Habitat and Distribution Modeling of Prehistoric Hippos (Hippopotamus sivalensis spp.) During Pleistocene in Java Island

Currently, there are only 2 extant species of hippos including common (Hippopotamus amphibius) and pygmy hippos (Choeropsis liberiensis) . But in prehistoric times, there were several species. During  Pleistocene these species were known to migrate to Java Island from Asian Continent and the species was Hippopotamus sivalensis spp. In this regard, this study aimed to model the habitat of H. sivalensis spp., ecology, and biodiversity of Hippopotamus sivalensis spp. based on the fossil record. The model was developed based on the Principal Component Analysis (PCA) method using the R statistical package. The results showed that there were 7 populations of H. sivalensis spp. that lived at various altitudes with an average of 177 m above sea level (95% CI : 123-232 m). According to PCA, there were at least 2 separate populations of H. sivalensis spp. One population occupies the forest while another occupies a habitat close to the coast. Currently the habitat for H. sivalensis spp. already changed. Based on habitat modeling, H. sivalensis spp. inhabit streams with submerged aquatic plants and shrubs and trees growing along river banks

Spatial Distributions and Model Selections of Commercial Estuarine Fish (Sciaenidae) Populations Related to Water Quality, Chl-a, and AML in Musi River mouth, South Sumatra

Estuary and river mouth are essential habitats for many commercial estuarine fishes, including the Sciaenidae family. While recently, estuaries have been threatened by anthropogenic marine litter (AML) transported from nearby land and river. An important type of AML is plastic litter since it takes a long degradation time. In the South Sumatra Province, Indonesia, one of the vital estuaries is the Musi estuary. This paper aims to map the spatial distributions of two Sciaenids, including Panna microdon and Otolithoides pama, and Sciaenid’s environmental covariates, including water quality, chlorophyll a, and plastic litters in Musi estuary and model the correlations of Sciaenids with their covariates. The maps were developed using GIS, and the model was validated using AIC methods. The data were collected from 3 river mouths in the west, central, and east of the Musi estuary. The data showed that the populations of both Sciaenids were higher in the east river mouth rather than in the west. Sciaenid populations were positively correlated with high salinity, DO, chlorophyll a, moderate transparency, and low temperature. A high load of AML’s frequency (7.54 items/m2) and weights (36.8 gram/m2) has reduced both Sciaenid populations in the central river mouth of the estuary. In contrast, low AML loads in the east have correlated with high Sciaenid populations. Model selection based on AIC values shows the best model for P.microdon retained an effect of AML weight with AIC values of 22.591 and 28.321 for O. pama. This concludes that the weight of plastic litter in estuary water was the main limiting factor for Sciaenid populations in Musi

APPLICATIONS OF CONVEX POLYGON AND KERNEL DENSITY ANALYSES TO MODEL THE HOME RANGES OF EQUATORIAL SPITTING COBRA Naja sputatrix (BOIE, 1827) IN GREEN AREAS OF UNIVERSITAS INDONESIA CAMPUS, WEST JAVA

Naja sputatrix (Boie, 1827) or known as equatorial spitting cobra is one of venomous snake inhabiting wide green areas include Universitas Indonesia Campus. Currently the existence and conservation of cobra is threatened, then it is important to study cobra possible home ranges. This research is aiming to model the home range of equatorial spitting cobra in green areas of Universitas Indonesia Campus. The model was developed using the applications of Convex Polygon and Kernel Density. The Convex Polygon analysis shows that approximately 114.53 Ha or equals to 35.79% of green areas of Universitas Indonesia Campus was the home ranges of the cobra. While, based on the Kernel Density analysis, it confirms that up to 307.65 Ha or equals to 96.14% of green areas of Universitas Indonesia Campus were potentials as the home ranges of the cobra. Then it can be concluded that at least 30-90% of green areas of Universitas Indonesia Campus should be conserved to support the presences of N. sputatrix

LANDSCAPE ECOLOGY OF ENDEMIC BLACK-WINGED STARLING Acridotheres melanopterus tricolor (HORSFIELD, 1821) RELATED TO ENVIRONMENTAL FACTORS IN A TROPICAL SAVANNA OF INDONESIA

