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Bat Species (bat + species)
Selected AbstractsApplying Network Analysis to the Conservation of Habitat Trees in Urban Environments: a Case Study from Brisbane, AustraliaCONSERVATION BIOLOGY, Issue 3 2006MONIKA RHODES conectividad de perchas; fauna que utiliza oquedades; planificación de la conservación; red sin escala; Tadarida australis Abstract:,In Australia more than 300 vertebrates, including 43 insectivorous bat species, depend on hollows in habitat trees for shelter, with many species using a network of multiple trees as roosts. We used roost-switching data on white-striped freetail bats (Tadarida australis; Microchiroptera: Molossidae) to construct a network representation of day roosts in suburban Brisbane, Australia. Bats were caught from a communal roost tree with a roosting group of several hundred individuals and released with transmitters. Each roost used by the bats represented a node in the network, and the movements of bats between roosts formed the links between nodes. Despite differences in gender and reproductive stages, the bats exhibited the same behavior throughout three radiotelemetry periods and over 500 bat days of radio tracking: each roosted in separate roosts, switched roosts very infrequently, and associated with other bats only at the communal roost. This network resembled a scale-free network in which the distribution of the number of links from each roost followed a power law. Despite being spread over a large geographic area (>200 km2), each roost was connected to others by less than three links. One roost (the hub or communal roost) defined the architecture of the network because it had the most links. That the network showed scale-free properties has profound implications for the management of the habitat trees of this roosting group. Scale-free networks provide high tolerance against stochastic events such as random roost removals but are susceptible to the selective removal of hub nodes. Network analysis is a useful tool for understanding the structural organization of habitat tree usage and allows the informed judgment of the relative importance of individual trees and hence the derivation of appropriate management decisions. Conservation planners and managers should emphasize the differential importance of habitat trees and think of them as being analogous to vital service centers in human societies. Resumen:,En Australia, más de 300 vertebrados, incluyendo 43 especies de murciélagos insectívoros, dependen de oquedades en árboles para refugiarse; muchas de ellas perchan en una red de múltiples árboles. Utilizamos datos de cambio de perchas en Tadarida australis (Microchiroptera: Molossidae) para construir una representación reticular de las perchas diurnas en los suburbios de Brisbane, Australia. Los murciélagos fueron capturados en un árbol con un grupo de varios cientos de individuos y liberados con transmisores. Cada percha utilizada por los murciélagos representó un nodo individual en la red, y los movimientos de murciélagos entre perchas constituyeron los eslabones entre los nodos. A pesar de las diferencias de género y etapas reproductivas, los murciélagos mostraron el mismo comportamiento en tres períodos de radiotelemetría y en más de 500 días de seguimiento de murciélagos: cada uno utilizó perchas separadas, cambiaban de percha poco frecuentemente, y se asociaron con otros murciélagos sólo en las perchas comunales. Esta red fue semejante a una red sin escala en la que la distribución del número de eslabones de cada percha cumplió una ley potencial. A pesar de estar dispersas en un área geográfica extensa (>200 km2), cada percha estaba conectada con otras por menos de tres eslabones. Una percha (el centro o percha comunal) definió la arquitectura de la red porque tenía a la mayoría de los eslabones. El hecho de que la red mostrara propiedades libres de escala tiene implicaciones profundas para la gestión de árboles que funcionan como perchas. Las redes libres de escala proporcionan alta tolerancia a eventos estocásticos como la remoción aleatoria de perchas, pero son susceptibles a la remoción selectiva de nodos centrales. El análisis de redes es una herramienta útil para el entendimiento de la organización estructural del uso de de árboles y permite el juicio informado de la importancia relativa de árboles individuales y por lo tanto la derivación de decisiones administrativas apropiadas Los planificadores y gestores de la conservación deberían enfatizar la importancia diferencial de árboles y considerarlos análogos a los centros de servicio vitales en las sociedades humanas. [source] Nested distributions of bat flies (Diptera: Streblidae) on Neotropical bats: artifact and specificity in host-parasite studiesECOGRAPHY, Issue 3 2009Bruce D. Patterson We examined the structure of ectoparasitic bat fly infestations on 31 well-sampled bat species, representing 4 Neotropical families. Sample sizes varied from 22 to 1057 bats per species, and bat species were infested by 4 to 27 bat fly species. Individual bats supported smaller infracommunities (the set of parasites co-occurring on an individual host), ranging from 1 to 5 fly species in size, and no bat species had more than 6 bat fly species characteristically associated with it (its primary fly species). Nestedness analyses used system temperature (BINMATNEST algorithm) because it is particularly well-suited for analysis of interaction networks, where parasite records may be nested among hosts and host individuals simultaneously nested among parasites. Most species exhibited very low system temperatures (mean 3.14°; range 0.14,12.28°). Simulations showed that nested structure for all 31 species was significantly stronger than simulated values under 2 of the 3 null hypotheses, and about half the species were also nested under the more stringent conditions of the third null hypothesis. Yet this structure disappears when analyses are restricted to "primary" associations of fly species (flies on their customary host species), which exclude records