Varias ofertas de postdoc, director de campo, y voluntariado en Sudáfrica

Postdoc Project either on  Reproductive Competition and Sociality or alternatively on Environmental harshness and social stress

(NOTE: We also advertise 2 paid positions as field managers for 1.5 to 4 years, and unpaid volunteer positions for 2-12 months. See other advertisements or ask via email carsten.schradin@iphc.cnrs.fr)

We are looking for a highly motivated postdoc to join the striped mouse project www.stripedmouse.com and our group at the University of the Witwatersrand (Johannesburg). The postdoc is paid via a grant of the South African NRF for two years from Prof. Neville Pillay at the University of the Witwatersrand. The postdoc is expected to spend most of the time at the Succulent Karoo Research Station, conducting field work, analysing and publishing data.

We have two possible projects for a postdoc. Both projects are of similar interest to us. When applying, please state for which of the two projects you apply.


Project 1: Reproductive Competition (Seasonal Unpredictability and Social Flexibility)

For this project, a long-term dataset on social organisation of striped mice will be available for analyses (from 2003 to present) and further data collection will extend to 2021. Sociality (% of solitary versus group-living striped mice) will be studied in relation to population density and the intensity of reproductive competition, which is (i) very high during the spring breeding season when all females breed, (ii) absent during most summer dry seasons, (iii) low during summers with unexpected rains when few females breed (6 out of 17 summers in the current data set).

Questions and predictions: We expect that reduced reproductive competition during summer breeding will lead to more social instability in spring compared to summer, i.e. groups to be more stable in summer. We will also study which factors differ between females that breed during the summer vs. females that don’t. Finally, the impact of rare summer breeding on population dynamics will be studied.

Time planning: Preferred start is July 2020 and the position must be started in 2020. The postdoc is expected to be in the field for most of the time but can plan two slots of 3 months each to spend at the University of the Witwatersrand.



Project 2: Environmental harshness and social stress in a biodiversity hotspot: corticosterone might not be the only nor the best measure

Animals have to cope with harsh environments and with stress but these phenomena are not synonymous. Stress is the activation of the sympathetic nervous system (SNS) and the hypothalamic-pituitary (HPA) axis, leading to the secretion of catecholamines and glucocorticoids, providing extra energy to overcome the stressor inducing stress. Environmental conditions are termed harsh when they are long-lasting and life threatening, such as seasonal food shortage. Thus, while harshness demands energy saving, stress demands increased energy expenditure, predicting that the stress response will change as environmental harshness changes. In our study model, the African striped mouse Rhabdomys pumilio, we will measure several indicators of stress under varying conditions of harshness, some for the first time in an eco-physiological framework. We will evaluate three different aspects to differentiate between effects of harshness (dry season) and social stress (reproductive competition during the moist season) on survival, and fitness. These include: 1) neuropeptide y as an indicator of sympathetic activity and thus short-term stress; 2) corticosterone as an indicator of mid-term investment in increased energy expenditure; 3) Measures of resting metabolic rate and how these are related to corticosterone levels. Our study will be the first to assess how the stress response adapts to environmental harshness, predicting that in the harsh dry season, the HPA axis will be downregulated, while the response of the SNS will not change seasonally, allowing for an immediate response to life threatening events such as predation. Thus, we predict an adaptive desynchronization of the SNS and the HPA axis, a phenomenon so far only described as pathology in humans. This project will contribute fundamentally to our understanding of how to distinguish harshness from stress and how animals can cope with these two phenomena adaptively via different mechanisms.

Time planning: Preferred start is July 2020 and the position must be started in 2020. The postdoc is expected to be in the field for most of the time but can plan to spend 1-2 months in Strasbourg (France) for laboratory analyses and 4 months at at the University of the Witwatersrand.



Key requirements: Strong statistical skills. Strong CV with 3 publications from the PhD and at least 1 publication per year from postdoc studies, some of them in high ranking journals (impact factor >3). Willingness to spend considerable time in the field in South Africa. Ability to analyse data and to write manuscripts while being field based.



What you will learn: Strong field skills and understanding of theory underlying social evolution / eco-physiology of stress.



How to apply: In a single PDF, send a letter of motivation, your academic CV, and contact details of a minimum of 2 (better more) referees to Carsten Schradin, carsten.schradin@iphc.cnrs.fr and Neville Pillay, neville.pillay@wits.ac.za.

Application deadline: Skype interviews will be held beginning of March, so best send your application latest the 17th February, giving us time to contact your referees for a letter of reference. If necessary, a second call will be published in March 2020.




More information:

www.stripedmouse.com

http://www.iphc.cnrs.fr/-Carsten-Schradin-.html

https://www.researchgate.net/profile/Neville_Pillay.