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Resource Partitioning (resource + partitioning)
Selected AbstractsResource Partitioning in Sympatric Cynopterus bats in Lowland Tropical Rain Forest, ThailandBIOTROPICA, Issue 2 2007Sara Bumrungsri ABSTRACT Diet and habitat use of the closely related and size-overlapping sympatric Cynopterus brachyotis and C. sphinx were established in lowland dry evergreen forest, Thailand, between March 1998 and March 2000. Feces from netted bats were analyzed, and the recapture rate determined. Although both species share a set of food plants, and fruits from early successional forest contribute about half of their diet, C. brachyotis, the smaller of the two species, ate a significantly greater proportion of fruits from early successional forest than C. sphinx. The latter ate a significantly greater proportion of fruit species in larger size classes. More C. brachyotis were captured in early successional forest in almost every month, while C. sphinx is more common in old-growth forest. However, the capture rate of C. sphinx increased in early successional forest in the mid-dry season when its preferred fruits become available. The recapture rate of C. brachyotis in early successional forest was significantly higher than that of C. sphinx, and the reverse situation was observed in old-growth forest. Male C. sphinx had a significantly higher recapture rate in early successional forest than females. Fruit size and habitat use are the major determinants of resource partitioning between these size-overlapping congeners. [source] Resource partitioning between lake-dwelling Atlantic salmon (Salmo salar L.) parr, brown trout (Salmo trutta L.) and Arctic charr (Salvelinus alpinus (L.))ECOLOGY OF FRESHWATER FISH, Issue 4 2000L. Jørgensen Abstract , Resource partitioning between Atlantic salmon parr, brown trout and Arctic charr was studied throughout the ice-free season in a north Norwegian lake. Juvenile salmon and trout (,160 mm) utilized the littoral zone and juvenile charr the profundal, while adult trout and charr (>160 mm) were found in both. Juvenile salmon and trout had a similar diet, although trichopteran larvae were more important for the trout and chironomid pupae and three-spined sticklebacks for the salmon parr. Small salmon and trout parr (,120 mm) had a higher diet overlap than larger parr (121,160 mm). The feeding habits of adult trout were similar to that of juvenile trout, but the former took larger prey items. At the population level, both salmon and trout were generalistic feeders with a broad diet, but at the individual level, both species had specialized on a single or a few prey categories. Juvenile charr were segregated from salmon and trout in both habitat and food utilization; they had a narrow diet consisting of chironomids and zooplankton, possibly reflecting their confinement to the profundal habitat which have a low diversity of potential prey. Larger charr also took zoobenthos and sticklebacks in the littoral zone., [source] Effects of herbivore species richness on the niche dynamics and distribution of blue sheep in the Trans-HimalayaDIVERSITY AND DISTRIBUTIONS, Issue 6 2009Tsewang Namgail Abstract Aim, To understand the community structure of mountain ungulates by exploring their niche dynamics in response to sympatric species richness. Location, Ladakh and Spiti Regions of the Western Indian Trans-Himalaya. Methods, We used the blue sheep Pseudois nayaur, a relatively widely distributed mountain ungulate, as a model species to address the issue. We selected three discrete valleys in three protected areas with similar environmental features but varying wild ungulate species richness, and studied blue sheep's diet and habitat utilization in them. Habitat variables such as slope angle, distance to cliff and elevation at blue sheep locations were recorded to determine the habitat width of the species. Faecal pellets were collected and microhistological faecal analysis was carried out to determine the diet width of blue sheep in the three areas with different ungulate species richness. Blue sheep's niche width in terms of habitat and diet was determined using the Shannon's Index. Results, The habitat width of blue sheep had a negative relationship with the number of sympatric species. However, contrary to our expectation, there was a hump-shaped relationship between blue sheep's diet width and the sympatric species richness, with the diet width being narrower in areas of allopatry as well as in areas with high herbivore species richness, and the greatest in areas with moderate species richness. Main conclusions, We suspect that the narrow diet width in allopatry is out of choice, whereas it is out of necessity in areas with high herbivore species richness because of resource partitioning that enables coexistence. We suggest that interactions with sympatric species lead to niche adjustment of mountain ungulates, implying that competition may play a role in structuring Trans-Himalayan mountain ungulate assemblages. Given these results, we underscore the importance of including biotic interactions in species distribution models, which have often been neglected. [source] Comparative life-history traits in a fig wasp community: implications for community structureECOLOGICAL ENTOMOLOGY, Issue 2 2010MAHUA GHARA 1. Whether life-history traits can determine community composition and structure is an important question that has been well explored theoretically, but has received scant empirical attention. Life-history traits of a seven-member community of galler and parasitoid fig wasp species (Chalcidoidea), developing within the inflorescences (syconia) of Ficus racemosa (Moraceae) in India, were determined and used to examine community structure and ecology. 