Variable performance of individuals: the role of population density and endogenously formed landscape heterogeneity
Article first published online: 15 AUG 2003
Journal of Animal Ecology
Volume 72, Issue 5, pages 725–735, September 2003
How to Cite
Pfister, C. A. and Peacor, S. D. (2003), Variable performance of individuals: the role of population density and endogenously formed landscape heterogeneity. Journal of Animal Ecology, 72: 725–735. doi: 10.1046/j.1365-2656.2003.00742.x
- Issue published online: 15 AUG 2003
- Article first published online: 15 AUG 2003
- Received 13 September 2002;accepted 11 April 2003
- consumer–resource interactions;
- growth autocorrelation;
- individual variation;
- individual-based model;
- Tectura scutum
- 1Individuals can show positive correlations in performance (e.g. growth and reproduction) through time beyond the effects of size or age. This ‘performance autocorrelation’ has been attributed previously to traits that differ among individuals or to extrinsic generators of environmental heterogeneity.
- 2A model of mobile consumers on a dynamic resource showed that consumer foraging gave rise to resource heterogeneity that in turn generated autocorrelation in growth in consumers.
- 3Resource heterogeneity and growth autocorrelation were most pronounced when consumers were poorer foragers, moving locally and with an imperfect ability to identify the highest resource cells.
- 4The model predicted that lowered population density enhanced resource heterogeneity and the strength of growth autocorrelation.
- 5Consistent with model predictions, an experiment with tidepool limpets demonstrated that autocorrelation in growth changed with population density, with individuals in lower density tidepools showing stronger temporal correlations in growth.
- 6Our model and empirical results contrast with those of previous studies with plants, where dominance and suppression increases with increasing density.
- 7Our results suggest that growth autocorrelation can occur without invoking size-dependent advantages, intrinsic trait differences or extrinsic generators of environmental heterogeneity.