|
|
Phylogeny and genetic diversity of two solitary African mole-rat genera \kur{Heliophobius} and \kur{Georychus}
UHROVÁ, Michaela
Two solitary genera of African mole-rats, Heliophobius and Georychus, had been for a long time considered as monotypic, yet some of the recent studies proposed species complexes. This thesis evaluates intrageneric relationships of both genera by using extended dataset of six nuclear markers and a large number of loci acquired during ddRADseq. Both datasets confirmed highly genetically structured populations within both genera. Nevertheless, while multilocus coalescent based on nuclear markers defined nine gene pools within Heliophobius and five within Georychus, processing of ddRADseq data revealed both, significantly finer (fineRADstructure) or broader (Infomap) structure. Based on the genetic evidence, we are inclined towards using two species within genus Heliophobius, comprised of northern and southern lineages separated by Eastern Arc Mountains, and one species for all evolutionary lineages of Georychus. The final taxonomic revision should await further morphological, ecological, or behavioural studies.
|
|
|
Mammalian energetic savings in subterranean environment. The case of African mole-rats.
OKROUHLÍK, Jan
Mole-rats are placental mammals which are perfectly adapted to subterranean life. In this thesis I present novel findings on working metabolism and thermoregulatory physiology of mole-rats. These animals cope with low availability of food and have thus employed multiple strategies how to conserve energy and/or use it more effectively. Among other adaptations this resulted in lower resting body temperature, tolerance to increase in body temperature during exercise or while at rest, surprisingly efficient cooling while digging and precise diurnal and seasonal timing of activity with regards to environmental conditions. My focus in this work is on the digging metabolic rate and thermoregulation of social Fukomys mechowii and solitary Heliophobius argenteocinereus in soft and hard substrate, thermoregulatory abilities of Fukomys darlingi, seasonal changes of activity in free living Heliophobius argenteocinereus measured as daily energy expenditure and, finally, energetic consequences of the daily activity patterns of Fukomys anselli.
|
|
|
Ecology and activity of mesic Afrotropic mole-rats
LÖVY, Matěj
This Ph.D. thesis focuses on the ecology and activity of mesic Afrotropic mole-rats. In particular, ecological characteristics in habitats of two mole-rat species with different social system, the solitary Heliophobius argenteocinereus and social Fukomys whytei, were analysed in an area of sympatry and the results are discussed in relation with available ecological data on other species. Two studies bring to light novel data on the ecology and behaviour of the free-living largest social bathyergid, the giant mole-rat Fukomys mechowii, especially in relation to ecological characteristics in its natural habitat, burrow system architecture, kin structure and spatial and temporal activity patterns. In the final study, new data on the field metabolism of the silvery mole-rat H. argenteocinereus are presented. These new findings are discussed in further detail and expand upon existing explanations for low resting metabolism in subterranean rodents and the differences in field metabolism in relation to seasonality of habitat.
|
guest ::