thought to be atypical, transient, or potential contaminants. Despite comprising a small fraction of total parasite records, such anomalies represent a considerable part of the statistical state-space, offering the illusion of significant ecological structure. Only well understood and well documented systems can make distinctions between primary and other occurrence records. Generally, nestedness appears best developed in host-parasite systems where infestations are long-term and accumulate over time. Dynamic, short-term infestations by highly mobile parasites like bat flies may appear to be nested, but such structure is better understood in terms of host specificity and accidental occurrences than in terms of prevalence, persistence, or hierarchical niche relations of the flies. [source] Influence of climate and reproductive timing on demography of little brown myotis Myotis lucifugusJOURNAL OF ANIMAL ECOLOGY, Issue 1 2010Winifred F. Frick Summary 1. Estimating variation in demographic rates, such as survival and fecundity, is important for testing life-history theory and identifying conservation and management goals. 2. We used 16 years (1993,2008) of mark,recapture data to estimate age-specific survival and breeding probabilities of the little brown myotis Myotis lucifugus LeConte in southern New Hampshire, USA. Using Kendall & Nichols' (1995) full-likelihood approach of the robust design to account for temporary emigration, we tested whether survival and breeding propensity is influenced by regional weather patterns and timing of reproduction. 3. Our results demonstrate that adult female survival of M. lucifugus ranged from 0·63 (95% CL = 0·56, 0·68) to 0·90 (95% CL = 0·77, 0·94), and was highest in wet years with high cumulative summer precipitation. First-year survival [range: 0·23 (95% CL = 0·14, 0·35) to 0·46 (95% CL = 0·34, 0·57)] was considerably lower than adult survival and depended on pup date of birth, such that young born earlier in the summer (c. late May) had a significantly higher probability of surviving their first year than young born later in the summer (c. mid-July). Similarly, the probability of young females returning to the maternity colony to breed in the summer following their birth year was higher for individuals born earlier in the summer [range: 0·23 (95% CL = 0·08, 0·50) to 0·53 (95% CL = 0·30, 0·75)]. 4. The positive influence of early parturition on 1st-year survival and breeding propensity demonstrates significant fitness benefits to reproductive timing in this temperate insectivorous bat. 5. Climatic factors can have important consequences for population dynamics of temperate bats, which may be negatively affected by summer drying patterns associated with global climate change. 6. Understanding long-term demographic trends will be important in the face of a novel disease phenomenon (White-Nose Syndrome) that is associated with massive mortalities in hibernating bat species, including M. lucifugus, in the northeastern United States. [source] Host sex and ectoparasites choice: preference for, and higher survival on female hostsJOURNAL OF ANIMAL ECOLOGY, Issue 4 2007PHILIPPE CHRISTE Summary 1Sex differences in levels of parasite infection are a common rule in a wide range of mammals, with males usually more susceptible than females. Sex-specific exposure to parasites, e.g. mediated through distinct modes of social aggregation between and within genders, as well as negative relationships between androgen levels and immune defences are thought to play a major role in this pattern. 2Reproductive female bats live in close association within clusters at maternity roosts, whereas nonbreeding females and males generally occupy solitary roosts. Bats represent therefore an ideal model to study the consequences of sex-specific social and spatial aggregation on parasites' infection strategies. 3We first compared prevalence and parasite intensities in a host,parasite system comprising closely related species of ectoparasitic mites (Spinturnix spp.) and their hosts, five European bat species. We then compared the level of parasitism between juvenile males and females in mixed colonies of greater and lesser mouse-eared bats Myotis myotis and M. blythii. Prevalence was higher in adult females than in adult males stemming from colonial aggregations in all five studied species. Parasite intensity was significantly higher in females in three of the five species studied. No difference in prevalence and mite numbers was found between male and female juveniles in colonial roosts. 4To assess whether observed sex-biased parasitism results from differences in host exposure only, or, alternatively, from an active, selected choice made by the parasite, we performed lab experiments on short-term preferences and long-term survival of parasites on male and female Myotis daubentoni. When confronted with adult males and females, parasites preferentially selected female hosts, whereas no choice differences were observed between adult females and subadult males. Finally, we found significantly higher parasite survival on adult females compared with adult males. 5Our study shows that social and spatial aggregation favours sex-biased parasitism that could be a mere consequence of an active and adaptive parasite choice for the more profitable host. [source] Phylogeographic structuring and volant mammals: the case of the pallid bat (Antrozous pallidus)JOURNAL OF BIOGEOGRAPHY, Issue 7 2007Sarah E. Weyandt Abstract Aim, To examine the phylogeographic pattern of a volant mammal at the continental scale. The pallid bat (Antrozous pallidus) was chosen because it ranges across a zone of well-studied biotic assemblages, namely the warm deserts of North America. Location, The western half of North America, with sites in Mexico, the United States, and Canada. Methods, PCR amplification and sequencing of the mitochondrial control region was performed on 194 pallid bats from 36 localities. Additional sequences at the cytochrome- b locus were generated for representatives of each control-region