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Incubation effort in Common Pochard and its determinants
Drekslerová, Šárka ; Hořák, David (advisor) ; Musil, Petr (referee)
Incubation of avian eggs is an energy demanding process. Incubating parent faces a conflict between investment into optimal thermal conditions for developig embryos and meeting of own energy requirements. This applies especially in uniparental incubators such as ducks. During incubation, female utilizes energy from fat storage or actual food intake. The proportion of energy used from food than may reflect the time spent by female on the nest. The utilizing of these both sources ratio plays a role in time spent on nest. The aim of the thesis was to describe an incubation rhythm in females of Common Pochard (Aythya ferina) and relate them to climatic variables and changes in body mass. Data were collecetd for three years in the Poodříí Landscape Protected Area at free-living females. We placed a weighting mechanism under the nest with conected datalogger recording voltage variations, which offered me an information about female body mass and time and duration of recesses. Incubation rhytm of females was described by time spent on time ("incubation constancy"), recess frequency and recess duration. Females left the nest most grequently at night-time and during dawn and dusk. Probable explanation of this pattern is better food availability in the night-time and lower risk of nest predation by predators...
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Influence of external conditions on egg incubation in lapwings (genus Vanellus) in temperate and subtropical climate
Pešková, Lucie ; Šálek, Miroslav (advisor) ; Hořák, David (referee)
During incubation, most birds require the presence of at least one parent to ensure suitable incubation conditions for embryo development. The main factors that affect the development of the embryo are temperature, humidity and egg turning. In this work, incubation conditions were investigated in two biparental Lapwing species (genus Vanellus), the Northern Lapwing (Vanellus vanellus), which faces the risk of egg cooling in temperate areas, and the Red-wattled Lapwing (Vanellus indicus), which faces the risk of egg overheating in the subtropics. A laboratory experiment testing the thermal properties of the Red-wattled Lapwing nest lining showed that it selects lining material that slows down temperature growth during egg heating, thus ensuring suitable thermal conditions during parental absence at high ambient temperatures. Temperature and egg turning during incubation were recorded by an artificial egg with a built-in sensors placed in the nests of both target species; data collected by the sensors were stored by a base-station located nearby. The average egg temperature was 32.5 řC for the Northern Lapwing, and 35.0 řC for the Red-wattled Lapwing. Egg temperature in both species fluctuated significantly, affected by many factors. Egg temperature increased with increasing ambient temperature, it...
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Temperature-dependent activity of egg-white antimicrobial proteins in precocial and altricial birds
Novotná, Lucie ; Javůrková, Veronika (advisor) ; Krist, Miloš (referee)
Microorganisms are considered to be crucial selective factor affecting reproductive success of birds. It is hypothesized that egg-white antimicrobial proteins and incubation behavior are the most important defense mechanisms that eliminates the risk of microbial trans-shell infection. The latest studies supposed that incubation temperatures may significantly affect the antimicrobial activity of egg white proteins. The concentration of egg white antimicrobial proteins as well as incubation patterns differ among altricial and precocial species of birds. However, experimental study testing the effect of incubation temperature on the antimicrobial potential of antimicrobial egg white proteins in altricial and precocial birds is missing. In this study we tested in manipulative experiment the effect of partial and full incubation, the concentration of lysozyme and ovotransferrin and their interactions on the antimicrobial activity of egg whites of two model species - Japanese quail (Coturnix japonica) and home pigeon (Columba livia). Antimicrobial protein activity was determined by the agar well diffusion method against two Gram-positive bacteria - Bacillus subtilis and Micrococcus luteus that have been documented as pathogenic egg-white invaders of several birds. Moreover, we analyzed the effect of...
