I've been bringing him the pale desert willow flowers every day since he moved in two and a half weeks ago, and he's always ignored them; he's also ignored other white/pale flowers, instead going for the brighter/darker ones. And so when I was shopping for new trees for his little corner of the world (i've transplanted baby volunteer desert willows from elsewhere in the garden, but it'll be years before they're big enough to provide any real shade, if they even survive) I decided to get a darker-purple flowering desert willow (they also come in a medium-lavender). And so of course this morning of course he finally "discovered" the pale flowers (i scattered a handful of both kinds at the entrance to his burrow), eating them before going to check out the purple ones... :)