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Weekly Citation Summary 2017 - Week 30

Weekly Citation Summary 2017 - Week 30

The following are titles of recently published papers focussing on navigation and orientation. Summaries of all have been circulated to members of the Animal Navigation Forum and full papers are available in the ANG Resources directory at the link below (available to non-members).

Bingman, V. P. & MacDougall-Shackleton, S. A. 2017 The avian hippocampus and the hypothetical maps used by navigating migratory birds (with some reflection on compasses and migratory restlessness). Journal of Comparative Physiology A 203, 465-474. doi: 10.1007/s00359-017-1161-0. Bingman31 2017

The homology between the avian hippocampal formation (HF) and mammalian hippocampus nurtures the expectation that HF plays a fundamental role in navigation by migratory birds. Indeed, HF of migratory birds displays anatomical properties that differ from non-migratory species. Using a hypothetical framework of multiple maps of differing spatial resolution and range, homing pigeon data suggest that HF is important for navigating by landscape features near familiar breeding, over-wintering, and stop-over sites. By contrast, HF would be unimportant for an olfactory navigational map, which could be operational over unfamiliar space farther away from a goal location, nor is there any evidence for HF involvement in the sun or geomagnetic compass. The most intriguing question that remains open is what role HF may play in navigation when a migrant is thousands kms away from a familiar area, where homing pigeon data are uninformative and a geomagnetic map may be operational. Beyond navigation, successful migration depends on seasonal timing and often becoming nocturnally active. There is little evidence that HF plays a role in the timing of circannual and circadian cycles. Rather, circadian pacemakers including the pineal gland may control circadian timing of nocturnal restlessness and photoperiodic seasonal pacemakers likely control circannual expression.

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Wiltschko, R. 2017 Navigation. Journal of Comparative Physiology A 203, 455-463. doi: 10.1007/s00359-017-1160-1. Wiltschko122 2017

Experiments with migrating birds displaced during autumn migration outside their normal migration corridor reveal two different navigational strategies: adult migrants compensate for the displacement, and head towards their traditional wintering areas, whereas young first-time migrants continue in their migratory direction. Young birds are guided to their still unknown goal by a genetically coded migration program that indicates duration and direction(s) of the migratory flight by controlling the amount of migratory restlessness and the compass course(s) with respect to the geomagnetic field and celestial rotation. Adult migrants that have already wintered and are familiar with the goal area approach the goal by true navigation, specifically heading towards it and changing their course correspondingly after displacement. During their first journey, young birds experience the distribution of potential navigational factors en route and in their winter home, which allows them to truly navigate on their next migrations. The navigational factors used appear to include magnetic intensity as a component in their multi-modal navigational ‘map’; olfactory input is also involved, even if it is not yet entirely clear in what way. The mechanisms of migratory birds for true navigation over long distances appear to be in principle similar to those discussed for by homing pigeons.


  • 28 July 2017
  • Animal Navigation Group

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