Hi Gang, Last fall there was a nice discussion about hummingbirds, red flowers, and related matters. I enjoyed all the comments at the time. I recalled a relevant article but didn't know where/how to find it. Now I've found it and, because it is in an open access journal, you can all read the article online (RodrÃguez-Gironés and Santamaria. PLoS Biology. 2004. 2:1515-1519). Why Are So Many Bird Flowers Red? http://biology.plosjournals.org/perlserv/… The nice thing about the article is that it clears up some aspects of what is known but also poses some questions. For instance, the authors document the strong correlation between red flowers and bird pollinators and provide a crucial citation from Peter Raven. However, they also address the confounding facts that many red flowers are not bird-pollinated and that birds may pollinate flowers of many colors. The correlation between red flowers and bird pollinators is real, but it is not absolute. The puzzle is explored in terms of natural selection and competition. Cordially, Joe Conroe TX Wet and cool all month