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Rapid losses and degradation of natural habitats in the tropics are driving catastrophic declines and extinctions of native biotas, including angiosperms. Determining the ecological and life-history correlates of extinction proneness in tropical plant species may help reveal the mechanisms underlying their responses to habitat disturbance, and assist in the pre-emptive identification of species at risk from extinction. We determined the predictors of extinction proneness in 1884 locally extinct ( n = 454) and extant ( n = 1430) terrestrial angiosperms (belonging to 43 orders, 133 families, and 689 genera) in the tropical island nation of Singapore (699.4 km2), which has lost 99.6% of its primary lowland evergreen rainforest since 1819. A wide variety of traits such as geographical distribution, pollination system, sexual system, habit, habitat, height, fruit/seed dispersal mechanism, and capacity for vegetative re-sprouting were used in the analysis. Despite controlling for phylogeny (as approximated by family level classification), we found that only a small percentage of the variation in the extinction probability could be explained by these factors. Epiphytic, monoecious, and hermaphroditic species and those restricted to inland forests have higher probabilities of extinction. Species dependent on mammal pollinators also probably have higher extinction probabilities. More comparative studies that use species traits to identify extinction-prone plant species are needed to guide the enormous, but essential task of identifying species most in need of conservation action. [ABSTRACT FROM AUTHOR]

Despite the alarming rate of tropical deforestation, the long-term conservation value of forest fragments remains poorly understood. We report on the avifaunal turnover in an isolated 4 ha tropical forest fragment in Singapore (i.e. Singapore Botanic Gardens rainforest fragment (SBGRF)) between 1898 and 1998. Over 100 years, the SBGRF lost 18 (49%) species and gained 20 species. More forest-dependent species (3) were lost from the SBGRF than survived (1) or colonised it (no species). Conversely, significantly more introduced species (4) colonised the fragment than were previously recorded (1 species). Significantly more nectarivores survived (8 species) or colonised (9 species) than were lost (two species). In essence, while the avian species richness in the SBGRF remained relatively constant after a century, its species composition underwent significant changes. The avian species composition in the SBGRF in 1998 appeared to be more similar to that of the contemporary smaller and younger Singaporean secondary forest patches than to either the larger and older forest reserves or to the SBGRF 100 years ago. Our study suggests that small isolated tropical forest fragments may have limited long-term conservation value for native forest bird species. [ABSTRACT FROM AUTHOR]

Widespread and rapid losses of natural habitats and biodiversity have made the identification of extinction-prone species a major challenge in conservation biology. We assessed the relative importance of biologically relevant species traits (e.g., body size, ecological specialization) obtained from published records to determine the extinction probability of butterflies in a highly disturbed tropical landscape (i.e., Singapore). We also developed a taxon-specific model to estimate the extinction proneness of butterflies in Southeast Asia. Logistic regression analyses showed that adult habitat specialization, larval host plant specificity, geographical distribution, sexual dichromatism, and congenor density were significant and independent determinants of butterfly extinctions in Singapore. Among these traits, specificity of larval host plant and adult habitat specialization were the best correlates of extinction risks. We used this phenomenological extinction-regression model to estimate the relative extinction proneness of 416 butterfly species in Southeast Asia. Our results illustrate the utility of available taxon-specific data for a localized area in estimating the extinction proneness of closely related species on a regional scale. When intensive field studies are not forthcoming, especially in regions suffering from rapid biodiversity losses (e.g., Southeast Asia), similar approaches could be used to estimate extinction threats for other taxonomic groups. [ABSTRACT FROM AUTHOR]

The purpose of our research was to explore the limits of rat-python- Sarcocystis distribution among rats on the offshore tropical islands of Singapore, and to examine the effect of island size, insular isolation, landscape peculiarities and anthropogenic disturbance. Commensal rats ( Rattus rattus) inhabited all of these islands, regardless of the island's size, proximity to the mainland, biogeographic features, and/or degree of anthropogenic interference. Rats caught on Sakijang Pelepah Island had well deliminated white bellies that are similar to those of sylvatic or feral rats. The prevalence of Sarcocystis spp. on individual islands ranged from 57 to 100%. This is consistent with the range found in forested habitats on Singapore Island. It also exhibited a similar diversity to Sarcocystis spp. and the predominance of Sarcocystis singaporensis. On Sakijang Pelepah Island, one rat (white bellied) was exceptionally heavily infected with both Sarcocystis villivilosi and Sarcocystis sulawesiensis. The muscles of the rats from nearly all of the islands contained immature sarcocysts, which implies that active transmission is taking place on these islands. This suggests that reticulated pythons ( Python reticulatus), which are the definitive hosts of rat Sarcocystis, might have been established or frequented in all the islands of Singapore. Our study shows that the Sarcocystis infection load of the rats was negatively correlated with human disturbance, hinting that human disturbance restricts the pythons’ mobility and thus, reduces infection of Sarcocytis in the islands rats. [ABSTRACT FROM AUTHOR]