2. Gallers were pro-ovigenic (all eggs are mature upon adult emergence) whereas parasitoids were synovigenic (eggs mature progressively during adult lifespan). Initial egg load was correlated with body size for some species, and there was a trade-off between egg number and egg size across all species. Although all species completed their development and left the syconium concurrently, they differed in their adult and pre-adult lifespans. Providing sucrose solutions increased parasitoid lifespan but had no effect on the longevity of some galler species. While feeding regimes and body size affected longevity in most species, an interaction effect between these variables was detected for only one species. 3. Life-history traits of wasp species exhibited a continuum in relation to their arrival sequence at syconia for oviposition during syconium development, and therefore reflected their ecology. The largest number of eggs, smallest egg sizes, and shortest longevities were characteristic of the earliest-arriving galling wasps at the smallest, immature syconia; the converse characterised the later-arriving parasitoids at the larger, already parasitised syconia. Thus life history is an important correlate of community resource partitioning and can be used to understand community structure. 4. This is the first comprehensive study of life-history traits in a fig wasp community. The comparative approach revealed constraints and flexibility in trait evolution. [source] Morphological variation in relation to flower use in bumblebeesENTOMOLOGICAL SCIENCE, Issue 2 2006Maki N. INOUE Abstract To understand resource partitioning in a bumblebee community, we analyzed various morphological characters. A total of 1269 individuals of six bumblebee species, Bombus ardens, B. hypocrita, B. diversus, B. ignitus, B. honshuensis and B. beaticola, were examined and principal component analysis showed that the bumblebee species were clearly differentiated. Glossa, prementa and head lengths were positively correlated with the second component, and a longer proboscis was associated with a narrower body, which may help bees to intrude into and access deep-lying nectar sources. Bombus diversus, with a long proboscis and narrow body, preferred flowers with a long corolla tube, whereas B. hypocrita and B. ignitus, which have short proboscises and wide bodies, visited flowers with short corollas or dish-shaped flowers. Two pairs of consubgeneric species that have similar morphological characteristics, B. ardens and B. beaticola, and B. hypocrita and B. ignitus, divided flower resources by habitat selection and seasonal partitioning. For resource partitioning among bumblebee species, not only morphology but also other factors, such as habitat and seasonal preference, flower use, foraging behavior, and interspecific interactions, are responsible. [source] A network management tool for resource-partition based layer 1 virtual private networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 2 2009Jing Wu A Layer 1 Virtual Private Network (L1-VPN) has two models for service management: the resource-partition based model and the domain-service based model. In this paper, we present a network management tool for resource-partition based L1-VPNs. A Transaction Language One (TL1) proxy is designed to achieve resource partitioning at the network element level. Building on top of a TL1 proxy, we implemented a User-Controlled LightPath (UCLP) system to support physical network brokers to assign and allocate virtually dedicated resources to customers, and to enable customers to directly manage their resources. With such a capability, customers are able to create wide area networks based on their traffic pattern, and to adjust their traffic pattern based on available resources. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. [source] Lizard community structure along environmental gradientsJOURNAL OF ANIMAL ECOLOGY, Issue 2 2010Lauren B. Buckley Summary 1. ,How the total number of individuals in a community is divided among its species is governed by both the distribution of species along landscape-scale environmental gradients and by local resource partitioning. In vertebrate ectotherms, abiotic environmental conditions may constrain geographic distributions more strongly than local population densities due to thermal constraints on resource acquisition and due to behavioural thermoregulation. 