Analisis Spasial dan Temporal Penggunaan Habitat Gajah Sumatra Berdasarkan Data GPS Collar

Abstract

Gajah sumatra (Elephas maximus sumatranus) diklasifikasikan sebagai Critically Endangered dan menghadapi tekanan yang semakin meningkat akibat hilangnya habitat dan fragmentasi lanskap. Penelitian ini menganalisis dinamika wilayah jelajah dan preferensi habitat seekor gajah betina (Bunga Lestari) di Taman Nasional Bukit Barisan Selatan (TNBBS), Indonesia, menggunakan data GPS collar yang direkam dengan interval satu jam dari tahun 2020 hingga 2025 (total 30.687 titik lokasi). Dataset dibagi menjadi tiga segmen temporal kontinu berdasarkan kesenjangan perekaman: Segmen 1 (Mei 2020–Oktober 2021, n = 12.202), Segmen 2 (Mei 2022–April 2023, n = 7.909), dan Segmen 3 (Juli 2024Oktober 2025, n = 10.576). Wilayah jelajah diestimasi menggunakan Autocorrelated Kernel Density Estimation (AKDE) dalam kerangka Continuous Time Movement Model (CTMM), sementara preferensi habitat dinilai menggunakan Manly's Selection Ratio dengan pendekatan use–availability (Design III). AKDE menghasilkan estimasi wilayah jelajah yang berbeda secara substansial antar segmen: 4.282,02 km² (Segmen 1, model OU anisotropik), 345,21 km² (Segmen 2, model OUF anisotropik), dan 1.576,38 km² (Segmen 3, model OUF isotropik). Rasio area inti terhadap total wilayah jelajah relatif konsisten, berkisar dari 23,1% hingga 27,2%. Semak belukar secara konsisten menjadi tipe habitat yang paling dipilih (wi = 1,588; p < 0,001), sedangkan hutan secara signifikan dihindari secara keseluruhan (wi = 0,750; p < 0,001) meskipun merupakan tipe tutupan lahan yang paling tersedia dalam wilayah jelajah (58,62%). Area perkebunan, meskipun ketersediaannya rendah (3,31%), juga dipilih secara signifikan (wi = 1,278; p < 0,001). Analisis temporal mengungkapkan bahwa hutan secara dominan digunakan pada siang hari, kemungkinan untuk termoregulasi, sementara semak belukar terutama dimanfaatkan pada malam hari untuk aktivitas mencari pakan. Temuan ini mengindikasikan penurunan kualitas habitat alami dan meningkatnya risiko konflik manusia–gajah di dalam Taman Nasional Bukit Barisan Selatan.

The Sumatran elephant (Elephas maximus sumatranus) is classified as Critically Endangered and is facing increasing pressure from habitat loss and landscape fragmentation. This study analyzed the home-range dynamics and habitat preferences of a female elephant (Bunga Lestari) in Bukit Barisan Selatan National Park (TNBBS), Indonesia, using GPS collar data recorded at one-hour intervals from 2020 to 2025 (a total of 30,687 location points). The dataset was divided into three continuous temporal segments based on recording gaps: Segment 1 (May 2020–October 2021, n = 12,202), Segment 2 (May 2022–April 2023, n = 7,909), and Segment 3 (July 2024–October 2025, n = 10,576). Home range was estimated using Autocorrelated Kernel Density Estimation (AKDE) within the Continuous Time Movement Model (CTMM) framework, while habitat preference was assessed using Manly’s Selection Ratio with a use–availability (Design III) approach. AKDE produced substantially different home-range estimates among segments: 4,282.02 km² (Segment 1, anisotropic OU model), 345.21 km² (Segment 2, anisotropic OUF model), and 1,576.38 km² (Segment 3, isotropic OUF model). The ratio of core area to total home range was relatively consistent, ranging from 23.1% to 27.2%. Shrubland was consistently the most selected habitat type (w? = 1.588; p < 0.001), whereas forest was significantly avoided overall (w? = 0.750; p < 0.001), despite being the most available land-cover type within the home range (58.62%). Plantation areas, although limited in availability (3.31%), were also selected significantly (w? = 1.278; p < 0.001). Temporal analysis revealed that forest habitats were predominantly used during the daytime, likely for thermoregulation, while shrublands were mainly used at night for foraging activities. These findings indicate a decline in the quality of natural habitat and an increasing risk of human elephant conflict within Bukit Barisan Selatan National Park.