Flock flying improves pigeons' homing: GPS track analysis of individual flyers versus small groups

Abstract

The effects of aggregation in navigating animals have generated growing interest in field and theoretical studies. The few studies on the effects of group flying on the performance of homing pigeons (Columba livia) have led to controversial conclusions, chiefly because of the lack of appropriate technology to follow pigeons during their entire homeward flight. Therefore, we used GPS data-loggers in six highly pre-trained pigeons from a familiar release site first by releasing them six times individually, then six times as a group from the same site, and finally, again six times individually. Flight data showed that the homing performance of the birds flying as a flock was significantly better than that of the birds released individually. When flying in a flock, pigeons showed no resting episodes, shorter homing times, higher speed, and almost no circling around the start zone in comparison to individual flights. Moreover, flock-flying pigeons took a nearly direct, "beeline" route to the loft, whereas individually flying birds preferred to follow roads and other longitudinal landmarks leading towards the loft, even when it caused a detour. Our results show that group cohesion facilitates a shift towards more efficient homing strategies: individuals prefer navigating by familiar landmarks, while flocks show a compass orientation.

Fast and accurate decisions through collective vigilance in fish shoals

“…Uncertainty in a novel environment is typically indicated by a high frequency of turning and a slower traveling speed (18)(19)(20)(21). This was also the case here as focal fish in all groups showed increased tortuosity as they moved into the decision zone; however, only solitary individuals and those in smaller groups reduced their speed.…”

A collective navigation hypothesis for homeward migration in anadromous salmonids

“…Theo retical work predicts that collective migratory strategies might evolve under a wide range of eco logical scenarios (Torney et al 2009(Torney et al , 2010Guttal and Couzin 2010;Shaw and Couzin 2013), and it may be no coincidence that migrations and other navigational feats are often undertaken by large groups (Beauchamp 2011;Milner Gulland et al 2011). Homing pigeons return more efficiently when released as groups than they do as individu als (Biro et al 2006;Dell'Ariccia et al 2008), and birds with less information can benefit from fol lowing others (Flack et al 2012). Theories, like (unpublished data)…”

Flight responses by a migratory soaring raptor to changing meteorological conditions

“…This is because study of flight strategies of birds requires precise spatial data collected at extremely high temporal frequencies [2 -4]. Until recently, research in this area was constrained by limitations of data from short-duration tracking [4 -6], infrequent GPS satellite telemetry [7] or GPS data loggers requiring manual download [3,[8][9][10]. Because large, wary and sparsely distributed birds of prey are difficult to recapture for data logger retrieval and impractical to track over long distances with gliders, there have historically been no tools useful to study the in-flight micro-scale decisions birds make over long distances.…”