_______________________Dave Powell, USDA Forest Service, www.forestryimages.org
USDA Forest Service Archives, USDA Forest Service, www.forestryimages.org
The Large Male
The largest males are less social than females and smaller males. They tend to associate with smaller groups of similarly sized males, spar less often, and maintain more space between themselves (Weckerly, 2001). There are two hypotheses considering the asocial nature of the large male. One possibility considers the enormous resource demands of the large male that would require him to create space between himself and others (Geist and Petocz, 1977; Main et al. 1996). The other possibility, the large-male hypothesis, instead removes smaller males from the large male group because of the likely event that the small male with have a consequential agonistic encounter with a larger male (Freeman, et al. 1992). Large male groups tend to be made up of similarly sized males, a social makeup that reduces the temptation for these males to engage in dangerous agonistic behavior
Environmental Contribution
Elk are able to adapt to a number of different environments. They adopt hiding, the selfish-herd affect, migration, and competition as survival techniques. Grouping is often dependent upon the makeup of the surrounding environment as well as risk of predation, availability of mates, and seasonal availability of food. High resource needs and avoidance of agonistic interactions with younger males were mentioned as reasons for large males to remain solitary. The solitary and the small group life have also been mechanisms for predator-avoidance. Remaining solitary is a form of hiding for the large bull. This is common among large males in the forested areas that provide dense cover but less warning time (Geist, 1982). By hiding, solitary males avoid being spotted as a stand-out member of a large group. In a group of smaller animals, the large bull would gain little from selfish-herd mentality because of his conspicuousness. In more open areas the large bull finds it advantageous to make use of the selfish herd technique. While hiding is out of the question in an open area, multiple large males can combine senses and warn one another of approaching danger.
Elk flourish in regions with or without abundant supplies of food. Survival techniques play a role in developing social behavior. In areas where food is generally abundant but perhaps seasonally limited, such as the forests of Michigan, competition among elk is often not pressing enough to drive a herd to migrate. These regions are stabilized habitats for elk (Bender and Haufler, 1999). In such regions, animals compete with one another by quickly eating preferred foods. The intensity of this passive competition affects social bonds, and as intensity rises, animals move farther from one another and social bonds become weaker (Geist, 1982).
Competition becomes more pronounced in areas where food is severely limited. Herds found in this situation will generally migrate. In areas where food is abundant year-round, competition is rare and social groups are more noticeable (Bender and Haufler, 1999). Competition for food among elk parallels competition for social rank. There is a correlation between rank and feeding time in elk. Higher ranked individuals eat earlier and in the center of the feeding sites, while lower ranked animals eat later and around the perimeter (Veilberg, et al. 2004). Interference competition does not appear to be prevalent among elk populations. Interference competition appears unlikely because no relationship has been found between low social rank and poor health resulting from agonistic interactions with dominant animals (2004).
_________________________Photo courtesy of Phil Myers www.animaldiversity.org
