A Dispersive Migration in the Atlantic Puffin and Its Implications for Migratory Navigation

Abstract

Navigational control of avian migration is understood, largely from the study of terrestrial birds, to depend on either genetically or culturally inherited information. By tracking the individual migrations of Atlantic Puffins, Fratercula arctica, in successive years using geolocators, we describe migratory behaviour in a pelagic seabird that is apparently incompatible with this view. Puffins do not migrate to a single overwintering area, but follow a dispersive pattern of movements changing through the non-breeding period, showing great variability in travel distances and directions. Despite this within-population variability, individuals show remarkable consistency in their own migratory routes among years. This combination of complex population dispersion and individual route fidelity cannot easily be accounted for in terms of genetic inheritance of compass instructions, or cultural inheritance of traditional routes. We suggest that a mechanism of individual exploration and acquired navigational memory may provide the dominant control over Puffin migration, and potentially some other pelagic seabirds, despite the apparently featureless nature of the ocean.

Individual variability in the migratory path and stopovers of a long-distance pelagic migrant

“…As an additional measure of route consistency, we also calculated the mean distance between the outward route of each individual in the first year and (1) its own route(s) in the second (and/or subsequent) year(s), and (2) the route(s) from other individuals, randomly chosen from the set of birds tracked in the second (and/or subsequent) year(s) (see Guilford et al 2011 for a similar approach). The distance between routes was calculated as the mean distance between each position on one route and the nearest position on another route.…”

“…Migrants possibly develop individual strategies to cope with particularly harsh conditions found along the route, which may be modulated by individual learning. This process may develop through successive refinements following a set of exploratory movements carried out during the first years of migration (Guilford et al 2011), which are typical of many seabird species (Baker 1980;Ǻkesson & Weimerskirch 2005;Dias et al 2011). This mechanism would be particularly relevant in species without cultural inheritance of migratory behaviour; juvenile shearwaters, probably like most procellariiformes, migrate on their own (Ǻkesson & Weimerskirch 2005).…”

“…This individual-based approach has been made possible by technological advances in tracking systems, which have allowed researchers to discover the previously unknown migratory routes of several species (e.g. Green et al 2002;Alonso et al 2008;Bairlein et al 2012), and to analyse in detail intraindividual variation in migratory patterns, such as year to year consistency in time and space Guilford et al 2011;Vardanis et al 2011;Stanley et al 2012). Repeated measures of single individuals can also provide fundamental cues to understanding the causes of variability in migratory behaviour (for example, the relative role of genetic background versus environmental conditions; van Noordwijk et al 2006), and also to unveil the mechanisms underlying long-distance navigation (Alerstam 2006;Guilford et al 2011).…”

“…Green et al 2002;Alonso et al 2008;Bairlein et al 2012), and to analyse in detail intraindividual variation in migratory patterns, such as year to year consistency in time and space Guilford et al 2011;Vardanis et al 2011;Stanley et al 2012). Repeated measures of single individuals can also provide fundamental cues to understanding the causes of variability in migratory behaviour (for example, the relative role of genetic background versus environmental conditions; van Noordwijk et al 2006), and also to unveil the mechanisms underlying long-distance navigation (Alerstam 2006;Guilford et al 2011). By repeatedly tracking individual birds it was possible, for example, to show that (at least some) terrestrial long-distance migrants do not rely on learned visual maps of landscape features for most of the journeys to and from the wintering areas (Vardanis et al 2011).…”

“…Most studies carried out so far on fidelity to migratory paths and stopovers have focused on species that migrate mostly over land, such as passerines, storks, geese and raptors (Fox et al 2002;Berthold et al 2004;Catry et al 2004;Alerstam et al 2006;Vardanis et al 2011;Stanley et al 2012). While some studies have analysed spatial consistency during migration in pelagic travellers (Hunter et al 2003;Phillips et al 2005;Broderick et al 2007;Guilford et al 2011), none have attempted to disentangle the fidelity to routes or paths from individual consistency in winter destinations. By controlling for the effect of winter destination we can understand whether the route consistency revealed by species that use several geographically isolated wintering areas is a consequence of their fidelity to wintering sites or whether it is an individual choice for a specific path in subsequent years.…”