Ian Singleton | University of Kent (original) (raw)
Papers by Ian Singleton
Figure 2. Distribution, Genomic Diversity, and Population Structure of the Genus Pongo (A) Sampli... more Figure 2. Distribution, Genomic Diversity, and Population Structure of the Genus Pongo (A) Sampling areas across the current distribution of orangutans. The contour indicates the extent of the exposed Sunda Shelf during the Last Glacial Maximum. The black rectangle delimits the area shown in Figure 1 A. n indicates the number of sequenced individuals. See also Table S 4. (B) PCA of genomic diversity in Pongo. Axis labels show the percentages of the total variance explained by the first two principal components. Colored bars in the insert represent the distribution of nucleotide diversity in genome-wide 1 - Mb windows across sampling areas. (C) Bayesian clustering analysis of population structure using the program ADMIXTURE. Each vertical bar depicts an individual, with colors representing the inferred ancestry proportions with different assumed numbers of genetic clusters (K, horizontal sections).
IUCN, International Union for Conservation of Nature, helps the world find pragmatic solutions to... more IUCN, International Union for Conservation of Nature, helps the world find pragmatic solutions to our most pressing environment and development challenges. IUCN works on biodiversity, climate change, energy, human livelihoods and greening the world economy by supporting scientific research, managing field projects all over the world, and bringing governments, NGOs, the UN and companies together to develop policy, laws and best practice. IUCN is the world’s oldest and largest global environmental organization, with more than 1,000 government and NGO members and almost 11,000 volunteer experts in some 160 countries. IUCN’s work is supported by over 1,000 staff in 60 offices and hundreds of partners in public, NGO and private sectors around the world. Web: www.iucn.org IUCN Species Survival Commission The Species Survival Commission (SSC) is the largest of IUCN’s six volunteer commissions with a global membership of 8,000 experts. SSC advises IUCN and its members on the wide range of t...
Orangutans are on the brink of extinction with serious declines in population sizes. Many attempt... more Orangutans are on the brink of extinction with serious declines in population sizes. Many attempts have been made to protect this species including a reintroduction program as a new approach mandated by the Indonesian government. In the present study we are reporting the assessments of Sumatran orangutan well-being during the rehabilitation and reintroduction process by measuring fecal glucocorticoid metabolites (FGCM). The samples were collected from the rehabilitation facility Batu Mblin, Sibolangit Medan, and from the reintroduction station Jantho, Aceh Province, both operated by the Sumatran Orangutan Conservation Project (SOCP). Fecal samples were collected from 6 individuals between 2011 and 2013. The lowest FGCM levels were found at the rehabilitation station. After transport to the release station, but before the animals were released, we already found an elevation of FGCM, presumably reflecting a response to the new environment and transportation stress. The highest levels ...
Molecular Ecology, 2015
Investigating how different evolutionary forces have shaped patterns of DNA variation within and ... more Investigating how different evolutionary forces have shaped patterns of DNA variation within and among species requires detailed knowledge of their demographic history. Orang-utans, whose distribution is currently restricted to the Southeast Asian islands of Borneo (Pongo pygmaeus) and Sumatra (Pongo abelii), have likely experienced a complex demographic history, influenced by recurrent changes in climate and sea levels, volcanic activities and anthropogenic pressures. Using the most extensive sample set of wild orang-utans to date, we employed an approximate Bayesian computation (ABC) approach to test the fit of 12 different demographic scenarios to the observed patterns of variation in autosomal, X-chromosomal, mitochondrial and Y-chromosomal markers. In the best-fitting model, Sumatran orang-utans exhibit a deep split of populations north and south of Lake Toba, probably caused by multiple eruptions of the Toba volcano. In addition, we found signals for a strong decline in all Sumatran populations ~24 ka, probably associated with hunting by human colonizers. In contrast, Bornean orang-utans experienced a severe bottleneck ~135 ka, followed by a population expansion and substructuring starting ~82 ka, which we link to an expansion from a glacial refugium. Therefore, we showed that orang-utans went through drastic changes in population size and connectedness, caused by the recurrent contraction and expansion of rainforest habitat during Pleistocene glaciations, and probably also by the impact of hunting by early humans. Our findings also emphasize the fact that important aspects of the evolutionary past of species with complex demographic histories might remain obscured when applying overly simplified models.