2. ,We investigate whether local density and species richness are decoupled for lizard communities within the Southwest US by comparing 18 species-abundance distributions. 3. ,While species richness decreases strongly with decreasing temperature, there is no significant relationship between temperature or resource availability (net primary productivity) and the total number of individuals within a community. Consequently, in more species-rich communities species have lower mean abundances. 4. ,This suggestion that lizard species richness is not a function of an area's capacity to support more individuals questions for this group species diversity theories based on this assumption. [source] Cavity use and reproductive success of nesting macaws in lowland forest of southeast PeruJOURNAL OF FIELD ORNITHOLOGY, Issue 1 2009Katherine Renton ABSTRACT Competition for nest sites by sympatric species can lead to resource partitioning among species. We examined the partitioning of cavity resources by Red-and-green Macaws (Ara chloropterus), Blue-and-yellow Macaws (A. ararauna), and Scarlet Macaws (A. macao) in the lowland forest of southeast Peru. Red-and-green Macaws nested primarily in cavities in emergent Dipteryx trees, and Blue-and-yellow Macaws nested predominantly in palm snags. Scarlet Macaws had the broadest nesting niche, and their use of cavities overlapped that of the other two species. These differences in cavity use may be related to differences in size, with Red-and-green Macaws the largest of the three species (90 cm long, 1050,1320 g), followed by Scarlet Macaws (85 cm long, 1060,1123 g) and Blue-and-yellow Macaws (70 cm long, 1086 g). We did not observe interspecific conflicts between Blue-and-yellow Macaws and the other two species. However, Scarlet and Red-and-green macaws frequently compete for cavities, perhaps contributing to the use of a wider range of cavity resources by the smaller, less competitive Scarlet Macaws. For the three macaw species combined, 40 of 84 nests (48%) were successful, fledging either one or two young (mean = 1.4 ± 0.43). The overall reproductive output (including failed nests) was 0.60 ± 0.68 fledglings per nesting pair, with no difference between macaw species (P > 0.18). A lack of alternative nest substrates for large macaws may drive resource partitioning by sympatric species, with specialization on either emergent trees or palm snags, whereas less competitive species like Scarlet Macaws need to be flexible and use a variety of nest sites. RESUMEN La competencia por sitios de anidación entre especies simpatricas favorece la repartición de recursos. Evaluamos la repartición del recurso de cavidades entre la guacamaya roja (Ara chloropterus), guacamaya azul y amarilla (A. ararauna), y guacamaya escarlata (A. macao) en la selva tropical húmeda del sureste de Perú. La guacamaya roja anidó principalmente en cavidades en árboles emergentes de Dipteryx, y la guacamaya azul y amarilla anidó en palmeras muertas. La guacamaya escarlata presentó el nicho de anidación más amplio, sóbrelapando su uso de cavidades con las otras dos especies. Estas diferencias en uso de cavidades podrían estar relacionadas con diferencias en tamaño corporal, la guacamaya roja es la especie mas grande (90 cm largo, 1050,1320 g), seguido por la guacamaya escarlata (85 cm largo, 1060,1123 g) y la guacamaya azul y amarillo (70 cm largo, 1086 g). No observamos conflictos interespecificos de la guacamaya azul y amarilla con las otras dos especies. Sin embargo, las guacamayas roja y escarlata competieron frecuentemente por las cavidades, que contribuiría al rango mas amplio de cavidades usadas por la mas pequeña, menor competitivo, guacamaya escarlata. Para las tres especies, 40 de 84 nidos (48%) fueron exitosos, con uno o dos volantones (promedio = 1.4 ± 0.43). La productividad reproductiva (incluyendo nidos fracasados) fue de 0.60 ± 0.68 volantones por pareja, que no varió entre las especies (P > 0.18). Una falta de sustratos alternos para anidación por las guacamayas podría impulsar la repartición de recursos entre las especies simpatricas, con especialización sobre árboles emergentes o palmeras muertas, mientras la menor competidora guacamaya escarlata necesita ser flexible, utilizando una variedad de sitios de anidación. [source] Morphology,diet relationships in four killifishes (Teleostei, Cyprinodontidae, Orestias) from Lake TiticacaJOURNAL OF FISH BIOLOGY, Issue 3 2009E. Maldonado This study explores the relationship between morphology and diet in four Andean killifishes (Orestias) from Lake Titicaca that are known to differ in habitat use. Species that fed preferentially on amphipods (Orestias albus) or molluscs (Orestias luteus) separated in multivariate space from other species that feed on cladocera and algae (Orestias agassii and Orestias jussiei). Generally, specimens feeding on cladocera were characterized by a short, blunt nose with a small mouth; whereas, specimens feeding on amphipods exhibited a long snout with a large mouth. Specimens including molluscs in their diet tended to have a larger posterior part of the head and the larger opercles than others; while the occurrence of substratum in gut content was generally related to a short but deep head. The present analysis suggests that the littoral O. jussiei has an intermediate phenotype and diet between the pelagic (O. agassii) and benthic (O. albus and O. luteus) species. Results suggest that resource partitioning was occurring and that several morphological traits relate to characteristics of the diet, and it is inferred that the benthic, the pelagic and the littoral zones in the lake host different prey communities constituting distinct adaptive landscapes. [source] Foraging habitats based on the diet of female northern fur seals (Callorhinus ursinus) on the Pribilof Islands, AlaskaJOURNAL OF ZOOLOGY, Issue 4 2006T. K. Zeppelin Abstract Scats (fecal samples) collected between 1987 and 2000 on northern fur seal Callorhinus ursinus rookeries of St Paul (n=2968) and St George Islands (n=1203), Alaska, were used to examine the relationship between breeding sites and food habits of adult female seals. On the basis of the frequency of occurrence (FO) and per cent minimum number of individual prey (%MNI) in scats, juvenile walleye pollock Theragra chalcogramma and gonatid squid Gonatopsis borealis/Berryteuthis magister and Gonatus madokai/Gonatus middendorffi were the dominant prey species consumed overall. Other primary prey (FO>5%) included Pacific sand lance Ammodytes hexapteus, Pacific herring Clupea pallasi, northern smoothtongue Leuroglossus schmidti, Atka mackerel Pleurogrammus monopterygius, Pacific salmon (Oncorhynchus spp.) and other squid of the Gonatus genus. We identified five rookery complexes from a cluster analysis of the FO of primary prey in scats. Rookery complexes were separated geographically and each was further defined by characteristic patterns in the representation of prey types typically associated with specific hydrographic domains. Diet differences were observed among rookeries on the north and south side of St George Island and on the east, south and south-west side of St Paul Island. The rookery clusters observed in this study provide evidence of resource partitioning among adult female northern fur seals and have important implications for fur seal conservation and management. [source] Another diet of worms: the applicability of polychaete feeding guilds as a useful conceptual framework and biological variableMARINE ECOLOGY, Issue 3-4 2005Paulo Roberto Pagliosa Abstract A fundamental question in guild studies is how to separate species into guilds. In a seminal manuscript, Fauchald & Jumars [Oceanography and Marine Biology Annual Review17 (1979) 193] summarized polychaete feeding biology and proposed a conceptual framework to test hypotheses on the sympatric occurrence of congeners with limited morphological differentiation. Twenty-six years after this publication, few studies have tested the validity and practical functioning of this scheme of polychaete feeding guilds and then only using part of the classification. The objective of the present study was to analyze the applicability of polychaete feeding guilds to ecological and environment assessments. Two data sets from Santa Catarina Island Bay, southern Brazil, were used. The first data set deals with spatial distribution of natural polychaete assemblages along the bay. The second data set treats fauna in urbanized versus relatively pristine mangroves. Multivariate analysis showed similar patterns in sample groups formed using guilds or densities and composition data. The role of feeding guilds in benthic systems was assessed through comparison with environmental variables. The polychaete assemblage from the Bay was related to sediment type. Motile and discretely motile carnivores and herbivores with jawed probosces matched coarse sands; surface deposit feeders and filter feeders were found in fine sands; and surface and subsurface deposit feeders and carnivores, all with soft probosces matched silt and clay sediments. The data analyses in mangroves showed surface deposit feeders and filter feeders in undisturbed sites and omnivorous species in disturbed ones. The polychaete feeding guilds appear relevant to assembly rules based on resource availability, to resource partitioning and to interspecific competition. [source] Biodiversity in microbial communities: system scale patterns and mechanismsMOLECULAR ECOLOGY, Issue 7 2009J. JACOB PARNELL Abstract The relationship between anthropogenic impact and the maintenance of biodiversity is a fundamental question in ecology. The emphasis on the organizational level of biodiversity responsible for ecosystem processes is shifting from a species-centred focus to include genotypic diversity. The relationship between biodiversity measures at these two scales remains largely unknown. By stratifying anthropogenic effects between scales of biodiversity of bacterial communities, we show a statistically significant difference in diversity based on taxonomic scale. Communities with intermediate species richness show high genotypic diversity while speciose and species-poor communities do not. We propose that in species-poor communities, generally comprising stable yet harsh conditions, physiological