|
|
Flight initiation distances and life histories in birds: comparison of intra- and interspecific approaches
Brzobohatá, Tereza ; Albrecht, Tomáš (advisor) ; Klvaňa, Petr (referee)
Information about the distance, in which the birds flee from predators, may help us to better understand avian escape behavior and stress responses. These distances are influenced by many life-history traits and related factors, both on intraspecific and interspecific levels. This bachelor's thesis is trying to summarize the current knowledge of agents influencing flight initiation distances (FID) of birds, in the form of a literary research. The first section deals with antipredator behavior in birds, and explains methods that are used for measuring critical distances. In the second part of thesis, factors affecting flight initiation distances on intraspecific level are described. The main emphasis is on impact of age characteristics, body sizes, reproductive investments and geographical distribution. The last chapter summarizes the information about relationships between FID and life-history traits on interspecific level. The age of the individual, levels of stress hormones, the effect of the season and biotop are described in detail. Powered by TCPDF (www.tcpdf.org)
|
|
|
Diversity of cockroach mating behaviour (Blattodea: Blaberidae)
Dvořák, Tomáš ; Kotyková Varadínová, Zuzana (advisor) ; Nedvěd, Oldřich (referee)
Mating behaviour of cockroaches is spectacular phenomenon with three different mating patterns traditionally distinguished. The most common and probably ancestral is type A - female climbing. Then it is type B - male climbing and type C - no climbing. Mating type was described in around 30 Blaberidae species. As it is the only cockroach family where all three types are present, it is an interesting model group for studying evolutionary questions. The main goal of the thesis was detail exploration and description of mating sequences in 21 Blaberidae species, 17 of which haven't been examined in this aspect before. An intrageneric diversity in mating patterns (genus Pycnoscelus) was described for the first time. Moreover, in case of P. tenebrigera, it was not possible to assign its mating pattern to any of the three traditional types. Multidimensional statistical analysis and biological interpretation of qualitative behavioural elements revealed two well separated clusters of mating sequensces. Consequently, we propose to distinguish only two types of mating pattern - ancestral type (identical with type A) and derived type. We also discussed the relationship between wing reduction and occurence of derived mating types. Evaluation of quantitative behavioural elements revealed positive correlation between...
|
|
|
Latitudinal trends in avian life-histories
Krejčířová, Zuzana ; Albrecht, Tomáš (advisor) ; Reif, Jiří (referee)
Most studies on bird focus on northern temperate zone species. However, the vast majority of birds occupies tropical environments. In birds, differences between tropical and temperate zone species in various life-history traits have long been assumed. These differences may reflect variation in solving the survival-reproduction trade-off, with temperate species preferring actual reproduction over the survival and tropical species preferring the oposite. In this bachelor thesis I summarize the result of literature search focusing on latitudinal trends in selected life-history traits in birds. In the first part of thesis I provide an overview of differences between the temperate and tropical zone in environmental conditions often assumed to closely affect the evolution of avian life histories. In the second part of the thesis, I focus on particular life-history traits where the differences between tropical and temperate species were detected. Latitudinal trends in chosen life history associated traits (clutch size, longevity and life span, basal metabolic rate) indeed seem to correspond with the general prediction of comparatively slow pace of life in tropical species.
|
|
|
Flight initiation distances and life histories in birds: comparison of intra- and interspecific approaches
Brzobohatá, Tereza ; Albrecht, Tomáš (advisor) ; Klvaňa, Petr (referee)
Information about the distance, in which the birds flee from predators, may help us to better understand avian escape behavior and stress responses. These distances are influenced by many life-history traits and related factors, both on intraspecific and interspecific levels. This bachelor's thesis is trying to summarize the current knowledge of agents influencing flight initiation distances (FID) of birds, in the form of a literary research. The first section deals with antipredator behavior in birds, and explains methods that are used for measuring critical distances. In the second part of thesis, factors affecting flight initiation distances on intraspecific level are described. The main emphasis is on impact of age characteristics, body sizes, reproductive investments and geographical distribution. The last chapter summarizes the information about relationships between FID and life-history traits on interspecific level. The age of the individual, levels of stress hormones, the effect of the season and biotop are described in detail. Powered by TCPDF (www.tcpdf.org)
|
|
|
Geographical variation in functional traits of European birds
Kopsová, Lenka ; Hořák, David (advisor) ; Remeš, Vladimír (referee)
Each species has specific adaptations to its environment, and since environmental parameters reveal geographic trends, it is reasonable to expect the existence of geographic trends in species characteristics as well. The aim of this study has been to evaluate the effect of environmental conditions on geographic variability of functional traits of European birds. I have analysed the effect of temperature, precipitation, productivity, altitude and habitat type (forest, open habitats, bush, settlements, wetlands) on clutch size, number of clutches per breeding season, egg size, incubation length, age of maturity, body mass, wing, tail, bill and tarsus length. I have used data from the European breeding bird atlas, so that I have calculated mean values of all the traits for quadrats 50x50 km, and then related them to environmental characteristics using OLS and GLS. Clutch size increases with temperature, whereas the number of clutches decreases with it, indicating possible trade-off between clutch size and the number of clutches, whose result is determined by the length of breeding season. Egg size decreases with temperature, possibly due to higher survival of large eggs (and consequently juveniles) in cold regions. Incubation length increases with both temperature and environmental productivity,...
|
|
|
Trade-off between egg size and number at the level of bird families
Špaldoňová, Alexandra ; Hořák, David (advisor) ; Reif, Jiří (referee)
Trade-off between offspring size and number belongs to the most discussed concepts in the life history theory. The aim of this study was to elucidate the relationship between egg size, clutch size and female body mass at the family level in bird's and to examine whether there is the relationship between offspring size and number and life history traits specific for particular bird families. From published sources, I collected data about 5.073 species belong in 146 families. Most species of birds lay smaller clutches, on average three eggs. In 112 families from 130 tested eggs size was positively correlated with female body mass. There is evidence that egg size and clutch size are inversely related in 83 families from 130 tested but only for 34 families was significant. The relationship exists independently of female body mass across bird families and this suggests a trade-off between these traits. The relationship between the strength and shape of egg size-number correlations and life history characteristics of bird families was not frequent. According to results, the strength of correlation seems to be related to development mode and diet type. The negative egg size-number correlation is stronger when incubation period and fledging time is longer and in birds with longer lifespan. The...
|
|
| |
guest ::
