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C. Schaik, S. Wich, S. Utami, Kisar Odom (2005)
A simple alternative to line transects of nests for estimating orangutan densitiesPrimates, 46
Sophia Balcomb, C. Chapman, R. Wrangham (2000)
Relationship between chimpanzee (Pan troglodytes) density and large, fleshy‐fruit tree density: Conservation implicationsAmerican Journal of Primatology, 51
(1995)
Statview 4.5
A. Marshall, L. Salas, Suzette Stephens, Nardiyono, Linda Engström, E. Meijaard, Scott Stanley (2007)
Use of limestone karst forests by Bornean orangutans (Pongo pygmaeus morio) in the Sangkulirang peninsula, east Kalimantan, IndonesiaAmerican Journal of Primatology, 69
R. Buij, S. Wich, A. Lubis, E. Sterck (2002)
Seasonal movements in the Sumatran orangutan (Pongo pygmaeus abelii) and consequences for conservationBiological Conservation, 107
Brandon Foltz, J. Snell, G. Thompson, J. Kemeny, J. Snell (1957)
Introduction to finite mathematics
(2005)
SPSS for Windows, release 14.0
H. Morrogh-Bernard, Simon Husson, S. Page, J. Rieley (2003)
Population status of the Bornean orang-utan (Pongo pygmaeus) in the Sebangau peat swamp forest, Central Kalimantan, IndonesiaBiological Conservation, 110
A. J. Marshall
Geographic variability in orangutan socioecology
Jefferson Hall, L. White, Bila‐Isia Inogwabini, I. Omari, H. Morland, E. Williamson, K. Saltonstall, P. Walsh, C. Sikubwabo, Dumbo Bonny, Kaleme Kiswele, A. Vedder, Kathy Freeman (1998)
Survey of Grauer's Gorillas (Gorilla gorilla graueri) and Eastern Chimpanzees (Pan troglodytes schweinfurthi) in the Kahuzi-Biega National Park Lowland Sector and Adjacent Forest in Eastern Democratic Republic of CongoInternational Journal of Primatology, 19
(2004)
Orangutan population and habitat viability assessment: final report
C. Schaik, A. Priatna, D. Priatna (1995)
Population Estimates and Habitat Preferences of Orangutans Based on Line Transects of Nests
S. Wich, R. Buij, C. Schaik (2004)
Determinants of orangutan density in the dryland forests of the Leuser EcosystemPrimates, 45
Andrea Johnson, C. Knott, Bhayu Pamungkas, Monalisa Pasaribu, A. Marshall (2005)
A survey of the orangutan (Pongo pygmaeus wurmbii) population in and around Gunung Palung National Park, West Kalimantan, Indonesia based on nest countsBiological Conservation, 121
H. D. Rijksen, E. Meijaard (1999)
Our vanishing relative. The status of wild orangutans at the close of the twentieth century
S. Laing, S. Buckland, R. Burn, D. Lambie, A. Amphlett (2003)
Dung and nest surveys: estimating decay ratesJournal of Applied Ecology, 40
A. Plumptre (2000)
Monitoring mammal populations with line transect techniques in African forestsJournal of Applied Ecology, 37
A. Plumptre, V. Reynolds (1996)
Censusing chimpanzees in the Budongo Forest, UgandaInternational Journal of Primatology, 17
C. Tutin, Richard Parnell, L. White, Michel Fernandez (1995)
Nest building by lowland gorillas in the Lopé Reserve, Gabon: Environmental influences and implications for censusingInternational Journal of Primatology, 16
B. Goossens, L. Chikhi, M. Ancrenaz, I. Lackman‐Ancrenaz, P. Andau, M. Bruford (2006)
Genetic Signature of Anthropogenic Population Collapse in Orang-utansPLoS Biology, 4
B. Goossens, L. Chikhi, M. Jalil, M. Ancrenaz, I. Lackman‐Ancrenaz, M. Mohamed, P. Andau, M. Bruford (2004)
Patterns of genetic diversity and migration in increasingly fragmented and declining orang‐utan (Pongo pygmaeus) populations from Sabah, MalaysiaMolecular Ecology, 14
A. Marshall, Nardiyono, Linda Engström, Bhayu Pamungkas, Jhon Palapa, E. Meijaard, Scott Stanley (2006)
The blowgun is mightier than the chainsaw in determining population density of Bornean orangutans (Pongo pygmaeus morio) in the forests of East KalimantanBiological Conservation, 129
E. Meijaard, S. Wich (2007)
Putting orang-utan population trends into perspectiveCurrent Biology, 17
A. Plumptre, Debby Cox (2005)
Counting primates for conservation: primate surveys in UgandaPrimates, 47
F. H. Hildebrand (1952)
Revised list of treespecies, collected in the division “Samarinda” (East Borneo)
A. Almasi, A. Blom, I. Heitkönig, J. Kpanou, H. Prins (2001)
A survey of the apes in the Dzanga-Ndoki National Park, Central African Republic: a comparison between the census and survey methods of estimating the gorilla (Gorilla gorilla gorilla) and chimpanzee (Pan troglodytes) nest group densityAfrican Journal of Ecology, 39
A. Plumptre, V. Reynolds (1997)
Nesting Behavior of Chimpanzees: Implications for CensusesInternational Journal of Primatology, 18
R. Buij, I. Singleton, E. Krakauer, C. Schaik (2003)
Rapid assessment of orangutan densityBiological Conservation, 114
D. Brugière, D. Sakom (2001)
Population density and nesting behaviour of lowland gorillas (Gorilla gorilla gorilla) in the Ngotto forest, Central African RepublicJournal of Zoology, 255
A. E. Russon, A. Susilo (1999)
