Dramatic Orientation Shift of White-Crowned Sparrows Displaced across Longitudes in the High Arctic

Abstract

Advanced spatial-learning adaptations have been shown for migratory songbirds, but it is not well known how the simple genetic program encoding migratory distance and direction in young birds translates to a navigation mechanism used by adults. A number of convenient cues are available to define latitude on the basis of geomagnetic and celestial information, but very few are useful to defining longitude. To investigate the effects of displacements across longitudes on orientation, we recorded orientation of adult and juvenile migratory white-crowned sparrows, Zonotrichia leucophrys gambelii, after passive longitudinal displacements, by ship, of 266-2862 km across high-arctic North America. After eastward displacement to the magnetic North Pole and then across the 0 degrees declination line, adults and juveniles abruptly shifted their orientation from the migratory direction to a direction that would lead back to the breeding area or to the normal migratory route, suggesting that the birds began compensating for the displacement by using geomagnetic cues alone or together with solar cues. In contrast to predictions by a simple genetic migration program, our experiments suggest that both adults and juveniles possess a navigation system based on a combination of celestial and geomagnetic information, possibly declination, to correct for eastward longitudinal displacements.

First-Time Migration in Juvenile Common Cuckoos Documented by Satellite Tracking

“…Nevertheless, the straight southward directed part of the route and the faster migration of the juvenile cuckoo suggests it relied on inherited directional guiding to reach the wintering area. Potential compensation could be based on simple (sign) navigation using celestial and geomagnetic cues as found in displaced juvenile songbirds [7, 35]. …”

Northern magnetic displacements trigger endogenous fuelling responses in a naive bird migrant

“…A study by Schiffner and Wiltschko (2011) showed that homing pigeons are able to determine latitude based on magnetic intensity on a local scale, and the wheatears in our experiments may have used the total field intensity to determine the direction of displacement. Whether migratory birds are able to detect E-W displacements based only on magnetic parameters is unknown (Åkesson et al 2005;Gould 2008), hence we can only conclude that the young wheatears did not respond to the unexpected magnetic combinations Fig. 1 Geographic positions corresponding to the magnetic fields used for the simulated displacements.…”

Regulation of Nuclear Import/Export of Carbohydrate Response Element-binding Protein (ChREBP)

“…It is worth noting that a few studies testing the orientation in cages indicate that the distinction may not be that clear-cut: some juvenile migrants do tend to show compensatory behaviour after displacement when tested in cages (Åkesson et al, 2005;Thorup and Rabøl, 2007), and in some species migrations undertaken by juveniles spread out over large areas and later converge into narrowly defined routes, the latter also hinting at an ability to navigate in juveniles [e.g. marsh warblers (Thorup and Rabøl, 2001); Eleonora's falcons (Gschweng et al, 2008)].…”