[Brian]

A couple of other fun facts about the studies at Utah State university.
1. They have bred Valley Garters (t.s.fitchi) from Utah to Red spotted garters (t.s.concinnus) from Oregon creating integrades to test how well these snakes could withstand the newt toxins. One might expect that they would have less immunity since the Valley garters throughout most of their range aren't sympatric (don't exist with) the newts. What they found was the opposite. The integrades had more immunity. One person I talked to hypothesized this may be because the valley garters eat a lot of toads (woodhouse and boreal) which both have toxins which the Valley garters are immune to and the red spotted garters have the immunity to the newts.

2. They have also produced a paper about how the garters not only are imune to this toxin but actually store it in their livers and if a bird or other predator were to eat them (and their liver) they would likely die from the toxins. They hypothesized that because of this the red may be a warning for birds. You would think then that snakes with more red would be more successfull but their are many areas in Utah and Idaho where valley garters don't have a lot of red. Perhaps these populations aren't eating the toxic toads and newts which would reinforce selective predation on the less red animals. There is no evidence that toxins are anyway related to the red on the snakes.