Incubation temperature affects sex, so if you're herping in an area where the eggs somewhat recently were warmer than average, that's probably it.
-----
0.1 2006 Western Hognose (Bebe)
0.1 age unknown Cane Toad (Hengo)
0.1 2005 White-Banded Sheen Skink (Minerva)
1.0 2006 Northern Diamondback Terrapin (Queequeg)
1.0 2006 Madagascan Speckled "Hognose" (Sigmund)
1.0 2008 Bullsnake (Winkle)
1.2 2008 Eastern Collared Lizards (Pancho, Lupe, and Chica)
2.0 2009 Eastern Collared Lizards (Cesar and Nino)