Ecological studies of Medium to large mammals in oil palm plantation, Miri, Sarawak

Good or evil? Palm oil has always been in the centre of a decade long controversy. While it contributes to the economy, alleviates poverty and is by far the most land-efficient oil crop, it comes at the cost of local ecosystems and devastates lands which are highly biodiverse such as Borneo (Laurence et al., 2014). Approximately 12.5% of the land in Sarawak has already been converted to oil palm plantations (MPOB, 2017). Monocrops have proved to be much lower in biodiversity compared to forested areas as it lacks necessary resources for many species. Despite efforts from the Roundtable of Sustainable of Oil Palm (RSPO) to push for sustainable oil palm practices such as maintaining High Conservation Value Forest (HCVF), knowledge gaps on the effects of management practices towards the local fauna still exists and comprehension on the carrying capacities of the oil palm are still limited. It is therefore critical to conservation to figure out how to improve oil palm plantation to be more hospitable to wildlife. Among the most threatened taxonomic group due to fragmentation are mammals as they are highly sensitive to anthropogenic pervasion to and into their habitats. Medium to large mammals were selected as a focus group in this study as they are regarded as keystone species and are excellent bioindicators for healthy ecosystems. A one-year long camera trap survey of medium to large mammals is currently being conducted to provide baseline data on mammalian diversity and its persistence within the HCV forest fragments and oil palm matrix in regards to management practices for management decision. We have recorded various species of conservation importance in forest fragments. This includes the Sunda Pangolin (Manis javanica), Sun Bear (Helarctos malayanus) and Sambar Deer (Rusa unicolor). An adaptive management plan and integrated conservation strategy will be formulated at the end of the project to contribute to the preservation, sustenance and enhancement of the HCVF areas and in the oil palm areas

Medium to Large Terrestrial Mammals

Mammals are one of the most susceptible taxa to local extinction because of habitat fragmentation and loss (Dirzo et al., 2014). Partly due to their sensitivity to their surrounding, mammals are often used for biodiversity assessments and monitoring programmes around the globe as they are reliable ecosystem quality indicators (Ahumuda et al., 2011). However, as tropical medium to large mammals are often cryptic and elusive in nature (Mohd-Azlan, 2006), they are difficult to study. Therefore comprehension of the persistence of medium to large mammals within forest fragments especially in agricultural landscapes in this region is important as they remain scarce in scientific literature. Remnant forest fragments within the plantation area may potentially provide refugia and support the existence of medium to large mammals as many studies have indicated that oil palm plantation harbours lower diversity of wildlife compared to forested areas

Small Mammals

The Bornean tropical rainforests harbour some of the most remarkable diversity of flora and fauna in the world (Jennings et al., 2015; Sodhi et al., 2004). Tropical biodiversity is highly threatened by land conversion for agricultural purposes. This calls for greater conservational prioritization (Wilcove & Koh, 2010; Fitzherbert et al., 2008) as many have become fragmented and disconnected. There are a total of 247 species of mammals recorded in Borneo, and small mammals make up approximately 81%, which can be sub-categorized into bats, shrews, treeshrews, rats, mice, squirrels and flying squirrels (Phillipps & Phillipps, 2016). Borneo is regarded as one of the biodiversity hotspots, sustaining a high concentration of endemism, including approximately 19% of mammals (5% of the 99 bats species and 26 Rodentia), 20% of snakes and 6% of birds (Mohd-Azlan & Lawes, 2011).