The Indian house crow (Corvus splendens) has successfully invaded tropical and subtropical regions well beyond its native range, reaching pest proportions in many areas. The invasive population of house crows in Singapore (Southeast Asia) has increased at least 30-fold since 1985 and now numbers in excess of 130,000 birds. To understand the population ecology and behavior of the house crow in Singapore, we undertook regular population size and roost surveys, dissections of birds shot (to provide age structure and breeding status), detailed nestsite observations, and monitoring of coastal dispersal. Using a discrete-time, density-dependent population model to synthesize this information, we demonstrated that at least 41,000 crows will need to be culled in the first year of a control program, and equivalent effort committed each year thereafter, to be confident of suppressing the Singapore population from its 2001 density of 190 birds/km² to the management target of <10 birds/km⊃2 within a 10-year period. This figure drops to 32,000 if culling is combined with other management strategies such as resource limitation and nest destruction. Complete eradication of the house crow from Singapore may be an unrealistic goal due to potential difficulties in detecting crows at low population densities and influx of migrants from neighboring Malaysia. Our study has implications for pest-bird management in other cities in Asia, Africa, and the Middle East, and presents a surrogate population-dynamics management tool for use in regions where the house crow has become established as a pest species, but where limited local field data is available. [ABSTRACT FROM AUTHOR]

The looming mass extinction of biodiversity in the humid tropics is a major concern for the future[SUP1], yet most reports of extinctions in these regions are anecdotal or conjectural, with a scarcity of robust, broad-based empirical data[SUP2-4]. Here we report on local extinctions among a wide range of terrestrial and freshwater taxa from Singapore (540 km[SUP2]) in relation to habitat loss exceeding 95% over 183 years[SUP5,6]. Substantial rates of documented and inferred extinctions were found, especially for forest specialists, with the greatest proportion of extinct taxa (34-87%) in butterflies, fish, birds and mammals. Observed extinctions were generally fewer, but inferred losses often higher, in vascular plants, phasmids, decapods, amphibians and reptiles (5-80%). Forest reserves comprising only 0.25% of Singapore's area now harbour over 50% of the residual native biodiversity. Extrapolations of the observed and inferred local extinction data, using a calibrated species-area model[SUP7-9], imply that the current unprecedented rate of habitat destruction in Southeast Asia[SUP10] will result in the loss of 13-42% of regional populations over the next century, at least half of which will represent global species extinctions. [ABSTRACT FROM AUTHOR]

Presents a study which investigated the roost-site-selection patterns of house crows in Singapore to help develop management recommendations for controlling urban crows. Description of the study area; Methods used; Results of the study; Discussion.

Reports that a large proportion of forest-dependent bird species have disappeared from Singapore, probably due to heavy forest loss that started in the 1800s. Bird fauna that seems to have relaxed (attained a lower and relatively stable diversity following habitat destruction) in Singapore; Use of mist-netting; Comparison of understory bird communities of two lowland rainforest fragments in Singapore (Nee Soon and MacRitchie) with two continuous forests in Sarawak (Malaysia) (Matang Wildlife Sanctuary and Gunung Gading National Park); Comparison of community characteristics, population characteristics (e.g. sex ratio) and individual quality (e.g. prevalence of ectoparasites) among avifaunas of the forests; Bird species and individuals that were caught in continuous forests than in fragments; Rare species in Gading; Proportion of adults and the sex ratios that did not differ among the forests; Ectoparasite prevalence and intensity that also did not differ among the forests; Study that shows that avian communities in rainforest fragments are depauperate but show few signs of environmental stress; Possibility of long-term resilience in some forest bird species; Importance of protecting large tracts of tropical lowland rainforest to preserve rare forest-dependent avifauna.

The house crow (Corvus splendens) has reached pest proportions in Singapore and requires an integrated system of population control measures. One such crucial component, possibly reducing its breeding success, was the focus of our study. We compared the nest sites (n=30) of the house crow with randomly selected sites (n=30) to determine which environmental variables, if any, are indicative of preferred nest sites. The chi-squared test revealed the yellow flame tree (Peltophorum pterocarpum) to be the preferred tree species used for nesting. We formulated our model based on 11 preselected variables using binary logistic regression and evaluated the strength of support for each model (relative to all other models) using the second order model selection criterion AICc. The results indicate that house crows selected nests in areas that were more urbanised and open, with higher disturbance, nearer bin centres and food centres, and nested in trees that had larger crown volume, density and diameter. Based on these results, we suggest that urban managers can alter the landscape characteristics to make them less conducive for nesting crows. Such measures might include minor adjustments to the design of existing bin centres to prevent crows from entering, planting alternative, less suitable tree species in future, and regular pruning of trees with larger and denser crowns. [Copyright &y& Elsevier]

