National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
New findings of physiological and ecological aspects of hibernating bats
Ungrová, Zdislava ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
Bats can be found in almost all climatic zones. They have to deal with unfavorable conditions of environment to survive and reproduce sucessfully. Especially in temperate zones they have to deal with cold temperatures and lack of food during a winter season. To save energy bats enter a short, diurnal torpor or a hibernation. Usually, hibernation lasts all winter and is disturbed by short bouts of arousals. During both hibernation and torpor a physiological changes occur in bodies of bats. Body temperature decreases from endothermic levels, metabolic rates are reduced as well as respiratory rate and pulse. These changes are mainly influenced by weight and body size, diet, ambient temperature, sex and reproductive status. With the developement of new technologies, these changes can be measured more accurately than they have been in past, whether in a field or in a laboratory. But not all physiological processes are well explained. We have little knowledge especially about mechanism of arousal from hibernation. During awakening bats are infected by fungus Geomyces destructans that affects their immune system. In Norh America fungus causes a disease called White- Nose syndrome (WNS), that is responsible for death of millions of bats, especially endangered is Myotis lucifugus. In Europe, this disease is reffered...
Social organization and communication of flying foxes focused on the genus Rousettus
Vašíčková, Pavla ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
Within the family Pteropodidae there are different types of social systems, depending on the species. Reproductive activity of Egyptian fruit bat (Rousettus aegyptiacus) is based on the latitude, when in milder latitudes individuals tend to be seasonally monoestry, southerly living individuals are less synchronous. Gestation lasts about four months and in most cases one young is born and mother cares about it. Egyptian fruit bats often inhabit caves, while there may live thousands of individuals and even more together. Pteropodidae are focused on plant food, which they choose according to the many criteria. Members of the genus Rousettus belong to the food generalists and their diet includes trees and herbs, from which they consume fruits, flowers, nectar, pollen, shoots and leaves. They were also observed by eating beetles of the family Scarabidae. Flying foxes of the genus Rousettus are special, because they orient by echolocation. They emit short broadband signals through the vibration of the language, whose length ranges from 50-100 s. From other chiropteran families they differ through the way of production the signals. In addition to echolocation senses of smell and sight are key in terms of communication. The smell is important mainly in attracting a partner, for mutual recognition between...
Social organization and mating systems in the genus Myotis
Wnuková, Lucie ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
We can find a big variety of social organizations and mating systems in order Chiroptera. The most common is polygamy where paternal care is typically missing. In temperate zone, there is seasonal change of climate what is influencing sociality and mating of Chiroptera which are adopting so called temperate cycle. This cycle is characteristic also for our species Myotis. During summer, females live in nursery colonies to make the nursing of the youngsters easier. In every specie of this order living in Czech Republic females are having only one cub. Shelters of the nursery colonies are for example in the cavities of trees, buildings or other gaps. Myotis myotis and M. Blythi, which originally occupied the caves, in our conditions are living in buildings. Number of individuals in the colony varies and depends on type of shelter. In species M. bechsteinii, M. nattereri and M. daubentonii, female colonies are disrupted into several sub-groups living in different shelters. This social organization is called fission-fusion. Even though males are being solitary during this period of time, we can find them also in female groups or they can form an only male group. Mating occurs usually in autumn when nursery colonies break up, probably during swarming. In winter, they are hibernating in their hibernacula which are...
Social behaviour and ecology of bats of the genus Pipisttrellus
Jahelková, Helena ; Horáček, Ivan (advisor) ; Řehák, Zdeněk (referee) ; Červený, Jaroslav (referee)
43 Summary of results of presented research Since discrimination of two cryptic species inside Pipistrellus pipistrellus s.l based on echolocation calls (Jones & van Parijs 1993), social calls (Barlow & Jones 1997), and molecular data (Barratt et al. 1997), the genus Pipistrellus have been studied intensively. The mainstream of my research were reproduction strategies and vocalization behaviour of Nathusius's pipistrelle (Pipistrellus nathusii). It is a small European insectivorous species, which is known for his migratory behaviour. The dominant mating system is resource-defence polygyny. Males vocalize during flight (songflight) and from entrances of their day roosts (sedentary display). Advertising calls occur during whole active season, but they considerable increase during mating season. Males show strong fidelity to their mating roosts whereas females are fixed to maternity colonies (Schmidt 1984, Rachwald 1992, Gerell-Lundberg & Gerell 1994, Furmankiewitz 2003, Petersons 2004). This species exhibits variability in mating behaviour in different countries, probably due to long- distance migrations. In Czech Republic, the species was considered to be rare and only sporadic indications of reproduction were found (Hanák & Gaisler 1976, Šefrová & Buřič 1998). Main research area of my study was in South...
