Meeting Abstract

P2.71  Sunday, Jan. 5 15:30  Reproductive Investment Patterns in a Captive Population of Alligator Snapping Turtles (Macrochelys temminckii) THOMPSON, D.M.*; LIGON, D.B.; Oklahoma State University; Missouri State University denise.thompson17@gmail.com

Identifying resource allocation patterns is fundamental to understanding reproductive investment strategies that maximize maternal fitness. Turtles are useful model organisms for such studies because most species do not invest in parental care; therefore, variation in maternal investment can be assessed solely from variation in clutch characteristics (e.g., egg size and egg number). We examined alligator snapping turtle maternal investment patterns by measuring reproductive output of captive turtles reared under similar conditions. Larger females tended to produce larger eggs (r² = 0.420, p < 0.0001), but the number of eggs per clutch (mean = 34) did not correlate with female body size (r² = 0.140, p = 0.1867). However, larger females exhibited greater total reproductive effort as clutch mass positively correlated with female size (r² = 0.441, p = 0.0095). Hatchling size increased with increasing egg size (r² = 0.162, p < 0.0001); thus, larger females produced larger offspring (r² = 0.284, p < 0.0001). Additionally, females with greater body condition produced hatchlings that were both larger (r² = 0.1089, p < 0.0001) and had greater body condition (r² = 0.027, p = 0.0082). We found that resource availability affected the number of eggs females produced, and that as the number of eggs per clutch increased, egg size decreased (partial correlation r² = 0.27, t = –13.32, p < 0.0001). These results indicate that alligator snapping turtles primarily increase maternal investment by producing more eggs rather than larger eggs and that female size and body condition have potentially important implications for hatchling condition and, ultimately, survival.