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Anticoagulant rodenticides (ARs) are used worldwide for the control of rodent pests and are the main method of control of rat pest populations in agricultural areas. The main aim of this review is to discuss the risk of ARs to non-target wildlife in oil palm areas in Southeast Asia, mainly Indonesia and Malaysia. We discussed AR use in oil palm areas and toxicities of ARs on target and non-target animals. We also reviewed published literature on wildlife species reported in oil palm areas in Southeast Asia and utilizing this information, we assessed the hazard risk of ARs to non-target wildlife in oil palm plantations. ARs are a secondary exposure hazard to rodent-consuming mammalian carnivores, such as leopard cats and civets, and rodent-consuming raptors, such as barn owls. Consumption of dead poisoned prey puts scavengers, such as water monitors, at high risk for AR exposure. Domestic livestock and granivorous birds are at high risk for AR exposure via primary exposure to toxic bait, while omnivores such as macaques and wild pigs are at moderate risk for both primary and secondary exposure to ARs. The effects of ARs on barn owls have been well studied in the field and in laboratory secondary toxicity studies. Thus, the nest-box occupancy and reproductive parameters of local barn owl populations can be monitored as an indicator of the AR exposure level in the area. Clinical Trials Registration: No clinical trials were involved in this study. [ABSTRACT FROM AUTHOR]

In Peninsular Malaysia, barn owls (Tyto javanica javanica) have been utilized as biological control of rats since the 1960s. In this study, the impact of introduced barn owls on rat populations in an oil palm plantation in Sabah, Malaysia, were studied. There were three treatment areas in this study: T1 (barn owl area) was an oil palm plot where no rodenticides were applied and rat control relied solely on predation of the introduced barn owls, T2 was an oil palm plot where one fixed baiting campaign was carried out per year, and T3 was an oil palm plot where two fixed baiting campaigns were carried out per year. Rat abundance and fresh fruit bunch (FFB) damage were assessed monthly throughout the four-year study period. The dominant species at all treatment areas was the House rat, Rattus rattus diardii. Both rat abundance and FFB damage were higher in the first year of study at all three treatment areas. FFB damage was lowest at T3 compared to the other two treatment areas throughout the entire study period, probably due to the intensive baiting carried out at T3. FFB damage at T1 was comparable to FFB damage at T2 (with the exception of the first year of study). Additionally, FFB damage at T1 after the first year was frequently below the 5% FFB damage threshold level. The results of this study indicate that introduced barn owl control of rat pests was sufficient for at least three years and perhaps more. [ABSTRACT FROM AUTHOR]

Rats ( Rattus species) are the most notorious vertebrate pests in Malaysian oil palm plantations. Although many studies have been conducted on Asian rats, little attention has been paid to their species composition and phylogenetic relationships in oil palm plantations in Peninsular Malaysia. We determined the mitochondrial cytochrome oxidase subunit I (COI) gene sequence (708 bp) for 216 individual rats collected from five oil palm plantations in Peninsular Malaysia. Phylogenetic analysis in conjunction with comparison with sequences from the nucleotide sequence database revealed five distinct lineages in the Malaysian oil plantations: Rattus tiomanicus , Rattus argentiventer , Rattus exulans , Rattus tanezumi , and a taxon corresponding to the Malayan house rat, which was most frequently observed (∼50%). The last taxon has traditionally been classified as a synonym of Rattus rattus ( Rattus rattus diardii ) or Rattus tanezumi , but our phylogenetic analysis placed it as an independent lineage, which is not particularly closely related to R. rattus or R. tanezumi , and which we refer to as Rattus diardii . The construction of the network showed that there is considerable genetic variation within the lineages of R. diardii and R tiomanicus , suggesting that these two species are native to the Malay Peninsula.

Purpose: The carbon footprint of palm oil on mineral soils based on primary data from Malaysia was published in 2011, but a study for palm oil grown on peat is missing. The estimation of greenhouse gas emissions (GHG) of oil palm planted on peat in Malaysia was divided into three main components, namely GHG emissions from land use change, peat oxidation due to the establishment of oil palm plantations, and operations during cultivation and milling processes. The study collected comprehensive primary data for the latter and derived a best estimate for the other emissions to provide guidance for the most appropriate values and uncertainty range for oil palm planted on peat. The study highlights uncertainties and gaps in knowledge and provides recommendations for reducing GHG emissions for oil palm planted on peat.Methods: GHG emissions were estimated based on published data (LUC and peat oxidation) as well as from comprehensive primary data from operations at plantations mainly on peat in Sarawak and the palm oil mills for the period of 3 years. For this study, the data is partitioned into three case scenarios: (a) base case, where oil palm plantation is assumed from previously logged-over (PSF) with medium level of peat oxidation and 50% of the mills have the facilities to capture methane; (b) best-case scenario, where oil palm is assumed planted from previously degraded PSF or land with lowest estimation of peat oxidation and mills with methane capture facilities; and (c) worst-case scenario, where oil palm is assumed planted from previously virgin PSF with the highest estimation of peat oxidation and mills with methane capture facilities. GHG emissions from cultivation and milling stage were modeled using the System for Integrated Environmental Assessment of Product (SimaPro, version 8) with Ecoinvent database (ver 3).Results and discussion: Total GHG emissions for oil palm planted on peat for three scenarios arising from three main components range from 12.4 t CO2 eq ha−1 (best case) to 76.6 t CO2 eq ha−1 (worst case). These variations depend on C stock of previous vegetation, depth of drainage, length of time of drainage, amount of nitrogen fertilizer used, and use of methane capture facilities at the palm oil mills.Conclusions: GHG emissions for oil palm planted on peat can be reduced by developing plantations from degraded PSF or grassland with low carbon stock, with effective water management coupled with methane capture facilities at the mill and judicious application of nitrogen fertilizers using precision application according to requirement of the site based on diagnosis of nutrient requirement from soils and foliar analyses. In Malaysia, only 13% of the areas planted with oil palm are on the peat soil. Therefore, the overall GHG emission at the national level (13% planted on peat and 87% on mineral soils) can be further reduced by around 4.1 t CO2 eq ha−1 year−1. [ABSTRACT FROM AUTHOR]

The interaction and the interplay of climate change with oil palm production in the Southeast Asia region are of serious concern. This particularly applies in Malaysia due to its rank as the second largest palm oil producer in the world. The anthropogenic activities and the agroecological practices in oil palm plantation, including excessive use of fertilisers, bush fire due to land clearing, and cultivation on peatland, have exacerbated the effects of climate change featuring extreme events, drought, flooding, heatwave, as well as infestation of pest and diseases. These adverse impacts on oil palm production highlight the significance of deploying effective adaptation strategies. The study aims to examine the impact of climate change on oil palm production and identify the farmers' adaptation strategies to the impacts of climate change in Malaysia. This study was conducted a comprehensive review of the articles published from 2000 to 2021 in the contexts of climate change and oil palm production in Malaysia. The review shows that climate change has a range of impacts on the oil palm production in Malaysia. As a result, several adaptation options were identified, such as breeding of hybrid varieties that are tolerant and resistant to heat; sustainable management of soil; pit and tranches to enhance water management in plantation areas; minimal use of fertilisers, herbicides, and pesticides; zero burning; and minimum tillage. The reviewed studies recommended the following to mitigate the adverse impacts of climate change: sustainable national policy on climate change, conservation of the existing carbon stock, effective management of tropical rainforest biodiversity, afforestation for carbon sequestration, and reduction in greenhouse gas (GHG) emission., (© 2021. The Author(s).)