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How evolution of coloration in parrots (Psittaciformes) affects species conservation through human preferences
Lišková, Silvie ; Šumbera, Radim (referee) ; Frynta, Daniel (advisor)
Each year, several new species are recognized as threatened or endangered. Today's worldwide zoos and aquariums are highly concerned in their conservation and the species kept in large numbers have high chances for possible future reintroduction. However, the selection of the species kept is decided by men and as such can be affected by human aesthetic preferences. The aim of this thesis was to test the hypothesis that zoos preferentially keep species that are attractive rather than endangered, using the parrot family (Psittaciformes) as an example. We collected data from 460 human respondents who evaluated the attractiveness of parrots presented on painted illustrations. After analyzing which traits affect the perceived beauty we found that humans prefer parrots that are big, long-tailed and colourful (blue, orange and yellow). There was a considerable agreement among the respondents. We repeatedly confirmed significant positive association between the perceived beauty and the size of worldwide zoo population. In addition of perceived beauty, area of distribution and body size appeared significant predictors of zoo population size. In contrast, the effects of conservation status and taxonomic uniqueness appeared insignificant. Our results suggest that zoos preferentially keep beautiful parrots and pay less...
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Aggregation behaviour of cockroaches (Blattaria: Blaberidae): intraspecific and interspecific preference
Varadínová, Zuzana ; Frynta, Daniel (advisor) ; Janda, Milan (referee)
Cockroaches (Blattaria) are considered to be nearly universally gregarious insect order. In spite of this fact most of the research effort has been devoted to the behaviour of domiciliary species. It is thus not surprising we still do not have comparable information about aggregation behaviour in common laboratory blaberid species. We have investigated aggregation behaviour of adult males and females in six blaberid species: four South American species (Blaberinae: Eublaberus posticus, Eublaberus distanti, Blaberus discoidalis, Blaberus craniifer) and two Madagascar species (Oxyhaloinae: Gromphadorhina portentosa, Princisia vanwaerebeki). Intraspecific aggregation behaviour was determined using two approaches: the binary choice tests arena and free interaction arena tests. Results obtained with both methods were largely consistent. We have found that blaberid clades clearly differed in their aggregation patterns. (1) Females of Eublaberus species aggregated while only a slight and less consistent aggregation tendency was recorded in conspecific males. (2) Both sexes of Blaberus species aggregated, especially when tested in the arena. (3) The Madagascar hissing cockroaches of the Gromphadorhina-Princisia clade are not gregarious, the aggregation tendency was entirely absent in the males of both species and...
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