Comment on "On the regulation of populations of mammals, birds, fish, and insects" III.
Stochasticity in time series explains concave responses of per capita growth rate to population size. The gradients with the natural log of population size have more biological importance because they measure strength of density compensation. Its weakening with increasing body size across taxa (Sibly et al., Reports, 22 July 2005, p. 607) is consistent with slower responses in ascent than descent toward carrying capacity. Time series therefore suggest that populations of large-bodied animals underfill their environments.
School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK. cpd@soton.ac.uk
C Patrick
CP
Doncaster
D000818:Animals; D001717:Birds; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005399:Fishes; D007313:Insecta; D016015:Logistic Models; D008322:Mammals; D008433:Mathematics; D008954:Models, Biological; D011156:Population Density; D011157:Population Dynamics; D011158:Population Growth; D012044:Regression Analysis; D013269:Stochastic Processes