Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions - Marino - 2010 - Ethology - Wiley Online Library

Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions - Marino - 2010 - Ethology - Wiley Online Library: "According to current theory, anti-predator benefits promote group formation in open-dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti-predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual"