Fat deposition and migration capacity of robinserithacus rebeculaand goldcrestsregulus regulusat ottenby, Sweden

To investigate migration strategy we have studied the visually observable fat deposits of Robins and Goldcrests and made calculations of flight distance capacity. High fat deposits found in Robins and Goldcrests after one night migrations to Ottenby suggest that these birds could migrate two or more nocturnal stages without refuelling. The long periods needed to recover depleted fat reserves could be one reason for Robins storing fat for more than one nights’ migration. Recoveries in the same autumn of Robins ringed at Ottenby confirm our suggested pattern of fat deposition and migration strategy.