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. Location The Republic of Singapore (103°50′E, 1°20′N) located at the southern tip of Peninsular Malaysia. Methods Seventeen islands were surveyed for vascular plants, springtails, butterflies and birds. Correlation analysis, simple linear and multiple regression analyses and the nestedness index were used to test the hypotheses that (1) area is the best predictor of species/genus richness at both the community and specific/generic levels; (2) there is no correlation between population density and island area; and (3) species/genera are distributed as nested subsets. Results Area was the most significant factor in determining the island distribution of springtails, butterflies and birds at both the community and specific/generic levels, although there were disparate responses to the biogeographical variables between the three taxonomic groups, as well as between common species within each group. Individual species displayed disparate responses to biogeographical variables, suggesting that patterns of distribution at the community level may not be a good indicator of the population dynamics of individual species/genera. Plant species richness did not show any correlation with any of the tested variables. Population densities of springtails, butterflies and birds were positively correlated with area, contradicting the assumption of the equilibrium theory of island biogeography that population density of island species is independent of area. Population densities of plants showed no correlation with any of the tested biogeographical variables. Vascular plant, springtail, butterfly and bird communities on the islands showed... [ABSTRACT FROM AUTHOR]

Studies bird use of linear areas of a tropical city. Park connector design and management in Singapore; Abundance of human-associated bird species.

In this paper, we explore the ways in which young people in a highly urbanised setting experience and develop constructions of nature. We do so by using Singapore as our case study, an Asian context in which urbanisation is total (Singapore's population is totally urbanised). Based on focus group discussions, we conclude that young Singaporeans have little interest in and affinity for nature. This stems from a few factors: growing up in a highly urban environment in which contact with nature is limited; over-protective parents of two-children families who worry about the 'dangers' their children are exposed to when playing in natural areas; and the abundance of other recreational and entertainment options. This predisposes them to adopting the rationality of the State in privileging development priorities above conservation imperatives. We conclude by suggesting that certain activities be introduced to bring people, especially children, to nature areas so that their civic and emotional development may be enhanced. [ABSTRACT FROM AUTHOR]

In this paper, we address a research lacuna in the area of human experience of, and interaction with, nature. We focus on women in an urbanized setting, exploring their actual and desired experiences of the natural world, using Singapore as a case study. Our intention is to contribute to both the evolving theoretical and empirical discussions on this subject. Based on data collected from focus group discussions and household questionnaires, we conclude that women's relationships with nature in Singapore are underscored by a strong inclination towards nurturing: teaching, tending and caring, in a way that is not as apparent in men's relationships with nature. Women's relationships with nature may also be conceptualized in terms of 'danger' and 'delight', a fine balance between ambivalent experiences of fear and enjoyment. In comparing results based on the Singapore context with those in Britain, sources of enjoyment appear to be similar, but the different social situations have resulted in different sources of fear. We conclude by putting forward some recommendations for planning and designing green areas that may enhance women's use and enjoyment of nature areas. [ABSTRACT FROM AUTHOR]

Singapore Island suffered one of the highest known deforestation rates in the tropics from the mid-to-late 19th century when over 95% of its native lowland forest was cleared. We compared the current bird community structure and composition among three habitat types, i.e., old (>50 years, 7–935 ha) and young (⩽50 years, 29–49 ha) naturally regenerating secondary forests and abandoned wooded plantations (27–102 ha) dominated by exotic species. Forest patch area had the strongest influence on the current species richness. The overall bird richness was not greater in most mature forest patches, but 20 species were only found in the old secondary forests and five of these were found in <50% of these patches. The rapid decrease in the number of forest species in plantations was offset by an increase in the number of open habitat species. Comparisons with current bird communities in nearby mainland forest sites (Peninsular Malaysia) suggest that the forest avifauna of Singapore is depauperate. The preservation of larger mature and maturing forests is therefore required for conserving the extant forest avifauna in Singapore. Connecting isolated patches can also be envisioned to facilitate movements of forest birds that have low densities and restricted distribution. [Copyright &y& Elsevier]

Biodiversity is spatially organized by climatic gradients across elevation and latitude. But do other gradients exist that might drive biogeographic patterns? Here, we show that rainforest's vertical strata provide climatic gradients much steeper than those offered by elevation and latitude, and biodiversity of arboreal species is organized along this gradient. In Philippine and Singaporean rainforests, we demonstrate that rainforest frogs tend to shift up in the rainforest strata as altitude increases. Moreover, a Philippine-wide dataset of frog distributions shows that frog assemblages become increasingly arboreal at higher elevations. Thus, increased arboreality with elevation at broad biogeographic scales mirrors patterns we observed at local scales. Our proposed 'arboreality hypothesis' suggests that the ability to exploit arboreal habitats confers the potential for larger geographical distributions because species can shift their location in the rainforest strata to compensate for shifts in temperature associated with elevation and latitude. This novel finding may help explain patterns of species richness and abundance wherever vegetation produces a vertical microclimatic gradient. Our results further suggest that global warming will 'flatten' the biodiversity in rainforests by pushing arboreal species towards the cooler and wetter ground. This 'flattening' could potentially have serious impacts on forest functioning and species survival.