Olfactory Guidance in Foraging by Procellariiforms

Abstract

Systematic field experiments show that procellariiform birds, viz., Black-footed Albatrosses (Diomedea nigripes), shearwaters (Puffinus griseus, P. creatopus, P. puffinus, P. bulleri, and P. tenuirostris), Northern Fulmars (Fulmarus glacialis), and storm-petrels of several species, are consistently attracted to sources of food-related odors under natural conditions at sea with controlled visual cues. They approach predominantly from down-wind, in proportions above control levels, when food odors are presented as surface slicks, slicks spread in large shallow pools of plastic floating on the ocean, and by saturated wicks on free-floating rafts. Control stimuli and odorous materials unrelated to food do not attract procellariiforms. Birds of other orders are not attracted by any odorous stimulus, and approach the areas from all directions only when discrete visual stimuli are added. Observations and photographs reveal a flight pattern displayed only by procellariiforms in their apparent foraging approaches to food-related stimuli. Tube-nosed birds are most numerous under conditions of reduced visibility, high winds, large swells, and turbulent ocean surface. The results of this study strongly support the view, previously based on comparative anatomy and uncontrolled observations, that procellariiforms use olfaction in locating food.