The function of daylight flying in British bats

A national survey of the incidence of daylight flying of bats in mainland Britain was organized from September 1985 until March 1988. A total of 420 records of daylight flying were received by 1 May 1988. One hundred and forty-four reports were from winter (October to March), 271 from summer (April to September) and five were undated. Peak activity occurred during April and in August/September.
Activity in both winter and summer was greatest between 12:00 and 16:00h. The numbers of bats involved in each sighting varied between 1 and 200. In summer 87% and in winter 91% of observations were of single individuals. Numbers of daylight-flying bats, relative to roost visitor reports sent to the Nature Conservancy Council, increased with increasing latitude during both summer and winter. This means that an individual is more likely to fly in daylight the further north in Britain it lives. The effect of day-to-day variation in climatic variables on emergence was investigated for records from 1987. In April 1987 emergence occurred on days which followed significantly cooler nights than nights preceding days without emergence. During the remainder of the summer of 1987, however, no climatic effects were significant. During winter 1987 emergence occurred on days which were significantly warmer and sunnier.
These data suggest that during summer the primary function of emergence during daylight is to feed to make good energy deficits that have accrued because of inadequate intake during nocturnal foraging. During winter, bats time their daylight emergences to coincide with good feeding conditions, as has been shown previously for winter nocturnal emergence. It is possible daylight emergence occurs during winter primarily because the endogenous cycle during hibernal torpor cannot accurately synchronize arousal with periods of darkness.     

Adaptability and vulnerability of high flying Neotropical aerial insectivorous bats to urbanization

Aim Urbanization is a dominant demographic trend throughout the world that involves massive habitat alterations. Understanding how urbanization affects biota is a crucial prerequisite for development and application of effective species conservation programmes. Our study focuses on Neotropical high flying aerial insectivorous bats, an ecologically important, but so far seriously understudied group of vertebrates. Location Panama. Methods Using acoustic monitoring, we assessed and compared species occurrence, composition and activity of aerial insectivorous bats at three site categories located on the isthmus in Panama: forest, urban areas and a forest–town interface. Results In 2 years of field work, we recorded 44,744 bat passes over the microphone and identified a total of 25 aerial insectivorous bat species. Species richness was highest in the forest, decreased towards the forest–town interface and was lowest at the urban sites, while dominance (Berger‐Parker‐Index) increased from the forest to the urban sites. Overall, general bat activity (passes min^?1) was highest at the forest–town interface and lowest at the urban sites. Multivariate analysis suggests compositional differences in species occurrence and activity among site categories with mainly molossid species occurring in urban areas. Main conclusions Our results clearly demonstrate species‐specific differences between high flying aerial insectivorous bats concerning their adaptability and vulnerability to urban areas. Our results suggest that a suite of morphological traits including species mobility determine persistence of aerial insectivorous species in cities. Our results underline the necessity for detailed assessments of species‐specific habitat requirements and dynamics of species occurrence and activity over time to develop meaningful conservation tools targeted at aerial insectivorous bats.     

Integration and dissociation of limb elements in flying vertebrates: a comparison of pterosaurs, birds and bats

Flapping flight has evolved independently in three vertebrate clades: pterosaurs, birds and bats. Each clade has a unique flight mechanism involving different elements of the forelimb. Here, patterns of limb integration are examined using partial correlation analysis within species and matrix correlation analysis across species to test whether the evolution of flapping flight has involved developmental dissociation of the serial homologues in the fore- and hind limb in each clade. Our sample included seven species of birds, six species of bats, and three species of pterosaurs for which sufficient sample sizes were available. Our results showed that, in contrast to results previously reported for quadrupedal mammals, none of the three clades demonstrated significant integration between serial homologues in the fore- and hind limb. Unexpectedly, there were few consistent patterns of within-forelimb correlations across each clade, suggesting that wing integration is not strongly constrained by functional relationships. However, there was significant integration within the hind limbs of pterosaurs and birds, but not bats, possibly reflecting the differing functions of hind limbs (e.g. upright support vs. suspension) in these clades.     

Histochemical observations on the female reproductive tract of bats. IV. Mucopolysaccharides in the uterus of three species of bats

The three species of bats studied show glycogen, neutral, sialo- and sulfomucins in the cells of the uterine epithelium and glands. Elaboration of these mucins occurs during anestrus in Pteropus giganteus and during proestrus in Taphozous longimanus. In Megaderma lyra lyra only glycogen is observed during anestrus and proestrus. Neutral, and sialomucins in addition to glycogen are observed during estrus. The concentration of these mucins increases progressively and is maximum at the time of implantation, decreasing thereafter in all the three species of bats. The elaboration and increase of mucins is probably under the influence of hormones of the ipsilateral ovary.     

