NESTING FAILURE IN BURYING BEETLES AND THE ORIGIN OF COMMUNAL ASSOCIATIONS

Information on reproductive success and the probability of nest failur e was gathered from 11 recent studies of Nicrophorus defodiens, which readily forms communal breeding associations and Nicrophorus orbicolli s, which rarely tolerates consexuals in the nest. Nicrophorus defodien s was subject to a high rate of nest failure on larger carcasses and c onsequently, is expected to achieve little reproductive benefit by exc luding a rival during nest initiation. Nicrophorus orbicollis, on the other hand, was successful on a higher proportion of carcasses of all sizes and is predicted to gain substantial benefits by excluding a riv al. These findings support the hypothesis that high rates of nest fail ure can promote the evolution of tolerance and incipient communality a mong unrelated adults, even in the absence of immediate reproductive g ains.