As body weight increases, rmax:
Maximum intrinsic growth rate generally declines with increasing body mass because large organisms tend to have slower life histories. Metabolic and developmental scaling produce later maturity, longer gestation or development, longer generation intervals, and fewer offspring per unit time. Even when large species have high adult survival, delayed and infrequent reproduction lowers the rate at which descendants accumulate. Small organisms commonly mature quickly and reproduce repeatedly, yielding high rmax under favorable conditions. Across broad taxonomic comparisons, this relationship is oft
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 11