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1

Roosts and activity areas of Nyctinomops macrotis in northern Arizona

100%
Corbett R. J. M., Chambers C. L., Herder M. J.
Acta Chiropterologica
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2008
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tom 10
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nr 2
Female big free-tailed bats Nyctinomops macrotis have been captured over water in northern Arizona in high elevation (> 2,400 m) forests and low elevation (1,500 m) desert scrub vegetation. We hypothesized that roost sites were in vertical walls of cliffs that were up to 25 km away from capture sites given the flight capability of these bats. During summer 2005 we captured eight females over ponds and attached radio transmitters to locate day roosts. We also identified locations used during nightly movements from 1 to 6 nights of radio tracking. We found three day roosts for seven bats; average distance (± SE) from a capture site to a roost was 12.1 ± 3.0 km. Roosts were small maternity colonies used by ≥ four N. macrotis in cracks or crevices in upper portions of vertical cliffs and faced south or southeast. Average dimensions for ponds where we found N. macrotis were 24 × 46 m, larger than the average pond size (14 × 19 m) where we did not capture this species. We identified 73 night locations for five N. macrotis and for one individual with 32 night locations calculated a 95% activity area (minimum convex polygon method) of 29,590 ha. Straight line distance between successive locations averaged 5.1 ± 0.8 km. Maximum distance detected from roost averaged 25.3 ± 4.9 km. We conservatively estimated a maximum flight speed of 61 km per hour. Most locations were in desert scrub vegetation but three bats moved to higher elevations, using pinyon-juniper (Pinus edulis-Juniperus spp.) woodland and ponderosa pine (Pinus ponderosa) forest. The maternity roosts we located for N. macrotis were remote, difficult to access, and within protected areas (national parks) in northern Arizona; however, foraging areas and ponds used for drinking are managed by different public or private agencies. These features are not as well protected and could be critically important in this arid environment.
2

An experimental test of gating derelict mines to conserve bat roost habitat in southeastern Australia

84%
Slade C. P., Law B. S.
Acta Chiropterologica
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2008
|
tom 10
|
nr 2
Management of derelict mines to improve subterranean bat habitat and minimise safety risks to the unsuspecting public is occurring more frequently. Many caves and mines around the world have had gates placed at mine and cave entrances as a means of maintaining bat habitat and preventing human access, but there have been few replicated experiments to test their effectiveness. We experimentally tested a staged installation of a template gate at two mines while monitoring another two un-gated derelict mines in southeastern Australia. We recorded changes in numbers, behaviour and the relative species abundance of two bat species (Rhinolophus megaphyllus and Miniopterus schreibersii) before and after the gates were installed. The template gate (20 mm diameter plastic tubing) was installed in three stages, with the initial horizontal bar spacing at 450 mm, followed by a spacing of 300 mm and a final spacing of 125 mm. Bat numbers and behaviour were largely unaffected by bar spacings of 450 mm and 300 mm. The major findings were that immediately after the installation of bars at the final spacing (125 mm gap), numbers of bats declined significantly and a significant increase in the number of aborted exit and entry flights was observed. Detectors proved to be inadequate at quantifying changes in the relative abundance of species. Eleven days after the final installation there were no significant differences between the numbers of bats leaving gated and control mines, suggesting bats had learnt to negotiate the bars after a short period of time. However, flight behaviour was still affected after habituation, especially baulking at the structure when bats attempted to re-enter before dawn. The low replication of mines in the experiment warrants caution in extrapolating this result. Until further gating experiments are carried-out, we recommend site specific monitoring whenever mines are gated.
3

Describing roosts used by forest bats: the importance of microclimate

84%
Boyles J. G.
Acta Chiropterologica
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2007
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tom 09
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nr 1
Adequate descriptions of roosting habitat are vital to the management and conservation of bats. However, most studies on bat roosting preference report only structural characteristics of roosts and surrounding habitat, and ignore potentially important factors in roost selection. I argue that the current methods for describing the roosting habitat of tree-roosting bats can be improved, and that more emphasis should be placed on designing studies to determine why bats choose particular roosts. Herein, I focus on measuring microclimate in roosts because it universally influences habitat selection. Specifically, roost temperature is easily measured and is likely an important microclimate variable used by bats in roost selection. Variation in structural characteristics of roosts is often assumed to correlate with variation in microclimate of the roost; however, empirical data are too scarce to verify this assumption. I suggest improvements to the current methods of describing roost characteristics and suggest the inclusion of new methods to describe microclimate. In summation, I argue that there are methods of measuring roost characteristics that may be beneficial to use in conjunction with the methods currently being used, and that microclimate should be considered when designing future studies.
4

Use of leaves as roosts by the Gervais's fruit-eating bat, Artibeus cinereus (Phyllostomidae: Stenodermatinae) and proposed modifiability index

84%
Machado D. A., Merida M. S., Munoz-Romo M.
Acta Chiropterologica
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2008
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tom 10
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nr 1
5

Characteristics of the northernmost population of Rhinolophus ferrumequinum in the Carpathian Basin

84%
Bihari Z.
Acta Theriologica
|
2001
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tom 46
|
nr 1
Roost utilisation by Rhinolophus ferrumequinum (Schreber, 1774) was investigated between 1984 and 1998 in north-eastern Hungary. Exploration of summer and winter roosts, monitoring and bat-banding were implemented to find movements between the colonies. Data on roost utilisation by this species in south-eastern Slovakia, collected in a similar way, were included for comparison. Twenty-two marked bats were recaptured. The studied bats created nursery colonies in Hungarian churches and moved to Slovakian mines and caves to hibernate in winter. The population used two main hibernacula, two large nursery roosts and one temporary roost but several other roosts were also visited. The area occupied by the population was 5180 km . R. ferrumequinum living in SE Slovakia and NE Hungary formed probably a separate population on the northern edge of the species range. This population is a part of the metapopulation of the species.
6

Temperature and humidity differences between roosts of the fruit bat, Rousettus aegyptiacus (Geoffroy, 1810), and the refugia of its ectoparasite, Afrocimex constrictus

67%
Reinhardt K., Naylor R. A., Siva-Jothy M. T.
Acta Chiropterologica
|
2008
|
tom 10
|
nr 1
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