We used microsatellite DNA markers to identify the extent to which multiple paternity within litters occurs
among species of New World natricine snakes. We selected seven species to represent the three major clades of
Natricinae and all three subclades of the gartersnake clade. Microsatellite DNA genotyping of dams and litters confirmed
multiple paternity within litters of six species, including Thamnophis radix, T. sauritus, Storeria dekayi, S.
occipitomaculata, Nerodia rhombifer, and Regina septemvittata. Multiple paternity was not evident in one litter of nine
Thamnophis melanogaster. Together with published data documenting multiple paternity in T. bulteri, T. elegans, T.
sirtalis, and N. sipedon, these results confirm the phylogenetically widespread occurrence of multiple paternity among
New World natricines, emphasizing the need to consider phylogenetic (historical) explanations when analyzing snake
mating systems
