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1

Flight activity of bats at the entrance of a natural cave

100%
Berkova H., Zukal J.
Acta Chiropterologica
|
2006
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tom 08
|
nr 1
Activity patterns of bats were investigated at the entrance of a natural karstic cave (Kateřinská cave, Czech Republic). The activity was recorded automatically with a double infrared light barrier allowing discrimination between those bats leaving and those entering the cave. Five periods were defined on the basis of bat flight activity: A) Hibernation period (November–late March), with very low activity; B1) Departure period 1 (late March–mid April), with intensive departure during the first quarter of the night; B2) Departure period 2 (mid April–beginning of June), with emergence activity in the first quarter, and a small number of bats entering the cave in the fourth part of the night. The peak of activity was in the second part of the night. C) Summer period (mid June–mid July), with low activity. D) Autumn period (late July–late October), with very high activity and increasing number of bats entering the cave. The peak of activity was around midnight. All periods showed a non-random temporal distribution and a concentration of flight activity around specific time. There was a positive correlation between the number of bat passes through the entrance and outside ambient temperature and a negative correlation between the number of passes and barometric pressure. Rain had no significant effect on the level of bat activity.
2

Does a live barn owl (Tyto alba) affect emergence behavior of serotine bats (Eptesicus serotinus)?

100%
Petrzelkova K. J., Zukal J.
Acta Chiropterologica
|
2003
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tom 05
|
nr 2
We studied the impact of predation risk on emergence behavior of a maternity colony of Eptesicus serotinus. Observations were made during sets of three consecutive nights — control, treatment and post-treatment. On treatment nights, a trained individual of barn owl (Tyto alba) was displayed during the emergence of the colony. Presence of the owl did not induce any significant change in the emergence parameters with exception of the degree of clustering. In pregnancy bats increased their clustering during treatment and post-treatment nights. The presence of the owl induced changes in relationships among emergence parameters. If bats emerged earlier when predation risk supposed to be higher, they increased their degree of clustering to decrease the individuals' probability of being attacked. We conclude that clustering in emergence is an important anti-predation strategy.
3

A comparison between emergence and return activity in pipistrelle bats Pipistrellus pipistrellus and P. pygmaeus

81%
Petrzelkova K. J., Downs N. C., Zukal J., Racey P. A.
Acta Chiropterologica
|
2006
|
tom 08
|
nr 2
Bats may be vulnerable to predation during evening emergence and morning return to their roosts. Early emergence increases the risk of exposure to raptorial birds, but emerging late confers a risk of missing the dusk peak of aerial insects. Here, both emergence and return activity was studied in detail at the same roosts for the first time. We investigated six maternity colonies of pipistrelle bats (Pipistrellus pipistrellus and P. pygmaeus) in NE Scotland and recorded light levels and time of emergence and return of the bats with respect to sunset and sunrise on the same nights. Parameters of return activity generally occurred at lower light intensities than those of emergence. Therefore, the interval between dawn return and sunrise was generally longer than that between sunset and dusk emergence. Emergence and return were equal in duration. Bats clustered more on emergence in comparison with return during pregnancy and lactation, whereas during postlactation this trend was reversed.
4

Mitochondrial DNA confirms low genetic variation of the greater mouse-eared bats, Myotis myotis, in Central Europe

61%
Bryja J., Uhrin M., Kanuch P., Bemova P., Martinkova N., Zukal J.
Acta Chiropterologica
|
2010
|
tom 12
|
nr 1
Recent data shows that range expansion of the greater mouse-eared bat Myotis myotis (Borkhausen, 1797) to Central Europe occurred mainly from the Iberian glacial refugium and in a lesser extent from South-eastern Europe. Here we present sequences of the mitochondrial control region obtained from 16 localities in the Czech Republic, Slovakia, and NW Romania. From the 97 sequences, 87 were identical with the haplotype H1, the most frequent one of haplogroup A occurring throughout Western Europe, and nine sequences (eight haplotypes) differed from H1 only by one substitution. This confirms decrease of genetic variability from south to north and colonisation of Central Europe from the Iberian Peninsula. However, we found a new haplotype, which is closely related to sequences from haplogroup D so far described in the nominative form of this species only from Greece and Bulgaria, which suggests two possible scenarios. First, colonization route from the Balkan refugium existed in this species as well, which is supported also by recently published analyses of historical DNA. Second, the Balkan haplotype entered Central Europe via interspecific hybridisation with M. blythii, a species, in which the haplogroup D is the most frequent in Europe and which is known to have colonised Europe from south-east.
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