Population status of the Bornean orang-utan Pongo pygmaeus in a vanishing forest in Indonesia: the former Mega Rice Project

AbstractAs peat-swamp forests in Borneo become progressively more fragmented, the species that inhabit them are increasingly threatened, notably the Endangered Bornean orang-utan Pongo pygmaeus. The area of a failed agricultural project known as the Mega Rice Project in Central Kalimantan, Indonesia, is composed of fragments of peat-swamp forest that are reported to contain orang-utans, although no comprehensive survey has previously been conducted. In a portion of this area we identified remaining forest fragments, using satellite imagery, and surveyed line transects for orang-utan sleeping nests to determine the density, abundance and distribution of the species. The total area of peat-swamp forest in the study area is 76,755 ha, 59,948 ha of which comprises patches at least as large as the home range of a female orang-utan (250 ha). We estimate a mean population density of 2.48 ± SE 0.32 individuals km−2 and a population of 1,700 ± SE 220 or 1,507 ± SE 195 individuals, based on a 25 and 250 ha minimum patch size threshold, respectively. This is c. 40–45% of the original population, and the fragmented population is unlikely to be viable in terms of long-term demographic and genetic stability. To ensure persistence of this population of orang-utans, direct conservation action to connect forest fragments and prevent further loss of peat-swamp forest will be required, including re-establishing the hydrological regime, reforesting barren areas and fighting fires.

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Population status of the Bornean orang-utan (Pongo pygmaeus) in the Sebangau peat swamp forest, Central Kalimantan, Indonesia

Biological Conservation ◽

10.1016/s0006-3207(02)00186-6 ◽

2003 ◽

Vol 110 (1) ◽

pp. 141-152 ◽

Cited By ~ 97

Author(s):

H Morrogh-Bernard ◽

S Husson ◽

S.E Page ◽

J.O Rieley

Keyword(s):

Pongo Pygmaeus ◽

Population Status ◽

Swamp Forest ◽

Peat Swamp Forest ◽

Central Kalimantan ◽

Peat Swamp ◽

Orang Utan

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Interactions between a wild Bornean orang-utan and a Philippine slow loris in a peat-swamp forest

Primates ◽

10.1007/s10329-014-0422-6 ◽

2014 ◽

Vol 55 (3) ◽

pp. 365-368

Author(s):

Helen C. Morrogh-Bernard ◽

Jessica M. Stitt ◽

Zeri Yeen ◽

K. A. I. Nekaris ◽

Susan M. Cheyne

Keyword(s):

Slow Loris ◽

Swamp Forest ◽

Peat Swamp Forest ◽

Peat Swamp ◽

Orang Utan

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Ecosystem-scale measurements of CO2 and CH4 fluxes from a tropical peatland in Sarawak, Malaysia

10.5194/egusphere-egu2020-21496 ◽

2020 ◽

Author(s):

Frankie Kiew ◽

Guan Xhuan Wong ◽

Ryuichi Hirata ◽

Angela Tang ◽

Lulie Melling

Keyword(s):

Global Warming ◽

Eddy Covariance ◽

Global Warming Potential ◽

Environmental Changes ◽

Hydrological Regime ◽

Swamp Forest ◽

Peat Swamp Forest ◽

Eddy Covariance Technique ◽

Peat Swamp ◽

Tropical Peatlands

Tropical peatlands of Southeast Asia are a globally important carbon reservoir, storing an enormous amount of soil organic carbon as peat. These ecosystems are complex and poorly understood with large unknown biogeochemical processes. Despite the huge carbon stocks in these ecosystems, data on ecosystem-scale carbon dioxide (CO2) and methane (CH4) fluxes are still limited in comparison with mid- and high-latitude peatland ecosystems. The recent increase in the intensity of climate anomaly such as El Ni&#241;o may alter the hydrological regime of this ecosystem, thus affects its carbon cycling. It is crucial to quantify the CO2 and CH4 fluxes of the ecosystem and understand their responses to environmental changes to predict the role of peat swamp forest in global carbon cycles. To date, the application of the eddy covariance technique to measure the ecosystem-scale CO2 and CH4 fluxes in tropical peatlands is still limited to few studies in Malaysia and Indonesia.In 2010, we established a long-term greenhouse gas fluxes monitoring using the eddy covariance technique over a peat swamp forest in Sarawak, Malaysia. Here, we present the net ecosystem exchange of CO2 (NEE) and CH4 (FCH4) from February 2014 to January 2017 (3 years). We had quantified the NEE and FCH4, the diurnal and seasonal variations of NEE and FCH4, and the response of NEE and FCH4 to GWL. The FCH4 was determined half-hourly as the sum of eddy CH4 flux and CH4 storage change in an air column below the flux measurement height. We had determined the global warming potential of this ecosystem from annual NEE and FCH4 using sustained-flux global warming potential (SGWP).&#160; The annual FCH4 was converted into a CO2 equivalent unit using an SGWP factor of 45 which represents the SGWP for CH4 over a timescale of 100 years. Our preliminary result showed that the CH4 emission potentially offset the CO2 sequestration, which was higher than those reported in other regions in the world.

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Locomotor behavior of wild orangutans (pongo pygmaeus wurmbii) in disturbed peat swamp forest, Sabangau, Central Kalimantan, Indonesia

American Journal of Physical Anthropology ◽

10.1002/ajpa.21495 ◽

2011 ◽

Vol 145 (3) ◽

pp. 348-359 ◽

Cited By ~ 23

Author(s):

Kirsten L. Manduell ◽

Helen C. Morrogh-Bernard ◽

Susannah K.S. Thorpe

Keyword(s):

Locomotor Behavior ◽

Pongo Pygmaeus ◽

Swamp Forest ◽

Peat Swamp Forest ◽

Central Kalimantan ◽

Peat Swamp ◽

Pongo Pygmaeus Wurmbii

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Proboscis monkeys and their swamp forests in Sarawak

Oryx ◽

10.1017/s0030605300027526 ◽

1988 ◽

Vol 22 (2) ◽

pp. 69-74 ◽

Cited By ~ 10

Author(s):

Elizabeth L. Bennett

Keyword(s):

Financial Support ◽

Conservation Action ◽

Swamp Forest ◽

Peat Swamp Forest ◽

Peat Swamp ◽

The Status ◽

Forest Habitats ◽

Proboscis Monkeys

Proboscis monkeys, endemic to the island of Borneo, are declining in Sarawak. Their mangrove and peat swamp forest habitats are being degraded or destroyed and people continue to hunt them despite their protected status. Surveys between 1984 and 1986 established the status of this monkey and its habitats in this Malaysian state. The author who participated in the surveys, receiving some financial support from the Oryx 100% Fund, discusses the results and makes recommendations for future conservation action.

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