affected by the amount of food, types of food, water, illness, and more. Box turtle eggs are flexible, oblong and are (depending on the taxon) on average 2–4 cm long weighing 5-11 g. The normal clutch size is 1-7 eggs. In captivity and in the southern end of their range, box turtles can have more than one clutch per year, while the average clutch size is larger in more northern populations. Delayed fertility has been observed in female turtles during which a box turtle pair will mate and the female will hold onto the male’s sperm within the cloaca for a period of months or even years before fertilizing and laying a clutch of eggsTurtles can defend themselves from predation by hiding, closing their shell and biting. The risk of death is greatest in small animals due to their size and weaker carapace and plastron. While the shell of an adult box turtle is seldom fractured, the box turtle is still vulnerable to surprise attacks and persistent gnawing or pecking. Common predators are mammals like minks, skunks, raccoons, dogs and rodents, but also birds (e.g. crows, ravens) and snakes (e.g. racers, cottonmouths) are known to kill box turtles. Diet North American box turtles are omnivores with a varied diet, as a box turtle will "basically eat anything it can catch". Invertebrates (amongst others insects, earth worms, millipedes) form the principal component, but the diet also consists for a large part (reports range from 30 to 90%) of vegetation. The diet is amended with fruits (amongst others from cacti, apples and several species of berry) and gastropods (Heliosoma, Succinea). While reports exist that during their first five to six years, box turtles are primarily carnivorous and adults are mostly herbivorous, there is no scientific basis for such a difference. Distribution and habitat Box turtles are native to North America. The widest distributed species is the common box turtle which is found in the United States (subspecies carolina, major, bauri, triunguis; south-central, eastern, and southeastern parts) and Mexico (subspecies yukatana and mexicana; Yucatán peninsula and northeastern parts). The western box turtle is endemic to the south-central and southwestern parts of the U.S. (and adjacent Mexico) while the spotted box turtle is endemic to northwestern Mexico only. The Coahuilan box turtle is only found in Cuatro Ciénegas Basin (Coahuila, Mexico). Habitat Because box turtles occupy a wide variety of habitats (which both vary