Javan langurs (Trachypithecus auratus) are a group of primate animals that are endemic to Indonesia which is protected. In Indonesia we called it Lutung Jawa. The IUCN data states that Javan langurs are listed in Appendix II of CITES or may not be traded as Vulnerable. This is because these animals are increasingly rare due to their declining population (Eliana et al. 2017). The decline in the Javan langur population is caused by various factors and the main factor in humans. Javan langurs are wild animals whose natural habitat is in the forest. Various habitat damages such as forest burning, deforestation, land conversion, and illegal hunting have resulted in an increasingly depressed natural ecosystem of the Javan langurs.
As a wild animal, Javan langurs are not only primates but also have an important ecological role for the preservation of forest biodiversity. As the name implies, this Javan langurs can be found in the forests of Java Island. Based on data from the Javan Langur Center (JLC) in 2010, it is known that the Javan langur population is only around 2,700 scattered throughout Java (Raditya 2020). This number is decreasing as new cases of death or hunting of Javan langurs are found. The most recent case occurred in the protected forest area of Malang, East Java, where the discovery of a dead Javan langur hanging from a tree and only the head and skin remaining (Raditya 2020).
Usually, Javan langurs are hunted for their meat. The existence of a myth in consuming Javan langur meat causes poaching of this animal to continue. The myth that has developed is information that Javan langurs meat can increase vitality and can cure diseases (Hartik 2020). Of course, this information is not true and is only a myth in society. This condition indicates that the Indonesian people still uphold the beliefs or myths of their ancestors. Besides, the lack of knowledge and public awareness of the importance of preserving wildlife has led to habitat destruction and illegal hunting.
Important information that should be known and disseminated to the public is not only the knowledge that Javan langurs are endemic animals that must be protected, but also the ecological role of these animals. Javan langurs have an important role in preserving nature in the forest. This can be seen from the living habits of Javan Langurs. A langurs is a primate group that is often called folivorous or leaf eaters. However, Javan langurs also eat fruits because of their sweet taste and soft structure (Kool 1993). Some types of plant species that feed langurs are matoa (Pmetia pinnata), antap (Streculia subpeltata), rasamala (Altingia excelsea), sengon (Albizia chinensis), banana kele (Musa sp.), and others.
The eating habit of Javan langurs is one of the unique things which, when explored more deeply, actually has an important role in ecology. Javan langurs have a habit of eating by using their right and left hands simultaneously when eating fruit. The eating habits of Javan langurs are mostly done in trees and often move from one tree to another. The behavior of eating fruit and moving when eating indicates that Javan langurs have an ecological role in influencing the pattern of forest regeneration (Lambert and Garber 1998). Indirectly, Javan Langurs helps to spread the seeds from the edible fruit so that the seeds can grow in various places depending on the location of the tree where the seeds from the fruit eaten are dumped. These seeds will have the opportunity to grow into new plants which will encourage the diversity of tree species in the forest.
One simple example of the above explanation is when Javan langurs eat the fruit (Pmetia pinnata), then the seeds are dropped or scattered in another place so the seeds can grow in that location. Thus, Javan langurs helps to spread the seeds of trees in the forest, thereby increasing the diversity of species in the forest. Therefore, behind its wild and vigilant nature of humans, it turns out that Javan langurs play an important role in the preservation of flora biodiversity in the forest. This is something that is not widely realized by humans, including Indonesian society in general.
So actually there are many things we can learn from the Javanese Langurs life habits. As fellow living beings, Javan langurs still plays a role in its surroundings. Therefore, it is fitting for us to help preserve nature and everything in it. Being a greedy human being by continually exploiting nature will only backfire for future generations of people. Nature and other living things teach us that we must live side by side to protect and preserve each other. Also, Javan langurs is a small part of the inspirational story of endemic Indonesian creatures. Let us preserve this natural biodiversity so that it is no longer a replica or image in a museum that we can introduce to future generations, but real biodiversity in nature.
BIBLIOGRAPHY
Eliana D, Nasution EK, Indarmawan. 2017. Eating behavior of the Javan Langurs Trachypithecus auratus in the Baturaden 7 Shower Area, Mount Slamet, Central Java. Scripta Biologica. 4(2): 125-129.
Hartik A. 2020. Javan Lutung poaching in Malang due to myth increases vitality. regional.kompas.com [downloaded 02 September 2020].
Kool KM. 1993. The diet and feeding behavior of the silver leaf monkey (Trachypithecus auratus condaicus) in Indonesia. International Journal of Primatology. 14(5): 667-700.