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
Audubon's shearwater likely, as yet another synonym of "dichrous". The case of the more distinct "bannermani", the range of which is parapatric to that of the Pacific "dichrous", is more complicated. It has for some time been proposed as a distinct species, Bannerman's shearwater ("P. bannermani"). In the absence of more recent data to investigate this claim, its status continues to be altogether unresolved, though the case for it being at least a distinct subspecies in the "bailloni" clade seems good. Audubon's shearwater The Audubon's shearwater ("Puffinus lherminieri") is a common tropical seabird in the petrel family. Sometimes known as the dusky-backed