Birds are one of the most cost-effective groups to survey for monitoring human impacts on faunal ... more Birds are one of the most cost-effective groups to survey for monitoring human impacts on faunal communities and are consequently the best studied taxonomic group in urban areas. Urban bird assemblages are typically dominated by a few pest species, and need to be appropriately managed to reduce the aesthetic costs and health risks they may pose in highly-populated areas. Studies were conducted in Singapore (Feb.2000 to Feb.2001) to provide recommendations to manage urban birds, in particular to control the population of two invasive alien bird species: the house crow (Corvus splendens) and the Javan myna (Acridotheres javanicus). We then re-surveyed the same sites 9 years later (Mar.2010 to Feb.2011) to compare the changes in the abundance of the 20 most common urban bird species in Singapore over the past decade. We also tested whether the decrease in house crow abundance was correlated with increases in abundance of its co-invasive, the Javan myna, or with the Asian koel (Eudynamys scolopacea), a brood parasite of the house crow, across sites. In addition, we investigated competition between two myna species by comparing whether declines in the abundance of the common myna (Acridotheres trista) were correlated with increases in the abundance of the Javan myna. Our results showed that a total of 14 species recorded a signifi cant increase in abundance between the two surveys, two species signifi cantly decreased, and four species had no signifi cant change. There was also no signifi cant correlation between all the bird abundances, although changes in bird abundances were signifi cantly associated with certain changes in the urban environment such as spontaneous or cultivated green cover. We suggest that reduced density of house crow nests may actually result in increased vulnerability to, and hence success rate of, brood parasitism by the Asian koel, or there may be increased parasitism of other host species' nests. Meanwhile, competitive effects among the other birds may not be detectable at the scale of the transects used in our study.
Abstract Extraction of the branches of Garcinia dulcis afforded a xanthone with a novel oxygenati... more Abstract Extraction of the branches of Garcinia dulcis afforded a xanthone with a novel oxygenation pattern [1, 4, 6-trihydroxy-5-methoxy-7-(3-methylbut-2-enyl) xanthone] in addition to the triterpenoid friedelin and the known flavonoids 3′-(3-methylbut-2-enyl) ...
ABSTRACTClusters of four circular forest plots, 0.2 ha in total area, were inventoried for canopy... more ABSTRACTClusters of four circular forest plots, 0.2 ha in total area, were inventoried for canopy tree (≥30 cm gbh) and terrestrial herb floristic composition at 46 sites in the Central Catchment Nature Reserve, Singapore. The Nature Reserve covers a complex mosaic of lowland tropical forest of different successional stages, with much of the area covered in secondary forest 50–100 years old developed on exhausted agricultural soils. A total of 449 species of tree and 59 species of terrestrial herb were recorded from the clusters. Facultatively-terrestrial epiphytes were excluded from the analysis. Possible reasons for the low herb diversity are discussed. There was a marked similarity between ordinations (detrended correspondence analysis) of the clusters based on tree canopy composition weighted by species relative contribution to cluster total basal area and the herb flora composition, with a highly significant correlation between first axis scores of the two ordinations. Both ord...
Aim The primary objective of our study was to examine the factors affecting the distribution of v... more Aim The primary objective of our study was to examine the factors affecting the distribution of vascular plants, springtails, butterflies and birds on small tropical islands to understand how different groups of organisms with distinct biological traits respond to biogeographical variables, such as island area.
A heath community found on Pulau Sibu, an island lying off the east coast of Peninsular Malaysia,... more A heath community found on Pulau Sibu, an island lying off the east coast of Peninsular Malaysia, was found to consist of a low scrub, generally under 2 m in height, containing 24 species of vascular plants growing on hills overlooking the sea. It grew on a very shallow and acidic (pH 4.3) soil that was low in total nitrogen concentration (0.2%). Leaves of the seven most common shrub species, Ixonanthes reticulata. Melastoma malabathricum, Rhodamnia cinerea, Rhodomyrtus tomentosa, Schima wallichii. Styphelia malayana and ...
