Sun compass in animals internal clock to determine their heading, and that they had learnt the actual direction down to the sea on their particular beach. Lockley's experiments with Manx shearwaters ("Puffinus puffinus") showed that when released "under a clear sky" far from their nests (in Skokholm), the seabirds first oriented themselves and then "flew off in a direct line for Skokholm", making the journey rapidly. For example, one of the birds, released at Boston airport, arrived in Skokholm 12½ days later; Lockley calculated that if the birds flew for 12 hours per day, they must have travelled at 20 miles per hour, their
Persian shearwater off Oman and Socotra, Yemen, while "P. p. temptator" has been estimated to number fewer than 500 pairs on Moheli Island in the Comoros (reviewed by Brooke 2004). It is thought likely that more breeding colonies lie undiscovered elsewhere in the northern Indian Ocean (Onley and Scofield 2007), thus the total population probably includes more than 10,000 mature individuals. The population trend is believed to be downwards. Persian shearwater The Persian shearwater ("Puffinus persicus") is a seabird in the family Procellariidae formerly lumped in with Audubon's shearwater ("Puffinus lherminieri"). There are two listed subspecies of the Persian shearwater: After breeding,