FOOD SUPPLEMENTATION EXPERIMENTS WITH TERRESTRIAL VERTEBRATES - PATTERNS, PROBLEMS, AND THE FUTURE

Reviews 138 cases in which terrestrial vertebrates received supplemental food under field conditions. These cases are strongly biased toward small-bodied herbivores in north temperate environments. Most studies address population level questions and have supplied food over a short term (<1 yr) and on a small spatial scale (to <50 individuals). Individuals receiving supplemental food usually had smaller home ranges, higher body weights and advanced breeding relative to those on control areas. The typical population response to food supplementation was 2- to 3-fold increase in density, but no change in the pattern of population dynamics. In particular, food addition did not prevent major declines in fluctuating populations. Researchers have failed to examine behaviour of individuals under conditions of supplemental food when addressing questions of population regulation. -from Author