Toads vs Trout
A couple weeks ago I wrote up a day trip up to the Sierra to search for some amphibs, including the threatened Yosemite toad, Anaxyrus canorus. There has been some recent ecological debate regarding the practice of stocking land-locked high Sierra lakes with trout for sport fishing. In the recent issue of Copeia (2010, No. 3) Robert L. Grasso, et al., discusses the defenses of the Yosemite toad in dealing with non-native brook trout. They found that the trout reject (science speak for spit out) eggs, tadpoles, and recent metamorphs of the toads. This would imply that these lifestages contain chemical defenses that allows them to adequately deal with these invaders. Good news for the toads. However, brook trout still readily consume tadpoles of the native Pacific chorus frog, Pseudacris regilla. I vaguely recall a paper a year or two ago about the trout and yellow-leg frogs. I’ll have to dig it up. Copeia is the quarterly journal of the American Society of Ichthyologists and Herpetologists of which I am a member.