haplotype. modeltest was used to determine the best set of parameters to describe each data set, which were incorporated into analyses using paup*. Statistical parsimony and measurements of population differentiation (amova, FST) were also used to examine patterns of genetic diversity in pallid bats. Results, We detected three major lineages in the mitochondrial DNA of pallid bats collected across the species range. These three major clades have completely non-overlapping geographic ranges. Only 6 of 80 control-region haplotypes were found at more than a single locality, and sequences at the more conserved cytochrome- b locus revealed 37 haplotypes. Statistical parsimony generated three unlinked networks that correspond exactly to clades defined by the distance-based analysis. On average there was c. 2% divergence for the combined mitochondrial sequences within each of the three major clades and c. 7% divergence between each pair of clades. Molecular clocks date divergence between the major clades at more than one million years, on average, using the faster rates, and at more than three million years using more conservative rates of evolution. Main conclusions, Divergent haplotypic lineages with allopatric distributions suggest that the pallid bat has responded to evolutionary pressures in a manner consistent with other taxa of the American southwest. These results extend the conclusions of earlier studies that found the genetic structuring of populations of some bat species to show that a widespread volant species may comprise a set of geographically replacing monophyletic lineages. Haplotypes were usually restricted to single localities, and the clade showing geographic affinities to the Sonoran Desert contained greater diversity than did clades to the east and west. While faster molecular clocks would allow for glacial cycles of the Pleistocene as plausible agents of diversification of pallid bats, evidence from co-distributed taxa suggests support for older events being responsible for the initial divergence among clades. [source] The ecological impacts of a migratory bat aggregation on its seasonal roost in Kasanka National Park, ZambiaAFRICAN JOURNAL OF ECOLOGY, Issue 1 2010James W. Byng Abstract The ecological impacts of migratory species on their seasonal environments are poorly known. The effects of several million straw-coloured fruit bats (Eidolon helvum), which migrate seasonally to Kasanka National Park, Zambia each year, on the small area of mushitu,swamp' forest in which they roost, were investigated. The structure of the mushitu forest was profoundly altered by the presence of E. helvum, with increased roost tree mortality, lowering and opening of the forest canopy and a decrease in tree basal area. Eidolon helvum are also thought to increase the severity of fires within their roost site because the structural changes result in a drier microclimate. The effects of increased nitrogen and phosphorous input were less apparent. These findings suggest that the ecological impact of this migratory bat species on its seasonal environment could ultimately threaten the long-term viability of its seasonal roost. Résumé Les impacts écologiques des espèces migratrices sur leurs environnements saisonniers sont peu connus. Les effets de plusieurs millions de roussettes paillées africaines Eidolon helvum qui, chaque année, migrent de façon saisonnière vers le Parc National de Kasanka, en Zambie, furent étudiés dans la petite zone de forêt marécageuse àmushitu où elles se perchent. La structure de la forêt àmushituétait profondément modifiée par la présence d'E. helvum, qui augmentait la mortalité des arbres servant de perchoirs, qui faisait baisser la hauteur et la densité de la canopée et entraînait une diminution de la surface basale des arbres. On pense aussi que la présence d'E. helvum augmente la gravité des feux dans les sites de repos parce que les changements structurels aboutissent à un microclimat plus sec. Les effets de l'apport accru en azote et en phosphore étaient moins apparents. Ces découvertes suggèrent que l'impact écologique de cette espèce de chauve-souris migratrice sur son environnement saisonnier pourrait, à long terme, menacer la viabilité de ses lieux de repos saisonniers. [source] Hunting, disturbance and roost persistence of bats in caves at Ankarana, northern MadagascarAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Scott G. Cardiff Abstract Surveys and monitoring of 37 caves in and around the Ankarana Special Reserve, northern Madagascar, yielded evidence of hunting of bats and potential disturbance of bats by miners and tourists, and colony counts for several bat species of potential conservation concern. Colony size decreased by 95% and 14% for a colony of Hipposideros commersoni and a colony of Eidolon dupreanum, respectively, when recent evidence of hunting occurred at those colonies and those declines are probably attributable to hunting. Evidence of hunting occurred commonly at the roosts of those species and most commonly at the roosts of Rousettus madagascariensis. Hunting of pteropodids was associated with high vulnerability of roosts to hunters, little forest buffer between the cave and open savannah and the absence of tombs in the cave. Roost sites of the hunted species persisted for at least several years and this regularity may facilitate hunting. This work supports the ranking of E. dupreanum, R. madagascariensis and H. commersoni as species of conservation concern. Managers should consider the impact of tourist visits on bats and of increasing access to caves for tourism. Conservation efforts for the hunted species should also seek to protect vulnerable and unprotected cave roosts. Résumé Des études et un suivi continu de 37 grottes dans la Réserve Spéciale d'Ankarana et dans les environs, dans le nord de Madagascar, ont permis de récolter des preuves de la chasse aux chauves-souris et de l'éventuel dérangement des chauves-souris par des mineurs et des touristes; et des comptes de colonies pour plusieurs espèces dont le statut de conservation