| Cherry Head Redfoot Tortoise (Geochelone carbonaria) Egg Incubation |
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Clutch sizes vary from one to eight eggs, although some large clutches may reach 15 eggs. Red-foots are capable of clutching several times during the year. After the eggs have been removed, bury them halfway in a container of slightly moistened vermiculite (1:1 ratio vermiculite to water by weight) and place them in the incubator. There is some controversy among tortoise breeders as to whether or not tortoise eggs should be moved from their original orientation in the nest before artificial incubation. Some breeders are careful to mark the top of the eggs so that their orientation is not changed when they are moved to the incubator. Others see this procedure at unnecessary and do not believe disorienting the eggs in the incubator has an effect on hatch rate. According to Marchellini and Davis (1982), red-footed tortoise eggs that were rotated from their original positions had a lower hatch rate, poorer survival rates, and higher incidence of hatchling deformities. Different breeders have different results, but taking care not to rotate the eggs from their original orientation does not take much effort and may improve hatching rate and hatchling success. Do not incubate the eggs in a sealed container, sealed containers encourage CO2 buildup which can be detrimental to the developing eggs. Use a container with small holes punched in it so the eggs can breathe. The humidity in the incubator should be 80-100% and the incubator should be opened at least once a week, if not more, to allow fresh oxygen to reach the eggs. Red-foot eggs are temperature sex dependent, incubation temperatures above 88 degrees F (31 degrees C) will produce females, and temperatures below 82 degrees F (28 degrees C) will produce males. High temperatures however, can cause lower hatch rates and higher rates of deformed hatchlings. The ideal incubation temperature, if mixed-sex offspring are desired, is 84 degrees F (29 degrees C). Incubation periods range from 105 to 202 days, with an average of 155 days. After pipping, the baby tortoises will often spend a few days in their shell absorbing the yolk. Often hatchling tortoises will emerge with some yolk sac still present, cleanse the yolk sac with a mild disinfectant such as betadine and keep the hatchling on moist paper towels until the yolk is absorbed. Hatchling tortoises can be housed inside in aquariums on a substrate of peat moss and coco coir, and have the same temperature and lighting requirements as the adults. Make sure to provide areas of high humidity and a shallow water dish at all times, hatchling red-foots are very susceptible to dehydration. |





















