What a difference a day makes-female behaviour is less predictable near ovulation.

Area of Science:

• Ethology
• Animal Behavior
• Reproductive Biology

Background:

• Individual differences in animal behavior, or 'animal personalities,' are established.
• The stability and factors influencing these behavioral differences over time require further investigation.

Purpose of the Study:

• To determine if the reproductive cycle affects the stability of inter-individual behavioral differences in female mice.
• To assess the impact of reproductive state on social interest, anxiety-like behavior, and exploratory locomotion.

Main Methods:

• Female mice were tested twice, eight weeks apart, in four behavioral paradigms.
• Testing occurred either near ovulation or during the non-receptive phase of the reproductive cycle.
• Behavioral data were analyzed for consistency and group-level effects based on reproductive state.

Main Results:

• No significant group-level behavioral differences were observed between reproductive states.
• Behavioral stability (predictability over time) was significantly reduced near ovulation for social interest and anxiety-like behaviors.
• Reproductive state profoundly impacted individual behavioral consistency.

Conclusions:

• The reproductive cycle, particularly the phase near ovulation, influences behavioral stability in female mice.
• Females exhibit decreased behavioral predictability during periods critical for reproduction, suggesting acceptance of higher phenotypic plasticity costs.
• These findings highlight the dynamic nature of animal personalities in relation to reproductive strategies.