By: Tobin Seagel

Whistler Naturalists

Date: August 29, 2003

 

Meeting a mate with whom to settle down, build a home, have kids and grow old, is possibly the single most arduous event in many of our lives. It would be so much easier if there were simply a 1:1 sex ratio, but that’s no fun.  So I have good news for everyone…

 

… we’re not alone!!!

 

Many fish share our hardships.

 

Mating rituals of fish and humans are really quite similar. If you don’t believe me, I invite you down to both Garf’s and the River of Golden Dreams to compare. Large aggressive males often dominate spawning …er, …um dating. However, it is clear that these aggressive males are not the only active participants on the playing field. Alternate male strategies, such as cuckoldry, have evolved to ensure every male has a fair crack at passing on its genes.

 

In salmon and trout, jack males are common. Jacks are immature males that migrate upstream with the mature males. For example, if salmon species X usually spawns after four years, a jack of species X may migrate and attempt to spawn after only three years. They are easily recognizable by their smaller size and non-spawner coloring. They spawn by sneaking into redds (fish nests) and releasing their sperm at the same time as a mating pair. Sometimes, several jacks will gang up on a mature male, distracting him while another jack sneaks in and fertilizes the eggs.

 

Cuckoldry refers to a male whose partner has been unfathful to him. It is an evolutionary stable strategy for reproduction because it is favored by natural selection. In other words, the strong (and/or crafty) survive to produce the next generation!

 

The Kokanee are currently sqawning in Whistler valley.  A great place to view this amazing event is on the Valley Trail bridge over the River of Golden Dreams at the bottom of Lorimer Road.  The mature Kokanee are 6″-9″ long and bright pink with highlights of green.  If you’re lucky you may see a greenish jack, darting around and generally the mature males.  Pleas be respectful of the fish and view them from the bridge or the banks of the stream and take care to keep your dog out of the water.