Birds are one of the most cost-effective groups to survey for monitoring human impacts on faunal ... more Birds are one of the most cost-effective groups to survey for monitoring human impacts on faunal communities and are consequently the best studied taxonomic group in urban areas. Urban bird assemblages are typically dominated by a few pest species, and need to be appropriately managed to reduce the aesthetic costs and health risks they may pose in highly-populated areas. Studies were conducted in Singapore (Feb.2000 to Feb.2001) to provide recommendations to manage urban birds, in particular to control the population of two invasive alien bird species: the house crow (Corvus splendens) and the Javan myna (Acridotheres javanicus). We then re-surveyed the same sites 9 years later (Mar.2010 to Feb.2011) to compare the changes in the abundance of the 20 most common urban bird species in Singapore over the past decade. We also tested whether the decrease in house crow abundance was correlated with increases in abundance of its co-invasive, the Javan myna, or with the Asian koel (Eudynamys scolopacea), a brood parasite of the house crow, across sites. In addition, we investigated competition between two myna species by comparing whether declines in the abundance of the common myna (Acridotheres trista) were correlated with increases in the abundance of the Javan myna. Our results showed that a total of 14 species recorded a signifi cant increase in abundance between the two surveys, two species signifi cantly decreased, and four species had no signifi cant change. There was also no signifi cant correlation between all the bird abundances, although changes in bird abundances were signifi cantly associated with certain changes in the urban environment such as spontaneous or cultivated green cover. We suggest that reduced density of house crow nests may actually result in increased vulnerability to, and hence success rate of, brood parasitism by the Asian koel, or there may be increased parasitism of other host species' nests. Meanwhile, competitive effects among the other birds may not be detectable at the scale of the transects used in our study.
Abstract Extraction of the branches of Garcinia dulcis afforded a xanthone with a novel oxygenati... more Abstract Extraction of the branches of Garcinia dulcis afforded a xanthone with a novel oxygenation pattern [1, 4, 6-trihydroxy-5-methoxy-7-(3-methylbut-2-enyl) xanthone] in addition to the triterpenoid friedelin and the known flavonoids 3′-(3-methylbut-2-enyl) ...
ABSTRACTClusters of four circular forest plots, 0.2 ha in total area, were inventoried for canopy... more ABSTRACTClusters of four circular forest plots, 0.2 ha in total area, were inventoried for canopy tree (≥30 cm gbh) and terrestrial herb floristic composition at 46 sites in the Central Catchment Nature Reserve, Singapore. The Nature Reserve covers a complex mosaic of lowland tropical forest of different successional stages, with much of the area covered in secondary forest 50–100 years old developed on exhausted agricultural soils. A total of 449 species of tree and 59 species of terrestrial herb were recorded from the clusters. Facultatively-terrestrial epiphytes were excluded from the analysis. Possible reasons for the low herb diversity are discussed. There was a marked similarity between ordinations (detrended correspondence analysis) of the clusters based on tree canopy composition weighted by species relative contribution to cluster total basal area and the herb flora composition, with a highly significant correlation between first axis scores of the two ordinations. Both ord...
Aim The primary objective of our study was to examine the factors affecting the distribution of v... more Aim The primary objective of our study was to examine the factors affecting the distribution of vascular plants, springtails, butterflies and birds on small tropical islands to understand how different groups of organisms with distinct biological traits respond to biogeographical variables, such as island area.
A heath community found on Pulau Sibu, an island lying off the east coast of Peninsular Malaysia,... more A heath community found on Pulau Sibu, an island lying off the east coast of Peninsular Malaysia, was found to consist of a low scrub, generally under 2 m in height, containing 24 species of vascular plants growing on hills overlooking the sea. It grew on a very shallow and acidic (pH 4.3) soil that was low in total nitrogen concentration (0.2%). Leaves of the seven most common shrub species, Ixonanthes reticulata. Melastoma malabathricum, Rhodamnia cinerea, Rhodomyrtus tomentosa, Schima wallichii. Styphelia malayana and ...
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