Orangutans, 2008
of feeding time to different food types such as fruit, vegetable matter, bark, insects, and other... more of feeding time to different food types such as fruit, vegetable matter, bark, insects, and other items (e.g. Fox et al. 2004; Wich et al. 2006a; Chapter 8 this volume). Understanding a species' diet, however, also requires a comprehensive list of the food items eaten (Tutin et al. 1994; Rodman 2002). 9.1 Introduction This chapter compares orangutan diets, both across orangutan sites and relative to other great apes, based on current food lists. Orangutan diets are typically represented in terms of the allocation
Orangutans, 2008
Authors: Hardus, Madeleine E.; Lameira, Adriano R.; Singleton, Ian; Morrogh-Bernard, Helen C.; Kn... more Authors: Hardus, Madeleine E.; Lameira, Adriano R.; Singleton, Ian; Morrogh-Bernard, Helen C.; Knott, Cheryl D.; Ancrenaz, Marc; Utami Atmoko, S. Suci; Wich, Serge A. ... This article is hosted on another website. ... You may be required to register, activate a subscription or ...
Global change biology, Mar 27, 2016
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought... more The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000…
Current biology : CB, Jan 20, 2017
Figure S 1. Comparisons of five dental variables across P. abelii (red), P. pygmaeus (blue), P. t... more Figure S 1. Comparisons of five dental variables across P. abelii (red), P. pygmaeus (blue), P. tapanuliensis (black horizontal line), and P. p. palaeosumatrensis (green). Related to Figure 1 B. Variables include upper canine breadth (A), lower canine breadth (B), lower M 1 length (C), lower M 1 breadth (D), and lower M 1 area (E). For each boxplot, the middle line is the median value of the distribution, with the box representing the first (lower extreme) and third (upper extreme) quartile values (i. e., the interquartile range [IQR]), and the whiskers representing the lower and upper extreme values that are within 1.5 x IQR of the first and third quartile values. Exact permutation analyses suggested that P. tapanuliensis could be differentiated statistically from the P. abelii mean for both the upper (p-value <0.001) and lower canine breadths (p-value <0.001) and from the P. ' pygmaeus' palaeosumatrensis mean for lower M 1 length (p-value <0.001), breadth (p-value...
We studied the behaviour of captive Germain's Langur Trachypithecus germaini (Milne-Edwards) hous... more We studied the behaviour of captive Germain's Langur Trachypithecus germaini (Milne-Edwards) housed in a 3,000 m 2 naturalistic enclosure near Siem Reap, Cambodia. We studied a group of five individuals from May to July 2014, yielding 186 hours of data. We used instantaneous focal sampling to collect data on activities, social proximity, forest strata use and weather. The langurs were resting in 47.2% of scans, feeding in 43.6% of scans, traveling in 5.0% of scans, and grooming in 4.2% of scans. They spent 18.2% of their time in social proximity and varied in their time spent in different forest strata: the canopy (17.0%), understorey (53.7%) and forest floor (29.2%). The daily activity pattern showed three stages, feeding-resting-feeding. Feeding was inversely related to resting and grooming. More time was spent in the canopy and less on the floor during rain, while the opposite applied to sunny weather. Langurs were more often in social proximity during sunny weather. We additionally observed mycophagy and geophagy. The findings conform to the ecology of other Trachypithecus species and differences were likely due to the captive environment. An optimal pre-release environment should comprise a sufficient size, high-quality vegetation and appropriate feeding times, which may adjust the activity budget and pattern to fit a wild environment.