Social behaviour and acoustic communication in greater mouse-eared bat (Myotis myotis)
Porteš, Michal ; Jahelková, Helena (advisor) ; Bartonička, Tomáš (referee)
Order Chiroptera is characterized by great variability in foraging, roost and social strategies. Greater mouse-eared bat (Myotis myotis, Borkhausen 1797) is a model species of a bat in Europe and his seasonal organisation of population represents typical temperate bat cycle with females aggregated in large maternity colonies and solitery roosting males. Although the M.myotis is a model species, the majority of studies were focused on different aspects of maternity colonies biology and the biology of males is still poorly known. Recently founded aggregations of males of M. myotis in highway bridges allow to study social behaviour and acoustic communication of males on between individual level and discuss these findings with known information. While the bridge in Bernartice was inhabited by aggregation of males in individual roosts, in Voznice bridge we found besides males also a maternity colony of M. myotis. Harems of males were established from august until october. We found different pattern of seasonal roost occupancy in males with males with the highest level of mean occupancy having the highest level of female presence in roost. Vocalisation activity of males increased in august with highest level of activity in september. Males roosting closer to the flight entrance tended to have higher...
Behaviour and acoustic communication in Egyptian fruit bat
Vašíčková, Pavla ; Jahelková, Helena (advisor) ; Karadžos, Alexis (referee)
Egyptian fruit bats were observed in Prague Zoo, where stable conditions are provided (year-round food supply, stable temperature and roosts). The colony has bimodal breeding cycle. Births are synchronized and occur on the turn of April and May and in September. The mating occurs throughout the year but there is an increase during lactation and in the period outside parturitions. There is no obvious pattern in cluster dynamics. Bats roost in four clusters (left, middle, upper right and lower right). The presence of clusters throughout the year is stable except upper right cluster. There are changes in the number of clusters and in the number of individuals inside each cluster. Fruit bats occupy approximately the same spots in clusters, however young individuals show the highest variability. An autogrooming is balanced throughout the year, there is no regular pattern in the observation period and even no increase after artificial twilight. From these activities a licking of wing membranes and fur are the most often. The mother cares for her young especially during lactation and weaning, while the care decreases with a development of the young. This is especially true for the licking of the wing membranes. An allogrooming is the most common between male and female during lactation and in the period...
Social organization and mating systems in the genus Myotis
Wnuková, Lucie ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
We can find a big variety of social organizations and mating systems in order Chiroptera. The most common is polygamy where paternal care is typically missing. In temperate zone, there is seasonal change of climate what is influencing sociality and mating of Chiroptera which are adopting so called temperate cycle. This cycle is characteristic also for our species Myotis. During summer, females live in nursery colonies to make the nursing of the youngsters easier. In every specie of this order living in Czech Republic females are having only one cub. Shelters of the nursery colonies are for example in the cavities of trees, buildings or other gaps. Myotis myotis and M. Blythi, which originally occupied the caves, in our conditions are living in buildings. Number of individuals in the colony varies and depends on type of shelter. In species M. bechsteinii, M. nattereri and M. daubentonii, female colonies are disrupted into several sub-groups living in different shelters. This social organization is called fission-fusion. Even though males are being solitary during this period of time, we can find them also in female groups or they can form an only male group. Mating occurs usually in autumn when nursery colonies break up, probably during swarming. In winter, they are hibernating in their hibernacula which are...
Social organization and communication of flying foxes focused on the genus Rousettus
Vašíčková, Pavla ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
Within the family Pteropodidae there are different types of social systems, depending on the species. Reproductive activity of Egyptian fruit bat (Rousettus aegyptiacus) is based on the latitude, when in milder latitudes individuals tend to be seasonally monoestry, southerly living individuals are less synchronous. Gestation lasts about four months and in most cases one young is born and mother cares about it. Egyptian fruit bats often inhabit caves, while there may live thousands of individuals and even more together. Pteropodidae are focused on plant food, which they choose according to the many criteria. Members of the genus Rousettus belong to the food generalists and their diet includes trees and herbs, from which they consume fruits, flowers, nectar, pollen, shoots and leaves. They were also observed by eating beetles of the family Scarabidae. Flying foxes of the genus Rousettus are special, because they orient by echolocation. They emit short broadband signals through the vibration of the language, whose length ranges from 50-100 s. From other chiropteran families they differ through the way of production the signals. In addition to echolocation senses of smell and sight are key in terms of communication. The smell is important mainly in attracting a partner, for mutual recognition between...
Microclimate of different types of roosts in temperate bats: a review
Oppelová, Tereza ; Lučan, Radek (advisor) ; Jahelková, Helena (referee)
Chiropteran (Chiroptera) are still not so much explored order. It may be because of their night activity, hidden way of life and in large measure misunderstanding and mistrustfulness of people. Despite of progress during of last decade many of species are still insufficiently explored. Temperate bats are exhibited to many adverse conditions. Low temperature, temperature instability and seasonal food shortages forces bats to reduce their energetically costs to minimum. The need to adapt to these conditions leads to make new adaptations like torpor, social thermo genesis and hibernation. The important role is also choice of suitable roost with protection not only of bad weather and predators, but also with suitable microclimate, which helps to bats with energetically management.

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