Detecting nestmate recognition patterns in the fission-performing ant Aphaenogaster senilis: A comparison of different indices

Abstract

In this paper, we compare three indices for nestmate recognition behaviors in the ant Aphaenogaster senilis within and among colonies and populations: the classical Aggression Index, a multidimensional Principal Component Analysis (PCA) Behavioral Index incorporating all observed behaviors, and a Chemical Profile Index for cuticular hydrocarbon composition. With these indices, we quantified nestmate recognition behaviors between workers from a parent nest and between those from independent colonies. The PCA Behavioral Index performed as well as or better than the classical Aggression Index in distinguishing small differences in nestmate recognition. Correlation analysis of the PCA Behavioral Index with the Chemical Profile Index may assist in identifying the occurrence of colony fissions. The PCA Behavioral Index correlated strongly with the Chemical Profile Index, suggesting that hydrocarbon profiling may be used as an alternative to nestmate recognition assays. This correlation also suggests that nestmate recognition in A. senilis is a graded response rather than a threshold one. © 2005 Springer Science+Business Media, Inc.