tolerance and competitive trade-offs limit both the number of species that occur and the loss of genotypes due to decreases in already constrained fitness. In species-rich communities, natural environmental conditions result in well-defined community structure and resource partitioning. Disturbance of these communities disrupts niche space, resulting in lower genotypic diversity despite the maintenance of species diversity. Our work provides a model to inform future research about relationships between species and genotypic biodiversity based on determining the biodiversity consequences of changing environmental context. [source] How can we predict the effects of elevated CO2 on the balance between perennial C3 grass species competing for light?NEW PHYTOLOGIST, Issue 1 2002F. Teyssonneyre Summary ,,Changes in the balance between mixed plant species have been reported under elevated [CO2] compared with ambient atmospheric [CO2]. We hypothesized that species response to elevated CO2 in mixture can be explained by taking into account resource partitioning between mixed species. ,,This hypothesis was tested experimentally on three perennial C3 grass species (Lolium perenne, Festuca arundinacea and Holcus lanatus) grown in monocultures and in binary mixtures (Lolium,Festuca and Lolium,Holcus) under mild (frequent cuts) or severe (infrequent cuts) competition for light and at a high N supply (40 g N m,2). ,,Under mild competition for light, the dry matter yield response to elevated CO2 of the mixed grass species was similar to that observed in monocultures. By contrast, under severe light competition, the grass species that absorbed more light per unit leaf area (Holcus and Festuca), also had a greater response to elevated CO2 in mixture compared with monoculture. ,,Under our experimental conditions, we have shown that the dry matter yield response to CO2 in mixture can be predicted from both the species response in monoculture, and the light capture per unit leaf area in ambient CO2 of the mixed compared with the pure grasses. [source] The relative importance of spatial aggregation and resource partitioning on the coexistence of mycophagous insectsOIKOS, Issue 1 2005Kazuo H. Takahashi The relative importance of spatial aggregation and resource partitioning on coexistence was investigated for mycophagous insects in central Japan. The effects of spatial aggregation and resource partitioning were separated by a randomization procedure. From 124 patches of macrosporophores belonging to 37 species, 3275 individuals belonging to 14 families of Diptera and 11 individuals to Lepidoptera emerged. Since the level of identification varied among insect taxa, the analysis was made in three ways; 1) for all taxa to assess the stability of the whole community, 2) for drosophilid species to assess their persistence in the community, and 3) for species of Drosophila and Mycodrosophila to assess their persistence against congeneric and heterogeneric species. Both spatial aggregation and resource partitioning functioned for the stability of whole mycophagous insect community, and spatial aggregation played a more important role than resource partitioning. On the other hand, only spatial aggregation functioned for the persistence of drosophilid species in the community. According to the analysis on species of Drosophila and Mycodrosophila against congeneric and heterogeneric species, the relative importance of resource partitioning was smaller for the coexistence of within-genus species pairs than for that of between-genus species pairs. These results suggest that the relative importance of these two mechanisms depends on the phylogenetic and guild diversity of community. [source] Effects of species diversity on the primary productivity of ecosystems: extending our spatial and temporal scales of inferenceOIKOS, Issue 3 2004Bradley J. Cardinale The number of studies examining how species diversity influences the productivity of ecosystems has increased dramatically in the past decade as concern about global loss of biodiversity has intensified. Research to date has greatly improved our understanding of how, when, and why species loss alters primary production in ecosystems. However, because experiments have been performed at rather small spatial and short temporal scales, it is unclear whether conclusions can be readily extrapolated to the broader scales at which natural communities are most likely to influence ecosystem functioning. Here we develop a simple patch-dynamics model to examine some of the scale-dependent and independent qualities of the diversity-productivity relationship. We first simulate a typical diversity-productivity experiment and show that the influence of species richness on productivity is temporally dynamic, growing stronger through successional time. This holds true irrespective of whether resource partitioning or a sampling effect is the underlying mechanism. We then increase the spatial scale of the simulation from individual patches to a region consisting of many patch types. Results suggest that the diversity-productivity relationship is not influenced by spatial