Resource Abundance and Social Domin

Resource Abundance and Social Dominance
Differences in resource abundance may account for many
apparent contradictions in the literature concerning the presence
or absence of social dominance hierarchies. Dominance
hierarchies may not be readily apparent when resources are
plentiful. However, the absence of agonistic encounters does
not refute the existence of dominance hierarchies. When
resources are plentiful, animals in a herd commonly feed and
rest together, and dominant animals displace subordinates
less frequently.
Howery et al. (1998) found that drought weakened the
dams’ influence on location and habitat use of offspring as
water became scarce. Lazo (1994) reported that in winter and
spring, cattle herds maintained large home ranges and individuals
formed small parties. In the summer and autumn,
individuals formed large parties and smaller home ranges
concentrated near water and feed. He stated that even with
limited resources available, spatial segregation among herds
promoted social isolation more than exploitation of a territory
or home range.
The influence of social dominance on supplement consumption
depends on the relative availability of supplemental
feed and trough space. The proportion of sheep not consuming
supplement fed once daily in troughs increased from 0 to
31% as linear trough space was decreased from 24 to 4 cm
per animal (Arnold and Maller, 1974). However, excess
trough space could increase variation in hand-fed supplement
consumption. Wagnon (1966) observed that less fighting and
agonisticbehavior occurred during supplementation when
linear trough space was 91 cm/cow than when 180 cm/cow
was allowed. The smaller bunk allowance did not allow cows
to fight without backing away from the trough, and therefore
fewer animals were pushed away from the supplement. When
excessive trough space was allowed, dominant cows chased
others away from one side of the trough and spent more time
fighting than eating.
Larger quantities of supplement provided per animal can
reduce the variation in individual animal consumption and
the proportion of non-feeders. Foot et al. (1973) found that
the coefficient of variation (CV) of supplement intake was