Dominance and huddling behaviour in Bronze Mannikin Lonchura cucullata flocks

Abstract

Bronze Mannikins Lonchura cucullata form flocks of up to 30 birds at the end of the breeding season and huddle in communal nests during winter. Assuming there are thermoregulatory benefits associated with huddling for these small endotherms, particularly during winter, we predicted that dominant individuals in flocks would obtain the central locations within the huddles. We tested this prediction by determining the dominance hierarchies of six captive flocks of five individuals by examining interactions at a feeder. Mannikins were observed to huddle when cold‐stressed. Although mannikins do not naturally form linear huddles, for ease of observation we recorded the positions of individually marked birds in linear huddles at 5 °C before and after disturbances every half hour for 3 h. Captive flocks of mannikins established linear dominance hierarchies and dominant individuals obtained the central location within the huddle. The central position in the huddle may be beneficial in thermodynamically challenging environments through reduced energy expenditure.