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The authors report data on initial orientation of laughing doves (Streptopelia senegalensis) and black-billed wood doves (Turtur abyssinicus) displaced to sites, on land and at sea, 1-40 km from their home ground which was near the coast, in the area of the ORSTOM Ornithological Station of Mbour, Senegal. On the whole, the birds did not show the stereotyped directional tendencies often reported in studies on wild birds, but tended to be oriented in directions ap propriate for reaching the ground area; this was especially the case of the black-wood dove.

Systematic observations on seasonal incidence of the red admiral (Vanessa atalanta L.) in central-northern Italy were made in the course of four successive years. Our data show that our region is characterized by regular bidirectional migration which is particularly remarkable in October, during autumn migration to the overwintering sites. Red admirals' migration is highly directional: individuals fly along straight lines at the mean speed of 14 km/h, and produce highly oriented distributions of their vanishing bearings. This directional preference is not the result of passive displacement caused by winds, but is the expression of an internal tendency based on the use of a compass mechanism. Red admirals' seasonal incidence in our area significantly differs from that reported for the northern range of this butterfly species. This study constitutes the base of a long-term investigation aimed at clarifying the phenology and other aspects of migration of this butterfly species (origin and destination of migrants, mechanism of orientation) which, despite the amount of literature on this subject, are as yet not entirely understood.

Experiments were carried out with anosmic Cory's shearwaters to verify whether these birds, which are strictly nocturnal in their activity on land, use olfactory cues to localize individual nest burrows. Both the experimental birds, subjected to intranasal injection of zinc sulphate solution, which produces a reversible impairment of the olfactory mucosae, and unmanipulated controls were captured at their breeding colony on the island of Linosa (Pelagian Islands, Italy). Releases were carried out on the coast nearly 2 km away from the breeding colony. Recoveries at the nests showed that experimentals achieved significantly poorer homing success than controls. The view that the birds were disturbed in a non-specific way by experimental manipulation is weakened by the fact that injection of the same zinc sulphate solution into the coanae, a method only marginally involving the olfactory receptors, does not influence homing behaviour. Our results indicate that in Cory's shearwaters the search for individual burrows is based on, or at least complemented by, olfactory cues.

Twelve series of releases performed with first flight pigeons reared in four Italian lofts are reported. The presence of preferred compass directions (PCDs) in the initial orientation of the birds is clearly evident, even if less pronounced than in other countries. Young birds show initial bearings which are less homeward oriented and more polarized towards a PCD than do older pigeons.