Overall dynamic body acceleration as an indicator of dominance in Homing Pigeons (Columba livia)

The benefits of dominance are well known and numerous, including first access to resources such as food, mates and nesting sites. Less well studied are the potential costs associated with being dominant. Here, the movement of two flocks of domestic Homing Pigeons Columba livia - measured via accelerometry loggers - was recorded over a period of 2 weeks, during which the birds were confined to their lofts. Movement was then used to calculate each individual's daily overall dynamic body acceleration (ODBA, G), which can be used as a proxy for energy expenditure. The dominance hierarchy of the two flocks was determined via group-level antagonistic interactions, and had a significantly linear structure. The most dominant bird within each flock was found to move significantly more than conspecifics - on average, c. 39% more than the individual with the next highest degree of movement - indicating a possible cost to possessing the top rank within a hierarchy. Despite the dominance hierarchy being highly linear, this was not the case for ODBA, suggesting that energy expenditure may be more reflective of a despotic hierarchy. These results show the potential for the future use of accelerometry as a tool to study the fusion of energetics and behaviour.