Biology subjects

Supriatna, J.

Publications and source records attributed to Supriatna, J..

2 recordsLinked to original sources

bioRxiv2025

A novel citizen science-based wildlife monitoring and management tool for oil palm plantations

Agricultural expansion is one of the greatest threats to global biodiversity. At the same time, many wildlife species survive or even thrive in agricultural landscapes that retain patches of natural ecosystems. This is especially true for tropical oil palm (Elaeis guineensis, Jacq.) plantations that have both replaced tropical forest and other species-rich ecosystems, but as perennial crops can also function as wildlife habitat, especially if fragments of natural ecosystems are retained. There is an urgent need to understand how to manage and monitor wildlife in these fragmented oil palm landscapes. Still, the lack of large, quantitative datasets on species abundance impedes learning. We piloted a novel citizen science-based biodiversity monitoring system in Austindo Nusantara Jayas seven Indonesian oil palm estates, across different biogeographical regions, over a 5-year period. The company-wide monitoring system called PENDAKI, the Indonesian acronym for Care for Biodiversity, is the first of its kind in the palm oil industry. Here we demonstrate that such unstructured and opportunistic data collected mainly by lay people can result in valuable information on temporal and spatial changes in species occupancy. Between September 2019 and June 2024, PENDAKI has resulted in 148,286 wildlife observations, that included 699 reliably identified faunal and 186 floral species, with contributions from 3,950 employee contributors. We estimate species-specific occupancy rates using Bayesian occupancy modeling, ideally suited for opportunistic data where survey effort is unknown. We show that these occupancy data can reliably show temporal and spatial changes in the distribution of iconic wildlife such as orangutans (Pongo pygmaeus). We combined data from reliably identified species with at least 50 records to create the "Living Plantation Index", an estate-specific annual index of wildlife diversity based on occupancy estimates. We conclude that citizen science-based biodiversity monitoring works remarkably well in oil palm plantations because of the large number of people typically working there. In the process we discovered the emergence of co-benefits such as increasing environmental stewardship awareness across the workforce, raising the profile of the conservation department within the company. We also noted the benefits in terms of suitable data to meet regulatory and voluntary disclosure requirements.

scientific communication and education↗

bioRxiv2024

The importance of small island populations for the long term survival of endangered large-bodied insular mammals

Island populations of large vertebrates have experienced higher extinction rates than mainland populations over long timescales due to demographic stochasticity, genetic drift and inbreeding. Conversely, small island populations often experience relatively less anthropogenic habitat degradation than populations on larger islands, making them potential targets for conservation interventions such as genetic rescue to improve their overall genetic diversity. Here we determine the consequences and conservation implications of long-term isolation and recent human activities on genetic diversity of island populations of two forest-dependent mammals endemic to the Wallacea archipelago: the anoa (Bubalus spp.) and babirusa (Babyrousa spp.). Using genomic analyses and habitat suitability models, we show that, compared to closely related species, populations on mainland Sulawesi exhibit low heterozygosity, high inbreeding, and a high proportion of deleterious alleles. In contrast, populations on smaller islands possess fewer deleterious mutations despite exhibiting lower heterozygosity and higher inbreeding. Site frequency spectra indicate that these patterns reflect stronger, long-term purging in smaller island populations. Our results thus suggest that conservation efforts should focus on protecting small island habitats and avoiding translocations from mainland populations. This study highlights the crucial role of small offshore islands for the long-term survival of Wallaceas iconic and indigenous mammals in the face of development on the mainland. Significance statementWithin tropical archipelagos, such as the Wallacea biodiversity hotspot, larger islands experience greater resource exploitation compared to smaller ones, highlighting the potential of smaller islands as refuges for conservation. To investigate the genetic health of populations on small islands, we used genomic, occurrence, and environmental data from a system of replicated populations of anoa and babirusa across islands of varying sizes. In contrast to larger islands like Sulawesi, our results demonstrate that smaller offshore islands not only provide higher-quality habitats but also support populations that have efficiently purged harmful mutations. Thus, despite their known vulnerability over geological time-frames, small island populations can provide long term insurance against human-driven extinction and conservation efforts should prioritise habitat management over translocations.

evolutionary biology↗