And as for taking your jobs, if you lose out on a job to a recently arrived individual from a war torn country who can't speak English, perhaps your own CV needs some serious updating?
The competitive advantage of the first arrivals ('owners') compared with later arriving individuals ('intruders') has mainly been explained by three different hypothesis (Maynard Smith and Parker 1976).
The existing, but limited, evidence indicates that directional selection on timing of arrival at the breeding grounds favouring early arriving individuals is also common (Bêty et al. 2004; Smith and Moore 2005; Møller et al. 2010; Gienapp and Bregnballe 2012; Arnaud et al. 2013).
Birds that arrived earlier in spring were characterised by higher short-term flight performance than later arriving individuals (Fig. 1a).
Upon recording the choice, we removed the symbol so that later arriving individuals would not perceive the current-season symbol choices of previously settled individuals.
Colonizations are usually accompanied by adaptive changes, but it is a long standing question whether fast adaptations are constrained by the initial paucity of variation caused by a genetic bottleneck of only few arriving individuals [ 2].
Arrival at the breeding grounds was closely related to the difference between arrival and the date when the base developmental threshold was reached, i.e. early arriving individuals also arrived shortly after insects became available (r = 0.74, df = 7, p < 0.001).
As we are controlling for body size, which is closely linked to dominance (Elliott 1990; Cutts et al. 1999b), these findings support the VA hypothesis, i.e. that the first arriving individuals gain a competitive advantage caused solely by being resident.
