large continuous area across the pan-Amazonia region, and a habitat corridor from the Chocó-Darién ecoregion of Colombia running north along the Caribbean coast of Central America. Little habitat was predicted across the Atlantic Forest biome, which is now severely degraded. The current KBA network covered 18 % of medium to high suitability harpy eagle habitat exceeding the target representation (10 %). Four major areas of high suitability habitat lacking coverage in the KBA network were identified in the Chocó-Darién ecoregion of Colombia, western Guyana, and north-west Brazil. We recommend these multiple gaps of habitat as new KBAs for strengthening the current KBA network. Modelled area of habitat estimates as described here are a useful tool for large-scale conservation planning and can be readily applied to many taxa.

Avian extinctions induced by the oldest Amazonian hydropower mega dam: evidence from museum collections and sighting data spanning 172 years

Hydroelectric dams represent an emergent threat to lowland tropical forest biodiversity. Despite the large number of operational, under-construction, and planned hydroelectric dams, their long-term effects on biodiversity loss are still poorly documented. Here, we investigate avian extinctions resulting from the Tucuruí Hydroelectric Reservoir (THR), the oldest Amazonian mega dam, which impounded the Tocantins River in 1984. Our avian inventory—based on several sampling methods (mist-netting, point-counts, boat census and qualitative surveys) during 280 days of fieldwork from 2005 to 2007—was combined with an exhaustive search of museum vouchers and digital online databases of citizen science from the lower Tocantins River to identify long-term trends in species persistence and extinction in the THR influence area. The regional avifauna was comprised of 479 species, 404 of which were recorded during our fieldwork. Based on recent and historical records spanning 172 years, we found evidence for likely extinctions at THR influence area for 53 (11.06%) species that have remained entirely unreported since 1984. We were further able to estimate extinction probabilities for 20 species; 15 species were considered to be extinct, including Psophia interjecta and Pyrilia vulturina that are red-listed by IUCN. Our study serves as a baseline for avifaunal monitoring in the THR influence area and shows that degree of habitat specialization is a key factor in determining species extinctions caused by nonrandom habitat loss from either inundation or deforestation. Avian species extinctions will most likely continue across the area affected by the reservoir as a direct impact of alluvial forest loss and ongoing habitat degradation of upland forests.

DNA barcodes of birds from northern Colombia

DNA barcode datasets are a useful tool for conservation and aid in taxonomic identification, particularly in megadiverse tropical countries seeking to document and describe its biota, which is dropping at an alarming rate during recent decades. Here we report the barcodes for several low elevation bird species from northern Colombia with the goal to provide tools for species identification in this region of South America. We blood-sampled birds in a lowland tropical forest with various degrees of intervention using standard 3 × 12 m mist-nets. We extracted DNA and sequenced the COI barcode gene using standard primers and laboratory methods. We obtained 26 COI sequences from 18 species, 10 families and three orders and found that barcodes largely matched (but not always) phenotypic identification (> 90%) and they also facilitated the identification of several challenging passerine species. Despite our reduced sampling, our study represents the first attempt to document COI barcodes for birds (from blood samples) in this part of Colombia, which fills a considerable gap of sampling in this part of South America.

DNA barcodes from northern birds of Colombia

DNA barcode datasets are a useful tool for conservation and aid in taxonomic identification, particularly in megadiverse tropical countries seeking to document and describe its biota, which is dropping at an alarming rate during recent decades. Here we report the barcodes for several low elevation bird species from northern Colombia with the goal to provide tools for species identification in this region of South America. We blood sampled birds in a lowland tropical forest with various degrees of intervention using standard 10 × 12 mist-nets. We extracted DNA and sequenced the COI barcode gene using standard primers and laboratory methods. We obtained 28 COI sequences from 19 species, 10 families and 3 orders and found that barcodes largely matched (but not always) phenotypic identification (>90%) and they also facilitated the identification of several challenging passerine species. Despite our reduced sampling, our study represents the first attempt to document COI barcodes for birds (from blood samples) in this part of Colombia, which fills a considerable gap of sampling in this part of South America.

Pattern of tree diversity in lowland tropical forest in Nikiwar, West Papua, Indonesia

Trees are significant components of ecosystems built by several widespread species. For instance, Papua forest is known to comprise abiotic and biotic elements. Also, certain plants have grown in popularity to a point where they are discovered almost everywhere. The purpose of this study, therefore, was to investigate tree diversity, distribution, and the importance of conservation. Data were collected in four locations using a total of 24 sample plots spread across Idoor, Karst, Persemaian, and Torembi, where seven, four, seven, and five plots were allocated, respectively. These forests formed a mixed natural plantation comprising 76 species from 35 families. Furthermore, Idoor and Karst generated the highest species diversity and varied significantly compared to Persemaian, while Torembi showed similarities with the other three locations. This condition formed three ecosystem communities across Persemaian, Karst, Idoor, and Torembi. Also, the composition of the dominant species showed variations at the seedling and sapling levels believed to structure the understory, while the pole and tree levels characterized the overstory. The total species status was described as critically endangered (CR) of two species, vulnerable (VU) of six species, least concern (LC) of 28 species, and data deficient (DD) species. Therefore, location management is advised to not only pay significant attention in terms of economic benefits but also ecological, including the provisions for ex-situ and in-situ conservation to support sustainable forest management.