How Do Wild Box Turtles Find Each Other? Time after time while tracking a tagged turtle, I find that he/she has traveled a long straight route from a previous location and met with another turtle. Meetings/matings usually last 1 day, after which the turtles head off in different directions. How do they find each other with the extremely limited sight distances forests and ridges offer?
What is the smallest number of turtles necessary to maintain a viable population? How is each individual related to every other individual and how much DNA is contributed to a local population by transients? How are widely separated local populations related?
How did Historic Commercial Logging in the 20's and 30's impact Box turtle (and other herps) popuation numbers and survival? There were large areas of this region that were historically logged very heavily and areas that were lightly logged or not not logged (or developed) at all. Are the population numbers of herps we see today directly related to this and similar historic activites, and what are the implications for today's logging activities, especially in regions where herps are threatened or endangered.
The more that is discovered about this local population, the more questions that arise that need to be answered. There are a number of papers and projects that could come from additional research on the site.
How do Box turtles communicate? Do they communicate? Can they communicate their location? Box turtles can hear low frequencies, but can they also sense infrasound through their plastron, or otherwise? Do they produce and sense pheromones?
Solar Powered Transmitters This is not a big deal, someone just needs to do it. Telemetry transmitters are very expensive and often that high cost is the limiting factor in expanding turtles studies. In these days of surface mount components, programmable PIC chips, high density lithium batteries, and high energy solar cells, transmitters should be able to survive well past the life of the epoxy that is used to attach them.
Small solar cells (actually "arrays" containing a number of cells) produce enough energy daily to charge a small rechargable lithium coin cell battery which is able to power a 5 microwatt transmitter for a week or more without sun. Amourphous solar cells, like those used in solar powered calculators ($1.00 cost), are able to produce ample charging current even in filtered, indirect sunlight found under dense canopies, and under the light leaf cover of a resting form.
The cost of the components in my home-made transmitters is around $5 each including battery. One version uses a tiny "hearing aid"size AG13 battery (cost 10 cents each), that powers the transmitter for almost 90 days (change at 60 days). Each transmitter weighs 6.5 grams w/battery.
Datalogging GPS GPS receivers already exist, that meet nearly all the requirements required for turtle research: small size, good accuracy, configurable logging by time, distance or speed, sleep mode, motion detection, etc.
The trouble is, a GPS consumes considerably more power than a telemety transmitter, and require re-charging of the lithium batteries every 24 to 48 hours. Even the tiny GPS in millions of cell phones, reduces battery life if turned on.
What's needed is a logging GPS, small enough to be carried by a Box turtle for an entire season, that has the ability to charge a battery at a rate at least as great as the power is consumed. This would at least partly replace telemetry ad thread-trailing.
Items on this page are added as they come up.
Actual Travel Patterns and Distance VS GPS. Box turtles often travel much longer distances following more complex routes than point to point GPS distances would indicate. Until a suitable, low power recording GPS unit is available to attach to a turtle's carapace, thread trailing is the primary way to study this activity. (examples;)
Turtle M1 is found in a power line ROW apparently moving only 1 to 2 feet day-to-day, but thread trailing reveals that she is traveling up to 200 yards per day, in a flower peddle-like pattern, and returning to her original position. She repeats this activity for up to 8 days annually.
Turtle M4 regularly travels up and down a fern covered ROW slope in her primary activity area. Thread trailing shows that when going up-slope, she uses the game trail located in the middle of the ROW, but when traveling down-slope she zig-zags forest edge to forest edge and repeats this pattern all season.