Grooming in the veery and the American robin: Evidence for a simple timing hierarchy

Abstract

Grooming behaviours in the veery ( Catharus fuscescens ) and the American robin ( Turdus migratorius ) cluster into four hierarchical groups based on function and anatomy: (1) non-preening, (2) upper body and wing preening, (3) lower body cleaning, and (4) tail preening in the veery; (1) non-preening, (2) body preening, (3) wing preening and (4) tail preening in the robin. The frequency distributions of the number of consecutive acts per cluster and the number of cluster visits per bout approximate geometric distributions in both species. These results provide evidence for the generality of the timing hierarchy model.