Sex, long life and the evolutionary transition to cooperative breeding in birds

Abstract

Long life is a typical feature of individuals living in cooperative societies. One explanation is that group living lowers mortality, which selects for longer life. Alternatively, long life may make the evolution of cooperation more likely by ensuring a long breeding tenure, making helping behaviour and queuing for breeding positions worthwhile. The benefit of queuing will, however, depend on whether individuals gain indirect fitness benefits while helping, which is determined by female promiscuity. Where promiscuity is high and therefore the indirect fitness benefits of helping are low, cooperation can still be favoured by an even longer life span. We present the results of comparative analyses designed to test the likelihood of a causal relationship between longevity and cooperative breeding by reconstructing ancestral states of cooperative breeding across birds, and by examining the effect of female promiscuity on the relationship between these two traits. We found that long life makes the evolution of cooperation more likely and that promiscuous cooperative species are exceptionally long lived. These results make sense of promiscuity in cooperative breeders and clarify the importance of life-history traits in the evolution of cooperative breeding, illustrating that cooperation can evolve via the combination of indirect and direct fitness benefits.

Cheating and punishment in cooperative animal societies

“…[1,3,147]), understanding the life-history or behavioural traits that likely antedated the evolution of cooperation may help generate predictions about the ancestral conditions under which it arose (e.g. [148]). …”

The other facets of family life and their role in the evolution of animal sociality

“…in the European earwig F. auricularia; Wong & Kölliker, 2012;Kramer et al, 2017). Finally, note that further possibilities to apply advanced frameworks for cooperative breeding to the emergence of family life could, for instance, relate to the potential impact of additional environmental characteristics (such as variability and harshness; Jetz & Rubenstein, 2011;Koenig & Walters, 2015;Cornwallis et al, 2017) and life-history traits (such as longevity; Downing, Cornwallis & Griffin, 2015).…”

Social organization, demography and genetic mating system of a Tibetan cooperative breeder

“…In the northeastern population, the proportion of nests with helpers each year is very low (0-10%) and dispersal occurs in kin coalitions consisting of adults and juveniles of both sexes (Wang & Lu 2014b). This social system is different from the 'helper-at-thenest' system (grown offspring acting as helpers on their natal territories) that is commonly found among cooperatively breeding birds (Downing et al 2015). The two other populations have a 'helper-at-the-nest' system, but information was based on only 2 years of fieldwork.…”

“…This social system is different from the ‘helper‐at‐the‐nest’ system (grown offspring acting as helpers on their natal territories) that is commonly found among cooperatively breeding birds (Downing et al . ). The two other populations have a ‘helper‐at‐the‐nest’ system, but information was based on only 2 years of fieldwork.…”