Continuous radiotelemetric records of the deep body temperature of some unrestrained African mammals under near‐natural conditions

Abstract

The deep body temperatures of a wide range of animals have been recorded in the literature. The majority of these records has depended upon discrete measurements made while the animal was captive and restrained, or immediately after death by shooting. Estimates of the variation in deep body temperature have been achieved by making a series of measurements of rectal temperature of one animal at different times of the day, or by making a series of single measurements on several animals immediately upon captivity or sudden death at different times of the day. Until recently it has been impracticable to make continuous measurements of the deep body temperature of unrestrained mammals in a natural or nearnatural environment and virtually no such records existed when this study was undertaken. In consequence, there was no reliable information concerning the temporal pattern of the deep body temperature of a range of mammals under these circumstances, and it was not possible to determine the range of nychthemeral (24 hourly) variations in deep body temperature that occur among the mammalian species generally described as being homoeothermic.The development of miniature recorder systems and radiotelemetric systems for monitoring physiological parameters of unrestrained animals now makes the collection of such data technically feasible. A batteryoperated system of radiotelemetric thermometry designed for this purpose (Bligh & Robinson, 1963;Robinson, 1964) has been used to make a series of continuous

Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions

“…Our results confirm previous demonstrations of robust daily rhythmicity of core body temperature in camels (Bligh and Harthoorn, 1965;Bouâouda et al, 2014;El-Allali et al, 2013).…”

“…The lower temperature in the study by Bligh and Harthoorn (1965) can be explained by the fact that they measured body temperature in the camel's hump, whereas Bouâouda et al (2014) The robustness of the core body temperature rhythm was between 40 and 80%, depending on whether it was calculated for individual animals or for the group as a whole, which is consistent with the findings in sheep, goats, horses, and cattle (Piccione et al, 2003). When the animals were maintained in a stable environment (without a light-dark cycle or a cycle of ambient temperature), core body temperature still exhibited near-24-hour rhythmicity, thus confirming the endogenous nature of the rhythm previously documented in a large number of species (Refinetti, 2010), including the camel (El-Allali et al, 2013).…”

“…Although Bligh and Harthoorn (1965) and Bouâouda et al (2014) found the mean core body temperature of the camel to be considerably lower (around 37.0 °C) than we did (38.0 °C), El-Allali et al (2013) obtained a mean very similar to the one we obtained (37.9 °C). The lower temperature in the study by Bligh and Harthoorn (1965) can be explained by the fact that they measured body temperature in the camel's hump, whereas Bouâouda et al (2014) The robustness of the core body temperature rhythm was between 40 and 80%, depending on whether it was calculated for individual animals or for the group as a whole, which is consistent with the findings in sheep, goats, horses, and cattle (Piccione et al, 2003).…”

“…In the camel, in particular, only a few studies have examined daily rhythmicity, and they focused on individual variables such as body temperature (Bligh and Harthoorn, 1965;Bouâouda et al, 2014;El-Allali et al, 2013), sweat rate (Abdoun et al, 2012), plasma aldosterone (Khaldoun et al, 2002), plasma melatonin (El-Allali et al, 2005), and biomarkers of bone formation (Al-Sobayil, 2010).…”

The deep body temperature of an unrestrained Welsh Mountain sheep recorded by a radiotelemetric technique during a 12‐month period

“…If this generality is accepted, then the thermoregulatory performance of the sheep under field conditions is unexceptional. However, a recent comparative study ofthe nychthemeral variation of body temperature of some mammals in East Africa (Bligh & Harthoorn, 1964) has indicated that there are species-specific differences in the degree of thermostability of mammals. In that study, where nychthemeral variations of up to 30 C were recorded in some species, the sheep was found to be the most thermostable.…”