As I'm now on the academic journal kick, I've found an article that supports the early introduction of "greens" to our RES friends. To summarize (as I can't post the article here; it would be a violation of the usage rights of the university - sorry!) it says because we know that RES switch to mainly herbivorous diets later in adulthood, McCauley and Bjorndal show that there is nothing to say that young turtles couldn't also benefit from this diet. (Previously, it was thought - according to the article - that young RES ate a primarily carnivorous diet because they couldnt actually eat enough plant material in terms of volume per day to give them the energy they needed each day - they have since found this to be false.)
Article: Response to Dietary Dilution in an Omnivorous Freshwater Turtle: Implications for Ontogenetic Dietary Shifts.
Authors: McCauley, Shannon J.
Bjorndal, Karen A.
Source: Physiological & Biochemical Zoology; Jan/Feb99, Vol. 72 Issue 1, p101, 8p
Abstract: Several species of freshwater turtles in the family Emydidae undergo an ontogenetic dietary shift; as juvenile turtles mature, they change from a primarily carnivorous to a primarily herbivorous diet. It has been hypothesized that this shift results from an unfavorable ratio of gut capacity to metabolic rate that prevents small reptiles from processing adequate volumes of plant material to meet their energetic demands. Effects of dietary dilution on intake were evaluated in two size classes of red-eared sliders (Trachemys scripta elegans) to test whether small reptiles have a lower capacity to compensate for low-quality diets through increased intake than do larger conspecifics. Artificial diets with an inert diluent were offered to two size classes of turtles, and mass-specific intakes of dry matter, energy, and nitrogen were calculated. Both small (28.7 &plusmin 4.9 g body mass, mean mass &plusmin SD) and large (1,230 &plusmin 94 g body mass) turtles compensated for dietary dilution and maintained constant energy and nitrogen intakes on diets with lower energy content than common aquatic plants. Thus, body size did not affect the ability to respond to nutritional dilution, which suggests that processing limitations imposed by small body size do not constrain juveniles from adopting an herbivorous diet. [ABSTRACT FROM AUTHOR]
