Homing in Leach's Petrel

L•ACH'S Petrel (Oceano'droma leucorhoa) is strictly a marine bird almost never sighted over land except when flying to its nesting burrow or when blown inland by gales (Boyd, 1954; Bagg and Eliot, 1937: 16). Griffin (1940) has suggested that these birds may be able to select a short overland route in preference to a much longer all-water route when they are released at a distance from their burrows. This implies that the birds have some means of orientation not dependent upon the familiarity of the territory over which they find themselves. The experiments described in this paper were an attempt to test the homing ability of Leach's Petrel over a wide range of distances, and especially under conditions in which the birds were presented a choice of flight paths. The petrels whose homing is described breed on Kent Island near Grand Manan, New Brunswick, Canada (44 ø 35' N, 66 ø 45' W).