pourrait être inquiétant. La taille des colonies avait baissé de 95% et de 14% respectivement pour Hipposideros commersoni et pour Eidolon dupreanum, lorsque des preuves récentes de chasse sont apparues dans ces colonies; ces déclins sont probablement dus à la chasse. Des preuves de chasse étaient réguliérement présentes aux dortoirs de ces espèces, et plus communes encore aux dortoirs de Rousettus madagascariensis. La chasse des ptéropodidés était associée à une grande vulnérabilité des dortoirs face aux chasseurs, à une petite zone forestière tampon entre la grotte et la savane ouverte, et à l'absence de tombes dans la grotte. Les sites de repos des espèces chassées existaient depuis plusieurs années au moins, et cette persistance pourrait faciliter la chasse. Ce travail soutient le classement de E. dupreanum, R. madagascariensis et H. commersoni parmi les espèces dont le statut de conservation est inquiétant. Les gestionnaires devraient considérer l'impact des visites de touristes sur les chauves-souris et de l'augmentation de l'accès aux grottes pour le tourisme. Les efforts de conservation des espèces chassées devraient aussi viser à protéger les dortoirs dans des grottes vulnérables et non protégées. [source] Life history, ecology and longevity in batsAGING CELL, Issue 2 2002Gerald S. Wilkinson Summary The evolutionary theory of aging predicts that life span should decrease in response to the amount of mortality caused by extrinsic sources. Using this prediction, we selected six life history and ecological factors to use in a comparative analysis of longevity among 64 bat species. On average, the maximum recorded life span of a bat is 3.5 times greater than a non-flying placental mammal of similar size. Records of individuals surviving more than 30 years in the wild now exist for five species. Univariate and multivariate analyses of species data, as well as of phylogenetically independent contrasts obtained using a supertree of Chiroptera, reveal that bat life span significantly increases with hibernation, body mass and occasional cave use, but decreases with reproductive rate and is not influenced by diet, colony size or the source of the record. These results are largely consistent with extrinsic mortality risk acting as a determinant of bat longevity. Nevertheless, the strong association between life span and both reproductive rate and hibernation also suggests that bat longevity is strongly influenced by seasonal allocation of non-renewable resources to reproduction. We speculate that hibernation may provide a natural example of caloric restriction, which is known to increase longevity in other mammals. [source] Multiple morphological characters needed for field identification of cryptic long-eared bat species around the Swiss AlpsJOURNAL OF ZOOLOGY, Issue 4 2010S. Ashrafi Abstract The identification of cryptic species may significantly change our view about their distribution, abundance, ecology and therefore conservation status. In the European Alps, molecular studies have revealed the existence of three sibling species of plecotine bats Plecotus auritus, Plecotus austriacus and, very recently, Plecotus macrobullaris. Knowledge of the ecological niche partitioning of cryptic species is a requisite to develop sound conservation policies. Yet, this requests the development of unambiguous identification methods easily applicable in the field. This study investigates the reliability of several morphological methods used for species recognition and proposes a new identification key for field workers. We captured 214 Plecotus bats from 29 sites in four bioregions within Switzerland, collected biopsy punches for genetic analysis, described and measured external morphological characters. All three species occurred as mono-specific colonies, except at one site where P. auritus and P. macrobullaris shared the same church attic. Qualitative traits alone did not allow a reliable separation of the three species. A series of multivariate analyses conducted on external linear measurements resulted in a discriminant function enabling correct species classification with a 97.5% probability. Compared with genetic analysis, our multivariate morphological method represents a valuable, rapid and cost-effective alternative. [source] Energy density patterns of nectar resources permit coexistence within a guild of Neotropical flower-visiting batsJOURNAL OF ZOOLOGY, Issue 1 2004Marco Tschapka Abstract Neotropical rainforests support guilds of nectar feeding bats (Phyllostomidae: Glossophaginae) with up to six coexisting species. To analyse guild structure and mechanisms of coexistence in a Costa Rican tropical lowland rainforest, the resource use and morphology of bats were compared to the energetic characteristics of preferred nectar resources and their spatio-temporal distribution. The relative abundance of nectar-feeding bats was determined from mistnet captures over 26 months. Food items were identified by analysis of pollen loads and faecal samples. Phenology, flower density and nectar sugar content of resource plants permitted quantitative estimations of resource availability expressed as energy density (kJ ha,1 day,1) throughout the annual cycle. Four glossophagine bat species co-occurred at La Selva: two permanent residents (Glossophaga commissarisi, Hylonycteris underwoodi) and two seasonal species (Lichonycteris obscura, Lonchophylla robusta) that were found in small numbers during a period of high nectar availability. The two resident species differed in their abundance and in their temporal feeding strategies. After the main flowering peak, the common G. commissarisi shifted to a more frugivorous diet, while the rarer H. underwoodi fed on the few remaining bat-flowers. Resource plant species differed in their energy density by up to two orders of magnitude. Hylonycteris underwoodi visited more often plant species with a low energy yield than G. commissarisi. Because of its smaller body size and a wing morphology that promotes fast flight, H. underwoodi appears to be better adapted to low