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Variability of eggshell colouration
Bubeníčková, Kateřina ; Svobodová, Jana (advisor) ; Sládeček, Martin (referee)
Bird´s Eggs Are Specific for Big Variability in Eggshell Coloration. This Eggshell Eoloration Is Caused by Two Pigments; Biliverdin and Protoporphyrin. Biliverdin Causes Bluegreen Color of the Egg and Protoporphyrin Causes RedBrown and Black Maculas on the Surface of the Eggshell. Many Hypotheses Try to Clarify the Reason of Resultant Variability in the Eggshell Coloration. The Final Reason of the Variability in the Eggshell Coloration Has Not Been yet Explained and this Is the Reason, Why this Topic Is Subject of Scientifical Researches. In the Theoretical Part of this Thesis Are Described Individual Hypotheses, Which Describe Variability in the Eggshell Coloration. These Theses Were Focused on Structural and Signal Function of Pigment and the Anemic Hypothesis; these are Explained in Detail in the thesis, because they are the subjects of this thesis´s Research. Signal Hypothesis Works with Theory, That Egg´s Pigmentation Informs the Partner about Female´s Condition Quality. Results of Recent Published Studies, Which Are Focused on Signal Function, Say, That 60% of Results Support the Theory, That Egg Maculation Relates to Female´s Body Condition. 80% of Studies about Signal Function Made There Researches on Passerines. This Is the Main Reason, Why Signal Function of Pigment Cannot Be Applied Generaly on All Bird Species, because the Signal function Was Not Properaly or None Tested on Other Species Than Passerines (Out of Few Exceptions). Anemic Hypothesis Might Explain the Variability in the Eggshell Coloration with Theory, Protoporphyrin, Which Is Derived in Higher Concetration from Blood Due the Anaemia Causes Higher Maculation on the Surface of Eggshell. Purpose of Practical Part of this Thesis Was Finding Out, Whether Female´s Condition Quality Depends on the Character of Color Maculation in Great tit (Parus major). Futhermore if There Exist Correlation between Ratio (of Immature Red Blood Cells and Total Sum of Red Blood Cells) and Eggshell Coloration. Results of the Study Show, that the Eggshell Coloration May Depend on female´s Conditon. Specifically, Red-Brown Macules with Lower Level of Intensity and Saturation Pronounce Larger Area of Melanin Based Ventral Stripe. In Conclusion, this Thesis Supports Signal Function Thesis of Protoporhyrin and Leads to the Fact, that Final Eggshell Coloration Has an Impact on the Female´s Body Condition. Results of this Thesis Does Not Prove any Relationship Between Ratio (of Immature Red Blood Cells and Total Sum of Red Blood Cells) and Eggshell Coloration. It Leads to the Fact, that there Is No Possible Support for Correlation between Anaemia and Variability in Eggshell Coloration in our Population of Great tit.
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