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Mean Body Temperature (mean + body_temperature)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Scaling of body temperature in mammals and birds

FUNCTIONAL ECOLOGY, Issue 1 2008
Andrew Clarke
Summary 1We examine variation associated with phylogeny in the scaling of body temperature in endotherms, using data from 596 species of mammal and 490 species of bird. 2Among higher groups of mammals there is statistically significant scaling of body temperature with mass in Marsupialia (positive), Ferae and Ungulata (both negative). In mammalian orders where data are available for at least 10 species, scaling is negative in three orders (Carnivora, Erinaceomorpha and Artiodactyla), positive in one (Chiroptera) and not significant in seven others. There is no relationship apparent between the scaling of body temperature and the existence of gut fermentation. As expected, monotremes exhibit the lowest body temperatures, but within marsupials diprotodonts have a mean body temperature higher than several placental groups; the traditional ranking of body temperatures in the sequence monotremes , marsupials , placentals is thus misleading. 3In birds, scaling relationships are significant only for Ciconiiformes (strongly negative) and Passeriformes (weakly positive). 4When allowance is made for phylogenetic effects, there is no significant relationship between temperature in body mass in mammals overall, but an inverse and almost significant relationship in birds. 5This study indicates a complex relationship between body mass, body temperature and metabolic rate in mammals and birds, mediated through ecology. [source]

An experimental test of the link between foraging, habitat selection and thermoregulation in black rat snakes Elaphe obsoleta obsoleta

JOURNAL OF ANIMAL ECOLOGY, Issue 6 2001
Gabriel Blouin-Demers
Summary 1Most physiological processes are temperature-dependent. Thus, for ectotherms, behavioural control of body temperatures directly affects their physiology. Ectotherms thermoregulate by adjusting habitat use and therefore thermoregulation is probably the single most important proximate factor influencing habitat use of terrestrial reptiles, at least in temperate climates. 2Snakes have been shown to raise their body temperature following feeding in a laboratory thermal gradient, presumably to enhance digestion. This experiment was exported to the field to explore the link between feeding, habitat selection and thermoregulation in free-ranging snakes. 3Experimental feeding was conducted in the laboratory and in the field on black rat snakes (Elaphe obsoleta obsoleta) that had temperature-sensitive radio-transmitters surgically implanted. 4Snakes had higher mean body temperatures following feeding than prior to feeding in a laboratory thermal gradient. 5Some, but not all evidence, indicated that black rat snakes increased their mean body temperature following feeding in the field. Indices of thermoregulation indicated that the snakes thermoregulated more carefully and more effectively after they had eaten. 6Forest edges provided the best opportunities for thermoregulation in the study area. Black rat snakes were less likely to move following feeding when fed in edges than when fed in the forest and were more likely to be found in edges following feeding, whether they had been fed in the forest or in an edge. 7Results of this study and one previous study suggest that thermoregulatory behaviour of snakes following feeding in the laboratory is a reliable predictor of their behaviour in the field. A review of 13 studies of the thermoregulatory behaviour of snakes following feeding in the laboratory revealed that not all species behave similarly. However, the quality and number of studies currently available is not adequate for testing hypotheses about which species should change thermoregulatory behaviour in response to eating and which should not. [source]

Suboptimal thermoregulation in male adders (Vipera berus) after hibernation imposed by spermiogenesis

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2007
GÁBOR HERCZEG
In ectotherms, the main behavioural option for thermoregulation is the adjustment of daily and seasonal activity to the thermal quality of the environment. While active, ectotherms thermoregulate by shuttling in between thermally differing microhabitat patches. Here, we focused on the question of whether other behavioural or physiological processes could force ectotherms to maintain activity during thermally unfavourable periods, when accurate thermoregulation is impossible. Using laboratory experiments and field data we compared the thermoregulation of male adders (Vipera berus) between two periods in spring when (1) only males and (2) also females and juveniles had terminated their winter hibernation. We found that males thermoregulated actively both in the lab and in the field. Accurate thermoregulation was only possible during the second period because of the low thermal quality of the environment. Male adders maintained a lower mean body temperature in the field than in the laboratory within both periods, and in addition their body temperature during the first period was on average 4 °C lower than during the second period. The thermal qualities of the natural basking sites showed a similar pattern. We discuss the results in the context of a potential trade-off between spermiogenesis and thermoregulation, where the benefits of early spermiogenesis coupled with inaccurate thermoregulation are higher than the associated costs. The results support the contention that the earlier spring emergence of the male compared with female adders is explainable by natural selection favouring early initiation of spermiogenesis, and hence sex differences in phenology. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92, 19,27. [source]