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Productivity of environment and colouration of South African birds
Kubíková, Tereza ; Hořák, David (advisor) ; Albrecht, Tomáš (referee)
Understanding the relationships between species traits and the environment is essential for assessment of functional diversity. The variation in avian plumage colouration has attracted much scientific attention for a long time. It is thought that the colouration of birds is a product of interaction between environmental and sexual selection forces. Using two complementary three-matrix approaches (fourth-corner and RLQ analyses) I investigate geographical variation in plumage colouration of birds living along environmental gradient of productivity in South Africa. I suppose that productivity of environment could explain the part of variation in colouration of species at large geographical scales. I compiled information about 14 plumage traits for 649 species. Co- inertia analysis revealed that more vari-coloured species (e.g. with more saturated and vivid plumage), species with carotenoids in feather, blue-green or predominantly black species occur mainly in productive habitats such as moist savannas and woodlands in the north-east of the country. On the contrary pale species (e.g. greyishbrown), whose feathers are brighter (have higher values of brightness), occupy arid habitats in the west. It shows that another pattern such as iridescence, sexual dimorphism and brightness of particular body region exhibit...
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Environment and avian song: case of South African birds
Mikula, Peter ; Albrecht, Tomáš (advisor) ; Linhart, Pavel (referee)
Relationship between animal signalization and environmental conditions, where these species are living, is one of crucial topics of ecology. Using two complementary statistical approaches (fourth-corner and RLQ analyzes) I investigated geographical variation in parameters of bird vocalization in South Africa (RSA) and Lesotho. Altogether, I used nine quantitative and five qualitative acoustic traits for 472 bird species and nine environmental variables which could significantly influence parameters of their vocalization. My results supported findings of previous studies about the important effect of body size on species-specific vocal characteristics. In passerines, analyzes corrected for body size showed that the number of elements and element types were increasing with variability of natural conditions and were highest in very arid and climatically unpredictable areas. Element and element type rate were positively associated with altitude. Minimal song frequency in passerines and frequency range of vocalization in other birds were negatively correlated with average temperature of warmest and coldest month of the year, respectively. Similarly, environmental variables significantly influenced distribution of several qualitative song traits in passerines. Passerines, where female song and...
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The relationship between diversity patters, spatial distribution and life-histories in African birds
Tószögyová, Anna ; Storch, David (advisor) ; Šizling, Arnošt Leoš (referee)
Species with particular traits are not randomly distributed across landscape. Habitats provide the templet on which evolution forges characteristic morphologies and life-history strategies and environmental determinants in an ecological processes represent a filter for certain species with appropriate traits. It is essential to understand how spatial differences in community composition are affected by geographical patterns in a distribution of species characteristics. I was interested in searching and determining the relationships between species traits and environmental parameters within avifauna of south Africa. I investigated the effect of which variables of environment most influenced bird assemblage composition and distribution of species traits in space. Relationships between the environmental factors and the species traits and life-history stategies were investigated using RLQ analysis, a multivariate ordination method able to relate a species trait table to an environmental table by way of a species presence/absence table. The first axis of the RLQ analysis was highly statistically significant and explained most of the variability. It was strongly positively related to increasing productivity, to atributes reflecting vegetation character and to availability of water sources. The rest of...
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Productivity of environment and colouration of South African birds
Kubíková, Tereza ; Hořák, David (advisor) ; Albrecht, Tomáš (referee)
Understanding the relationships between species traits and the environment is essential for assessment of functional diversity. The variation in avian plumage colouration has attracted much scientific attention for a long time. It is thought that the colouration of birds is a product of interaction between environmental and sexual selection forces. Using two complementary three-matrix approaches (fourth-corner and RLQ analyses) I investigate geographical variation in plumage colouration of birds living along environmental gradient of productivity in South Africa. I suppose that productivity of environment could explain the part of variation in colouration of species at large geographical scales. I compiled information about 14 plumage traits for 649 species. Co- inertia analysis revealed that more vari-coloured species (e.g. with more saturated and vivid plumage), species with carotenoids in feather, blue-green or predominantly black species occur mainly in productive habitats such as moist savannas and woodlands in the north-east of the country. On the contrary pale species (e.g. greyishbrown), whose feathers are brighter (have higher values of brightness), occupy arid habitats in the west. It shows that another pattern such as iridescence, sexual dimorphism and brightness of particular body region exhibit...
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