and scattered nectar resource levels. The two seasonal species differed greatly in body mass, which suggests different strategies for high-quality resource tracking. Large body mass in Lonchophylla robusta provides an energy buffer that permits daily commuting flights between a permanent roost and profitable foraging areas, while the small Lichonycteris obscura seems to track resources nomadically. It is proposed that energy density may be a major niche dimension that restricts access of species to certain habitats and that may profoundly influence the structure of nectar-feeding bat guilds. [source] Postnatal growth and reproductive biology of Rhinolophus hipposideros (Chiroptera: Rhinolophidae)JOURNAL OF ZOOLOGY, Issue 3 2004Guido Reiter Abstract The timing of birth and postnatal growth in lesser horseshoe bats Rhinolophus hipposideros were studied during 2000 and 2001 at three maternity roosts located in the provinces of Carinthia and Salzburg, Austria. Postnatal growth curves for length of forearm and body mass were determined separately for the different colonies and years. Cooler weather during June 2001 coincided with a median birth date that was 8 days later than in 2000, whilst the difference between colonies was 4 and 5 days, respectively, for the pooled data of both years. Cool temperatures in June also coincided with a longer duration of the parturition period. Postnatal growth rates were higher than in most other bat species but differences between years and colonies were considerable. These differences may be attributed to the ambient roost temperatures, whereby the young of two cooler roosts showed significantly reduced growth rate during 8 days of cool weather in 2000. Moreover, later born and therefore smaller pups were more strongly affected by low temperatures than earlier born and larger ones. The mean length of forearm of young lesser horseshoe bats at the beginning of September equalled that of adult bats, whilst their body mass was still lower. Non-volant juveniles did not cluster following the nightly emergence of adult females, and a preferred location within the roosts could not be identified. High and very low roost temperatures, however, did have an influence on the location of non-volant young in the colonies. [source] Social and population structure of a gleaning bat, Plecotus auritusJOURNAL OF ZOOLOGY, Issue 1 2000A. C. Entwistle Abstract Brown long-eared bats Plecotus auritus occupying 30 summer roosts in north-east Scotland were studied over 15 years. During this time 1365 bats were ringed, and a further 720 recaptures were made. Individual bats showed a high degree of roost fidelity, returning to one main roost site; < 1% of recaptured bats had moved among roost sites, and all recorded movements (n= 5) were < 300 m. Adults of both sexes were loyal to the roost sites at which they were first captured, indicating long-term use of roosts. At least some juveniles (n= 32) of both sexes returned to the natal roost. Mark,recapture estimates indicated that colonies of this species were substantially larger (c. 30,50 individuals) than assumed in previous studies. Plecotus auritus differs from most other temperate zone, vespertilionid species in that there was no evidence of sexual segregation during summer, with males present in all colonies throughout the period of occupancy. Population structure in summer seems to be consistent with a metapopulation model, with discrete sub-populations showing minimal interchange. The group size, colony composition and population structure described in this species may be associated with the wing shape (particularly aspect ratio) and foraging behaviour of P. auritus. It is postulated that relative motility, linked to wing structure, may affect the distribution of individuals, and may have implications for the genetic structure of this species. Correlations between aspect ratio and both colony size and migratory behaviour, across British bat species, indicate that wing shape could be an important factor contributing to patterns of social behaviour and genetic structuring in bats. [source] Activity following arousal in winter in North American vespertilionid batsMAMMAL REVIEW, Issue 4 2006JUSTIN G. BOYLES ABSTRACT 1Many bat species hibernate to conserve energy during winter and like all hibernators they commonly arouse. During these arousals, some bats may undertake activities away from the hibernation site. Systematic ecological studies of the frequency and purpose of winter activity in temperate zone bats of North America are rare and much of the literature involves observations of single individuals or unmarked populations. 2We review the available literature on winter activity among North American vespertilionid bats to highlight the paucity of data on this subject and to stimulate future research. Due to the lack of repeated, systematic studies on most North American species, the conclusions drawn are general or pertain only to parts of the geographical range of any species. 3We suggest that winter activity is ubiquitous among temperate zone bats, but the degree and purpose of activity varies greatly between and within species. In general, cave-dwelling bats tend to be relatively inactive compared with tree and foliage roosting bats during winter. 4Cave-dwelling and tree cavity-dwelling species do not appear to feed, but they do drink and occasionally copulate during the hibernation period. Species that hibernate in foliage or leaf litter are the most active species during winter and may feed and drink throughout winter, although they probably do not copulate because of their solitary nature. 