The population of wild Asian elephants Elephas maximus is declining worldwide; therefore, understanding the dynamics of the remaining population is critical for effective conservation. We monitored the population and distribution of elephants in Salakpra Wildlife Sanctuary, Thailand between May 2010 and March 2011. Using 32 camera trap locations and 1391 trap nights, we recorded 882 elephant photos. A total of 180 individuals were identified in the photos and classified as follows: 55 adult males, 60 adult females, 11 sub-adult males, 17 sub-adult females, 18 juveniles, and 19 calves. The age structure ratio (based on adult females) was 0.9 : 1.0 : 0.2 : 0.3 : 0.3 : 0.4, and the ratio of reproductive ability between adult females, juveniles, and calves was 1.0 : 0.3 : 0.3. The ratio between adult females and infants was highest in areas containing a high concentration of salt licks, which could indicate that salt licks are a keystone resource for wild Asian elephants.
ContextLarge forest-dwelling mammals are highly sensitive to habitat structure. Thus, understanding the responses of reintroduced banteng (Bos javanicus d’Alton 1823) to their habitat is important for ensuring the sustainability of a reintroduction program. AimsThe aim of the present study was to evaluate the habitat preferences of banteng after reintroduction into the Salakphra Wildlife Sanctuary in Thailand on the basis of fieldwork conducted between January 2015 and November 2017. MethodsSeven banteng individuals bred at the Khao Nampu Nature and Wildlife Education Center were systematically reintroduced into the Salakphra Wildlife Sanctuary in 2015 (four individuals) and 2016 (three individuals). The banteng individuals were tracked via radio-collars and camera-traps. The maximum-entropy method (MaxEnt) and multiple logistic regressions (MLR) were used to identify habitat preferences. Kernel-density estimates (KDE) and a minimum convex polygon (MCP) were used to estimate the area of the habitat used. Key resultsIn total, 407 radio-signal locations showed that the MaxEnt habitat-preference models classified the banteng as associated with distance from villages and salt licks (regularised training gain of >1.0). Multiple logistic regressions form 32 camera-trap locations classified the banteng as associated with low elevations far from villages, guard stations and roads in a flat area (no aspect). The two methods for estimating habitat use provided similar results and showed that the reintroduced banteng used a wider range of habitat in the dry than in the wet season. ConclusionsThe results from the present study suggest that the reintroduced banteng individuals prefer low elevations and flat areas without human activity. ImplicationsThese findings are important for possible translocations elsewhere.
Background The populations of wild Asian elephants (Elephas maximus) have increased recently after a period of worldwide decline in protected areas. It is important to understand the dynamics and distribution of the remaining populations to ensure their conservation and prevent human-elephant conflicts. Methods We monitored the population distribution of elephants between 2016 and 2019 in the Phu Khieo Wildlife Sanctuary, Thailand. We set one hundred forty-nine camera trap locations; cameras recorded 38,834 photos over 6,896 trap nights. Elephants were captured in 4,319 photographs. The maximum entropy modeling software MaxEntwas used to identify elephants’ habitat preferences within 49 of the 149 total camera trap locations according to five environmental factors. Results One hundred fourteen elephants were identified. We identified 30 adult males, 43 adult females, 14 sub-adult males, nine sub-adult females, 11 juveniles, and seven calves. The age structure ratio based on adult femaleswas 0.7:1:0.3:0.2:0.3:0.2, and the ratio of reproductive ability between adult females, juveniles, and calves was 1:0.2:0.1. A suitable elephant habitat was determined to be 1,288.9 km2 using Area Under the Curve (AUC). An AUC = 0.061 indicated good performance. Our model classified habitat preferences associated with elevation, forests, salt licks, human activity, and slope. Conclusions According to our probability map this sanctuary can provide a suitable habitat for elephants. Our results indicate that effective management practices can protect wild Asian elephants in the region and reduce conflict between humans and elephants.
Habitat fragmentation due to human activities creates threats to wild Asian elephants (Elephas maximus) and increases human-elephant conflicts (HEC). This study analyzed connectivity maps among the core habitats of wild elephants in the eastern part of Thailand. Resistance surfaces, associated with geographic and land use features, were used to estimate the dispersal of wild elephants. An increase in roads, reservoirs, and agricultural areas in 2020 was noted. In addition, the increase of artificial water sources and roads has increased HEC. To reduce HEC, the study of suitable landscape corridors for wild Asian elephants can guide the development of effective connectivity among the habitat patches. The scattered locations of reserved forests induce wild elephants to enter agricultural areas. In 2020, during the dry season, wild elephants used 3552 habitat patches, 253 population patches (4875 km2), 8 breeding patches (68.1 km2), and 253 other patches (193.9 km2). However, habitat patches were reduced to 1961 patches (3850.9 km2) in the wet season. The 16 suitable corridors were recommended for connecting the finest wild Asian elephants. These suitable corridors can be used as a guideline to construct effective landscape corridors for wild Asian elephants’ movement among the habitat patches. This finding can help the local managers and villagers incorporate and design restoration areas for the movement and survival of wild Asian elephants and develop suitable areas for agricultural purposes.
Captive breeding is important for ex-situ conservation and the future reintroduction of bovids that become extinct in the wild. The age structure, development, and viability of captive-bred bantengs (Bos javanicus) are important to sustain the long-term reintroduction program in Salakphra Wildlife Sanctuary (SWF) and other areas. This research conducted a long-term population viability analysis (PVA) using height, weight, body condition scores (BSC), age structure, and development in captivity for a sustainable reintroduction program of bantengs in Thailand. Monthly development photographs of 23 founder individuals (12 males and 11 females) were assessed by three banteng experts, two researchers, and three members of the general public. The assessments of weight and BCS were not significantly different among the three groups, while height was underestimated by the general public. The PVA showed that the time to reach the maximum population in a captive banteng program is dependent on the carrying capacity of the habitat. The reduction of a small banteng founder group by the reintroduction of animals into the wild can negatively affect the population growth of the captive group. This information can be used to maintain the population viability of bantengs and sustain ex-situ conservation and the reintroduction program in Thailand and elsewhere.
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