Judul: Perilaku Harian Monyet Hitam Sulawesi (Macaca nigra) pada Masa Kebuntingan di Cagar Alam Tangkoko-Batuangus, Sulawesi Utara
Abstrak: Crested macaque (Macaca nigra), one of the seven endemic primates in Sulawesi is the most endangered macaque species that has been categorized as critically endangered by International Union for Conservation of Nature (IUCN). However, almost nothing is known about the reproductive biology in associated with the behavioral during pregnancy. The data is important to support a management and breeding programs such as pregnancy diagnostic and conservation program in this species. The research aimed to study the behavior of the crested macaques during pregnancy. Observations were performed on the 10 adult females of the Rambo 1 group (R1) which has been habituated at Tangkoko-Batuangus Nature Reserve, North Sulawesi. Behavioral data were collected using focal animal sampling and recorded using instantanaeous sampling on females during menstrual cycling, pregnancy, and after parturition (lactation). During five months observations, a total of 393,63 observation hours were recorded. The results showed that daily activities of the M. nigra during menstrual cycling were dominated by feeding (26.60%), foraging (15.95%), and locomotion (16.16%). Daily activities during pregnancy were dominated by feeding (27.03%), foraging (16.37%), and resting (13.45%), whereas after parturition (lactation) period was dominated by resting (26.12%), foraging (19.51%) and feeding (14.98%). The resting was the most activity in the end of pregnancy and few day after parturition. The diets which were collected successfully composed of the fruits (34 species, 20 families), arthropods (3 species, 2 families, 4 orders), fungi (4 genera and division), and plants (5 species and families). Climate influenced on the composition of the diet, especially on fruit and arthropods. In conclusion, the activity budgets were different during menstrual cycling, pregnancy, and lactation, especially feeding, foraging, locomotion, and resting.
Keyword: Bogor Agricultural University (IPB), diet, lactation, pregnancy, menstrual cycling, M. nigra

Judul: Behaviour and Food Preferences of Female Macaca nigra (Desmarest 1822) During Reproduction Phase in Tangkoko Conservation Forest Management Unit.
Abstrak: Fase reproduksi merupakan fase yang membutuhkan energi dalam jumlah besar, energi tersebut dapat berasal dari karbohidrat ataupun lemak. Betina dalam masa reproduksi membutuhkan makanan dengan kualitas dan kuantitas yang cukup untuk memberikan nutrien bagi janin, produksi ASI, dan perawatan infant. Induk akan beradaptasi dengan merubah pola tingkah laku dan jenis makanan untuk memenuhi kebutuhan tersebut, selain itu pengaruh paritas dan kondisi lingkungan dapat mempengaruhi pola tingkah laku dan preferensi makanan. Selama kebuntingan, Macaca nigra diketahui memiliki proporsi aktivitas yang berbeda pada tiap periode, sedangkan perilaku selama fase laktasi pada tiap periode tidak diketahui. Oleh karena itu, penelitian ini bertujuan untuk menganalisis pola perilaku setiap periode dan pemilihan makanan M. nigra pada fase non-siklus, bunting dan laktasi, serta hubungannya dengan pengaruh paritas betina dan lingkungan. Pengamatan dilakukan pada 30 individu M. nigra betina dari dua kelompok pada bulan Agustus 2018 hingga Juli 2019. Metode focal instantaneous sampling dilakukan untuk mengamati aktivitas harian betina selama 12 bulan. Metode focal continuous sampling untuk mencatat jenis makanan, indeks selektivitas untuk menganalisis preferensi jenis makanan, dan analisis proksimat untuk menganalisis kandungan nutrien. Hasil penelitian menunjukkan, pola perilaku M. nigra betina dipengaruhi oleh fase reproduksi betina, paritas betina, dan kondisi lingkungan. Betina pada akhir periode kebuntingan dan menyusui memiliki proporsi makan yang tinggi dan dominan memakan arthropoda. Betina primiparous melakukan banyak aktivitas istirahat. Preferensi makanan dapat dipengaruhi oleh faktor reproduksi, begitupula dengan pemilihan buah, dapat dipengaruhi oleh ketersediaan di alam. Buah favorit betina yaitu D. mangiferum dan Euginia sp. Proporsi aktivitas harian dan jenis makanan betina menyesuaikan dengan kebutuhan betina di tiap fase reproduksi., The reproductive phase is a phase that requires large amounts of energy, the energy dominantlycome from carbohydrates or fats. Females in reproductive period need good quality and enough quantity of food to provide nutrition for fetus, milk production, and infant care. The mother will adapt by changing the pattern of behavior and type of food to meet these needs, in addition the influence of parity and environmental conditions can affect the pattern of female behavior. During pregnant periods, Macaca nigra is known to have a different proportion of activity at each period, while the behavior during the lactation phase in each period is unknown. Therefore, this study aims to analyze the behavior patterns of each period and the selection of M. nigra food in the non-reproductive, pregnant and lactation phases, as well as its relationship to the influence of female parity and the environment. The observation was done on 30 female M. nigra individuals from two groups in August 2018 to July 2019. Focal instantaneous sampling method is done to observe the daily activities of females for 12 months. Focal continuous sampling to monitor food types, selectivity index to analyze food type preferences, and proximate analysis to analyze nutritional compound. The results showed that the female's M. nigra behavior pattern is influenced by the reproductive phase, parity, and environmental conditions. Females at the end of the pregnant and lactating periods have a high feeding proportion and predominantly eat arthropods. Primiparous females do a lot of resting activities. Food preferences can be influenced by reproductive
Keyword: aktivitas harian, seleksi makanan, monyet hitam sulawesi

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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