Habicher, Alexandra (2009) Behavioural Cost Minimisation and Minimal Invasive Blood-Sampling in Meerkats (S. suricatta, Herpestidae). PhD thesis, Universität zu Köln.
Meerkats (S. suricatta) are social mongooses inhabiting semiarid habitats in southern Africa. They are physiologically desert-adapted, but also utilise a high proportion of behavioural thermoregulation. This study investigated how thermoregulation by behaviour can aid to minimise the physiological costs of thermoregulation. In a first part, behavioural observations derived from 230 observation hours at the �Kalahari Meerkat Project� in South Africa were correlated to ambient factors such as temperature, radiation, humidity and wind speed. It could be shown that temperature had the most significant influence on the distribution of the behavioural data. Especially the meerkats' upper and lower critical temperatures, literature data obtained in the lab, could aid at explaining the proportions of time spent in sun, shadow and below, as well as the proportion of times spent with thermoregulatory behaviours (contact lying, sunbathing and piloerection). The influence of radiation added on the effect of temperature, as the animals utilised solar radiation to heat up at low ambient temperatures (TA) and avoided it at high TA. Influences of humidity and wind speed were of minor importance. It is evident, that meerkats utilise a high proportion of behaviour to minimise energetic costs. Extrapolating from physiological literature data, it can be assumed that this minimization can amount up to 18% by a single behaviour. In a second part, a minimal invasive method of blood sampling was presented for zoo animals, also suitable for wild animals. For the fist time, this study could sample blood using tsetse G. brevipalpis in zoo animals on an outside enclosure. Insects were attached to the zoo animals in a box on a collar. These blood samples could be used to obtain data on energy expenditure with the �Doubly-Labelled -Water� (DLW) method and data on hormone levels. In contrast to previous works, study animals were not restricted in their mobility and could move freely during the blood sampling period. As insects were attached to the meerkats with a box, this technique allowed to derive blood samples at defined points of time, although the use may be limited to species habituated to close human presence. For the first time, this thesis presents a dipteran species that can be used as a tool for minimally invasive blood sampling, unlike previous works, that have been working with South American reduviid species. When planning to work in a South American environment, it was shown that these commonly used reduviids can easily be sterilized with ionising radiation to minimise potential risks to the environment. It could be presented that not only reduviids posses beneficial properties as blood-sampling tools, but except for the obtained blood volumes, tsetse seem to be even more applicable as they were more reliable (in terms of feeding motivation) and less temperature-sensitive, both important criteria when working in the field. Introducing a so far unimplemented, African blood parasitic species to obtain minimal invasive blood samples, a long term goal derived from this work could be to find suitable insect candidates in every environment where field studies could benefit from minimally invasive blood sampling.
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