Modeling ApproachesVarious Animal SpeciesThese images show four different animals and the paths they follow, using odor to guide them to an unseen resource. 
Panel A, to the left, is an observer's reconstruction of the flight path of a petrel (a ocean-going sea bird) as it tracks an airborne plume of fish oil. These birds are known to locate their prey using odor cues, and can locate their nest burrows at night by approaching nesting colonies from downwind (suggesting that they are tracking odor plumes). 
Panel B, to the right, is an illustration of the swimming orientation of an immature codfish in a circular flow tank. The upper figure shows how, in clean water, the fish orients and swims in the direction of the flow. The lower panel shows that when the fish encounters a plume of squid extract injected into the flow through the small port in the floor of the tank, it changes its behavior and now orients into the flow and swims upstream. 
Panel C, to the left, shows that, in the moth Manduca sexta, males and females execute similar behaviors when tracking plumes of attractive odor. The left-hand panel shows the upwind flight path of an M. sexta male tracking a plume of female sex-attractant pheromone. The right-hand panel shows the flight path of an M. sexta female as she tracks a plume of chemicals evaporating from the fresh picked leaves of a preferred larval host plant, tomato. 
Finally, Panel D, to the right, is a schematic diagram of paths followed by salmon as they return to their home streams for mating. The fish move upstream into the larger river and then switch to a side-to-side counterturning behavior as they encounter the boundary between water coming from their homestream and non-homestream water. |