Development of species preferences in two hamsters, Phodopus campbelli and Phodopus sungorus: Effects of cross-fostering

Abstract

Experiments were conducted to investigate species-specific preferences in two closely related species of hamsters, Phodopus campbelli and Phodopus sungorus. Male hamsters that were raised with conspecifics spent more time investigating an anaesthetized conspecific male than a heterospecific male, and also spent more time investigating odours of conspecifics than those of heterospecifics (midventral gland, urine, and saccular secretion). Cross-fostered P. sungorus males reversed their normal preferences, spending more time investigating stimuli (anaesthetized males and all three odours) of the foster species. Cross-fostered P. campbelli males also investigated an anaesthetized male of the foster species more than a male of their own species, but did not show a preference for odours alone. Social experience during the 15 d immediately following weaning also influenced these preferences. If exposures during and after nesting were to heterospecifics the preference for heterospecifics was strengthened; if either period of experience was with a conspecific, this eliminated the preference for heterospecifics in P. sungorus but did not influence the lack of a preference in P. campbelli. Thus, early experience during both the nestling stage and the 15 d after weaning influenced responses to speciestypical cues in both species, but it had a more pronounced effect in P. sungorus.