Behavioral styles in European rabbits: social interactions and responses to experimental stressors.

The existence and consistency of individual behavioral types in response to challenging situations is of increasing interest in behavioral biology. In our study on European rabbits (Oryctolagus cuniculus), we (1) investigated correlations between social behavior during early development and responses to experimental stressors during later life, and (2) tested for consistencies in these responses across different situations. For this, we observed juveniles living in field enclosures in early summer and recorded agonistic and positive social interactions. In autumn, the animals were (a) introduced singly into a novel environment and were (b) confronted with predator (red fox Vulpes vulpes) odor. We recorded behavioral and physiological stress responses. In addition, we evaluated the predator odor test with an independent sample of animals. These latter results showed a correlation between the animals' behavioral and physiological response: Individuals, which reacted to the presence of fox odor by low scanning rates showed a high increase in serum corticosterone challenge concentrations, whilst the levels in high scanners remained stable. Overall, we found correlations among social behavior displayed during early development and behavioral responses in the two experimental tests, however the correlations between the different traits of social behavior and the responses during the two different experimental tests were not consistent. Animals which were involved in more agonistic interactions during their early development started to explore faster when entered into the novel environment. During the second test we found that rabbits which previously showed a higher frequency of positive social behavior responded to the presence of predator odor by more scanning. Moreover, the behavioral responses during both experimental tests were not correlated: fast explorers in the novel environment test did not show a more active response during the predator odor test. Due to this lack of consistent behavioral styles across both tests we conclude that the study fails to support the existence of domain-general behavioral phenotypes in European rabbits.