Meeting Abstract
Ecological variables affecting reproductive output often vary across a species’ range. In an effort to determine how maternal investment may vary across the range of the Western painted turtle (Chrysemys picta), we compared nests from populations of turtles from the northwestern (Idaho) and midwestern (Illinois) regions of their range. We measured maternal investment by measuring the size and mass of eggs, the number of eggs per clutch, and the number of clutches per mother. We found that females in Idaho lay more and larger eggs per nest than those from Illinois, but Illinois mothers lay more clutches. This may be because the laying season in Illinois is longer or the possible presence of more predators in Illinois. However, the influence of maternal size on clutch number is relatively consistent between the two locations. Egg mass and clutch size increase with maternal size in both locations, but in the Idaho population there is stronger correlation between maternal size and egg number than in Illinois. Additionally, later clutches have both fewer eggs and smaller eggs in both locations. Thus, it seems that larger mothers lay more eggs, and larger eggs, but the strength of this correlation may vary across the species range.
