So how much more in-depth is the Texas Snakes (Werler & Dixon) Hardcover compared to the Field Guide version? I have the field guide, and though I do like it, I was rather surprised to find that the diet information of the snakes was missing. How that happened is beyond me, but I hear that the hardcover does a pretty good job of describing the species found here in Texas. I'm wondering whether it's worth it to buy that book, seeing that i have the field guide. Any other suggestions related to Texas snakes (and other herps) or those of the Southwest are also appreciated. Thanks.