Pacific Salmon Migration
Biology 342Fall 2010
Frank Sosa, Wren Kominos-Marvell
Despite the variety of migratory behavior found in other populations migration itself is categorized as a single behavior . For many, migration evokes images of large and majestic animal movements such as Pacific Salmon’s upstream climb to their spawning site.
Pacific Salmon in their migration demonstrate a seasonal anadromous movement, in which the ocean provides the fish with a unique growth opportunity due to its abundance of food, while the river allows access to a past successful spawning location ensuring a good reproductive environment. Through migratory behavior Pacific Salmon have established themselves as one of the most well known fish populations in the entire world.
Salmon swim hundreds of of miles out to sea and during the spawning season, these fish manage to swim back in the direction of their natal pond, all the way up a river to mate just before they die. We are going to make sense of this amazing behavior using Tinburgen's 4 questions:
Phylogeny:Also known as evolution, phylogeny describes the history of a given behavior in evolutionary terms, including the ancestral state and selective pressures that may have contributed to the rise of behavior.
Ontogeny:Ontogeny is the developmental history of an organism. When looking at the ontogeny of an organism or species, it is important to look at the relationship between aspects of behaviors that are learned and aspects that are genetic.
Mechanism:Mechanism looks at the mechanical relationships between the cause and effect of a behavior.
Adaptation:Also know as function, adaptive value refers to the increase in survival fitness and reproductive success of the animal due to its performance of the behavior.