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The role of individual traits in the Northern Lapwing (Vanellus vanellus) females on breeding performance, mating status and male incubation effort
Sládeček, Martin ; Šálek, Miroslav (advisor) ; Fuchs, Roman (referee)
Feather ornaments and its role as a signals in sexual selection has been broadly studied topic in avian biology. However, vast majority of studies focus especially on role of male ornamentation and female preferences in sexual selection. Despite this fact, recent work shows, that similar palette of adaptive functions can be found for female feather ornaments, and male preferences for them, respectively. This study focuses on possible importance of female melanin-based ornaments and other individual on breeding performance in the Northern Lapwing (Vanellus vanellus), common polygynous wader breeding in agricultural landscape. No significant predictor of female investment to egg size was found. Long winged females with bigger proportion of secondaries changed during prenuptial moulting and bigger extent of melanin ornaments tended, surprisingly, to later timing of breeding. Contrary to this trend, extent of female ornamentation seems to be sexually selected trait by males. Analysis of male incubation behavior shows, that males incubate more in nests of more ornamented females, as well as in nests in later incubation stage. These findings seems to be in a good agreement with "Differential allocation hypothesis". On the other site, no effect of clutch egg sizes and timing of breeding was found....
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Influence of external conditions on egg incubation in lapwings (genus Vanellus) in temperate and subtropical climate
Pešková, Lucie ; Šálek, Miroslav (advisor) ; Hořák, David (referee)
During incubation, most birds require the presence of at least one parent to ensure suitable incubation conditions for embryo development. The main factors that affect the development of the embryo are temperature, humidity and egg turning. In this work, incubation conditions were investigated in two biparental Lapwing species (genus Vanellus), the Northern Lapwing (Vanellus vanellus), which faces the risk of egg cooling in temperate areas, and the Red-wattled Lapwing (Vanellus indicus), which faces the risk of egg overheating in the subtropics. A laboratory experiment testing the thermal properties of the Red-wattled Lapwing nest lining showed that it selects lining material that slows down temperature growth during egg heating, thus ensuring suitable thermal conditions during parental absence at high ambient temperatures. Temperature and egg turning during incubation were recorded by an artificial egg with a built-in sensors placed in the nests of both target species; data collected by the sensors were stored by a base-station located nearby. The average egg temperature was 32.5 řC for the Northern Lapwing, and 35.0 řC for the Red-wattled Lapwing. Egg temperature in both species fluctuated significantly, affected by many factors. Egg temperature increased with increasing ambient temperature, it...
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Effect of incubation temperature on growth of the working and conducting myocardium in the embryonic chick
Skuhrová, Kristýna ; Sedmera, David (advisor) ; Gregorovičová, Martina (referee)
It was shown almost 50 years ago that hypothermic incubation of chicken embryos results in a reduction in the size of embryos and an increase in the heart weight, presumably by hypertrophy (increase in cell volume). The chicken embryos were incubated in normothermia (37.5 ř C) and hypothermia (33.5 ř C) from the eleventh embryonic day. On the 17th day, the embryos were weighed and then their hearts were weighed. In agreement with the previous results, hypothermic embryos were 29% smaller and their hearts 18% heavier. The heart-to-body weight ratio was 67% higher in the hypothermic group. The measured cell size was very similar in the target areas and it was also between the two groups. The left ventricle width was twofold that the right one and the difference was not significantly higher in the hypothermia model. Purkinje fibers, the terminal part of the conduction system, were smaller than the working cardiomyocytes. Purkinje fibers were slightly enlarged after hypothermic incubation. The proliferation rate was measured by immunohistochemical labeling of anti-phospho histone H3. The experimental group showed much higher proliferation rate; it reached statistical significance in the right ventricle. Thus, hypothermic incubation resulted in increased growth of embryonic heart based on hyperplasia...
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The role of partial incubation in birds
Březinová, Monika ; Javůrková, Veronika (advisor) ; Sedláček, Ondřej (referee)
It was documented that many species of birds incubate their clutch before the clutch completion. This behaviour called partial or intermittent incubation usually takes only few hours per day. Eggs in clutch are from the time of laying until the time of full incubation exposed to many negative environmental factors and disturbances. These factors may reduce the viability of the embryo and brood survival. It is therefore predicted that birds use partial incubation as a protection against these negative factors. Most probable functions of partial incubation are a protection against clutch predation, intraspecific and interspecific brood parasitism, and antimicrobial actions linked with reduction of potentially harmful microorganisms on the eggshells and/or activation of proteins with antimicrobial potential in egg's yolk and albumen. This bachelor thesis summarizes overall knowledge of partial incubation, with special emphasis on its incidence and functions in birds. Moreover, this thesis reviews the problematics of synchronous and asynchronous hatching of partially incubated clutches. Although, based on literature review, partial incubation has strong impact on overall reproduction success in birds, study of this incubation behaviour is still neglected and more attention should be paid on comparative...