Journal of Medical Primatology
A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran or... more A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran orangutan (Pongo abelii) with a chronic persistent rectal prolapse that had been unsuccessfully treated by 6 previous surgeries. The rectal prolapse did not recur, and the orangutan was successfully released to the wild, 6 weeks later.
Science Advances, 2016
Positive news about Sumatran orangutans is rare. The species is critically endangered because of ... more Positive news about Sumatran orangutans is rare. The species is critically endangered because of forest loss and poaching, and therefore, determining the impact of future land-use change on this species is important. To date, the total Sumatran orangutan population has been estimated at 6600 individuals. On the basis of new transect surveys, we estimate a population of 14,613 in 2015. This higher estimate is due to three factors. First, orangutans were found at higher elevations, elevations previously considered outside of their range and, consequently, not surveyed previously. Second, orangutans were found more widely distributed in logged forests. Third, orangutans were found in areas west of the Toba Lake that were not previously surveyed. This increase in numbers is therefore due to a more wide-ranging survey effort and is not indicative of an increase in the orangutan population in Sumatra. There are evidently more Sumatran orangutans remaining in the wild than we thought, but ...
Primate Conservation, 2009
Orangutans, 2008
IngentaConnect. ...
Orangutans, 2008
Sexually mature male orangutans live in home ranges that are 3–5 times that of adult females and ... more Sexually mature male orangutans live in home ranges that are 3–5 times that of adult females and show very high overlap. Encounters among flanged males, while rare, are invariably antagonistic and may lead to injury or death. Their dominance relations are not always transitive, however, producing non-linear hierarchies, probably because they usually meet one on one. Flanged males in consortship with a receptive female frequently chase unflanged males trailing them, but never catch them, so that unflanged males often remain associated with the consort pair. Unflanged males are more tolerant among each other, although attacks also occur. The response of flanged males to long calls they hear depends on their dominance position: the dominant male approaches them, whereas the other males tend to avoid them. There is no conclusive information on the reaction of unflanged males. Data from Sumatra suggest that dominant flanged males and the males challenging them for local dominance were most commonly present in a given study area, suggesting that non-dominant males roamed more widely in search of uncontested access to females.
Figure 2. Distribution, Genomic Diversity, and Population Structure of the Genus Pongo (A) Sampli... more Figure 2. Distribution, Genomic Diversity, and Population Structure of the Genus Pongo (A) Sampling areas across the current distribution of orangutans. The contour indicates the extent of the exposed Sunda Shelf during the Last Glacial Maximum. The black rectangle delimits the area shown in Figure 1 A. n indicates the number of sequenced individuals. See also Table S 4. (B) PCA of genomic diversity in Pongo. Axis labels show the percentages of the total variance explained by the first two principal components. Colored bars in the insert represent the distribution of nucleotide diversity in genome-wide 1 - Mb windows across sampling areas. (C) Bayesian clustering analysis of population structure using the program ADMIXTURE. Each vertical bar depicts an individual, with colors representing the inferred ancestry proportions with different assumed numbers of genetic clusters (K, horizontal sections).
IUCN, International Union for Conservation of Nature, helps the world find pragmatic solutions to... more IUCN, International Union for Conservation of Nature, helps the world find pragmatic solutions to our most pressing environment and development challenges. IUCN works on biodiversity, climate change, energy, human livelihoods and greening the world economy by supporting scientific research, managing field projects all over the world, and bringing governments, NGOs, the UN and companies together to develop policy, laws and best practice. IUCN is the world’s oldest and largest global environmental organization, with more than 1,000 government and NGO members and almost 11,000 volunteer experts in some 160 countries. IUCN’s work is supported by over 1,000 staff in 60 offices and hundreds of partners in public, NGO and private sectors around the world. Web: www.iucn.org IUCN Species Survival Commission The Species Survival Commission (SSC) is the largest of IUCN’s six volunteer commissions with a global membership of 8,000 experts. SSC advises IUCN and its members on the wide range of t...
