No description available.

<I>Rhinolophus hipposideros </I>has declined across its range. This study aimed to investigate aspects of its roosting, reproductive and foraging ecology which may have caused this decline. <I>R. hipposideros </I>is confined to south west Britain. It selects roosts in areas of undulating countryside with hedgerows and tree lines. Roosts were located predominantly in the roof voids of 19^th century buildings with stone walls and slate roofs, close to woodland and connected to it by hedgerows or tree lines. <I>R. hipposideros </I>has a long gestation period (78 days) and proportionately larger neonate (34% mothers mass) compared to other bat species. Post-natal growth was one of the fastest recorded for a bat species. The number of pups produced by colonies averaged 38% of pre-parturition counts of adults. Ambient temperature in May was shown to influence the reproductive phenology of this species. Patterns of roost occupancy and activity were investigated in a maternity, satellite, night and hibernation roost. Numbers of adults in the maternity roost peaked just before parturition. The timing of emergence and return from the maternity roost each night was correlated with ambient light levels. The duration of foraging each night was correlated with date and was reduced on nights with heavy rainfall. The importance of night roosts to heavily pregnant bats was demonstrated. During the winter most feeding took place before the end of December but successful foraging occurred throughout the winter. <I>R. hipposideros </I>foraged in woodlands, hedgerows and tree lines within 2-3 km of the maternity roost. It hunted close to vegetative clutter catching prey by hawking, gleaning and in late pregnancy by fly-catching, using hedgerows and tree lines as commuting routes between foraging areas and roosts. The implications of this study for the conservation of this species are discussed and management recommendations made.

No description available.

Bats are known and documented to use bridge structures as roosts in various locations throughout the United States and abroad, but there is limited knowledge of how bats use bridges in New England. Significant population declines due to White-Nose Syndrome have resulted in several bat species being listed as state or federally threatened or endangered. If bats are using bridges as roosts, significant effort is required to ensure they are not disturbed or harmed during construction or maintenance work, requiring knowledge of assessment methods to identify likely roost locations in bridges. This thesis describes a two summer study evaluating the bat roosting potential in New England bridges. During this study, 191 bridges were rapidly screened throughout New England for bat roosting potential, with eighteen selected for more detailed evaluations. Various monitoring techniques to determine bat roosting potential were assessed at each bridge evaluated, including acoustic monitoring and analyses, infrared imaging, borescope inspection, visual inspection, emergence studies, and guano testing for species identification. The current federal form required to assess bat roosting in bridges slated for construction work was assessed for its appropriateness in the New England region. A supplemental form has been developed through this study that is recommended to be used in conjunction with the federal form to better assess roosting potential in New England bridges. Training and collaboration is also recommended for personnel completing forms and inspectors familiar with state bridges. When the study began, there was only one known bat bridge roost in New England known. After this two summer study, thirteen bridges have been positively identified as bat roosting sites in New England, with possible roosting at several other bridges. Information gathered through this study on bat roosting potential in bridges and the various monitoring techniques evaluated to positively identify bat roosting in bridges can be used as guidance for state Transportation Agencies developing protocol for construction at potential roosting sites.

Bat flies (Streblidae) are obligate blood-feeding ectoparasites of bats that display varying degrees of host specificity. A total of 265 streblid bat flies were collected from 122 bats belonging to the families Phyllostomidae and Natalidae from Utila, the smallest bay island of Honduras. Out of four host-parasite associations, three were considered primary. Out of the three bat species analyzed, one had significantly lower parasite prevalence and another had significantly higher parasite load and intensity. Both male and female bats were equally likely to be infested and variables of parasite density did not differ amongst host sex for any species. However, one species of bat had a significantly larger number of male parasites than female parasites. No significant relationships were found between variables of parasite density and host body mass or bat health (indicated by the ratio of mass to forearm length). The roosting ecology of the two cave roosting species in the study was considered and despite no apparent lack of dispersal barriers, the bat flies exhibited consistent primary associations. Examination of similar host-parasite relationship has many implications in parasite-host relationships and coevolution.

Various aspects of population ecology of Daubenton?s bat (Myotis daubentonii) were analyzed based on long-term data (1968?1984 and 1999?2009) gathered in a single model study area (ca. 10 km2) in South Bohemia, Czech Republic. Among others, population structure, roosting dynamics, movements between roosts and long-term trends in numbers of bats were described. Results of the study on patterns in reuse of tree cavities suggest that tree cavities may be reused for many consecutive seasons and that this has to be taken into consideration by conservation practices. The results of the study on microclimate of one maternity and one male colony roosting in man-made structures revealed that microclimatic differences may be one of the key factors in roosting preference between the two sexes. Further, a profound effect of changing energetic demands in females during different phases of the reproductive cycle may greatly influence their activity rhytms. In further two studies, the effect of climate on reproductive parameters of bats and abundance of ectoparasitic mites was analyzed. The results suggest that climatic variation greatly influenced reproductive parameters and parasitation of Daubenton?s bats. Last but not least, the seasonal dynamics of parasitation by ectoparasitic mites and the possible effect on bats? condition was analyzed. It was found out that seasonal dynamics in abundance of parasites is adjusted to the reproductive cycle and roosting dynamics of its host.

