{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T21:44:07Z","timestamp":1790027047781,"version":"4.0.1"},"reference-count":30,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T00:00:00Z","timestamp":1769990400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Austindo Nusantara Jaya"},{"name":"Austindo Nusantara Jaya"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    In 2020\u20132024, plantation workers at a large oil palm plantation in West Kalimantan recorded sightings of wild species of several species groups. They did not use a standardized field method and produced no comprehensive reports but recorded only one or a few species per visit. Such unstructured data are generally viewed as challenging for statistical analysis. Here, we used occupancy models to estimate what proportion of spatial units (both non-natural and forest) a given species occupied annually in the plantation. We tested models with different covariates for species for which most data were available: 13 birds, 3 reptiles and 7 mammals, among which the iconic Orangutan (\n                    <jats:italic>Pongo pygmaeus<\/jats:italic>\n                    ). For each species, the model which best fitted the data was selected. Two shortcomings in our data complicated the analyses. First, occupancy models require detection and non-detection records, but because no fixed species lists were used, there is no unique way to generate non-detections. We generated non-detection records in several ways and ran the models again to evaluate the consequences for occupancy estimates. Second, imbalances in sampling may occur because of a lack of sampling design to select study sites. Most concerning are sites surveyed only once in 2020\u20132024. We ran the models without those sites to examine whether results were different. Although the shortcomings mentioned turned out not to distort our results, the occupancy estimates were imprecise for many study species because of low detection rates, and extra efforts are needed to improve that.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0328960","type":"journal-article","created":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T18:53:11Z","timestamp":1770058391000},"page":"e0328960","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Occupancy estimation of wild species in a palm oil plantation using unstructured data"],"prefix":"10.1371","volume":"21","author":[{"given":"Arco J.","family":"van Strien","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8685-3685","authenticated-orcid":true,"given":"Erik","family":"Meijaard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"name":"Nardiyono","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Syafiie","family":"Suief","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Syahmi","family":"Zaini","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,2,2]]},"reference":[{"issue":"10","key":"pone.0328960.ref001","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1016\/j.tree.2008.06.012","article-title":"How will oil palm expansion affect biodiversity?","volume":"23","author":"EB Fitzherbert","year":"2008","journal-title":"Trends Ecol Evol"},{"key":"pone.0328960.ref002","article-title":"Oil Palm and Biodiversity. A situation analysis by the IUCN Oil Palm Task Force. Gland, Switzerland:","author":"E Meijaard","year":"2018","journal-title":"IUCN Oil Palm Task Force"},{"issue":"6730","key":"pone.0328960.ref003","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1126\/science.adf9856","article-title":"Tropical forest clearance impacts biodiversity and function, whereas logging changes structure","volume":"387","author":"CJ Marsh","year":"2025","journal-title":"Science"},{"key":"pone.0328960.ref004","unstructured":"HCV Resource Network. What are High Conservation Values? 2017.https:\/\/www.hcvnetwork.org\/about-hcvf"},{"issue":"6723","key":"pone.0328960.ref005","doi-asserted-by":"crossref","first-page":"795","DOI":"10.1126\/science.ado1629","article-title":"Diverse and larger tree islands promote native tree diversity in oil palm landscapes","volume":"386","author":"GB Paterno","year":"2024","journal-title":"Science"},{"key":"pone.0328960.ref006","article-title":"A novel citizen science-based wildlife monitoring and management tool for oil palm plantations","volume":"2025","author":"N Maharani","journal-title":"bioRxiv"},{"issue":"10","key":"pone.0328960.ref007","doi-asserted-by":"crossref","DOI":"10.1126\/sciadv.abe1603","article-title":"Long-term (1990-2019) monitoring of forest cover changes in the humid tropics","volume":"7","author":"C Vancutsem","year":"2021","journal-title":"Sci Adv"},{"issue":"6","key":"pone.0328960.ref008","doi-asserted-by":"crossref","first-page":"1450","DOI":"10.1111\/1365-2664.12158","article-title":"Opportunistic citizen science data of animal species produce reliable estimates of distribution trends if analysed with occupancy models","volume":"50","author":"AJ van Strien","year":"2013","journal-title":"J Appl Ecol"},{"issue":"10","key":"pone.0328960.ref009","doi-asserted-by":"crossref","first-page":"1024","DOI":"10.1111\/ddi.12463","article-title":"Unstructured citizen science data fail to detect long\u2010term population declines of common birds in Denmark","volume":"22","author":"J Kamp","year":"2016","journal-title":"Divers Distrib"},{"issue":"9","key":"pone.0328960.ref010","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1016\/j.tree.2009.03.017","article-title":"A new dawn for citizen science","volume":"24","author":"J Silvertown","year":"2009","journal-title":"Trends Ecol Evol"},{"issue":"6746","key":"pone.0328960.ref011","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1126\/science.adn4381","article-title":"North American bird declines are greatest where species are most abundant","volume":"388","author":"A