Comparing the Allostasis and Reactive Scope Model in African Striped Mice (Rhabdomys pumilio)
A two-year postdoc position in eco-physiology is available at the School of Animal, Plant and Environmental Sciences at the University of the Witwatersrand. Field work will be done at the Succulent Karoo Research Station. The postdoc will be mentored by Dr. Neville Pillay and Dr. Carsten Schradin (currently University of Zurich and expected to be at the CNRS in Strasbourg, France, from October 2012 onwards).
Project: Evolution of physiological adaptation: how can animals survive and reproduce in an environment characterized by variable droughts? The concepts of allostasis and reactive scope have been very successful in explaining physiological adaptation and stress in free ranging birds, but have been applied to only a limited number of species. We want to test predictions from both models for the first time in a mammalian species living in an extreme environment, the African striped mouse from the Succulent Karoo semi-desert of South Africa. We will test the predicted strong relationship between glucocorticoids and energy expenditure (allostasis model) and aim to measure homeostatic overload in free ranging animals, especially gluconeogenesis via muscle catabolism, i.e. muscle breakdown, a response to pathologically high glucocorticoid levels, as would be indicated by high uric acid blood levels (reactive scope model). We are especially interested in fitness consequences of ecologically mediated physiological adaptation.
Methods to be applied: The postdoc is expected to spend the majority of the time in the field. Methods include trapping, marking, measuring and observing striped mice. In the field, food availability will be measured via plant surveys. Blood samples will be collected for physiological measurements. An ABAXIS blood analyzer is available at the research station and the postdoc is expected to run this equipment. Blood glucose and blood ketone levels can be measured directly in the field. Experiments using hormone implants (increase of corticosterone levels during the dry season) will be possible. Blood samples will be sent to Dr. Schradin’s laboratory for hormone measurements. A respirometry laboratory has been set up at the research station. In collaboration with other projects currently running at the research station, it is possible to measure resting metabolic rate (RMR). We also plan to measure daily energy expenditure (DEE) using doubly labeled water in collaboration with Dr. S. Blanc from the CNRS in Strasbourg, France.
What we offer: Access to a unique long-term field study and a well-equipped field station. South Africa is country with many highlights, especially for ecologists and evolutionary biologists. The University of the Witwatersrand is in the centre of South Africa and offers good scientific infrastructure. It is internationally ranking similar to many European universities. The project offers opportunities for international collaborations. The project is funded for two years by the South African National Research Foundation (NRF). This includes research expenses (e.g. ABAXIS analyzer) and costs of travel for the project. The stipend from the NRF is 80 000 Rand / year and we anticipate to increase this to Rand135 000 / year via funding from the University of the Witwatersrand. This grant is sufficient for the living costs in South Africa (approx. 6000 Rand / month, including accommodation).
Requirements of the candidate: The postdoc we are looking for must be independent, creative and highly motivated. Applicants should have solid knowledge in at least two of these research areas: ecophysiology, behavioral endocrinology, evolutionary biology, ecology, physiology, animal behavior. Good statistical skills are a pre-requisite. Experience in field work and working with small mammals are of advantage. We expect the applicant to have good writing skills and a good publication record, since a minimum of two publications per year are expected from the successful candidate.
Application procedure and deadline: The position is available from June 2012 onwards. There is no deadline and applications will be reviewed in the order of applications. Applicants should make themselves available for skype interviews at the end of May. The application should be emailed to neville.pillay@wits.ac.za and cc to carsten.schradin@ieu.uzh.ch as a single pdf containing CV, list of publications, a statement of research interests, and the names of two to three references with contact details.
For additional information contact Neville Pillay at neville.pillay@wits.ac.za
Internet links:
School of Animal, Plant and Environmental Sciences at the University of the Witwatersrand:
Succulent Karoo Research Station:
CNRS in Strasbourg: http://www.iphc.cnrs.fr/-Strategie-scientifique,90-.html
Dr. Neville Pillay:
Dr. Carsten Schradin:
Key references
Awerman, J. L. and L. M. Romero (2010). Chronic psychological stress alters body weight and blood chemistry in European starlings (Sturnus vulgaris). Comparative Biochemistry and Physiology a-Molecular & Integrative Physiology 156(1): 136-142.
McEwen, B. S. and J. C. Wingfield (2010). What is in a name? Integrating homeostasis, allostasis and stress. Hormones and Behavior 57(2): 105-111.
Romero, L. M. (2012). Using the reactive scope model to understand why stress physiology predicts survival during starvation in Galápagos marine iguanas. General and Comparative Endocrinology.
Schradin, C., A. K. Lindholm, et al. (2012). Social flexibility and social evolution in mammals: a case study of the African striped mouse (Rhabdomys pumilio). Molecular Ecology 21: 541-553.