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
Diego Garcia Other nesting native birds include red-tailed tropicbirds ("Phaethon rubricauda"), wedge-tailed shearwaters ("Puffinus pacificus"), Audubon's shearwater ("Puffinus iherminierii"), black-naped terns ("Sterna sumatrana"), white (or fairy) terns ("Gygis alba"), striated herons ("Butorides striatus"), and white-breasted waterhens ("Amaurornis phoenicurus"). The 680-hectare Barton Point Nature Reserve was identified as an Important Bird Area for its large breeding colony of red-footed boobies. The island hosts introduced bird species from many regions, including cattle egrets ("Bubulcus ibis"), Indian barred ground dove, also called the zebra dove ("Geopelia striata"), turtle dove ("Nesoenas picturata"), Indian mynah ("Acridotheres tristis"), Madagascar fody ("Foudia madagascariensis"), and chickens ("Gallus gallus"). Currently, three