Johnston","year":"2025","journal-title":"Science"},{"issue":"5","key":"pone.0328960.ref012","doi-asserted-by":"crossref","first-page":"1388","DOI":"10.1111\/j.1523-1739.2010.01479.x","article-title":"Site-occupancy distribution modeling to correct population-trend estimates derived from opportunistic observations","volume":"24","author":"M K\u00e9ry","year":"2010","journal-title":"Conserv Biol"},{"issue":"10","key":"pone.0328960.ref013","doi-asserted-by":"crossref","first-page":"1052","DOI":"10.1111\/2041-210X.12254","article-title":"Statistics for citizen science: extracting signals of change from noisy ecological data","volume":"5","author":"NJB Isaac","year":"2014","journal-title":"Methods Ecol Evol"},{"key":"pone.0328960.ref014","volume-title":"Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence","author":"DI MacKenzie","year":"2018","edition":"2"},{"issue":"3","key":"pone.0328960.ref015","doi-asserted-by":"crossref","first-page":"690","DOI":"10.1111\/bij.12530","article-title":"The use of opportunistic data for IUCN Red List assessments","volume":"115","author":"D Maes","year":"2015","journal-title":"Biol J Linn Soc Lond"},{"issue":"1","key":"pone.0328960.ref016","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1111\/2041-210X.13090","article-title":"Occupancy models for citizen\u2010science data","volume":"10","author":"R Altwegg","year":"2019","journal-title":"Methods Ecol Evol"},{"key":"pone.0328960.ref017","unstructured":"Doser JW, Finley AO, K\u00e9ry M, Zipkin EF. Introduction to spOccupancy. 2022. [cited 2025 Jul 3]. https:\/\/doserlab.com\/files\/spoccupancy-web\/articles\/modelfitting"},{"key":"pone.0328960.ref018","doi-asserted-by":"crossref","first-page":"110102","DOI":"10.1016\/j.biocon.2023.110102","article-title":"Observers are a key source of detection heterogeneity and biased occupancy estimates in species monitoring","volume":"283","author":"BR Schmidt","year":"2023","journal-title":"Biol Conserv"},{"issue":"8","key":"pone.0328960.ref019","doi-asserted-by":"crossref","first-page":"1670","DOI":"10.1111\/2041-210X.13897","article-title":"spOccupancy: An R package for single\u2010species, multi\u2010species, and integrated spatial occupancy models","volume":"13","author":"JW Doser","year":"2022","journal-title":"Methods Ecol Evol"},{"key":"pone.0328960.ref020","unstructured":"R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical ComputingVienna, Austria. 2024.http:\/\/www.R-project.org\/"},{"key":"pone.0328960.ref021","unstructured":"Doser JW, K\u00e9ry M. Multi-Season Occupancy Models for Assessing Species Trends and Spatio-Temporal Occurrence Patterns. 2022. [cited 2025 Jul 3]. Available from: https:\/\/doserlab.com\/files\/spoccupancy-web\/articles\/spacetimemodelshtml"},{"issue":"6","key":"pone.0328960.ref022","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.tree.2023.01.001","article-title":"We need to talk about nonprobability samples","volume":"38","author":"RJ Boyd","year":"2023","journal-title":"Trends Ecol Evol"},{"issue":"3","key":"pone.0328960.ref023","doi-asserted-by":"crossref","first-page":"561","DOI":"10.1111\/cobi.13223","article-title":"The potential for citizen science to produce reliable and useful information in ecology","volume":"33","author":"ED Brown","year":"2019","journal-title":"Conserv Biol"},{"issue":"3","key":"pone.0328960.ref024","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1093\/biosci\/biz010","article-title":"Using semistructured surveys to improve citizen science data for monitoring biodiversity","volume":"69","author":"S Kelling","year":"2019","journal-title":"Bioscience"},{"issue":"1","key":"pone.0328960.ref025","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1111\/2041-210X.12838","article-title":"Estimates of observer expertise improve species distributions from citizen science data","volume":"9","author":"A Johnston","year":"2017","journal-title":"Methods Ecol Evol"},{"issue":"11","key":"pone.0328960.ref026","doi-asserted-by":"crossref","first-page":"2781","DOI":"10.1007\/s10531-022-02457-y","article-title":"Improving citizen science data for long-term monitoring of plant species in the Netherlands","volume":"31","author":"AJ van Strien","year":"2022","journal-title":"Biodivers Conserv"},{"issue":"6","key":"pone.0328960.ref027","doi-asserted-by":"crossref","first-page":"1498","DOI":"10.1111\/btp.12997","article-title":"Proximity to forest mediates trade\u2010offs between yields and biodiversity of birds in oil palm smallholdings","volume":"53","author":"KC Hamer","year":"2021","journal-title":"Biotropica"},{"issue":"8","key":"pone.0328960.ref028","doi-asserted-by":"crossref","first-page":"1939","DOI":"10.1111\/1365-2664.70098","article-title":"Limited evidence of biodiversity spillover from forest fragments into oil palm plantations in the Amazon","volume":"62","author":"MR Cardoso","year":"2025","journal-title":"J Appl Ecol"},{"issue":"1191","key":"pone.0328960.ref029","doi-asserted-by":"crossref","DOI":"10.56333\/tp.2025.007","article-title":"Quantifying and managing orangutan-induced disturbance on second-rotation oil palm plantations","volume":"101","author":"M Ancrenaz","year":"2025","journal-title":"Planter"},{"key":"pone.0328960.ref030","volume-title":"Applied hierarchical modeling in ecology: Analysis of distribution, abundance and species richness in R and BUGS","author":"M K\u00e9ry","year":"2016","edition":"1"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0328960","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T18:53:16Z","timestamp":1770058396000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0328960"}},"subtitle":[],"editor":[{"given":"Edvard","family":"Mizsei","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,2,2]]},"references-count":30,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2,2]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0328960","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,2]]}}}