Thus, when peripheral group members employ vigilance behavior more frequently, a premature conclusion about a possible adaptation to differential predation risk is best avoided.
Since then, a correlation between higher degree of vigilance and peripheral positions within a group is usually attributed to higher predation risk at the group periphery, in primates (Robinson 1981; van Schaik and Noordwijk 1989), birds (Inglis and Lazarus 1981; Keys and Dugatkin 1990; Black et al. 1992) and other species (see Table 5.3 in Caro 2005).
The monitoring of fluctuating vigilance by parameters of the peripheral nervous system, such as heart rate and electrodermal activity (EDA), proved to be unreliable due to the slow response rates of these indirect parameters.
Nevertheless, there is some evidence that this relationship may exist (Table 1): in many primate species, where social vigilance is dominance-related, also a central-peripheral spatial group structure, with central dominants and more peripheral subordinates, is found.
Based on the suggestions by Chance (1967) and on what has since then become known about primate social vigilance, we hypothesize that a central-peripheral group structure is reinforced by and arises from dominance related variation in social vigilance.
This highlights the importance of vigilance and monitoring in both central and peripheral IV access.
In order to investigate the possible contribution of these parameters to injuries in this population, this study aimed to evaluate the regional relative risk of the spine and peripheral joints and the glycemic and hydration levels and coincident motor reaction time and vigilance levels in ski and snowboard instructors, patrollers, and lift attendants.
This way we were able to test whether individual variation in social vigilance (i.c. scanning) alone is already sufficient to generate a central-peripheral group pattern.
The last result suggested that, besides reinforcing an existent group-structure, individual variation in social vigilance alone may even be sufficient to result in a central-peripheral group structure.
Our results showed that individual variation in social vigilance resulted in more spread out groups, decreased encounter rates between subordinates and reinforced the existing central-peripheral spatial structure of the group.
