Geoscience Reference
In-Depth Information
lenger. However, the study revealed predictors of contest success, so that we
could predict relative supremacy in a dyad. These predictors of supremacy
included length and weight and, to a lesser degree, age. These attributes alone
were not sufficient to predict the direction of supremacy in a dyad, however,
because the role of challenged feeding individual also proved to be associated
with contest success. And even when an individual occupied the same role
against the same adversary, we still could not fully predict the contest winner;
subsequent rechallenges often had a different outcome, indicating that some
motivational factor such as hunger can also play a decisive role. Hence, in the
badger's case it did not prove helpful to attempt construction of a dominance
hierarchy, linear or otherwise, from the provisioned patch data. A measure of
relative supremacy based on an individual's characteristics and role in a contest
proved to be more heuristically valuable.
To further complicate matters, it became clear that if more food sources
were provisioned at one site, so that contest competition was no longer neces-
sary for feeding access, scramble (Milinski and Parker 1991) became the pre-
ferred method of competition. This cast doubt on the relevance of our predic-
tors of relative supremacy derived from contest competition because most
natural badger foods are presented in a way that does allow such scramble
competition. Interestingly, however, the behavioral patterns of contest we
observed during feeding competition (e.g., side-to-side flank barging) were
also seen in male-male competition for estrous females. Analysis of those data
revealed that weight, length, and age as well as prior ownership were also pre-
dictors of copulation access, leading us to believe that these assets may indeed
have general relevance in predicting the outcome of competitive dyadic inter-
actions among similarly motivated badgers.
Social Groups
In terms of their constituent individuals, a group may be transient, as in herds
of wildebeest, or nearly permanent, as in packs of wolves. Some may even
move daily between these extremes; in the dry season, stable groups of capy-
baras may coalesce at water holes into transient herds (Macdonald 1981; Her-
rera and Macdonald 1989). Many groups can be defined spatially, in terms of
the proximity that members maintain to each other. Within territorial species,
cohabiting occupants constitute a spatial group, and may be brought together
by limited or variably available resources or by sociological advantage (Mac-
donald and Carr 1989). Membership of spatial groups can be assigned using
spatial criteria, within which indices of association can be derived from dyadic
