Dampak Penambahan Beban Terhadap Pergerakan Katak Pohon Jawa

Abstract

The commonly used method to assess amphibian movement is by using tag attachment. However tag attachment could disrupt animal movements and results in study bias. The objective of this study was to asess the impact of tag attachment (5% of body weight) on frequency and vertical movement at frog house of Gunung Gede Pangrango National Park (GGPNP). Active time of frog was determined through observation of frog’s movement activity hourly for 24 hours. Data on movement frequency was collected through observation of 16 frogs (6 males without tag, 6 males with tag, 2 females without tag and 2 females with tag) in the frog house. Frogs were observed using Partial-interval sampling method with interval length of observation at 1 minute and no lag time between intervals. Observations were performed at 17.30 to 18.30, 19.00 to 20.00, 20.30 to 21.30 and 22.00 to 23.00 by cataloguing movement (jumping, running, locomotion and resting). Vertical movement data were obtained through vertical position measurement of frogs from the ground every 30 minutes. Data from observations were analyzed using Kruskal-Wallis and Pearson chi-square test. Tag attachment on R. margaritifer caused lower vertical movement when compared with non-tagged frog. In males, tag attachment caused the reduction of rest time, decreased of walking activity and decrease of non-moved movement activity. In females, tag attachment caused the increase of running frequency. Frog movement was closely related to the frog’s effort to obtain foods and to avoid predator. The decrease of moving frequency caused by tag attachment, is presumedly caused by allocation of additional energy to lift the tag, thus reduced the energy allocation to other movements. However, increased moving frequency of several frogs might be due to the discomfort caused by tag attachment.

Metode untuk mengumpulkan data pergerakan amfibi dilakukan dengan cara menambahkan beban pada tubuh amfibi, mungkin menyebabkan gangguan terhadap individu yang diteliti dan mungkin juga mengakibatkan bias terhadap hasil penelitian. Penelitian ini bertujuan untuk menjelaskan dampak pemberian beban sebesar 5% dari bobot tubuh terhadap frekuensi bergerak dan pergerakan vertikal R. margaritifer yang dilakukan di dalam rumah katak di Taman Nasional Gunung Gede Pangrango. Penentuan waktu aktif bergerak diperoleh dengan cara mengamati aktivitas bergerak katak setiap 1 jam selama 1 x 24 jam. Pengambilan data frekuensi pergerakan diperoleh dengan cara mengamati pergerakan 16 individu katak (6 jantan tanpa beban, 6 jantan dengan beban, 2 betina tanpa beban dan 2 betina dengan beban) menggunakan metode Partial-interval sampling dengan panjang interval pengamatan selama 1 menit tanpa ada jeda waktu antar interval. Pengamatan dilakukan pada pukul 17.30 – 18.30, 19.00 – 20.00, 20.30 – 21.30 dan 22.00 – 23.00 WIB menggunakan kategori gerak melompat, berjalan, bergerak tidak berpindah dan diam. Data pergerakan vertikal diperoleh dengan cara mengukur posisi ketinggian katak terhadap tanah setiap 30 menit. Data hasil pengamatan dianalisis menggunakan uji Kruskal-Wallis dan Pearson chi-square.