No description available.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第24037号 / 情博第793号 / 新制||情||134(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 大手 信人, 准教授 小山 里奈, 教授 北島 薫 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Day-roosts are an essential resource for tree-hole roosting microbats (Microchiroptera), providing shelter, protection from predators and an appropriate microclimate for energy conservation and reproduction. Microbats often make use of multiple roosting sites, shifting between roosts frequently. Conservation of tree-hole roosting microbats requires an understanding of roost selection and fidelity to enable the protection of sufficient suitable roosting sites. In Australia, as in other countries, habitat loss, particularly in the form of large hollow-bearing trees, is threatening the survival of microbat populations. In addition, the renewal of natural roosts in Australia is very slow, as trees may need to be 100 years old for hollows to form. Where roosting resources are limited, such as in urbanised areas, batboxes may be used as a substitute. As bat-boxes are also accessible to researchers, these roosting sites can help to improve our understanding of roosting behaviour. / This thesis investigates the roosting behaviour of two sympatric microbat species: Gould’s wattled bat (Chalinolobus gouldii) and the white-striped freetail bat (Tadarida australis). These are insectivorous tree-hole roosting species, which naturally occur in urban Melbourne, Australia. Both species make use of bat-boxes at three sites in Melbourne, often sharing roosts with members of the other species. This provided an opportunity not only to study their use of bat-boxes for conservation management purposes, but to investigate factors influencing bat roost selection and fidelity. This study incorporated PIT tags (microchips) and a detector array at the bat-boxes, in addition to monthly manual bat-box inspections, as a method for monitoring roost-use. This approach enabled the collection of long-term, fine-scale roosting data. These data, along with captive and field-based experiments were used to examine the influence of parasites, microclimate and social structure on roost selection patterns and roost fidelity. The specific questions posed were whether tree-hole roosting bats: select roosts based on physical characteristics; perceive a cost of carrying ectoparasites and avoid infested roosts; select roosts to maintain social associations; and select for specific beneficial microclimates. / The patterns of roost selection, ectoparasite diversity, social structure, and the selection of roost microclimate differed between the two species. Microclimate of the bat-boxes was a strong influence on roost selection for both species, as it is for microbats generally. White-striped freetail bats preferred warmer roosts with stable humidity. For Gould’s wattled bats, the selection of roost microclimate differed between the sexes and even between separate, but adjacent, roosting groups. Patterns of preference indicated that individuals had knowledge of the available roosting sites. / The presence of parasites had no obvious influence on roost selection patterns in either species. The white-striped freetail bat was found to support lower ectoparasite diversity, which may be influenced by characteristics of the pelage and may partially explain why parasite load was not a useful predictor of roost selection in this species. In contrast, Gould’s wattled bat supported a larger diversity of ectoparasites, which showed clear patterns of distribution through the bat populations, and intra-specific and spatial variability. A radio-tracking study indicated that parasites in the roost and on the Gould’s wattled bat may influence their roosting behaviour. Additionally, experimental assessments of the bats’ grooming response to parasites indicated that the perceived costs of these parasites differed with parasites that remained permanently attached to the host eliciting a stronger response than those also found in the roost. The defensive mechanism against parasites that completed part of their life-cycle in the roost was expected to be avoidance behaviour, yet, in both captive and field experiments, these parasites did not strongly influence roost selection or fidelity. / Social associations among white-striped freetail bats appeared to be random, and did not explain roosting patterns. This may reflect the restricted sampling of roosting sites, and the possible role of the bat-boxes in this study as ‘satellite’ roosts, separate from a larger communal roost, likely to be in a large tree-hollow. Unlike white-striped freetail bats, Gould’s wattled bats showed fission-fusion social structure, driven by stronger female associations. The distribution and abundance of parasites was correlated with the social structuring of the host species, and host selection appeared to facilitate transmission. These patterns suggest that female Gould’s wattled bats, in particular, are choosing roosts based on the benefits of social association despite the cost of increased parasite risk, and may provide an explanation for sexual segregation in temperate tree-roosting bats. / This study demonstrates the species-specificity of roosting behaviour, and the importance of investigating several factors that influence roost selection, to better understand roost requirements. It also highlights the inherent complexity in roost selection by tree-hole roosting microbats, which may be making trade-offs between the benefits of social associations and the cost of parasitism, as well as choosing an optimal microclimate. Further investigation into interactions between these factors will greatly advance our understanding of roost selection and fidelity in tree-hole roosting bats.

No description available.