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The role of individual traits in the Northern Lapwing (Vanellus vanellus) females on breeding performance, mating status and male incubation effort
Sládeček, Martin ; Šálek, Miroslav (advisor) ; Fuchs, Roman (referee)
Feather ornaments and its role as a signals in sexual selection has been broadly studied topic in avian biology. However, vast majority of studies focus especially on role of male ornamentation and female preferences in sexual selection. Despite this fact, recent work shows, that similar palette of adaptive functions can be found for female feather ornaments, and male preferences for them, respectively. This study focuses on possible importance of female melanin-based ornaments and other individual on breeding performance in the Northern Lapwing (Vanellus vanellus), common polygynous wader breeding in agricultural landscape. No significant predictor of female investment to egg size was found. Long winged females with bigger proportion of secondaries changed during prenuptial moulting and bigger extent of melanin ornaments tended, surprisingly, to later timing of breeding. Contrary to this trend, extent of female ornamentation seems to be sexually selected trait by males. Analysis of male incubation behavior shows, that males incubate more in nests of more ornamented females, as well as in nests in later incubation stage. These findings seems to be in a good agreement with "Differential allocation hypothesis". On the other site, no effect of clutch egg sizes and timing of breeding was found....
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Temperature-dependent activity of egg-white antimicrobial proteins in precocial and altricial birds
Novotná, Lucie ; Javůrková, Veronika (advisor) ; Krist, Miloš (referee)
Microorganisms are considered to be crucial selective factor affecting reproductive success of birds. It is hypothesized that egg-white antimicrobial proteins and incubation behavior are the most important defense mechanisms that eliminates the risk of microbial trans-shell infection. The latest studies supposed that incubation temperatures may significantly affect the antimicrobial activity of egg white proteins. The concentration of egg white antimicrobial proteins as well as incubation patterns differ among altricial and precocial species of birds. However, experimental study testing the effect of incubation temperature on the antimicrobial potential of antimicrobial egg white proteins in altricial and precocial birds is missing. In this study we tested in manipulative experiment the effect of partial and full incubation, the concentration of lysozyme and ovotransferrin and their interactions on the antimicrobial activity of egg whites of two model species - Japanese quail (Coturnix japonica) and home pigeon (Columba livia). Antimicrobial protein activity was determined by the agar well diffusion method against two Gram-positive bacteria - Bacillus subtilis and Micrococcus luteus that have been documented as pathogenic egg-white invaders of several birds. Moreover, we analyzed the effect of...
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Incubation effort in Common Pochard and its determinants
Drekslerová, Šárka ; Hořák, David (advisor) ; Musil, Petr (referee)
Incubation of avian eggs is an energy demanding process. Incubating parent faces a conflict between investment into optimal thermal conditions for developig embryos and meeting of own energy requirements. This applies especially in uniparental incubators such as ducks. During incubation, female utilizes energy from fat storage or actual food intake. The proportion of energy used from food than may reflect the time spent by female on the nest. The utilizing of these both sources ratio plays a role in time spent on nest. The aim of the thesis was to describe an incubation rhythm in females of Common Pochard (Aythya ferina) and relate them to climatic variables and changes in body mass. Data were collecetd for three years in the Poodříí Landscape Protected Area at free-living females. We placed a weighting mechanism under the nest with conected datalogger recording voltage variations, which offered me an information about female body mass and time and duration of recesses. Incubation rhytm of females was described by time spent on time ("incubation constancy"), recess frequency and recess duration. Females left the nest most grequently at night-time and during dawn and dusk. Probable explanation of this pattern is better food availability in the night-time and lower risk of nest predation by predators...
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