Let me introduce myself, Muhammad Yoga Saputra, I am a student of the Forest Management study program at Sebelas Maret University, Surakarta. Through the 2024 SwaraOwa scholarship program, with my colleague Ratna Dwi Setyowati and we got the opportunity to research for a thesis on the Javanese slow loris (Nycticebus javanicus). The Javan slow loris is one of seven species of slow lorises that live and are distributed in Indonesia. Based on the International Union of Conservation of Nature Resources (IUCN) Red List 2021, the Javan slow loris is included in the critically endangered category and is also included in Appendix 1 by Conservation on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
We observed the population, distribution and habitat of the Javan slow loris in Mendolo Forest, Lebakbarang, Pekalongan. Mendolo Forest is located in 4 hamlets, namely Sawahan, Mendolo Kulon, Mendolo Wetan, and Krandegan. Field observations were carried out in the second-fourth week of September 2024. We were accompanied by the Mendolo Village Young Farmers Association (PPM) who always accompanied us in collecting data. During our observations, we found 8 individuals of Javan slow loris in the Mendolo Forest. In the four hamlets in Mendolo Village, only Mendolo Wetan Hamlet did not find the Javan slow loris species. Our observations start at 19.30 – 24.00. We took night observations because the Javan slow loris is a nocturnal animal and when exposed to a flashlight, the eyes of the Javan slow loris emit eye rays which makes it easier to find the Javan loris’s whereabouts compared to daytime observations. We used the line transect method, where the transects were placed in areas where the Javan slow loris was believed to be present.
During night observation, we found several species in the Mendolo Forest such as the Sunda pangolin (Manis javanica), Rekrekran- Javan surili (Presbytis fredericae), Wild Boar (Sus scrofa), Black Banded Barbet (Megalaima javensis), Sunda scops Owl ( Otus angelinae), and Sunda flying lemur (Galeopterus variegatus). Apart from that, during daytime observations we also found various species such as the Javan gibbon (Hylobates moloch), Serpent eagle (Spilornis cheela), black eagle (Ictinaetus malaiensis), banded kingfisher (Lacedo pulchella) and Javan langur (Trachypithecus auratus).
The Javan slow loris is a semi-solitary animal. This can be seen in our observations where almost all individuals of the Javan slow loris were found alone. However, one of the Javan slow lorises was found with its infant. Observing at night requires precision and patience because sometimes we misidentify when there are eyes light on the tree that there is a Javan slow loris. However, when you look closely the glow from the eyes can come from civets, squirrels, or from Sunda flying lemurs. Apart from taking population and distribution data, we also took habitat data for the Javan slow loris in the Mendolo Forest.
Habitat data collection was carried out during the day by creating several plots to identify the habitat of the Javan slow loris in the Mendolo Forest. The habitat of the Javan slow loris in the Mendolo Forest is generally found in stands of coffee and durian trees. Apart from that, the Javan slow loris can be found on jackfruit trees and trees containing sap, because the Javanese slow loris’ favorite food is the sap produced from twigs, stems, flowers or leaves. As in coffee stands, we saw that young coffee leaf twigs were often eaten by the Javan slow loris