Judul: Keanekaragaman jenis burung pada beberapa tipe habitat di Tambling Wildlife Nature Conservation (TWNC), Taman Nasional Bukit Barisan Selatan Lampung
Abstrak: Tambling Wildlife Nature Conservation (TWNC) is part of the Bukit Barisan Selatan National Park. The area called Tambling (Tampang-Belimbing) is a conservation area that conserve high biodiversity. TWNC is managed by PT Adhiniaga Kreasinusa (AKN). The purposes of this research are 1). to compare the diversity of bird species at several types of habitat in TWNC, those are coastal forest, lowland forest, plantation and grassland. 2). to identify the difference of bird species composition among types of habitat. 3). to know the local birds distribution related to the types of habitat in TWNC. This research was conducted from August to November 2009. Data of birds was collected using MacKinnon species list and point count method or IPA (Ponctuel Indices d'Abondance). Data of habitat was collected using vegetation analysis and habitat used approach. Data of vegetation was collected by sampling plot 20 x 100 m. T-test was used to determine differences in bird species diversity among the coastal forest, lowland forest, plantation, and grassland habitats at the 95% confidence level. The vegetation in the coastal forest habitat was dominated by beach hibiscus (Hibiscus tiliaceus) with Important Value Index (IVI) 114.49%. In the lowland forest habitat was dominated by meranti (Shorea sp) with IVI 66.71%. Vegetation in plantation habitat consisted of coffee (Coffea robusta) and cacao (Thebroma cacao). Grassland habitat is dominated by species kerawatan (Cyonodon dactylon) and rumput jarum (Andropoghon aciculatus). The total bird species found in four types of habitat were 116 species, comprising 38 families. Twenty-eight species are categorized as protected by Indonesian government regulation No. 7 of 1999, 12 species are listed in the IUCN (Critically Endangered and Near Threatened), and 19 species are listed in CITES (Appendix I and II). The highest bird Diversity Index was found in plantation habitat (H’=2.93). The Evenness Index in four habitat types are distributed evenly. The habitats that have the highest similarity are between lowland forest and plantation habitats (ISJ=0.54). T-test results shows that there is no significant differences among four habitats in terms of birds diversity, it was predicted because of small sample size and a narrow area of research. Bird species in each habitat type has a different level of dominance. Regarding vertical distribution, birds in coastal forest lived in C to E strata. Vertical distribution of birds in lowland forest was found in A to E strata. Vertical distribution of birds in plantation habitat was found from C to E strata. While in grassland habitat birds were only found in E strata. The common bird activities were perching, singing, flying, and walking. Bird activity that was mostly found at coastal forest, lowland forest, and plantation was perching. At grassland habitat, common bird activity was walking.
Keyword: 

Judul: Keanekaragaman jenis Burung pada beberapa tipe Habitat di Hutan Penelitian Dramaga, Bogor, Jawa Barat
Abstrak: Dramaga Research Forest, located in the outskirt of Bogor, provides a good habitat for birds. This research was aimed to study bird diversity, identifying habitat characteristics (around the forest path, along house edge, riparian habitat and the interior area) and recorded the activities of the local people around the forest. Point count, MacKinnon list, habitat profiling and interviews were conducted. Shannon-Wiener diversity indices and similarity level were calculated. The highest index of species diversity was in the interior area (2.34), followed by around the forest path (2.21), along house edge (1.97) and riparian habitat (1.86). The highest species richness, however, was in the riparian habitat (27 species), the forest path had 21 species, along house edge had 26 species, while the interior area was a home for 21 bird species. The highest similarity (0.81) was between forest path and interior area. On the activities of the local people, the most often was firewood harvesting. Other activities were hunting for cage birds, harvesting ferns, harvesting wild fruit and harvesting ant larvae. Activity that might disrupt the bird population was hunting.
Keyword: Bogor Agricultural University (IPB), Dramaga research forest, human activities, Bird diversity, Streptopelia chinensis, Orthotomus sepium

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: