Species recognition in wild-caught, laboratory-reared and cross-fostered Peromyscus californicus and Peromyscus eremicus (Rodentia, Cricetidae)

Experiments were performed to compare homospecific and heterospecific species choice in two closely related species of white-footed mice, Peromyscus californicus and P. eremicus. Both species significantly chose the homospecific stimulus animal. Significant homospecific choice was made by mice from sympatric but not from allopatric populations. Reciprocal cross-fostering between the two species resulted in significant choice for the heterospecific (foster) species by P. eremicus, and random choice by cross-fostered P. californicus. Laboratory-reared controls chose significantly for the homospecific chamber. No significant difference in choice performance was demonstrated between males and females, even when the oestrus stages of the females (both stimulus and test animals) were statistically controlled. A comparison of different test durations and temporal regimes of data collection was performed and 90 min was found to be the most efficient experiment duration with our apparatus.