Eimeria from bats of Bolivia: two new species from vespertilionid bats.

Between 1985 and 1987, fecal samples were collected from 71 bats representing 14 species (Desmodontidae, Molossidae, Noctilionidae, Phyllostomidae, Vespertilionidae) from 8 localities in 3 states (Beni, Pando, Santa Cruz) in Bolivia, South America. Of these, 2 black myotid bats (Vespertilionidae), Myotis nigricans, and 1 tent-making bat (Phyllostomidae), Uroderma magnirostrum, had oocysts in their feces that represent undescribed species of Eimeria. The new species from M. nigricans (2/4, 50%) has sporulated oocysts that are subspheroidal, 18.9 x 16.9 (17-23 x 14-20) microm, without a micropyle; oocyst residuum of 6-8 spheroidal globules and 1 highly refractile polar granule are present. The oocyst wall has 2 layers (approximately 1.3 microm thick), with a rough outer layer. Ovoidal sporocysts are 10.1 x 7.4 (7-14 x 5-10) microm, with a Stieda body, substieda body, and a sporocyst residuum. The new eimerian species from U. magnirostrum (1/2, 50%) has sporulated oocysts that are subspheroidal to ellipsoidal, 23.8 x 20.8 (20-26 x 19-24) microm, without micropyle or oocyst residuum, but 1-3 polar granules are present. The oocyst wall has 2 layers (approximately 1.5 microm thick), with a rough, mammilated outer layer. Ovoidal sporocysts are 11.6 x 8.6 (10-12 x 7-10) microm, with a Stieda body, substieda body and a sporocyst residuum.     

Isolation of fungi from bats of the Amazon basin.

A total of 2,886 bats captured in the Amazon Basin of Brazil were processed for the isolation of fungi. From the livers, spleens, and lungs of 155 bats (5.4%), 186 fungal isolates of the genera Candida (123 isolates), Trichosporon (26 isolates), Torulopsis (25 isolates), Kluyveromyces (11 isolates), and Geotrichum (1 isolate) were recovered. Seven known pathogenic species were present: Candida parapsilosis, C. guilliermondii, C. albicans, C. stellatoidea, C. pseudotropicalis, Trichosporon beigelii, and Torulopsis glabrata. Twenty-three culture-positive bats showed identical fungal colonization in multiple organs or mixed colonization in a single organ. The fungal isolation rates for individual bat species varied from 1 fungus per 87 bats to 3 fungi per 13 bats, and the mycoflora diversity for members of an individual fungus-bearing bat species varied from 16 fungi per 40 bats to 7 fungi per 6 bats. Of the 38 fungal species isolated, 36 had not been previously described as in vivo bat isolates. Of the 27 culture-positive bat species, 21 had not been previously described as mammalian hosts for medically or nonmedically important fungi.     

Obstetric flying squad service-a defence.

Eighty-one calls made by the obstetric flying squad in West Berkshire were assessed on the basis of a suggestion that patients would do as well, if not better, if they were brought straight to hospital by ambulance rather than await the arrival of the flying squad. Of the 81 calls, 36 were made to general-practitioner maternity units and 45 were made to patients'' homes. In both groups, the flying squad service was considered to be still of great value. Though slightly slower than an emergency ambulance call, it represents a much safer method of transporting an obstetric patient in an emergency.     

Elastogenesis in healing wounds in bats.

Full-thickness square wounds were made in the webs of fruit bats. Elastin was laid down in the healing scars of these wounds in two forms--as single fibers under the regenerated epidermis, and as bundles of fine fibers taking their origin and orientation from the cut ends of the web elastin bundles. This process continued over a period of 6 months, during which time other components of the scar became reduced in amount. The arrangement of the new elastin in the scar tissue was thus a replica of that seen in the normal web. There are indications in this study that elastin imparts elasticity to the scar.     

Vocal learning by greater spear-nosed bats.

Vocal learning is well known among passerine and psittacine birds, but most data on mammals are equivocal. Specific benefits of vocal learning are poorly understood for most species. One case where vocal learning should be favoured by selection is where calls indicate group membership and group mates are unrelated. Female greater spear-nosed bats, Phyllostomus hastatus, live in stable groups of unrelated bats and use loud, broadband calls to coordinate foraging movements of social group mates. Bats benefit from group foraging. Calls differ between female social groups and cave colonies, and playback experiments demonstrate that bats perceive these acoustic differences. Here I show that the group distinctive structure of calls arises through vocal learning. Females change call structure when group composition changes, resulting in increased similarity among new social group mates. Comparisons of transfers with age-matched half-sibs indicate that call changes are not simply due to maturation, the physical environment or heredity. These results suggest that studies testing vocal learning in mammals could profit by focusing on vocalizations that signify group membership.