The black-winged starling (Acridotheres melanopterus tricolor) is a bird species in Southeast Asia, and this species still exists within Indonesia's tropical savanna landscape. This study aims to estimate the population density of the A. m. tricolor and to model the relationship between this species density and its environmental factors in several land cover types in the Baluran National Park savanna landscape in Java. The environmental factors were Normalized Difference Vegetation Index (NDVI), land cover size, and distance to river obtained from Landsat 8 Operational Land Imager (OLI) and analyzed using Geographical Information System (GIS). General Additive Models (GAM) combined with Principal Component Analysis (PCA) was used to analyze the correlation of bird density with environmental factors. Based on the results, the average density of the A. m. tricolor was eight (8) inds./km2. The correlation model showed a significant positive relationship between bird density and NDVI and a significant negative relationship for distance to river factors, while land cover size did not significantly correlate with the bird density. These findings suggest that vegetation and access to water sources remain a relatively important environmental factors for supporting A. m. tricolor populations and this species conservation in the tropical landscape. The novelty of this research is satellite imagery and GIS usage to elaborate the landscape and habitat of A. m. tricolor. In addition, this study also contributes to modelling the most overarching environmental factors of A. m. tricolor in Indonesia's tropical savanna landscape

Habitat Preference Modeling of Prehistoric Giant Shark Megalodon During Miocene in Bentang Formation of West Java Coast

In the Miocene era about 20 million years ago, the South Coast of West Java was a sea and habitat for marine organisms including giant sharks Megalodon measuring about 18 meters long. This study aimed to model the habitat preference of the prehistoric gigantic shark Otodus megalodon population based on the fossil record. From fossil teeth, it revealed that the rock layer where the teeth found was Bentang formation from Miocene era. Many fossils of Megalodon had been unearthed from Bentang formation which is part of the South Coast of West Java. The habitat model was developed using the Sea Level Rise Inundation Tool of ArcGIS to estimate the sea depth and Megalodon’s habitat during the Miocene. The length of the teeth of O. megalodon found was ranged from 13 to 19 cm, indicating the presence of juvenile and adult O. megalodon. Based on the model, in the Miocene era, half of West Java was a sea with a depth ranging from 0 to 200 meters. At that time, it was estimated that juvenile O. megalodon occupied waters with a depth of 0-40 meters with an area of 1365 km2. Meanwhile, adult O. megalodon prefers a depth of 80-160 m and the frequency of habitat use increases at a depth of 200 m. The declining population of O. megalodon is associated with climate change and declining prey populations

Spatial diversity patterns of understory shrub community in Srengseng urban forest, Jakarta

Urban forests are one of the natural ecosystems in urban environments. One of the most important components of the urban forest ecosystem is the understory shrubs. Therefore, this study aims to estimate the diversity of understory shrubs in the Srengseng Urban Forest in Jakarta City. The biodiversity of understory shrubs is calculated using the Shannon-Wiener diversity index (H') and mapped using the Geographic Information System (GIS). In this study, 24 plots measuring 2 m by 2 m each were placed to survey the understory shrubs. In total, there were 20 species of shrubs identified, which belong to 12 families with average values of H' is 0.671. The results show that almost 62.78% of the total Srengseng Urban Forest area has a H' diversity range of 1.001–1.500. In comparison, 8.62% of total urban forest area has an H' diversity range of 0.501-1.000. The area of urban forest with the lowest diversity in the H' diversity range of 0.000 to 0.500 reaches 28.58%. The eastern parts of the urban forest have the highest H' in comparison to the other parts of the forest. This study contributes to the conservation and forestry management of forest at an urban scale by identifying parts of the urban forest that should be conserved in the Srengseng. To conclude, the eastern parts of Srengseng Urban Forest sizing 64,765 m2 should be prioritized for understory shrub conservation

Spatial Biodiversity of Birds in Land Covers of Wetlands on Jakarta’s North Coast

