Searching for a new home: decision making by dispersing brush mice

Natal dispersal occurs when young animals leave the area where they were born and reared and search the surrounding landscape for a new place to settle. Despite the importance of dispersal for both individuals and populations, search behavior by dispersers, including the decision-making process of choosing a place to settle, has not been investigated in the field. Here we draw on the mate search literature, in which the theory of decision making during search has been well developed, and ask whether there are behavioral similarities between habitat search and mate search. We used radiotelemetry to track dispersing juvenile brush mice (Peromyscus boylii) and determined whether their search behavior was consistent with any of three decision rules: threshold, best of n, and comparative Bayes. We found that search behavior by juveniles was most often consistent with comparative decision rules (best of n and comparative Bayes), suggesting that the decision-making processes involved in searching for a place to settle and searching for a mate may be quite similar.