Most of the turtles were wild caught specimens (the others are captive-bred offspring from the wild-caught adults). The majority of the animals were “road rescues,” unwanted pets, or turtles that were injured or ill. It seemed every time someone who knew me found a box turtle wandering on the roadside, I ended up caring for it. Years ago, before the current New Jersey legislation, it was possible to rehab turtles and return them to the location where they were found. For a turtle whose origin was unknown, finding a herper who would care for it was another option. However, the rest remained in my pens. (Now, with the current laws, releasing turtles or finding “homes” is no longer legal. I have a Scientific Holding Permit, and any turtle I obtain for rehab must remain in my care.)
The following information is important to understand the overall nature of my observations:
All the turtles were adults at the time they were found, and a significant number appeared to be quite old. Many of them (particularly those found twenty or thirty years ago) have lived out the remainder of their days in a peaceful setting, but eventually old age has taken its toll. Today, though there are still a few dozen turtles being kept outdoors, many are offspring of the original captives.
Over the years most of the collection was composed of eastern box turtles, Terrapene carolina carolina. There were also Gulf Coast (T. c. major), three-toed (T. c. triunguis), and intergrades in the group. About 90% of the eastern box turtles were from New Jersey, but some specimens were from North Carolina, Virginia, and Pennsylvania. Obviously, the Gulf Coast and three-toed box turtles were not originally from the Northeast, but their actual location of capture is unknown. There was also no way to determine from their previous keepers the home range of the eastern box turtles that were acquired after being maintained as pets for many years.
Several trends were obvious:
First, turtles that came from warmer climates were usually the first to emerge from hibernation. This was especially true during their first few years in captivity. This group included the Gulf Coast, three-toed, and eastern box turtles from Virginia and North Carolina. Individuals in this category were usually also the last to enter hibernation and would be wandering around weeks after the local turtles had permanently dug in for their winter sleep. During those years when unexpected “heat waves” occurred in January, February, or March, members of this group were the ones most likely to emerge.
A second observation is related to eastern box turtles that had been kept indoors as pets for many years and had not been allowed to hibernate. These also remained active a week or two longer than the local turtles that had always been housed outdoors. The former group also emerged a week or more earlier. Similarly, the offspring of box turtles from the collection also emerged somewhat earlier, but it should be noted that I housed all offspring indoors during the winter for at least two years. They therefore showed similarity to the pet box turtles not accustomed to hibernation.
Third, these trends were more pronounced during the turtles’ first few years of being allowed to hibernate outdoors. After the turtles had lived in the New Jersey climate for many years, the difference in hibernation lengths between the groups was less noticeable. Also, local turtles commonly faired better during the hibernation period than did those that were allowed to hibernate outdoors for the first time, or those that had been moved to New Jersey from other geographic areas. It seemed that box turtles kept indoors, or those that came from a home range with a “short winter,” never consumed enough food prior to hibernation. These usually emerged very light in weight, but they regained the lost ounces when allowed to rehydrate upon coming out of hibernation.
In conclusion, shorter hibernation lengths were most common in turtles originating from warmer climates regardless of the species. The variations in hibernation duration became less evident over time. Long-term captive adults housed indoors, or captive-bred young being hibernated outdoors for the first time, demonstrated similar behavior to the turtles from southern climes. From these data, it can be assumed local New Jersey box turtles not only have fewer problems adjusting to outdoor hibernation in a captive environment, but also “instinctively” enter hibernation earlier and emerge later. The non-native turtles or locals that either never hibernated or had not hibernated for years, apparently “prefer” to remain active, and they require time to habituate to their new environmental conditions.
Of course, these observations are based on a relatively small captive population. The conclusions do not imply that similar results would necessarily occur in other areas of the country, or under conditions that vary from those in my collection. Nonetheless, clearly local turtles are better suited to preparing for, and surviving, hibernation than are those that are not used to the region’s climatic conditions. But even box turtles that have never hibernated, and those coming from regions of the country where hibernation lengths are very short, have the ability to adapt to the conditions of another area of the country after time. (It should be noted, however, that without close monitoring and proper treatment, some of the non-local turtles would probably not have survived after emerging.)