5We encourage researchers to conduct studies on all aspects of winter activity for North American vespertilionids across wide latitudinal and altitudinal gradients. We suggest studies in the near future be focused on estimating the energetic costs and benefits of winter activity through determination of the frequency and intensity of winter feeding activity and more thorough examinations of movements within and among caves. Studies on common, wide-ranging species have the potential to illuminate large-scale patterns and differences and should be favoured over studies on rarer species. [source] The comparative phylogeography of Neotropical mammals: patterns of intraspecific mitochondrial DNA variation among bats contrasted to nonvolant small mammalsMOLECULAR ECOLOGY, Issue 9 2000A. D. Ditchfield Abstract The major aim of this study was to compare the phylogeographic patterns of codistributed bats and small nonvolant Neotropical mammals. Cytochrome b sequences (mitochondrial DNA) were obtained for a total of 275 bats representing 17 species. The tissue samples were collected in coastal Brazil, and were available from Mexico and the Guyana. The study concentrates on four species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Glossophaga soricina) which were well represented. The other 13 species were sequenced to test the generality of the patterns observed. In general, sequence divergence values within species were low, with most bat species presenting less than 4% average sequence divergence, and usually between 1 and 2.5%. Clades of highly similar haplotypes enjoyed broad distribution on a continental scale. These clades were not usually geographically structured, and at a given locality the number of haplotypes was high (8,10). As distance increased, some moderately divergent clades were found, although the levels of divergence were low. This suggests a geographical effect that varied depending on species and scale. Small nonvolant mammals almost invariably have high levels of sequence divergence (> 10%) for cytochrome b over much shorter distances (< 1000 km). The grain of intraspecific variation found in small nonvolant mammals is much finer than in bats. Low levels of geographical structuring cannot be attributed to a slower evolutionary rate of bat DNA in relation to other mammalian taxa. The phylogeographic pattern of bats contrasts sharply with the pattern found for Neotropical rodents and marsupials. [source] Scale-dependent responses to forest cover displayed by frugivore batsOIKOS, Issue 11 2008Naiara Pinto Despite vast evidence of species turnover displayed by Neotropical bat communities in response to forest fragmentation, the exact shape of the relationship between fragment area and abundance for individual bat species is still unclear. Bats' ample variation in diet, morphology, and movement behaviour can potentially influence species' perception of the landscape. Thus, studies describing fragment area at a single spatial scale may fail to capture the amount of forest available from the perspective of individual bat species. In the present paper, we study the influence of forest cover on bats inhabiting a fragmented forest in Mexico, focusing on some of the most common frugivore species: Artibeus jamaicensis, Carollia spp. (C. brevicauda/C. perspicillata) and Sturnira spp. (S. lilium/S. ludovici). We quantified forest cover at scales ranging from 50 to 2000,m, and measured the influence of forest cover on bat capture success, a surrogate for abundance. The three species displayed positive and significant scale-dependent associations with forest cover. Abundance of A. jamaicensis increased with forest cover measured at scales ranging between 500 and 2000,m, while Carollia spp. responded more strongly to variation in forest cover measured at scales 100,500,m. For Sturnira spp., abundance was a function of presence of creeks near mist-netting sites, and amount of secondary forest present at a 200,m scale. The observed variation in responses to forest cover can be explained in light of interspecific differences in diet, home range, and body size. Our results illustrate a method for measuring the effect of forest fragmentation on mobile species and suggest that changes in abundance in fragmented landscapes emerge from the interaction between species' traits and landscape structure. [source] Pond characteristics as determinants of species diversity and community composition in desert batsANIMAL CONSERVATION, Issue 5 2010O. Razgour Abstract Although water availability is known to affect landscape-scale patterns of wildlife diversity and distribution in arid environments, little is known about the microhabitat characteristics that shape the local-scale distribution of desert bats. We examined the relative importance of pond microhabitat characteristics for the conservation of bats, and hypothesized that in arid environments, patterns of bat diversity and community composition relate to the size of the pond and its hydroperiod (the number of months a pond holds water), a term we use to distinguish between permanent, semi-permanent and temporary ponds. We combined acoustic monitoring with video recording and an experimental approach to study bat activity over natural ponds in the Negev Desert, Israel. We found that both within and between ponds bat species richness and activity significantly increased with pond size. An experimental reduction of pond size led to a significant reduction in bat species richness and activity and affected the bat community composition. In contrast to pond size, pond hydroperiod did not affect bat diversity, as temporary ponds had equivalent levels of bat species richness and activity to permanent ponds. However, hydroperiod did couple with pond size to affect the bat community composition, whereby non-desert bat species that have a higher frequency of drinking were associated with larger and more permanent ponds. Our results highlight the importance of larger temporary ponds (ponds over 15 m in length and 0.5 m in depth) for the conservation of biodiversity in arid environments. [source] Effects of different secondary vegetation types on bat community composition in Central Amazonia, BrazilANIMAL CONSERVATION, Issue 2 2010P. E. D. Bobrowiec Abstract The process of secondary succession on degraded lands in the Amazon depends on their land-use histories. In this scenario, little is known about how animal communities respond to different types of secondary vegetation in the region. We