Pengaruh Camp Release dan Feeding Site terhadap Pola Aktivitas Orangutan (Pongo pygmaeus wurmbii) di Suaka Margasatwa Lamandau

Abstract

Reintroduksi merupakan salah satu upaya meningkatkan populasi orangutan dengan melepasliarkan hewan kembali ke habitat aslinya. Kemampuan adaptasi orangutan seperti kemampuan dalam mengenal jenis pakan hutan, dan kemampuan dalam membuat sarang tidur merupakan salah satu faktor keberhasilan reintroduksi orangutan. Hal tersebut berkaitan dengan prinsip pelepasliaran orangutan ke habitat alaminya yaitu dengan mengurangi interaksi langsung orangutan dengan manusia dan meningkatkan interaksi antar individu orangutan. Pelepasliaran di Suaka Margasatwa Lamandau menerapkan metode soft released (adanya dukungan pasca-pelepasliaran berupa pakan tambahan). SM Lamandau memiliki beberapa camp pantau pasca-pelepasliaran orangutan yaitu camp Gemini, camp Siswoyo, camp JL, camp Rasak, dan camp Buluh. Jenis vegetasi yang ditemukan di sekitar area camp mencapai 147 jenis, dan sebanyak 101 jenis merupakan sumber pakan utama orangutan. Kajian terhadap perubahan pola aktivitas orangutan yang dipengaruhi oleh keberadaan camp dan feeding site di sekitar hutan pelepasliaran penting untuk dilakukan, sebagai evaluasi dan identifikasi faktor yang memengaruhi keberhasilan reintroduksi. Tujuan dari penelitian ini adalah menganalisis pengaruh keberadaan camp release dan feeding site terhadap pola aktivitas orangutan di SM Lamandau, dengan ; (1) Mengukur intensitas kehadiran orangutan di camp dan feeding site. (2) Menganalisis korelasi intensitas kehadiran orangutan dengan kondisi fenologi (3) Menilai proporsi aktivitas, komposisi jenis pakan, dan penggunaan ketinggian orangutan. (4) Menilai tingkat perilaku human-oriented pada orangutan (sebagai respon terhadap keberadaan manusia di sekitar camp dan feeding site), dan (5) Menganalisis faktor berpengaruh terhadap tingkat perilaku human-oriented pada orangutan. Penelitian dilakukan selama lima bulan (Juli-November 2019). Pengamatan dilakukan di tiga lokasi berbeda yaitu; camp, feeding site, dan hutan (follow nest to nest). Pengamatan pola aktivitas, frekuensi kehadiran orangutan di camp dan feeding site, serta pengamatan perilaku human-oriented pada orangutan diamati menggunakan focal animal sampling, ad libitum, dan instantaneous record per 2 menit. Metode depth-interview digunakan pada informan yang terlibat interaksi dengan orangutan seperti staf camp dan pengunjung. Intensitas kehadiran orangutan di camp release dan di feeding site didominasi oleh kelompok induk. Tidak ada korelasi antara tingkat intensitas kehadiran orangutan di camp release dan feeding site dengan kondisi fenologi. Pola aktivitas orangutan dewasa dan orangutan remaja berbeda. Orangutan dewasa lebih banyak menghabiskan waktu untuk beristirahat terutama orangutan induk, sedangkan orangutan remaja lebih banyak menghabiskan waktu harian dengan makan. Hampir semua kelas-umur orangutan memakan pakan non-hutan (45-67%) ketika berada di camp dan feeding site. Orangutan cenderung melakukan aktivitas di ketinggian 0-10 m di semua lokasi pengamatan. Faktor yang memengaruhi intensitas kehadiran di camp dan feeding site dan pola aktivitas orangutan pasca-pelepasliaran adalah keberadaan camp release dan feeding site di dalam kawasan hutan pelepasliaran orangutan. Penelitian juga mengindikasi bahwa semua kategori orangutan diamati menunjukkan perilaku human-oriented terutama pada kategori promoting. Kategori promoting dan inhibiting lebih banyak dilakukan oleh orangutan remaja. Frekuensi promoting dan inhibiting lebih banyak dilakukan orangutan ketika berada di sekitar camp release dan feeding site. Faktor usia memengaruhi tingkat orientasi orangutan terhadap manusia (p-values;0,0008b)(R2-values;0,223 = means 22,3% model regresi dipengaruhi oleh usia orangutan saat diamati).

Reintroduction is one of the conservation efforts to increase the orangutan population by releasing them into their natural habitat. The adaptability of orangutans, such as foraging skill, and the ability to make sleeping nests, is one of the success factors for orangutan reintroduction. This is related to the principle of reintroduction, by reducing direct interactions between humans-orangutans then increasing interactions between individual orangutans. Releasing process at the Lamandau Wildlife Reserve applies the soft released method (there is post-release support by given additional feed). Lamandau WR has several post-release monitoring camps i.e. Gemini Camp, Siswoyo Camp, JL Camp, Rasak Camp, and Buluh Camp. In total 147 tree species found around the camp area, and as many as 101 species were the orangutan diet. It is important to analyze changes in orangutans‟ activity patterns that are influenced by the existence of camps and feeding sites around release forest, as an evaluation and identification of succesful factors of reintroduction. The aim of this study was to analyze the effect of the existence of camp releases and feeding sites on orangutans‟ activity pattern in Lamandau WR, with ; (1) measuring the intensity of orangutans‟ attendance at camp and feeding site, (2) analyzing the correlation between intensity of orangutans‟ attendance and phenological conditions, (3) assessing the proportion of activity budgets, diet composition, and vertical used orangutans, (4) assessing the human-oriented behavior rates in orangutans (as a response to the presence of humans around the camp and feeding site), and (5) analyzing the affecting factors of human-oriented behavior rates in orangutans. The study was conducted for five months (July-November 2019). Observations were made at three different locations, i.e. camp, feeding site, and forest (follow nest to nest). Observations on activity patterns, the frequency of orangutans‟ attendance at camp and feeding sites, as well as observations of human-oriented behavior in orangutans were observed using focal animal sampling, ad libitum, and instantaneous records every 2 minutes. The depth-interview method was used on informants involved in interactions with orangutans such as camp staff and visitors. The intensity of orangutans‟ attendance at the camp release and feeding site is dominated by mother group. There is no correlation between the intensity of orangutans‟ attendance at the camp release and feeding site with phenological conditions. The activity patterns of adult and adolescent are different. Adult orangutans spend more time resting, especially mother, while adolescent orangutans spend more time by feeding. Almost all sex-age class orangutans eat non-forest food (45-67%) while at the camp and feeding site. Orangutans tend to do activities at 0-10 m height of vertical used. Affected Factors of intensity of the presence and activity patterns of post-release orangutans are the presence of a release camp and a feeding site close to releasing point. The study also indicated that all categories of observed orangutans were show human-oriented behavior, especially in the promoting category. The promoting and inhibiting categories are mostly carried out by adolescent. Promoting and inhibiting is mostly done when they are around the camp release and feeding sites. Current ages affects the human-oriented behavior rates (p values;0.0008b)(R2-values;0.223 = means 22.3% regression model is affected by the current ages).