|
|
Parental care in crocodylians with an emphasis on acoustic communication between parent and young
Míka, Milan ; Frýdlová, Petra (advisor) ; Sedláček, Ondřej (referee)
Parental care for offspring encompasses a variety of behaviors aimed at increasing the offspring's survival rate. However, as the care of the offspring requires a lot of energy it raises a conflict between the parents. It would be more advantageous for each parent to leave a larger portion of parental care to the other. This would reduce the costs associated with care while increasing the success of gene transmission through offspring. This bachelor thesis describes parental care in several selected groups of animals. It reports the most common forms of parental care in these groups and, through individual examples, points out more complex or unusual forms and types of reproductive behavior. Examples are selected with consideration of similarities or differences with parental care in crocodiles. In the second part of this work, I focus on the order of Crocodylia, where parental care and acoustic communication are key elements of reproductive behavior and often determine the lives of crocodile offspring. I highlight similarities between crocodiles and their closest relatives, birds (Aves). Emphasis is placed on the analogy between crocodiles and birds and my observations suggest possibilities of ancestral behavior for the order Crocodylia and the entire group Archosauria. The result of the work is a...
|
|
|
Development of the climate during the Miocene based on the study of reptilian associations in northwest Bohemia
Chroust, Milan ; Mazuch, Martin (advisor) ; Zajíc, Jaroslav (referee) ; Sabol, Martin (referee)
The PhD thesis is about fossil crocodiles and turtles from the Most basin and their implication in paleoclimatic and paleoecological reconstruction. The thesis is composed of accompanying text together with four separate scientific papers included in the attachment. Dozens of bony fragments, which belong to fossil crocodiles and turtles, are known from the Most basin (NW Bohemia, Czechia). Surprisingly, the high biodiversity of fossil turtles was revealed. According to a study of fossil crocodiles and turtles we are able to reconstruct the ancient landscape (i.e., ecosystems), mean annual temperatures together with the extremes in summer and winter periods. However, for the proper reconstruction of paleotemperatures, the taxonomic description is mandatory. Fossil crocodiles and turtles lack the systematic review, while they are in fact the most abundant material compared to other fossil vertebrates (i.e., mammals, birds, etc.). Crocodylian material belongs to the genus Diplocynodon and thanks to the cranial material from the Tušimice site, we are able to describe it as Diplocynodon ratelii. The soft-shell turtles (Trionychinae) from the Břešťany site are described as Rafetus bohemicus including the new diagnostic characters. Another trionychid material is for now impossible to determine at the...
|
|
|
Factors influencing worldwide zoo collections of lizards, snakes, turtles and crocodiles: effect of conservation status, body size and their attractiveness to humans
Janovcová, Markéta ; Landová, Eva (advisor) ; Komárek, Stanislav (referee)
There is a large number of species existing in the world; each year, however, the number of the endangered ones rapidly increases. Nowadays, captive breeding becomes an option for their survival in refugees. Sufficient population with satisfactory breeding management gives hope for survival to the endangered species (in mid-term) or even possible future reintroduction to their natural habitat. WAZA is currently the world's leading association of worldwide zoos and similar breeding facilities. Because these institutions operate as a network to facilitate the exchange of reared individuals, for conservation purposes, their captive populations may be seen as one large population characterized by its size, i.e., the total number of individuals. Such view is currently recognized by many conservationists as the so-called concept of Noah's Ark. The space on the Ark is limited, therefore it is needed to heed the characteristics of the species aboard to maximize the conservation potential. Many factors influence the presence of species in zoological gardens. Following previous studies we selected some factors that may be important, i.e., body lenght, taxonomy, and IUCN status. Analysis of these factors among the main reptile clades shall reveal the pattern of reptile composition in worldwide zoos. One of the factors...
|
|
|
Factors influencing worldwide zoo collections of lizards, snakes, turtles and crocodiles: effect of conservation status, body size and their attractiveness to humans
Janovcová, Markéta ; Landová, Eva (advisor) ; Komárek, Stanislav (referee)
There is a large number of species existing in the world; each year, however, the number of the endangered ones rapidly increases. Nowadays, captive breeding becomes an option for their survival in refugees. Sufficient population with satisfactory breeding management gives hope for survival to the endangered species (in mid-term) or even possible future reintroduction to their natural habitat. WAZA is currently the world's leading association of worldwide zoos and similar breeding facilities. Because these institutions operate as a network to facilitate the exchange of reared individuals, for conservation purposes, their captive populations may be seen as one large population characterized by its size, i.e., the total number of individuals. Such view is currently recognized by many conservationists as the so-called concept of Noah's Ark. The space on the Ark is limited, therefore it is needed to heed the characteristics of the species aboard to maximize the conservation potential. Many factors influence the presence of species in zoological gardens. Following previous studies we selected some factors that may be important, i.e., body lenght, taxonomy, and IUCN status. Analysis of these factors among the main reptile clades shall reveal the pattern of reptile composition in worldwide zoos. One of the factors...
|
|
|
Keeping and breeding of CITES reptiles in Czech Republic
TRINHOVÁ, Leona
Czech Republic considerably participated on European terraristic history with breeding of many reptiles and amphibians.This thesis covers breeding of reptiles protected on Czech Republic territory by CITES agreement. Based on mapping performed by zoological gardens, other specialized facilities and private breeders, percentage graphs were created for both reptiles not bred in Czech Republic, those bred by terrarists so far without successful reproduction and also for reptiles successfully reproduced. Aim of this thesis was to find outbreeding level of endangered reptiles within Czech Republic.Graphs with breeding success results were created for each genus. It was discovered that the best breeding results exist for reptiles reared most commonly here; turtles are bred less successfully and the least percentage of success was found with crocodiles. Probable reasons for such results were clarified too.
|
guest ::