examined the effects of abandoned cattle pasture, Vismia - and Cecropia -dominated regrowth on the abundance of bat species and community composition in the Central Amazon, Brazil, based on 11 netting sites and on landscape characteristics. We captured 1444 bats, representing 26 species and two families (Phyllostomidae and Mormoopidae). Among the six most-captured Phyllostomidae bats, Sturnira lilium and Sturnira tildae had significantly higher capture rates in abandoned pasture, while Rhinophylla pumilio predominated in both Vismia - and Cecropia -dominated regrowth. An hybrid multidimensional scaling ordination revealed significant differences in the bat community among the three types of secondary vegetation. Phyllostominae bats were more common and richer in the less-disturbed areas of Cecropia -dominated regrowth, while Stenodermatinae species were more captured in abandoned pastures. Our results suggest that the type of secondary vegetation, together with its land-use history, affects bat community composition in the Central Amazon. The Phyllostominae subfamily (gleaning animalivores) was habitat selective and disappeared from areas experiencing constant disturbances. On the other hand, Stenodermatinae frugivorous bats often used and foraged in altered areas. We suggest that secondary vegetations in more-advanced successional stages can be used to augment the total area protected by forest conservation units. [source] Distribution and underground habitats of cave-dwelling bats in ChinaANIMAL CONSERVATION, Issue 4 2007H. Niu Abstract To understand the distribution and relative abundance of cave-dwelling bats and to identify those sites that would be important for conservation of bat species, 25 underground sites that had not been previously surveyed were investigated in this 3-year study (from December 2003 to April 2006) in Funiu Mountain of Henan province, China. Approximately 80 000 bats were recorded, representing 12 species. The most abundant species were Rhinolophus affinis, Miniopterus schreibersi and Hipposideros pratti. The roosts were evaluated for their conservation importance. The most important sites in the area are Yunhua and Nanzhao caves, which serve as hibernaculums and nursery roosts to c. 13 740 and 11 803 bats, respectively, representing seven species. By means of cluster and correspondence analysis, the distribution of bat species was different between the two sides of the mountain and was highly dependent on the size of the cave. The underground sites in the south region hosted c. 80% of the total bats, representing 11 species. The sites in the north region hosted 20% of the total bats, representing seven species. Presently, none of the caves in the region has adequate protection and some bat populations are under serious threat. Many large caves that contained large bat populations and several species of concern had been developed as tourist sites, and so some advice on protecting the most important local habitats was sought based on the assessment of the conservation status of underground sites. This paper presents basic data concerning the distribution of cave-dwelling bats and the patterns of cave use on Funiu Mountain. The data will help local governments and policy-makers develop suitable strategies to promote local tourisms while protecting important habitats of animal species. [source] Species richness and structure of three Neotropical bat assemblagesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2008KATJA REX We compared the assemblages of phyllostomid bats in three Neotropical rainforests with respect to species richness and assemblage structure and suggested a method to validate estimates of species richness for Neotropical bat assemblages based on mist-netting data. The fully inventoried bat assemblage at La Selva Biological Station (LS, 100 m elevation) in Costa Rica was used as a reference site to evaluate seven estimators of species richness. The Jackknife 2 method agreed best with the known bat species richness and thus was used to extrapolate species richness for an Amazonian bat assemblage (Tiputini Biodiversity Station; TBS, 200 m elevation) and an Andean premontane bat assemblage (Podocarpus National Park; BOM, 1000 m elevation) in Ecuador. Our results suggest that more than 100 bat species occur sympatrically at TBS and about 50 bat species coexist at BOM. TBS harbours one of the most species-rich bat assemblages known, including a highly diverse phyllostomid assemblage. Furthermore, we related assemblage structure to large-scale geographical patterns in floral diversity obtained from botanical literature. Assemblage structure of these three phyllostomid assemblages was influenced by differences in floral diversity at the three sites. At the Andean site, where understorey shrubs and epiphytes exhibit the highest diversity, the phyllostomid assemblage is mainly composed of understorey frugivores and nectarivorous species. By contrast, canopy frugivores are most abundant at the Amazonian site, coinciding with the high abundance of canopy fruiting trees. Assemblage patterns of other taxonomic groups also may reflect the geographical distribution patterns of floral elements in the Andean and Amazonian regions. