The more the better – polyandry and genetic similarity are positively linked to reproductive success in a natural population of terrestrial salamanders (Salamandra salamandra)

Although classically thought to be rare, female polyandry is wide-spread and may entail significant fitness benefits. If females store sperm over extended periods of time, the consequences of polyandry will depend on the pattern of sperm storage, and some of the potential benefits of polyandry can only be realized if sperm from different males is mixed. Our study aimed to determine patterns and consequences of polyandry in an amphibian species, the fire salamander, under fully natural conditions. Fire salamanders are ideal study objects, since mating, fertilisation and larval deposition are temporally decoupled, females store sperm for several months and larvae are deposited in the order of fertilization. Based on 18 microsatellite loci, we conducted paternity analysis of 24 female-offspring arrays, with, in total, over 600 larvae fertilised under complete natural conditions. More than one third of females were polyandrous and up to four males were found as sires. Our data clearly show ...