The effects of drought and fire on orangutans reintroduced into Sungai Wain forest, East Kalimantan
A. Russon, Andi Erman, R. Dennis (2001)
The population and distribution of orangutans (Pongo pygmaeus pygmaeus) in and around the Danau Sentarum Wildlife Reserve, West Kalimantan, IndonesiaBiological Conservation, 97
M. Ancrenaz, R. Calaque, I. Lackman‐Ancrenaz (2004)
Orangutan Nesting Behavior in Disturbed Forest of Sabah, Malaysia: Implications for Nest CensusInternational Journal of Primatology, 25
Marshall Aj, R. Lacy, M. Ancrenaz, O. Byers, Simon Husson, M. Leighton, E. Meijaard, N. Rosen, I. Singleton, Suzette Stephens, K. Holzer, S. Atmoko, Van Cp, W. Sa (2009)
Orangutan population biology, life history, and conservation: Perspectives from PVA models
(2006)
2006 IUCN red list of threatened species
N. Rosen, L. Sheeran, J. Nevadomsky (1995)
The Neglected ApeCurrent Anthropology, 36
J. Mackinnon (1974)
The behaviour and ecology of wild orang-utans (Pongo pygmaeus)Animal Behaviour, 22
P. Walsh, L. White (2005)
EVALUATING THE STEADY STATE ASSUMPTION: SIMULATIONS OF GORILLA NEST DECAYEcological Applications, 15
P. Cassey, B. McArdle (1999)
An assessment of distance sampling techniques for estimating animal abundanceEnvironmetrics, 10
H. Rijksen (1978)
A field study on Sumatran orang utans (Pongo pygmaeus abelii Lesson 1827). Ecology, behaviour and conservation.
M. Ancrenaz, O. Gimenez, Laurentius Ambu, Karine Ancrenaz, P. Andau, B. Goossens, J. Payne, A. Sawang, Augustine Tuuga, I. Lackman‐Ancrenaz (2004)
Aerial Surveys Give New Estimates for Orangutans in Sabah, MalaysiaPLoS Biology, 3
T. Wong, John Lui, M. Wong (2007)
Markov Chain Modelling of the Probabilistic Packet Marking AlgorithmInt. J. Netw. Secur., 5
A. Felton, Linda Engström, A. Felton, C. Knott (2003)
Orangutan population density, forest structure and fruit availability in hand-logged and unlogged peat swamp forests in West Kalimantan, IndonesiaBiological Conservation, 114
J. Pruetz, L. Marchant, J. Arno, W. McGrew (2002)
Survey of Savanna Chimpanzees (Pan troglodytes verus) in Southeastern SénégalAmerican Journal of Primatology, 58
T. Furuichi, H. Inagaki, Simon Angoue-Ovono (1997)
Population Density of Chimpanzees and Gorillas in the Petit Loango Reserve, Gabon: Employing a New Method to Distinguish Between Nests of the Two SpeciesInternational Journal of Primatology, 18
I. Singleton (2000)
Ranging behaviour and seasonal movements of Sumatran orang-utans Pongo pygmaeus abelii in swamp forests
S. T. Buckland, D. R. Anderson, K. P. Burnham, J. L. Laake, D. L. Borchers, L. Thomas (2001)
Introduction to distance sampling
L. White (1995)
Factors affecting the duration of elephant dung piles in rain forest in the Lopé Reserve, GabonAfrican Journal of Ecology, 33
M. Ancrenaz, B. Goossens, O. Gimenez, A. Sawang, I. Lackman‐Ancrenaz (2004)
Determination of ape distribution and population size using ground and aerial surveys: a case study with orang‐utans in lower Kinabatangan, Sabah, MalaysiaAnimal Conservation, 7
J. G. Kemeny, J. L. Snell, G. L. Thompson (1956)
Introduction to finite mathematics. Second edition
An accurate estimate for orangutan nest decay time is a crucial factor in commonly used methods for estimating orangutan population size. Decay rates are known to vary, but the decay process and, thus, the temporal and spatial variation in decay time are poorly understood. We used established line-transect methodology to survey orangutan nests in a lowland forest in East Kalimantan, Indonesia, and monitored the decay of 663 nests over 20 months. Using Markov chain analysis we calculated a decay time of 602 days, which is significantly longer than times found in other studies. Based on this, we recalculated the orangutan density estimate for a site in East Kalimantan; the resulting density is much lower than previous estimates (previous estimates were 3––8 times higher than our recalculated density). Our data suggest that short-term studies where decay times are determined using matrix mathematics may produce unreliable decay times. Our findings have implications for other parts of the orangutan range where population estimates are based on potentially unreliable nest decay rate estimates, and we recommend that for various parts of the orangutan range census estimates be reexamined. Considering the high variation in decay rates there is a need to move away from using single-number decay time estimates and, preferably, to test methods that do not rely on nest decay times as alternatives for rapid assessments of orangutan habitat for conservation in Borneo.
Ecological Applications – Ecological Society of America
Published: Jan 1, 2008
Keywords: Borneo ; decay rate ; decomposition rate ; Indonesia ; Markov chain analysis ; nest count ; orangutan ; Pongo pygmaeus ; primate ; survey methodology ; transect
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