Disruptive viability selection on adult exploratory behaviour in eastern chipmunks.

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Phenotypic variance within populations is maintained by heterogeneous selection pressures.
• Consistent behavioral differences, or personality, are observed in animal populations.
• The role of environmental fluctuations in selecting for specific animal personalities is understudied.

Purpose of the Study:

• To investigate viability selection on the personality trait of exploration in wild eastern chipmunks.
• To determine if fluctuating environmental conditions drive selection on exploration behavior.
• To understand the maintenance of phenotypic variance in relation to personality.

Main Methods:

• A 5-year field study on eastern chipmunks (Tamias striatus).
• Monitoring of exploration behavior (a personality trait) in adult and juvenile chipmunks.
• Analysis of viability selection over a 6-month period, considering seasonal environmental variations.

Main Results:

• No evidence of fluctuating selection on exploration behavior was found.
• Strong disruptive viability selection was observed in adult chipmunks, favoring extreme exploration scores (low or high).
• Individuals with intermediate exploration scores had lower survival rates; no selection was evident in juveniles.

Conclusions:

• Disruptive selection, not fluctuating selection, appears to maintain phenotypic variance in chipmunk exploration behavior.
• This selection pattern is independent of seasonal environmental variations.
• Disruptive selection on personality traits may be a key mechanism for maintaining variance in wild populations.