Allee effects in ants

1. Allee effects occur when the aggregation of individuals result in mutually beneficial intraspecific interactions whereby individual fitness, or per capita growth rate, increases with the number of individuals. Allee effects are common in social species due to their cooperative behaviours, such as breeding, feeding, or defence. Allee effects have important implications for many aspects of basic and applied ecology. Over the past decades, the study of Allee effects has influenced population dynamics, community ecology, endangered species management, and invasion biology. 2. Despite the fact that cooperation is the basis of their social structure, Allee effects have received little attention among eusocial insects. Extreme cooperation is common and reproductive specialization of individuals occurs due to division of labour. These life history traits suggest that the potential contribution of each caste to reproduction and survival may be differential and nonadditive. 3. We studied Allee...