Orangutans are on the brink of extinction with serious declines in population sizes. Many attempt... more Orangutans are on the brink of extinction with serious declines in population sizes. Many attempts have been made to protect this species including a reintroduction program as a new approach mandated by the Indonesian government. In the present study we are reporting the assessments of Sumatran orangutan well-being during the rehabilitation and reintroduction process by measuring fecal glucocorticoid metabolites (FGCM). The samples were collected from the rehabilitation facility Batu Mblin, Sibolangit Medan, and from the reintroduction station Jantho, Aceh Province, both operated by the Sumatran Orangutan Conservation Project (SOCP). Fecal samples were collected from 6 individuals between 2011 and 2013. The lowest FGCM levels were found at the rehabilitation station. After transport to the release station, but before the animals were released, we already found an elevation of FGCM, presumably reflecting a response to the new environment and transportation stress. The highest levels ...
Molecular Ecology, 2015
Investigating how different evolutionary forces have shaped patterns of DNA variation within and ... more Investigating how different evolutionary forces have shaped patterns of DNA variation within and among species requires detailed knowledge of their demographic history. Orang-utans, whose distribution is currently restricted to the Southeast Asian islands of Borneo (Pongo pygmaeus) and Sumatra (Pongo abelii), have likely experienced a complex demographic history, influenced by recurrent changes in climate and sea levels, volcanic activities and anthropogenic pressures. Using the most extensive sample set of wild orang-utans to date, we employed an approximate Bayesian computation (ABC) approach to test the fit of 12 different demographic scenarios to the observed patterns of variation in autosomal, X-chromosomal, mitochondrial and Y-chromosomal markers. In the best-fitting model, Sumatran orang-utans exhibit a deep split of populations north and south of Lake Toba, probably caused by multiple eruptions of the Toba volcano. In addition, we found signals for a strong decline in all Sumatran populations ~24 ka, probably associated with hunting by human colonizers. In contrast, Bornean orang-utans experienced a severe bottleneck ~135 ka, followed by a population expansion and substructuring starting ~82 ka, which we link to an expansion from a glacial refugium. Therefore, we showed that orang-utans went through drastic changes in population size and connectedness, caused by the recurrent contraction and expansion of rainforest habitat during Pleistocene glaciations, and probably also by the impact of hunting by early humans. Our findings also emphasize the fact that important aspects of the evolutionary past of species with complex demographic histories might remain obscured when applying overly simplified models.
Orangutans, 2008
of feeding time to different food types such as fruit, vegetable matter, bark, insects, and other... more of feeding time to different food types such as fruit, vegetable matter, bark, insects, and other items (e.g. Fox et al. 2004; Wich et al. 2006a; Chapter 8 this volume). Understanding a species' diet, however, also requires a comprehensive list of the food items eaten (Tutin et al. 1994; Rodman 2002). 9.1 Introduction This chapter compares orangutan diets, both across orangutan sites and relative to other great apes, based on current food lists. Orangutan diets are typically represented in terms of the allocation
Orangutans, 2008
Authors: Hardus, Madeleine E.; Lameira, Adriano R.; Singleton, Ian; Morrogh-Bernard, Helen C.; Kn... more Authors: Hardus, Madeleine E.; Lameira, Adriano R.; Singleton, Ian; Morrogh-Bernard, Helen C.; Knott, Cheryl D.; Ancrenaz, Marc; Utami Atmoko, S. Suci; Wich, Serge A. ... This article is hosted on another website. ... You may be required to register, activate a subscription or ...
Global change biology, Mar 27, 2016
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought... more The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000…
Current biology : CB, Jan 20, 2017
Figure S 1. Comparisons of five dental variables across P. abelii (red), P. pygmaeus (blue), P. t... more Figure S 1. Comparisons of five dental variables across P. abelii (red), P. pygmaeus (blue), P. tapanuliensis (black horizontal line), and P. p. palaeosumatrensis (green). Related to Figure 1 B. Variables include upper canine breadth (A), lower canine breadth (B), lower M 1 length (C), lower M 1 breadth (D), and lower M 1 area (E). For each boxplot, the middle line is the median value of the distribution, with the box representing the first (lower extreme) and third (upper extreme) quartile values (i. e., the interquartile range [IQR]), and the whiskers representing the lower and upper extreme values that are within 1.5 x IQR of the first and third quartile values. Exact permutation analyses suggested that P. tapanuliensis could be differentiated statistically from the P. abelii mean for both the upper (p-value <0.001) and lower canine breadths (p-value <0.001) and from the P. ' pygmaeus' palaeosumatrensis mean for lower M 1 length (p-value <0.001), breadth (p-value...
We studied the behaviour of captive Germain's Langur Trachypithecus germaini (Milne-Edwards) hous... more We studied the behaviour of captive Germain's Langur Trachypithecus germaini (Milne-Edwards) housed in a 3,000 m 2 naturalistic enclosure near Siem Reap, Cambodia. We studied a group of five individuals from May to July 2014, yielding 186 hours of data. We used instantaneous focal sampling to collect data on activities, social proximity, forest strata use and weather. The langurs were resting in 47.2% of scans, feeding in 43.6% of scans, traveling in 5.0% of scans, and grooming in 4.2% of scans. They spent 18.2% of their time in social proximity and varied in their time spent in different forest strata: the canopy (17.0%), understorey (53.7%) and forest floor (29.2%). The daily activity pattern showed three stages, feeding-resting-feeding. Feeding was inversely related to resting and grooming. More time was spent in the canopy and less on the floor during rain, while the opposite applied to sunny weather. Langurs were more often in social proximity during sunny weather. We additionally observed mycophagy and geophagy. The findings conform to the ecology of other Trachypithecus species and differences were likely due to the captive environment. An optimal pre-release environment should comprise a sufficient size, high-quality vegetation and appropriate feeding times, which may adjust the activity budget and pattern to fit a wild environment.
Journal of Medical Primatology
A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran or... more A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran orangutan (Pongo abelii) with a chronic persistent rectal prolapse that had been unsuccessfully treated by 6 previous surgeries. The rectal prolapse did not recur, and the orangutan was successfully released to the wild, 6 weeks later.
Science Advances, 2016
Positive news about Sumatran orangutans is rare. The species is critically endangered because of ... more Positive news about Sumatran orangutans is rare. The species is critically endangered because of forest loss and poaching, and therefore, determining the impact of future land-use change on this species is important. To date, the total Sumatran orangutan population has been estimated at 6600 individuals. On the basis of new transect surveys, we estimate a population of 14,613 in 2015. This higher estimate is due to three factors. First, orangutans were found at higher elevations, elevations previously considered outside of their range and, consequently, not surveyed previously. Second, orangutans were found more widely distributed in logged forests. Third, orangutans were found in areas west of the Toba Lake that were not previously surveyed. This increase in numbers is therefore due to a more wide-ranging survey effort and is not indicative of an increase in the orangutan population in Sumatra. There are evidently more Sumatran orangutans remaining in the wild than we thought, but ...
Primate Conservation, 2009
Orangutans, 2008
IngentaConnect. ...
Orangutans, 2008
Sexually mature male orangutans live in home ranges that are 3–5 times that of adult females and ... more Sexually mature male orangutans live in home ranges that are 3–5 times that of adult females and show very high overlap. Encounters among flanged males, while rare, are invariably antagonistic and may lead to injury or death. Their dominance relations are not always transitive, however, producing non-linear hierarchies, probably because they usually meet one on one. Flanged males in consortship with a receptive female frequently chase unflanged males trailing them, but never catch them, so that unflanged males often remain associated with the consort pair. Unflanged males are more tolerant among each other, although attacks also occur. The response of flanged males to long calls they hear depends on their dominance position: the dominant male approaches them, whereas the other males tend to avoid them. There is no conclusive information on the reaction of unflanged males. Data from Sumatra suggest that dominant flanged males and the males challenging them for local dominance were most commonly present in a given study area, suggesting that non-dominant males roamed more widely in search of uncontested access to females.