Meeting Abstract
In monogamous species territorial cooperation is hypothesized to play a major role in the success of pair-bonded animals in maintaining and defending a single territory. The sexually monogamous California mouse (Peromyscus californicus) is an ideal species for studying territorial cooperation as they form lifelong pair-bonds and both exhibit high levels of territorial behavior. While territorial behavior has been studied in the laboratory and field, division of labor within mated pairs has not. We used a territorial intrusion paradigm where either a male or female intruder in a cage box was placed into a chamber housing pair-bonded residents that were in one of three conditions; non-parental, with pups of a young age (<1 week), or older pups (>2 weeks). Pups of different ages were used due to differences in pup locomotery abilities. Division of labor was measured by noting whether one or both resident animals approached the cage box or stayed at the nest, whether one of the pair enforced retreat of the other to the nest, the total duration of time spent at the cage box or next to the nest, and ultrasonic vocalizations produced in response to the intruder. Preliminary data reveal that in 85% of trials only one mate approached the cage box while the other remained in the nest. In 25% division of labor was enforced by one mate pushing the other back to the nest before approaching the cage box. Across pairs, males and females were equally likely to approach the cage box, however within pairs the same individual approached the cage box regardless of intruder sex. This research shows that there is a defined division of labor within bonded California mice; however this division may be pair specific, not sex specific, suggesting that individual differences drive division of labor and not broader sexual differences.
