[R-sig-eco] Meaning and intrpretation of TSS and ROC in the biomod2 package in R

[Giacomo May]

Dear R users,
This is probably a pretty basic question, but since I am new to species distribution modeling  I was working through the explanatory vignette for the biomod2 package when I stumbled across it. So apparently TSS and ROC scores play a rather big role in the evaluation of the model but unfortunately no real explanation of their meaning or how they are to be interpreted is provided. I've been looking on the web as well but everything I found wasn't very satisfying so i was hoping to get some quick answers here. Can somebody maybe provide a short explanation of what is expressed through the TSS and ROC scores and what I can take from them ? Any help is greatly appreciated.
Best,
Giacomo