Geoscience Reference
In-Depth Information
Figure 10.1
Data on the interactions between male and female wood mice, illustrating the arbi-
trariness in defining a bout. In practice, the best definition of a bout depends on the purpose of the
analysis. The top row illustrates that grooming (of the female by the male) is split into a series of brief
nibbles partitioned by fleeting changes of position. Each period of nibbling might be defined as an
event or as a bout. If each nibble is an event, then the sequence of them might make up a bout of
grooming. Bouts might also be defined in terms of contact between the two mice, and in that case
the period during which the male was first grooming and then nasoanal sniffing the females consti-
tutes one bout of contact, during which the female was immobile. Finally, the entire period of
male-female interaction might be defined as a bout. This scheme is based on real data on the
behavior of wood mice. Depending on the model under analysis, grooming bouts could be distin-
guished as one continuous process or as a series of original grooming bouts in which a mouse shifts
between body positions. Even an interaction can be considered a bout if several criteria are fulfilled.
C = contact behavior, N = noncontact behavior, AP = approach, WT = wait, N-anal = nasoanal
contact.
bring into view the number of angels perched on the pinhead, but an impor-
tant point nonetheless emerges: the unit of much behavioral analysis is the
bout, and the usefulness of a definition of a bout is affected by the level of mag-
nification at which the analysis is being undertaken. Bouts must be defined
very carefully because their definition will have far-reaching statistical conse-
quences for any analysis in which they are involved and because of their role as
an indicator of motivation and neural processes.
From the mathematical point of view, when a behavior is modeled it is eas-
iest to keep definitions simple, so Haccou and Meelis (1995:7) define a bout
as a “time interval during which a certain act is performed. A bout length is the
duration of such a time interval.” In the calculation of transition matrices,
transitions to the same act are impossible, so diagonal elements in the matrix
are treated as zero (the notion of transitions from one bout of behavior to
