PhD Project title: Influence of sex-specific competition and density on demography in the great tit
The Research Group Animal Ecology of the research institute Centre for Ecological and Evolutionary Studies (CEES) has a vacancy for a full-time PhD position:
We are looking for a PhD student to study how competition explains the distribution, survival and reproductive rates in great tits. The PhD position is part of a unique large-scale project where we manipulate different aspects of competition (fledgling density and fledgling sex ratio) to study fitness consequences of competition and avian sex allocation.
Parents should invest equally in the two offspring sexes and hence adjust the sex ratio of their offspring to both the fitness costs and benefits of producing them. In this project we started to measure whether fitness benefits of producing a particular sex ratio dependent on the sex ratio in the population and whether parents adjust their reproductive decision to that. Two current projects (to be continued for one year) focus on the experimental effects of 1) fledgling density on the costs and benefits of brood size and 2) fledgling sex ratio on the fitness of the sexes.
We find promising results in the first experimental years: some plots have consistent low or high natural breeding densities, and reproductive investment and sex ratio are correlated with this breeding density. So far, experimental changes in fledging sex ratio did not affect reproductive investment and sex allocation decisions of the parents. Sex-specific and density dependent dispersal neutralized the effect of our experimental sex ratio skew and density manipulation in the next breeding season. Therefore, the aim of the new projects is to experimentally alter sex specific competition and density just before breeding by selective removal of breeders.
The questions are:
1) Do breeders adjust sex ratio of their offspring to skewed breeder sex ratio?
2) Do breeders adjust clutch size of their offspring to manipulated breeder density?
3) Are these changes adaptive?
4) How is settlement of the new generation affected by (sex specific) breeder removal?
To judge how optimal brood size and sex ratio depend on breeder density we will manipulate offspring brood size and sex ratio. The work of the PhD will concentrate on the offspring side (starting manipulations in 2008) while the joint project will concentrate on parental decisions (starting manipulation in spring 2009). We offer a stimulating working atmosphere, with ample opportunity for discussion and with top-quality science.
Requirements
Candidates must have a degree in biology, with specialisation in ecology, and a driver’s license. We are looking for an enthusiast researcher with ample experience in field research on birds. Theoretical interest in evolutionary ecological research is a prerequisite; knowledge of database management in Access is an advantage.
Conditions
The University of Groningen offers an appointment for a period of four years that should be completed with the defence of a PhD-dissertation. During the first year the stipend is € 1905,- for a Dutch student and € 1422,- per month for a foreign student (stipend lower than that for a Dutch student because of tax exemption) and will be adjusted to general price movements once a year. After one year, the performance of the candidate will be evaluated to decide whether there is sufficient progress to expect a successful completion of the PhD thesis within the remaining three years. A training programme is part of the agreement. You and your supervisor will make up a plan for the additional education and supervising that you specifically need.
Background
This PhD project is part of a large research grant on Sex-specific reproductive tactics: fitness consequences of avian sex allocation and dispersal strategies granted to Prof. dr. ir. J. Komdeur by the Dutch Organisation of Scientific research. The research will take place in the “Animal Ecology” research group. You will be supervised by Prof. dr. J.M. Tinbergen and Prof. dr. ir. J. Komdeur. The group participates in the Centre for Ecological and Evolutionary Studies (CEES) and the Graduate School Functional Ecology.
Information
Information about the position can be obtained from Prof. dr. Joost M. Tinbergen (phone ++31)-50-3632065 or -3632040), J.M.Tinbergen@rug.nl and Prof. dr. ir. Jan Komdeur (phone ++31)-50-3632056), J.Komdeur@rug.nl
Additional information
On the project and research group Animal Ecology:
http://www.rug.nl/biologie/animalecol
On CEES http://www.rug.nl/cees
On the Faculty of Mathematics and Natural Sciences http://www.rug.nl/fwn
Applications
Successful applications describe your motivation for applying for this position, list your previous relevant experiences and include a full CV and names of two references. Send your applications before 22nd February 2007 to Prof. dr. ir. J. Komdeur, Prof. dr. J.M. Tinbergen, Animal Ecology Group, Biological Centre, P.O.Box 14, 9750 AA Haren, Netherlands