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Extra-pair fertilizations and the opportunity for sexual selection in Barn swallows
Michálková, Romana ; Albrecht, Tomáš (advisor) ; Šálek, Miroslav (referee)
Generally it is assumed, that sexual selection drives the evolution of elaborate traits. The strength of sexual selection has traditionally been attributed to varinace in reproductive success among individuals. This variance is mainly caused by the number of mating partners and the number of sired offspring. Both males and females can increase their reproductive success by alternative reproductive strategies - extrapair copulations and intraspecific brood parasitism. In our study we tested the relationship between male ornamentation and success in extra-pair and within-pair paternity and the total male reproductive success in barn swallow (Hirundo rustica), a socially monogamous species with high levels of extrapair paternity. The results suggest more colourful throat to indicate male reproductive success. Dark rusty males were less often cuckolded and they have higher total fertilization success than drab ones. Tail length did not affect neither within- nor extra-pair fertilization success, however, previous studies have concluded that reproductive success of male barn swallows is positively related to the tail ornaments. Our results confirm that extra-pair paternity considerably increase variance in reproductive success among barn swallow males. We show that within-pair success may increase the...
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Intraspecific variability in population trends of farmland birds: influence of habitat and altitude
Hanzelka, Jan ; Reif, Jiří (advisor) ; Šálek, Miroslav (referee)
Farmland bird populations in Europe have been in decline for a long time. Agricultural intensification and growing a large share of crops that provide suboptimal breeding habitat could be the main causes of the observed decline. To explore these possible drivers, I focused on population trends of farmland bird species in different habitats in the Czech Republic over the periods 1982-1990 and 1990-2010. Specifically, I focused on the variability in trends within each species in respect to the differences in landscape management between the lowlands and mid-altitude areas before and after 1990. The expected effect of intensive farming in the lowlands until 1990 was reflected by a strong decline in populations of Northern Lapwing and Yellowhammer. The influence of less intensive farming in mid-altitude areas causing moderate population decline was confirmed rather by shrubs and trees species than farmland specialists. After 1990, less intensive farming in the lowlands should reduce the decline, which may have occurred, but compelling comparison of population trends between the two time periods was not possible for most species due to the lack of data. On the contrary, more intensive population decline in mid-altitudes after 1990, which should be the response to arable land abandonment, was not...
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Incubation strategies of selected duck species
Klvaňa, Petr ; Albrecht, Tomáš (advisor) ; Šálek, Miroslav (referee) ; Bureš, Stanislav (referee)
- 9 - Incubation strategies of selected duck species Summary of the PhD. thesis Avian incubation is an energetically demanding process. It holds true especially for uniparental incubators in which all incubation efforts are restricted to one individual. All ducks species breeding in northern hemisphere are representatives of birds with uniparental care. High demands of clutch formation and incubation make from ducks perfect model for testing factors influencing parent investment decisions. On the other hand parental investment to actual breeding attempt depends on many factors including breeding season duration, food supply, female's age, risk of predation or resilt of previous nesting attempt. So investigation of this complex problematic is extremely difficult. This thesis is focused on the most important phase of breeding cycle - incubation of clutch. Clutch incubation is associated with high energy cost to maintenance optimal temperature conditions for developing embryos. Morover incubation process can has large effect on female's body mass because of reduction of feeding time. Incubation strategy of success female include many partial tactic reducing predation risk of clutch and incubating female or eggs cooling. The incubation strategies of three ducks species were investigated in this thesis - Mallard...
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Effects of diet and feeding behaviour on nestlings quality in House Sparrow (Passer domesticus)
Lusková, Miroslava ; Klvaňová, Alena (advisor) ; Šálek, Miroslav (referee)
This study focused on analysing the diet composition of nestlings of different age during two breeding seasons in rural environment of agricultural farm near Veselí nad Lužnicí, South Bohemia. Feeding behaviour and habitat selection by parents was also monitored. Population decline of the species as a consequence of low invertebrates rate in nestlings diet and disappearing of important habitats are discussed. Most of studies on feeding behaviour in the Czech Republic focused only on feeding frequency. Two commonly used methods for diet determination, neck- collars and faecal analysis, were compared. The feeding frequency of male and female were also determined. Coleoptera (Scarebeidae) were the most often determined group in samples of feacals, while Diptera (Tipulidae) were the most often determined group in samples from ligatures. The differences between diet of younger and older nestling were assessed. While diet of young nestlings contained Diptera, Coleoptera dominated in diet of older nestlings. The vegetable food, mainly seeds of Poaceae, dominated in diet of older nestlings. Amount of food increased along age gradient (samples of older nestlings were heavier). Different effect of animal proportion in the nestling diet was determined. Increase in animal proportion in the dietof young nestlings caused...
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Ecology of Eurasian sparrowhawk in urban and rural areas
Kunca, Tomáš ; Šálek, Miroslav (advisor) ; Bohuslav, Bohuslav (referee)
Urban environments provide suitable habitats for species that are ready to adapt to the specific conditions. One of such species is Eurasian sparrowhawk (Accipiter nisus) that has adapted to the Prague city environment. This dissertation explores and describes selected aspects of sparrowhawks ecology in urban and rural environment. It focuses on comparison of selected aspects of sparrowhawk ecology between urban and rural study areas.
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Numbers of selected bird species in various types of village built-up area.
Kebrle, Dominik ; Zasadil, Petr (advisor) ; Šálek, Miroslav (referee)
In Czech rupublic and similar in most of Europe, some of agricultural landscape birds abundance is declining. The biggest decline was record by House Sparrow (Passer domesticus), probably causes by changes in building technique or by lack of food opportunities. The decline in the case of Greenfinch (Carduelis chloris) and Linnet (Caduelis cannabina) is attributed to the intensification in farming. In the case of Starling (Sturnus vulgaris) is persecution by human possible cause of decline. Estimate abundance overal of eleven bird species was conducted during nestling perion in 2015 in 20 villages situated in the southwest of Central Bohemia. It was select 10 villages with working farming, in these villages was define three census site of 1 ha in different types of bulit-up area (in the centre, in the edge and in factory farm area). In 10 remaining villages was define only two census sites (in the centre and in the edge) because absence of factory farm area. House Sparrow (Passer domesticus) and Collared Dove (Streptopelia decaocto) significantly favoring village centre in villages without factory farm. Tree Sparrow (Passer montanus) significantly prefers the edges in villages with factory farming. Black Redstart (Phoenicurus ochruros) significantly favoring village centre no matter on presence of factory farming. Effect of farming on increase of birds abundance wasn´t prove. Only Collared Dove (Streptopelia decaocto) significantly avoid factory farm area. In the case of other factors (bulit-up area, area of trees and shrubs, herb layer surface, proportion of new buildings, distance from factory farm area) was prove influece of trees and shrubs area on House Sparrow (Passer domesticus), which decline abundance with increase the area. It was also prove influence of bulit-up area on Starling (Sturnus vulgaris) which decline abundance with increase the area.
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