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 617,629. [source] Migration, Diet, or Molt?BIOTROPICA, Issue 4 2010Interpreting Stable-Hydrogen Isotope Values in Neotropical Bats ABSTRACT Migratory behavior in bats is poorly described, particularly in the Neotropics. Stable-hydrogen isotope (,D) analysis may allow tracking of altitudinal movements of bats but has not been explored. ,D values in rainwater (,Dp) deplete linearly with altitude and are reflected in the keratinous tissues of animals through diet. A mismatch between keratin ,D (,Dk) and that expected at the capture site based on ,Dp can indicate prior migration. We collected rainwater, claws and hair from eight bat species at two lower-montane forest sites in Nicaragua. Claw ,D for Carollia brevicauda and hair and claws for Desmodus rotundus (known to be non-migratory) fell within the predicted range based on rainwater (,17 to ,60,) suggesting these tissues were synthesized at the study site. ,D tissue values for Artibeus toltecus, Sturnira lilium, Glossophaga soricina, Anoura geoffroyi, and hair for C. brevicauda were more negative than predicted for the capture site (,60,) suggesting tissue synthesis at higher elevation and migration downslope to the capture site. However, our study area represents the highest elevation in the region; the nearest appropriate higher elevations are 350,500 km away and seasonal migration is expected to be<200 km. Thus we consider that seasonal shifts in ,Dp (9 to ,45,) may result in differences in species which molt at different times, and that diet may have driven differences in ,D. Our results suggest that the effects of molt timing and diet may first need to be understood before ,D may be successfully used to track bat movements. [source] Use of Olfaction During Prey Location by the Common Vampire Bat (Desmodus rotundus),BIOTROPICA, Issue 1 2007Joseph Wm. ABSTRACT The common vampire bat, Desmodus rotundus, feeds on mammalian blood and is a major agricultural pest in Latin America. One way to prevent bats from biting livestock is to understand how the bats locate the livestock. We confirmed the role of olfaction in foraging with a modified cafeteria trial. Bats significantly favored blood meals associated with scent (fur, feces) over meals lacking these olfactory cues. These results confirm earlier observations on the role of olfaction during prey location by this species, and have potential to facilitate eradication measures without extensive loss of other bat species. RESUMEN El vampiro común, Desmodus rotundus, se alimenta del sangre de los mamíferos y es una de las plagas agrícolas más destructivas en América Latina. Para mejor prevenir los murciélagos de mordiendo ganado, debemos comprender mejor cómo los vampiros localizan ganado. Confirmamos el rol de olfacción en forrajeo con una modificación de una prueba "cafetería". Los murciélagos se favorecen las comidas de sangre asociados con olor de vacas (pelos, fecas) sobre las que no tienen estos olores. Estos resultados se confirman observaciones anteriores sobre el rol de olfacción durante la detección de presas por estas especies, y tienen la posibilidad de facilitar medidas de control de vampiros sin la perdida extensiva de otras especies de murciélagos. [source] Bat Species Richness in Atlantic Forest: What Is the Minimum Sampling Effort?BIOTROPICA, Issue 2 2003Helena Godoy Bergallo ABSTRACT Species lists are sources of information for studies of both conservation and macroecology. It is, however, important to differentiate between relatively complete lists and extremely incomplete ones. The aim of this study was to evaluate how sampling effort typically used in inventories affects the number of bat species captured in areas of Atlantic Forest in southeastern Brazil. We also evaluated if the number of sampled sites, size of the sampled area, and sampling effort (net hours) affect species richness. We used previously reported data from studies in Rio de Janeiro, São Paulo, and Minas Gerais States, and our own data collected during 1989 and 2001. Nonlinear models fit well the data for Rio de Janeiro and Minas Gerais States and all states together, but not for São Paulo State. Genera richness showed a similar pattern to that of species richness. The model used to explain the relationship between species richness and size of the study area, number of sites, and sampling effort sampled was significant. The number of sites sampled explained a significant part of the variation observed; however, other variables contributed nothing to the model, suggesting that capturing beta diversity is the most important aspect of biodiversity surveys for bats, and that increasing net hours at a given location is much more inefficient than distributing net hours across locations. We suggest 1000 captures as the minimum necessary when sampling with mist nets to capture the majority of phyllostomid species for a given site (alpha diversity). In addition, we suggest that shifting the position of the mist nets between nights will increase the probability of capturing more species. RESUMO As listas de espécies são fontes de informações para estudos, tanto de conservação quanto de macroecologia. Entretanto, é importante diferenciar entre listas relativamente completas daquelas seriamente incompletas. O objetivo deste estudo foi avaliar como o esforco amostral mínimo tipicamente usado em inventários afeta o número de especies de morcegos capturados em áreas de Mata Atlãntica do sudeste do Brasil. Nós também avaliamos se o número de pontos amostrados, o tamanho da área amostrada e o esforço de captura (hora-rede) afetam a riqueza de espécies. Nós usamos dados disponíveis de estudos desenvolvidos nos estados do Rio de Janeiro, São Paulo e Minas Gerais, e os nossos próprios dados coletados de 1989 a 2001. Modelos não-lineares se ajustaram para os estados do Rio de Janeiro e Minas Gerais e todos os estados juntos, mas não para o Estado de São Paulo. A riqueza de g,neros mostrou o mesmo padrão da riqueza de espécies. O modelo usado para expliçãr a relacao entre riqueza de espécies e tamanho da área de estudo, número de pontos amostrados e esforço amostral foi significative. O número de pontos amostrados explicou uma parte significante da variação observada. Contudo, as outras variáveis não contribuiram para o modelo, sugerindo que capturar a diversidade Beta é o aspecto mais importante de inventários de biodiversidade para morcegos, e que o aumento de horas-rede numa dada localidade é muito mais ineficiente do que distribuir horas-rede entre localidades. Nós sugerimos 1000 capturas como o mínimo necessário para amostrar, com redes de neblina, a maioria das espécies de filostomídeos de uma dada área (diversidade Alfa). Adicionalmente, sugerimos que mudando a posição das redes entre noites aumentará a probabilidade de capturar um maior número de espéciesS. [source] | |||||||||||||||||||||||||