scale per se, but that the mechanism producing the relationship can change from sampling effects within individual patches to resource partitioning across patch types composing the region. This change occurs even though model dynamics are the same at both scales, suggesting that sampling effects and resource partitioning can represent different descriptions of the same biological processes operating concurrently at differing scales of observation. Lastly, we incorporate regional processes of dispersal and disturbance into the model and show that these processes can amplify the effect of species richness on productivity, resulting in patterns not easily anticipated from experiments. We conclude that the relative control of community structure by local versus regional processes may be a primary determinant of the diversity-productivity relationship in natural ecosystems. Therefore, past experiments having focused only on local processes might not reflect patterns and processes underlying diversity-productivity relationships in communities where disturbance and dispersal regulate species biomasses. [source] Fallback foods and dietary partitioning among Pan and gorillaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Juichi Yamagiwa Abstract Recent findings on the strong preference of gorillas for fruits and the large dietary overlap between sympatric gorillas and chimpanzees has led to a debate over the folivorous/frugivorous dichotomy and resource partitioning. To add insight to these arguments, we analyze the diets of sympatric gorillas and chimpanzees inhabiting the montane forest of Kahuzi-Biega National Park (DRC) using a new definition of fallback foods (Marshall and Wrangham: Int J Primatol 28 [2007] 1219,1235). We determined the preferred fruits of Kahuzi chimpanzees and gorillas from direct feeding observations and fecal analyses conducted over an 8-year period. Although there was extensive overlap in the preferred fruits of these two species, gorillas tended to consume fewer fruits with prolonged availability while chimpanzees consumed fruits with large seasonal fluctuations. Fig fruit was defined as a preferred food of chimpanzees, although it may also play a role as the staple fallback food. Animal foods, such as honey bees and ants, appear to constitute filler fallback foods of chimpanzees. Tool use allows chimpanzees to obtain such high-quality fallback foods during periods of fruit scarcity. Among filler fallback foods, terrestrial herbs may enable chimpanzees to live in small home ranges in the montane forest, whereas the availability of animal foods may permit them to expand their home range in arid areas. Staple fallback foods including barks enable gorillas to form cohesive groups with similar home range across habitats irrespective of fruit abundance. These differences in fallback strategies seem to have shaped different social features between sympatric gorillas and chimpanzees. Am J Phys Anthropol 140:739,750, 2009. © 2009 Wiley-Liss, Inc. [source] Intraspecific vicariant history and the evolution of adaptive morphological diversity in a fish species (Osmerus mordax)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009MARIE-FRANCE BARRETTE Vicariant geographic isolation and resource partitioning have long been independently identified as processes contributing to the morphological divergence of closely-related species. However, little is known about the extent to which vicariant history influences the adaptive ecological divergence associated with resource partitioning and trophic specialization within species. The present study thus quantified the contribution of vicariant historical genetic divergence to the adaptive contemporary morphological divergence of intraspecific feeding specialists in the Rainbow smelt (Pisces: Osmerus mordax). This species is characterized by the polyphyletic origin of two lacustrine feeding specialists originating in two intraspecific lineages associated with independent glacial refuges. The historical genetic segregation was initiated approximately 350 000 years ago, whereas the lacustrine trophic segregation arose within the past 10 000 years. Wild caught lacustrine smelt populations were grouped a priori based on known historical genetic identities (Acadian and Atlantic mitochondrial DNA clades) and contemporary feeding specializations (microphageous and macrophageous morphotypes). The present study demonstrated that independent suites of correlated morphological traits are associated with either vicariant history or contemporary feeding specializations. Second, functionally-similar feeding specialists exhibit distinct morphologies resulting largely from vicariant historical processes. Although, the evolutionary processes producing historical phenotypes remains unknown, the results obtained demonstrate how adaptive radiation associated with ecological resource partitioning and feeding specializations can be strongly influenced by intraspecific phenotypic diversification resulting from relatively recent vicariant histories. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 140,151. [source] Resource Partitioning in Sympatric Cynopterus bats in Lowland Tropical Rain Forest, ThailandBIOTROPICA, Issue 2 2007Sara Bumrungsri ABSTRACT Diet and habitat use of the closely related and size-overlapping sympatric Cynopterus brachyotis and C. sphinx were established in lowland dry evergreen forest, Thailand, between March 1998 and March 2000. Feces from netted bats were analyzed, and the recapture rate determined. Although both species share a set of food plants, and fruits from early successional forest contribute about half of their diet, C. brachyotis, the smaller of the two species, ate a significantly greater proportion of fruits from early successional forest than C. sphinx. The latter ate a significantly greater proportion of fruit species in larger size classes. More C. brachyotis were captured in early successional forest in almost every month, while C. sphinx is more common in old-growth forest. However, the capture rate of C. sphinx increased in early successional forest in the mid-dry season when its preferred fruits become available. The recapture rate of C. brachyotis in early successional forest was significantly higher than that of C. sphinx, and the reverse situation was observed in old-growth forest. Male C. sphinx had a significantly higher recapture rate in early successional forest than females. Fruit size and habitat use are the major determinants of resource partitioning between these size-overlapping congeners. [source] Nectarivory by Endemic Malagasy Fruit Bats During the Dry Season,BIOTROPICA, Issue 1 2006Daudet Andriafidison ABSTRACT Madagascar has a distinctive fruit bat community consisting of Pteropus rufus, Eidolon dupreanum, and Rousettus madagascariensis. In this study, we observed fruit bat visits to flowering baobabs (Adansonia suarezensis and Adansonia grandidieri) and kapok trees (Ceiba pentandra) during the austral winter. Eidolon dupreanum was recorded feeding on the nectar of baobabs and kapok, P. rufus was observed feeding on kapok only and no R. madagascariensis were seen. Three mammals species, two small lemurs (Phaner furcifer and Mirza coquereli) and E. dupreanum, made nondestructive visits to flowering A. grandidieri and are therefore all potential pollinators of this endangered baobab. This is the first evidence to show that A. grandidieri is bat-pollinated and further demonstrates the close link between fruit bats and some of Madagascar's endemic plants. Eidolon dupreanum was the only mammal species recorded visiting A. suarezensis and visits peaked at the reported times of maximum nectar concentration. Pteropus rufus visited kapok mostly before midnight when most nectar was available, but E. dupreanum visited later in the night. These differences in timing of foraging on kapok can be explained either by differing distances from the roost sites of each species or by resource partitioning. We advocate increased levels of protection, education awareness, and applied research on both mammal-pollinated baobab species and fruit bats, and suggest that both baobabs and bats are candidate "flagship species" for the threatened dry forests of Madagascar. RESUME Madagascar a une remarquable communauté de chauves-souris frugivores comprenant Pteropus rufus, Eidolon dupreanum et Rousettus madagascariensis. Dans le cadre de la présente étude, nous avons observé les visites que les chauves-souris effectuent sur les baobabs (Adansonia suarezensis et Adansonia grandidieri) et les kapokiers (Ceiba pentandra) en floraison durant l'hiver austral. Eidolon dupreanum a été observé se nourrissant du nectar des baobabs et des kapokiers, Pteropus rufus a été observé en train de se nourrir des kapokiers uniquement, et aucun Rousettus madagascariensis n'a pu être recensé. Trois espèces de mammifères, deux lémuriens (Phaner furcifer, Mirza coquereli) et Eidolon dupreanum, effectuent des visites non destructives des fleurs d' A. grandidieri et sont, de ce fait, des pollinisateurs potentiels de cette espèce de baobab en danger. Il s'agit de la première preuve qu' A. grandidieri est pollinisé par les chauves-souris. Cette observation démontre aussi le lien étroit qui existe entre les chauves-souris frugivores et quelques-unes des plantes endémiques de Madagascar. Eidolon dupreanum est la seule espèce observée sur Adansonia suarezensis et les visites sont plus fréquentes aux heures de concentration maximale de nectar. Pteropus rufus visite les kapokiers, surtout avant minuit, lorsque les nectars sont encore disponibles. En revanche, la visite effectuée par Eidolon dupreanum a lieu plus tard dans la nuit. Cette différence d'heures de fourrage sur les kapokiers pourrait être justifiée par l'inégalité de la distance des gîtes de chaque espèce ou par le partage des ressources. Aussi recommandons-nous le renforcement des mesures de protection, des activités d'IEC et de la recherche appliquée aux espèces de baobab pollinisées par des mammifères et les chauves-souris frugivores. Nous suggérons l'intégration des baobabs et des chauves-souris dans la liste des espèces " flagship" pour les forêts caducifoliées en danger à Madagascar. [source] | ||||||||||||||||||||||||||||