Susanne Åkesson is one of the foremost academics working in the field of animal navigation. Her recent paper: “Timing avian long-distance migration: from internal clock mechanisms to global flights” is impressive and important.
Please see attached the whole paper: Timing avian long-distance migration: from internal clock mechanisms to global flights.
One of the critical questions is how animals, here she especially covers birds, decide when to set out for their migrations. Obviously getting your timing wrong and arriving in the wrong place in the wrong season is catastrophic.
She covers the short daily body cycle but also the yearly cycle of breeding, moulting and migration.
One of the issues has always been how these internal body clocks which tend to drift are recalibrated. Åkesson covers the issue of how calibrations with daytime could work, as in the tropics, birds such as cuckoos, wintering in the Congo must know when to return to Europe to breed. Equally birds in the high arctic with long summers with no nights have to know when to leave to go south in the autumn.
Tracking time must interact with tracking distance (some type of odometer). Migrating birds must know how far they have flown on their long journeys to know where they are in relationship to their target destination.
Equally careful synchronisation must take place (especially for seabirds) to make their journeys to their breeding grounds. They must arrive on time to find partners and bring up their offspring.