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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.
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Bioenergetics of reproduction and postnatal development of two species of social mole-rat of genus \kur{Fukomys}
ZEMANOVÁ, Milada
The resting metabolic rate of mole-rats was measured with a close-flow respirometry system and body temperature was recorded with a rectal thermometer at an ambient temperature within and below adult thermoneutrality range. The development of ability to thermoregulate was monitored for pups of Fukomys sp. Huddling and presence of adults reduced the body heat loss of pups of all monitored age, but no effect was observed on the metabolic rate of the pups until they were two months old. Huddling had no effect on resting metabolic rate and body temperature in adult giant mole-rats Fukomys mechowii. The maternal cost of reproduction was evaluated in females from two species of the genus Fukomys. The energetic expenditure of females increased with pup´s age.
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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.
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