Variation in habitat choice and delayed reproduction: Adaptive queuing strategies or individual quality differences?

In most species, some individuals delay reproduction or occupy inferior breeding positions. The queue hypothesis tries to explain both patterns by proposing that individuals strategically delay breeding (queue) to acquire better breeding or social positions. In 1995, Ens, Weissing, and Drent addressed evolutionarily stable queuing strategies in situations with habitat heterogeneity. However, their model did not consider the non - mutually exclusive individual quality hypothesis, which suggests that some individuals delay breeding or occupy inferior breeding positions because they are poor competitors. Here we extend their model with individual differences in competitive abilities, which are probably plentiful in nature. We show that including even the smallest competitive asymmetries will result in individuals using queuing strategies completely different from those in models that assume equal competitors. Subsequently, we investigate how well our models can explain settlement patterns in the wild, using a long-term study on oystercatchers. This long-lived shorebird exhibits strong variation in age of first reproduction and territory quality. We show that only models that include competitive asymmetries can explain why oystercatchers' settlement patterns depend on natal origin. We conclude that predictions from queuing models are very sensitive to assumptions about competitive asymmetries, while detecting such differences in the wild is often problematic.

Does Climbing the ‘Social Ladder’ Increase Life Satisfaction? A Comparison of the UK and Switzerland

It is a widely held belief that status and wealth affect subjective well-being (SWB). This is reflected in the efforts of many people to climb up the ‘social ladder’ and to transcend their social background. By being upwardly mobile, they hope to benefit from various rewards they believe to be associated with desirable societal positions. However, findings from a range of disciplines provide evidence that these benefits are not to be taken for granted. Thus, we decided investigate the question of how upward social mobility impacts life satisfaction, the cognitive component of SWB.