Salas R, Müller W, Stienen E, Matheve H, Vanden Broecke B, Verbruggen F, Lens L
Behavioural Ecology and Ecophysiology Research Group, University of Antwerp, Antwerp 2610, Belgium.
InnovOcean Campus, Flanders Marine Institute, Ostend 8400, Belgium.
R Soc Open Sci. 2024 May 1;11(5):231431. doi: 10.1098/rsos.231431. eCollection 2024 May.
Colonies of ground-nesting species often have heterogeneous nest densities and their offspring experience different social conditions depending on the size and location of the breeding territory. For example, unintentional territory crossing by mobile chicks can trigger strong aggression from neighbouring adults, as observed in semi-precocial gulls. This would be expected to shape chicks' movement tendencies, exploratory behaviour and propensity for social contact through aversive feedback learning or pre-natal maternal effects, as mothers may pre-adapt their offspring's behaviour to the expected early life conditions. Therefore, we hypothesize that lesser black-backed gull chicks reared in denser areas of the breeding colony will move less, have smaller home ranges and have fewer social contacts with chicks from neighbouring nests. To test this, we first cross-fostered full clutches between and within high- and low-density parts of the colony, and then used ultra-wideband tags to track free-ranging chicks. In line with our predictions, we found that chicks reared in denser areas had a lower movement activity and smaller home ranges. However, these chicks still had more social contacts, although not necessarily with a higher number of unique individuals. Pre-natal breeding density had no significant effect on any of the parameters. We conclude that parental nest choice strongly affects the early social environment of their chicks, which can shape the development of their (social) phenotype, with potentially long-lasting consequences.
地面筑巢物种的群体通常具有不同的巢穴密度，其后代根据繁殖领地的大小和位置经历不同的社会条件。例如，如在半早成鸟海鸥中观察到的，移动的雏鸟意外穿越领地会引发邻近成年鸟的强烈攻击。通过厌恶反馈学习或产前母体效应，这预计会塑造雏鸟的运动倾向、探索行为和社交接触倾向，因为母亲可能会使后代的行为预先适应预期的早期生活条件。因此，我们假设在繁殖群体密度较高区域饲养的小黑背鸥雏鸟移动较少、活动范围较小，并且与相邻巢穴的雏鸟社交接触较少。为了验证这一点，我们首先在群体的高密度和低密度区域之间以及内部对整窝雏鸟进行了交叉寄养，然后使用超宽带标签追踪自由活动的雏鸟。与我们的预测一致，我们发现饲养在密度较高区域的雏鸟运动活跃度较低且活动范围较小。然而，这些雏鸟仍然有更多的社交接触，尽管不一定是与更多不同的个体。产前繁殖密度对任何参数均无显著影响。我们得出结论，亲代的巢穴选择强烈影响其雏鸟的早期社会环境，这可以塑造其（社会）表型的发育，可能产生持久的后果。
