Field test of the pheromone hypothesis for homing by pacific salmon.

Experimental groups of juvenile coho salmon (Oncorhynchus kisutch) were released to elucidate the relative importance of site-specific ("imprinted") odors and intraspecific odors ("pheromones") in homing. Adult salmon returned to their release site rather than a hatchery containing both adult and juvenile salmon of their population. Furthermore, salmon sharing the same parents returned to different sites, suggesting that local movements are not strongly influenced by siblings or other conspecifics.