Wetlands are suitable habitats for the coastal bird community. One of the important wetlands is located on Jakarta’s North Coast. Here, this study aims to assess the spatial biodiversity of birds in various land covers of wetlands on Jakarta’s North Coast. In total, there were 23 species belonging to 12 bird families. Ardeidae, Rallidae, and Silviidae bird families have more species compared to other families. The biodiversity H' values in the wetlands dominated by mangrove cover were the highest, at 2.527, followed by the wetlands having less mangrove cover and more water bodies and fish ponds only having H’ values equal to 1.811. The arboreal, small-to-medium-sized birds belong to Nectariniidae, Ploceidae, Silviidae, and Dicaeidae were widely distributed across all land cover. In contrast, the wetlands characterized by mangrove cover dominance combined with muddy substrate coasts were dominated by mid-large water birds belong to Anatidae, Scolopacidae, Ciconiidae, Rallidae, Ardeidae, Phalacrocoracidae, Anhingidae, and Alcedinidae. It is recommended to protect the mangroves and reforest the wetlands with mangroves to provide more habitats for the coastal bird community.

Markov Chain and Cluster Model of Green Algae Phytoplankton (Chlorophyceae) Diversity and Spatial Distribution Pattern along Stream, Water Quality, and Land Use Gradients in Krukut River, Jakarta City

Green algae phytoplankton (Chlorophyceae) have a wide aquatic distribution, including saltwater and freshwater environments. Compared to the ones living in saltwater, green algae diversity in freshwater ecosystems in rivers is influenced by stream gradients, water quality, and land uses. Meanwhile, in Jakarta, 17 rivers have the potential to provide a habitat for green algae communities. Due to anthropogenic activities, river streams have been affected by influences that may affect the water quality and green algae community along stream gradients. One of the critical rivers in Jakarta is the Krukut river, which has the most extended stream spanning over 40 km and downstream in Jakarta bay. This study aims to model the diversity and distribution pattern of green algae in the Krukut river from its upstream segment in Jakarta city, surrounded by settlements, to the downstream segments in Jakarta bay. The distribution model uses the Cluster Analysis and Markov Chain Model to elaborate the probabilities of green algae phytoplankton distribution in downstream, midstream, and upstream segments of the Krukut river. The results show that 7 species of Chlorophyceae have been recorded in the Krukut river. All species had a high likelihood of being found downstream, particularly Cosmarium sp., Eudorina sp., Spyrogyra sp., and Volvox sp. Regarding distribution, all phytoplankton species have a high probability (4%–31%) and tendency to be distributed from upstream and midstream to downstream rather than from downstream to midstream and upstream, with probability ranges of 2%–27%. The probability and tendency of phytoplankton distribution towards downstream directions avoiding upstream were related to the deteriorating water quality in the upstream, characterized by high turbidity, low dissolved oxygen, and more acidic water

Spatial Biodiversity of Birds in Land Covers of Wetlands on Jakarta’s North Coast

Wetlands are suitable habitats for the coastal bird community. One of the important wetlands is located on Jakarta’s North Coast. Here, this study aims to assess the spatial biodiversity of birds in various land covers of wetlands on Jakarta’s North Coast. In total, there were 23 species belonging to 12 bird families. Ardeidae, Rallidae, and Silviidae bird families have more species compared to other families. The biodiversity H' values in the wetlands dominated by mangrove cover were the highest, at 2.527, followed by the wetlands having less mangrove cover and more water bodies and fish ponds only having H’ values equal to 1.811. The arboreal, small-to-medium-sized birds belong to Nectariniidae, Ploceidae, Silviidae, and Dicaeidae were widely distributed across all land cover. In contrast, the wetlands characterized by mangrove cover dominance combined with muddy substrate coasts were dominated by mid-large water birds belong to Anatidae, Scolopacidae, Ciconiidae, Rallidae, Ardeidae, Phalacrocoracidae, Anhingidae, and Alcedinidae. It is recommended to protect the mangroves and reforest the wetlands with mangroves to provide more habitats for the coastal bird community.