Introduction

The escalation of land use conversion to agriculture is one of the key drivers of the decline in critical ecosystem function and biodiversity. Vast areas of forest in the tropics have been cleared and planted for various agricultural crops including oil palm, which is one of the most important crops in many tropical countries especially Indonesia and Malaysia. The establishment of oil palm plantations is an incredibly intensive process, involving converting native vegetation, usually degraded land or logged over forest to a plantation, often leaving behind fragmented and isolated rainforest in an oil palm matrix

Birds

Significant proportions of the Bornean rainforest have been converted to agricultural landscapes (i.e. oil palm (Elaeis guineensis Jacq) plantation), resulting in many of its remaining forests being fragmented and isolated. These forest patches are regarded as ecologically depauperate and have lower conservation value as many keystone species are absent, which has reduced ecological functions (Miller-Rushing et al., 2019). However, to minimise the impact of the monoculture plantations on the ecosystem, forest remnants’ roles should not be neglected as they retain some of the biodiversity remnants. Additionally, forest fragments that maintain a certain degree of environmental or social significance are regarded as high conservation value forests (HCVF) (Jennings et al., 2003)

Case study 11: The use of camera traps to monitor medium to large mammals in HCVAs, Wilmar Oil Palm Plantation, Miri, Sarawak

Wilmar has a long-term collaboration with UNIMAS since 2013 to conduct biodiversity monitoring (including camera trapping for monitoring mammals) at its oil palm estates in the Miri Division in Sarawak. The biodiversity monitoring sites consist of three HCVAs that are located within the estates. These forested areas are designated as HCVAs as they contain substantial proportions of remnant native biodiversity. Camera trapping has been extensively used in wildlife research as it is highly effi cient and cost-effective for monitoring mammals (Tobler et al., 2008; Rovero et al., 2014), especially in the case of tropical rainforests where species can be cryptic and elusive in nature (Azlan, 2006). Three mammalian surveys via camera trapping were conducted in the Wilmar Oil Palm Plantation, Miri, Sarawak in years 2013-2014, 2014-2015 and 2018-2020. Study sites consisted of three High Conservation Value Areas (HCVAs) that are located within the estates of Saremas 1, Saremas 2 and Segarmas. Bukit Durang is the largest HCVA measuring 989.9ha, Segarmas HCVA is 147.9ha and the smallest is Saremas 1 HCVA at 116.3ha (see accompanying map). Bukit Durang HCVA is classifi ed as HCV 1 while Saremas 1 and Saremas 2 HCVAs are classed as HCV 4. These forests were designated as HCVAs as they contain substantial proportions of remnant native biodiversity. The HCVs are managed by Wilmar’s Eco Management Unit (EMU) under the Sustainability Division and fi nanced by the individual estates. Wilmar Oil Palm Plantation is certifi ed by MSPO, ISCC and RSPO

Ecology, occurrence and distribution of wild felids in Sarawak, Malaysian Borneo

Sarawak is the largest state in the megadiversecountry of Malaysia. Its rich biodiversity is threatened byland-use change and hunting, with mammalian carnivoresparticularly affected. Data on the ecology, occurrence anddistribution of small carnivores are crucial to inform theireffective conservation, but no large-scale assessments havepreviously been conducted in Sarawak. Here we examinethe status of the five species of felids in Sarawak based ondata from camera-trap studies overyears (May–February) acrossstudy areas, including protected areasof various sizes, production forests and forest matrix withinoil palm plantations. Felids were detected at%ofcamera stations. The marbled catPardofelis marmorataandSunda clouded leopardNeofelis diardihad higher probabil-ities of occurrence in protected than unprotected areas, andvice versa for the leopard catPrionailurus bengalensisandbay catCatopuma badia. The marbled and bay cats weremostly diurnal, and the leopard cat was predominantly noc-turnal; activity patterns did not substantively differ betweenprotected and unprotected sites. The probabilities of oc-currence of marbled and bay cats increased with greaterdistance from roads. The leopard cat and flat-headed catPrionailurus planicepswere more likely, and the cloudedleopard less likely, to occur near rivers. Flat-headed catspreferred peat swamp forest, bay cats lowland forest, andmarbled cats and clouded leopards occurred in both low-land and montane forest. Felids may tolerate higher eleva-tions to avoid anthropogenic disturbance; therefore, it iscritical to preserve lowland and mid-elevation habitatsthat provide refugia from climate change and the destruc-tion of lowland habitat